[PATCH 4.14 00/64] 4.14.18-stable review

[PATCH 4.14 00/64] 4.14.18-stable review

[Greg Kroah-Hartman]

This is the start of the stable review cycle for the 4.14.18 release.
There are 64 patches in this series, all will be posted as a response
to this one.  If anyone has any issues with these being applied, please
let me know.

Responses should be made by Wed Feb  7 18:21:22 UTC 2018.
Anything received after that time might be too late.

The whole patch series can be found in one patch at:
	kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.14.18-rc1.gz
or in the git tree and branch at:
  git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.14.y
and the diffstat can be found below.

thanks,

greg k-h

-------------
Pseudo-Shortlog of commits:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Linux 4.14.18-rc1

Ian Abbott <abbotti@mev.co.uk>
    fpga: region: release of_parse_phandle nodes after use

Sebastian Andrzej Siewior <bigeasy@linutronix.de>
    serial: core: mark port as initialized after successful IRQ change

KarimAllah Ahmed <karahmed@amazon.de>
    KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL

KarimAllah Ahmed <karahmed@amazon.de>
    KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL

KarimAllah Ahmed <karahmed@amazon.de>
    KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES

Ashok Raj <ashok.raj@intel.com>
    KVM/x86: Add IBPB support

KarimAllah Ahmed <karahmed@amazon.de>
    KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX

Darren Kenny <darren.kenny@oracle.com>
    x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL

Arnd Bergmann <arnd@arndb.de>
    x86/pti: Mark constant arrays as __initconst

KarimAllah Ahmed <karahmed@amazon.de>
    x86/spectre: Simplify spectre_v2 command line parsing

David Woodhouse <dwmw@amazon.co.uk>
    x86/retpoline: Avoid retpolines for built-in __init functions

Dan Williams <dan.j.williams@intel.com>
    x86/kvm: Update spectre-v1 mitigation

Paolo Bonzini <pbonzini@redhat.com>
    KVM: VMX: make MSR bitmaps per-VCPU

Josh Poimboeuf <jpoimboe@redhat.com>
    x86/paravirt: Remove 'noreplace-paravirt' cmdline option

Tim Chen <tim.c.chen@linux.intel.com>
    x86/speculation: Use Indirect Branch Prediction Barrier in context switch

David Woodhouse <dwmw@amazon.co.uk>
    x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel

Colin Ian King <colin.king@canonical.com>
    x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable"

Dan Williams <dan.j.williams@intel.com>
    x86/spectre: Report get_user mitigation for spectre_v1

Dan Williams <dan.j.williams@intel.com>
    nl80211: Sanitize array index in parse_txq_params

Dan Williams <dan.j.williams@intel.com>
    vfs, fdtable: Prevent bounds-check bypass via speculative execution

Dan Williams <dan.j.williams@intel.com>
    x86/syscall: Sanitize syscall table de-references under speculation

Dan Williams <dan.j.williams@intel.com>
    x86/get_user: Use pointer masking to limit speculation

Dan Williams <dan.j.williams@intel.com>
    x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec

Dan Williams <dan.j.williams@intel.com>
    x86/usercopy: Replace open coded stac/clac with __uaccess_{begin, end}

Dan Williams <dan.j.williams@intel.com>
    x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec

Dan Williams <dan.j.williams@intel.com>
    x86: Introduce barrier_nospec

Dan Williams <dan.j.williams@intel.com>
    x86: Implement array_index_mask_nospec

Dan Williams <dan.j.williams@intel.com>
    array_index_nospec: Sanitize speculative array de-references

Mark Rutland <mark.rutland@arm.com>
    Documentation: Document array_index_nospec

Andy Lutomirski <luto@kernel.org>
    x86/asm: Move 'status' from thread_struct to thread_info

Andy Lutomirski <luto@kernel.org>
    x86/entry/64: Push extra regs right away

Andy Lutomirski <luto@kernel.org>
    x86/entry/64: Remove the SYSCALL64 fast path

Dou Liyang <douly.fnst@cn.fujitsu.com>
    x86/spectre: Check CONFIG_RETPOLINE in command line parser

William Grant <william.grant@canonical.com>
    x86/mm: Fix overlap of i386 CPU_ENTRY_AREA with FIX_BTMAP

Josh Poimboeuf <jpoimboe@redhat.com>
    objtool: Warn on stripped section symbol

Josh Poimboeuf <jpoimboe@redhat.com>
    objtool: Add support for alternatives at the end of a section

Josh Poimboeuf <jpoimboe@redhat.com>
    objtool: Improve retpoline alternative handling

Paolo Bonzini <pbonzini@redhat.com>
    KVM: VMX: introduce alloc_loaded_vmcs

Jim Mattson <jmattson@google.com>
    KVM: nVMX: Eliminate vmcs02 pool

Jesse Chan <jc@linux.com>
    ASoC: pcm512x: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE

Jesse Chan <jc@linux.com>
    pinctrl: pxa: pxa2xx: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE

Linus Walleij <linus.walleij@linaro.org>
    iio: adc/accel: Fix up module licenses

Jesse Chan <jc@linux.com>
    auxdisplay: img-ascii-lcd: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE

Borislav Petkov <bp@suse.de>
    x86/speculation: Simplify indirect_branch_prediction_barrier()

Borislav Petkov <bp@alien8.de>
    x86/retpoline: Simplify vmexit_fill_RSB()

David Woodhouse <dwmw@amazon.co.uk>
    x86/cpufeatures: Clean up Spectre v2 related CPUID flags

Thomas Gleixner <tglx@linutronix.de>
    x86/cpu/bugs: Make retpoline module warning conditional

Borislav Petkov <bp@suse.de>
    x86/bugs: Drop one "mitigation" from dmesg

Borislav Petkov <bp@suse.de>
    x86/nospec: Fix header guards names

Borislav Petkov <bp@suse.de>
    x86/alternative: Print unadorned pointers

David Woodhouse <dwmw@amazon.co.uk>
    x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support

David Woodhouse <dwmw@amazon.co.uk>
    x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes

David Woodhouse <dwmw@amazon.co.uk>
    x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown

David Woodhouse <dwmw@amazon.co.uk>
    x86/msr: Add definitions for new speculation control MSRs

David Woodhouse <dwmw@amazon.co.uk>
    x86/cpufeatures: Add AMD feature bits for Speculation Control

David Woodhouse <dwmw@amazon.co.uk>
    x86/cpufeatures: Add Intel feature bits for Speculation Control

David Woodhouse <dwmw@amazon.co.uk>
    x86/cpufeatures: Add CPUID_7_EDX CPUID leaf

Andi Kleen <ak@linux.intel.com>
    module/retpoline: Warn about missing retpoline in module

Peter Zijlstra <peterz@infradead.org>
    KVM: VMX: Make indirect call speculation safe

Peter Zijlstra <peterz@infradead.org>
    KVM: x86: Make indirect calls in emulator speculation safe

Waiman Long <longman@redhat.com>
    x86/retpoline: Remove the esp/rsp thunk

Michael Ellerman <mpe@ellerman.id.au>
    powerpc/64s: Allow control of RFI flush via debugfs

Michael Ellerman <mpe@ellerman.id.au>
    powerpc/64s: Wire up cpu_show_meltdown()

Liu, Changcheng <changcheng.liu@intel.com>
    scripts/faddr2line: fix CROSS_COMPILE unset error


-------------

Diffstat:

 Documentation/admin-guide/kernel-parameters.txt |   2 -
 Documentation/speculation.txt                   |  90 ++++
 Makefile                                        |   4 +-
 arch/powerpc/Kconfig                            |   1 +
 arch/powerpc/kernel/setup_64.c                  |  38 ++
 arch/x86/entry/common.c                         |   9 +-
 arch/x86/entry/entry_32.S                       |   3 +-
 arch/x86/entry/entry_64.S                       | 130 +----
 arch/x86/entry/syscall_64.c                     |   7 +-
 arch/x86/include/asm/asm-prototypes.h           |   4 +-
 arch/x86/include/asm/barrier.h                  |  28 +
 arch/x86/include/asm/cpufeature.h               |   7 +-
 arch/x86/include/asm/cpufeatures.h              |  22 +-
 arch/x86/include/asm/disabled-features.h        |   3 +-
 arch/x86/include/asm/fixmap.h                   |   6 +-
 arch/x86/include/asm/msr-index.h                |  12 +
 arch/x86/include/asm/msr.h                      |   3 +-
 arch/x86/include/asm/nospec-branch.h            |  86 +--
 arch/x86/include/asm/pgtable_32_types.h         |   5 +-
 arch/x86/include/asm/processor.h                |   5 +-
 arch/x86/include/asm/required-features.h        |   3 +-
 arch/x86/include/asm/syscall.h                  |   6 +-
 arch/x86/include/asm/thread_info.h              |   3 +-
 arch/x86/include/asm/tlbflush.h                 |   2 +
 arch/x86/include/asm/uaccess.h                  |  15 +-
 arch/x86/include/asm/uaccess_32.h               |   6 +-
 arch/x86/include/asm/uaccess_64.h               |  12 +-
 arch/x86/kernel/alternative.c                   |  28 +-
 arch/x86/kernel/cpu/bugs.c                      | 134 +++--
 arch/x86/kernel/cpu/common.c                    |  70 ++-
 arch/x86/kernel/cpu/intel.c                     |  66 +++
 arch/x86/kernel/cpu/scattered.c                 |   2 -
 arch/x86/kernel/process_64.c                    |   4 +-
 arch/x86/kernel/ptrace.c                        |   2 +-
 arch/x86/kernel/signal.c                        |   2 +-
 arch/x86/kvm/cpuid.c                            |  22 +-
 arch/x86/kvm/cpuid.h                            |   1 +
 arch/x86/kvm/emulate.c                          |   9 +-
 arch/x86/kvm/svm.c                              | 116 +++++
 arch/x86/kvm/vmx.c                              | 660 ++++++++++++++----------
 arch/x86/kvm/x86.c                              |   1 +
 arch/x86/lib/Makefile                           |   1 +
 arch/x86/lib/getuser.S                          |  10 +
 arch/x86/lib/retpoline.S                        |  57 +-
 arch/x86/lib/usercopy_32.c                      |   8 +-
 arch/x86/mm/tlb.c                               |  33 +-
 drivers/auxdisplay/img-ascii-lcd.c              |   4 +
 drivers/fpga/fpga-region.c                      |  13 +-
 drivers/iio/accel/kxsd9-i2c.c                   |   3 +
 drivers/iio/adc/qcom-vadc-common.c              |   4 +
 drivers/pinctrl/pxa/pinctrl-pxa2xx.c            |   4 +
 drivers/tty/serial/serial_core.c                |   2 +
 include/linux/fdtable.h                         |   5 +-
 include/linux/init.h                            |   9 +-
 include/linux/module.h                          |   9 +
 include/linux/nospec.h                          |  72 +++
 kernel/module.c                                 |  11 +
 net/wireless/nl80211.c                          |   9 +-
 scripts/faddr2line                              |   8 +-
 scripts/mod/modpost.c                           |   9 +
 sound/soc/codecs/pcm512x-spi.c                  |   4 +
 tools/objtool/check.c                           |  89 ++--
 tools/objtool/orc_gen.c                         |   5 +
 63 files changed, 1355 insertions(+), 643 deletions(-)

[PATCH 4.14 01/64] scripts/faddr2line: fix CROSS_COMPILE unset error

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Liu, Changcheng <changcheng.liu@intel.com>

commit 4cc90b4cc3d4955f79eae4f7f9d64e67e17b468e upstream.

faddr2line hit var unbound error when CROSS_COMPILE isn't set since
nounset option is set in bash script.

Link: http://lkml.kernel.org/r/20171206013022.GA83929@sofia
Fixes: 95a879825419 ("scripts/faddr2line: extend usage on generic arch")
Signed-off-by: Liu Changcheng <changcheng.liu@intel.com>
Reported-by: Richard Weinberger <richard.weinberger@gmail.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: NeilBrown <neilb@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 scripts/faddr2line |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -44,10 +44,10 @@
 set -o errexit
 set -o nounset
 
-READELF="${CROSS_COMPILE}readelf"
-ADDR2LINE="${CROSS_COMPILE}addr2line"
-SIZE="${CROSS_COMPILE}size"
-NM="${CROSS_COMPILE}nm"
+READELF="${CROSS_COMPILE:-}readelf"
+ADDR2LINE="${CROSS_COMPILE:-}addr2line"
+SIZE="${CROSS_COMPILE:-}size"
+NM="${CROSS_COMPILE:-}nm"
 
 command -v awk >/dev/null 2>&1 || die "awk isn't installed"
 command -v ${READELF} >/dev/null 2>&1 || die "readelf isn't installed"

[PATCH 4.14 02/64] powerpc/64s: Wire up cpu_show_meltdown()

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michael Ellerman <mpe@ellerman.id.au>

commit fd6e440f20b1a4304553775fc55938848ff617c9 upstream.

The recent commit 87590ce6e373 ("sysfs/cpu: Add vulnerability folder")
added a generic folder and set of files for reporting information on
CPU vulnerabilities. One of those was for meltdown:

  /sys/devices/system/cpu/vulnerabilities/meltdown

This commit wires up that file for 64-bit Book3S powerpc.

For now we default to "Vulnerable" unless the RFI flush is enabled.
That may not actually be true on all hardware, further patches will
refine the reporting based on the CPU/platform etc. But for now we
default to being pessimists.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/Kconfig           |    1 +
 arch/powerpc/kernel/setup_64.c |    8 ++++++++
 2 files changed, 9 insertions(+)

--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -164,6 +164,7 @@ config PPC
 	select GENERIC_CLOCKEVENTS_BROADCAST	if SMP
 	select GENERIC_CMOS_UPDATE
 	select GENERIC_CPU_AUTOPROBE
+	select GENERIC_CPU_VULNERABILITIES	if PPC_BOOK3S_64
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_SMP_IDLE_THREAD
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -884,4 +884,12 @@ void __init setup_rfi_flush(enum l1d_flu
 	if (!no_rfi_flush)
 		rfi_flush_enable(enable);
 }
+
+ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	if (rfi_flush)
+		return sprintf(buf, "Mitigation: RFI Flush\n");
+
+	return sprintf(buf, "Vulnerable\n");
+}
 #endif /* CONFIG_PPC_BOOK3S_64 */

[PATCH 4.14 03/64] powerpc/64s: Allow control of RFI flush via debugfs

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michael Ellerman <mpe@ellerman.id.au>

commit 236003e6b5443c45c18e613d2b0d776a9f87540e upstream.

Expose the state of the RFI flush (enabled/disabled) via debugfs, and
allow it to be enabled/disabled at runtime.

eg: $ cat /sys/kernel/debug/powerpc/rfi_flush
    1
    $ echo 0 > /sys/kernel/debug/powerpc/rfi_flush
    $ cat /sys/kernel/debug/powerpc/rfi_flush
    0

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kernel/setup_64.c |   30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -38,6 +38,7 @@
 #include <linux/memory.h>
 #include <linux/nmi.h>
 
+#include <asm/debugfs.h>
 #include <asm/io.h>
 #include <asm/kdump.h>
 #include <asm/prom.h>
@@ -885,6 +886,35 @@ void __init setup_rfi_flush(enum l1d_flu
 		rfi_flush_enable(enable);
 }
 
+#ifdef CONFIG_DEBUG_FS
+static int rfi_flush_set(void *data, u64 val)
+{
+	if (val == 1)
+		rfi_flush_enable(true);
+	else if (val == 0)
+		rfi_flush_enable(false);
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int rfi_flush_get(void *data, u64 *val)
+{
+	*val = rfi_flush ? 1 : 0;
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n");
+
+static __init int rfi_flush_debugfs_init(void)
+{
+	debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush);
+	return 0;
+}
+device_initcall(rfi_flush_debugfs_init);
+#endif
+
 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	if (rfi_flush)

[PATCH 4.14 04/64] x86/retpoline: Remove the esp/rsp thunk

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Waiman Long longman@redhat.com

commit 1df37383a8aeabb9b418698f0bcdffea01f4b1b2

It doesn't make sense to have an indirect call thunk with esp/rsp as
retpoline code won't work correctly with the stack pointer register.
Removing it will help compiler writers to catch error in case such
a thunk call is emitted incorrectly.

Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support")
Suggested-by: Jeff Law <law@redhat.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Kees Cook <keescook@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1516658974-27852-1-git-send-email-longman@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/asm-prototypes.h |    1 -
 arch/x86/lib/retpoline.S              |    1 -
 2 files changed, 2 deletions(-)

--- a/arch/x86/include/asm/asm-prototypes.h
+++ b/arch/x86/include/asm/asm-prototypes.h
@@ -38,5 +38,4 @@ INDIRECT_THUNK(dx)
 INDIRECT_THUNK(si)
 INDIRECT_THUNK(di)
 INDIRECT_THUNK(bp)
-INDIRECT_THUNK(sp)
 #endif /* CONFIG_RETPOLINE */
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -36,7 +36,6 @@ GENERATE_THUNK(_ASM_DX)
 GENERATE_THUNK(_ASM_SI)
 GENERATE_THUNK(_ASM_DI)
 GENERATE_THUNK(_ASM_BP)
-GENERATE_THUNK(_ASM_SP)
 #ifdef CONFIG_64BIT
 GENERATE_THUNK(r8)
 GENERATE_THUNK(r9)

[PATCH 4.14 05/64] KVM: x86: Make indirect calls in emulator speculation safe

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Zijlstra peterz@infradead.org

commit 1a29b5b7f347a1a9230c1e0af5b37e3e571588ab

Replace the indirect calls with CALL_NOSPEC.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rga@amazon.de
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: https://lkml.kernel.org/r/20180125095843.595615683@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/emulate.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -25,6 +25,7 @@
 #include <asm/kvm_emulate.h>
 #include <linux/stringify.h>
 #include <asm/debugreg.h>
+#include <asm/nospec-branch.h>
 
 #include "x86.h"
 #include "tss.h"
@@ -1021,8 +1022,8 @@ static __always_inline u8 test_cc(unsign
 	void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
 
 	flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
-	asm("push %[flags]; popf; call *%[fastop]"
-	    : "=a"(rc) : [fastop]"r"(fop), [flags]"r"(flags));
+	asm("push %[flags]; popf; " CALL_NOSPEC
+	    : "=a"(rc) : [thunk_target]"r"(fop), [flags]"r"(flags));
 	return rc;
 }
 
@@ -5350,9 +5351,9 @@ static int fastop(struct x86_emulate_ctx
 	if (!(ctxt->d & ByteOp))
 		fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE;
 
-	asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n"
+	asm("push %[flags]; popf; " CALL_NOSPEC " ; pushf; pop %[flags]\n"
 	    : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags),
-	      [fastop]"+S"(fop), ASM_CALL_CONSTRAINT
+	      [thunk_target]"+S"(fop), ASM_CALL_CONSTRAINT
 	    : "c"(ctxt->src2.val));
 
 	ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK);

[PATCH 4.14 06/64] KVM: VMX: Make indirect call speculation safe

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Zijlstra peterz@infradead.org

commit c940a3fb1e2e9b7d03228ab28f375fb5a47ff699

Replace indirect call with CALL_NOSPEC.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rga@amazon.de
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: https://lkml.kernel.org/r/20180125095843.645776917@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/vmx.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9118,14 +9118,14 @@ static void vmx_handle_external_intr(str
 #endif
 			"pushf\n\t"
 			__ASM_SIZE(push) " $%c[cs]\n\t"
-			"call *%[entry]\n\t"
+			CALL_NOSPEC
 			:
 #ifdef CONFIG_X86_64
 			[sp]"=&r"(tmp),
 #endif
 			ASM_CALL_CONSTRAINT
 			:
-			[entry]"r"(entry),
+			THUNK_TARGET(entry),
 			[ss]"i"(__KERNEL_DS),
 			[cs]"i"(__KERNEL_CS)
 			);

[PATCH 4.14 07/64] module/retpoline: Warn about missing retpoline in module

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andi Kleen ak@linux.intel.com

commit caf7501a1b4ec964190f31f9c3f163de252273b8

There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.

To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.

If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.

[ tglx: Massaged changelog ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/cpu/bugs.c |   17 ++++++++++++++++-
 include/linux/module.h     |    9 +++++++++
 kernel/module.c            |   11 +++++++++++
 scripts/mod/modpost.c      |    9 +++++++++
 4 files changed, 45 insertions(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -11,6 +11,7 @@
 #include <linux/init.h>
 #include <linux/utsname.h>
 #include <linux/cpu.h>
+#include <linux/module.h>
 
 #include <asm/nospec-branch.h>
 #include <asm/cmdline.h>
@@ -93,6 +94,19 @@ static const char *spectre_v2_strings[]
 #define pr_fmt(fmt)     "Spectre V2 mitigation: " fmt
 
 static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE;
+static bool spectre_v2_bad_module;
+
+#ifdef RETPOLINE
+bool retpoline_module_ok(bool has_retpoline)
+{
+	if (spectre_v2_enabled == SPECTRE_V2_NONE || has_retpoline)
+		return true;
+
+	pr_err("System may be vunerable to spectre v2\n");
+	spectre_v2_bad_module = true;
+	return false;
+}
+#endif
 
 static void __init spec2_print_if_insecure(const char *reason)
 {
@@ -278,6 +292,7 @@ ssize_t cpu_show_spectre_v2(struct devic
 	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
 		return sprintf(buf, "Not affected\n");
 
-	return sprintf(buf, "%s\n", spectre_v2_strings[spectre_v2_enabled]);
+	return sprintf(buf, "%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+		       spectre_v2_bad_module ? " - vulnerable module loaded" : "");
 }
 #endif
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -794,6 +794,15 @@ static inline void module_bug_finalize(c
 static inline void module_bug_cleanup(struct module *mod) {}
 #endif	/* CONFIG_GENERIC_BUG */
 
+#ifdef RETPOLINE
+extern bool retpoline_module_ok(bool has_retpoline);
+#else
+static inline bool retpoline_module_ok(bool has_retpoline)
+{
+	return true;
+}
+#endif
+
 #ifdef CONFIG_MODULE_SIG
 static inline bool module_sig_ok(struct module *module)
 {
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2855,6 +2855,15 @@ static int check_modinfo_livepatch(struc
 }
 #endif /* CONFIG_LIVEPATCH */
 
+static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
+{
+	if (retpoline_module_ok(get_modinfo(info, "retpoline")))
+		return;
+
+	pr_warn("%s: loading module not compiled with retpoline compiler.\n",
+		mod->name);
+}
+
 /* Sets info->hdr and info->len. */
 static int copy_module_from_user(const void __user *umod, unsigned long len,
 				  struct load_info *info)
@@ -3021,6 +3030,8 @@ static int check_modinfo(struct module *
 		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
 	}
 
+	check_modinfo_retpoline(mod, info);
+
 	if (get_modinfo(info, "staging")) {
 		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
 		pr_warn("%s: module is from the staging directory, the quality "
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2165,6 +2165,14 @@ static void add_intree_flag(struct buffe
 		buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
 }
 
+/* Cannot check for assembler */
+static void add_retpoline(struct buffer *b)
+{
+	buf_printf(b, "\n#ifdef RETPOLINE\n");
+	buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
+	buf_printf(b, "#endif\n");
+}
+
 static void add_staging_flag(struct buffer *b, const char *name)
 {
 	static const char *staging_dir = "drivers/staging";
@@ -2506,6 +2514,7 @@ int main(int argc, char **argv)
 		err |= check_modname_len(mod);
 		add_header(&buf, mod);
 		add_intree_flag(&buf, !external_module);
+		add_retpoline(&buf);
 		add_staging_flag(&buf, mod->name);
 		err |= add_versions(&buf, mod);
 		add_depends(&buf, mod, modules);

[PATCH 4.14 08/64] x86/cpufeatures: Add CPUID_7_EDX CPUID leaf

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit 95ca0ee8636059ea2800dfbac9ecac6212d6b38f

This is a pure feature bits leaf. There are two AVX512 feature bits in it
already which were handled as scattered bits, and three more from this leaf
are going to be added for speculation control features.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-2-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/cpufeature.h        |    7 +++++--
 arch/x86/include/asm/cpufeatures.h       |    8 +++++---
 arch/x86/include/asm/disabled-features.h |    3 ++-
 arch/x86/include/asm/required-features.h |    3 ++-
 arch/x86/kernel/cpu/common.c             |    1 +
 arch/x86/kernel/cpu/scattered.c          |    2 --
 6 files changed, 15 insertions(+), 9 deletions(-)

--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -29,6 +29,7 @@ enum cpuid_leafs
 	CPUID_8000_000A_EDX,
 	CPUID_7_ECX,
 	CPUID_8000_0007_EBX,
+	CPUID_7_EDX,
 };
 
 #ifdef CONFIG_X86_FEATURE_NAMES
@@ -79,8 +80,9 @@ extern const char * const x86_bug_flags[
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) ||	\
+	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) ||	\
 	   REQUIRED_MASK_CHECK					  ||	\
-	   BUILD_BUG_ON_ZERO(NCAPINTS != 18))
+	   BUILD_BUG_ON_ZERO(NCAPINTS != 19))
 
 #define DISABLED_MASK_BIT_SET(feature_bit)				\
 	 ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  0, feature_bit) ||	\
@@ -101,8 +103,9 @@ extern const char * const x86_bug_flags[
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) ||	\
+	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) ||	\
 	   DISABLED_MASK_CHECK					  ||	\
-	   BUILD_BUG_ON_ZERO(NCAPINTS != 18))
+	   BUILD_BUG_ON_ZERO(NCAPINTS != 19))
 
 #define cpu_has(c, bit)							\
 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -13,7 +13,7 @@
 /*
  * Defines x86 CPU feature bits
  */
-#define NCAPINTS			18	   /* N 32-bit words worth of info */
+#define NCAPINTS			19	   /* N 32-bit words worth of info */
 #define NBUGINTS			1	   /* N 32-bit bug flags */
 
 /*
@@ -206,8 +206,6 @@
 #define X86_FEATURE_RETPOLINE		( 7*32+12) /* Generic Retpoline mitigation for Spectre variant 2 */
 #define X86_FEATURE_RETPOLINE_AMD	( 7*32+13) /* AMD Retpoline mitigation for Spectre variant 2 */
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
-#define X86_FEATURE_AVX512_4VNNIW	( 7*32+16) /* AVX-512 Neural Network Instructions */
-#define X86_FEATURE_AVX512_4FMAPS	( 7*32+17) /* AVX-512 Multiply Accumulation Single precision */
 
 #define X86_FEATURE_MBA			( 7*32+18) /* Memory Bandwidth Allocation */
 #define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* Fill RSB on context switches */
@@ -319,6 +317,10 @@
 #define X86_FEATURE_SUCCOR		(17*32+ 1) /* Uncorrectable error containment and recovery */
 #define X86_FEATURE_SMCA		(17*32+ 3) /* Scalable MCA */
 
+/* Intel-defined CPU features, CPUID level 0x00000007:0 (EDX), word 18 */
+#define X86_FEATURE_AVX512_4VNNIW	(18*32+ 2) /* AVX-512 Neural Network Instructions */
+#define X86_FEATURE_AVX512_4FMAPS	(18*32+ 3) /* AVX-512 Multiply Accumulation Single precision */
+
 /*
  * BUG word(s)
  */
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -71,6 +71,7 @@
 #define DISABLED_MASK15	0
 #define DISABLED_MASK16	(DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57)
 #define DISABLED_MASK17	0
-#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
+#define DISABLED_MASK18	0
+#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
 
 #endif /* _ASM_X86_DISABLED_FEATURES_H */
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h
@@ -106,6 +106,7 @@
 #define REQUIRED_MASK15	0
 #define REQUIRED_MASK16	(NEED_LA57)
 #define REQUIRED_MASK17	0
-#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
+#define REQUIRED_MASK18	0
+#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
 
 #endif /* _ASM_X86_REQUIRED_FEATURES_H */
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -745,6 +745,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 		cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
 		c->x86_capability[CPUID_7_0_EBX] = ebx;
 		c->x86_capability[CPUID_7_ECX] = ecx;
+		c->x86_capability[CPUID_7_EDX] = edx;
 	}
 
 	/* Extended state features: level 0x0000000d */
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -21,8 +21,6 @@ struct cpuid_bit {
 static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_APERFMPERF,       CPUID_ECX,  0, 0x00000006, 0 },
 	{ X86_FEATURE_EPB,		CPUID_ECX,  3, 0x00000006, 0 },
-	{ X86_FEATURE_AVX512_4VNNIW,    CPUID_EDX,  2, 0x00000007, 0 },
-	{ X86_FEATURE_AVX512_4FMAPS,    CPUID_EDX,  3, 0x00000007, 0 },
 	{ X86_FEATURE_CAT_L3,		CPUID_EBX,  1, 0x00000010, 0 },
 	{ X86_FEATURE_CAT_L2,		CPUID_EBX,  2, 0x00000010, 0 },
 	{ X86_FEATURE_CDP_L3,		CPUID_ECX,  2, 0x00000010, 1 },

[PATCH 4.14 09/64] x86/cpufeatures: Add Intel feature bits for Speculation Control

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit fc67dd70adb711a45d2ef34e12d1a8be75edde61

Add three feature bits exposed by new microcode on Intel CPUs for
speculation control.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-3-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/cpufeatures.h |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -320,6 +320,9 @@
 /* Intel-defined CPU features, CPUID level 0x00000007:0 (EDX), word 18 */
 #define X86_FEATURE_AVX512_4VNNIW	(18*32+ 2) /* AVX-512 Neural Network Instructions */
 #define X86_FEATURE_AVX512_4FMAPS	(18*32+ 3) /* AVX-512 Multiply Accumulation Single precision */
+#define X86_FEATURE_SPEC_CTRL		(18*32+26) /* Speculation Control (IBRS + IBPB) */
+#define X86_FEATURE_STIBP		(18*32+27) /* Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_ARCH_CAPABILITIES	(18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
 
 /*
  * BUG word(s)

[PATCH 4.14 10/64] x86/cpufeatures: Add AMD feature bits for Speculation Control

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit 5d10cbc91d9eb5537998b65608441b592eec65e7

AMD exposes the PRED_CMD/SPEC_CTRL MSRs slightly differently to Intel.
See http://lkml.kernel.org/r/2b3e25cc-286d-8bd0-aeaf-9ac4aae39de8@amd.com

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-4-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/cpufeatures.h |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -269,6 +269,9 @@
 #define X86_FEATURE_CLZERO		(13*32+ 0) /* CLZERO instruction */
 #define X86_FEATURE_IRPERF		(13*32+ 1) /* Instructions Retired Count */
 #define X86_FEATURE_XSAVEERPTR		(13*32+ 2) /* Always save/restore FP error pointers */
+#define X86_FEATURE_AMD_PRED_CMD	(13*32+12) /* Prediction Command MSR (AMD) */
+#define X86_FEATURE_AMD_SPEC_CTRL	(13*32+14) /* Speculation Control MSR only (AMD) */
+#define X86_FEATURE_AMD_STIBP		(13*32+15) /* Single Thread Indirect Branch Predictors (AMD) */
 
 /* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
 #define X86_FEATURE_DTHERM		(14*32+ 0) /* Digital Thermal Sensor */

[PATCH 4.14 11/64] x86/msr: Add definitions for new speculation control MSRs

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit 1e340c60d0dd3ae07b5bedc16a0469c14b9f3410

Add MSR and bit definitions for SPEC_CTRL, PRED_CMD and ARCH_CAPABILITIES.

See Intel's 336996-Speculative-Execution-Side-Channel-Mitigations.pdf

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-5-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/msr-index.h |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -39,6 +39,13 @@
 
 /* Intel MSRs. Some also available on other CPUs */
 
+#define MSR_IA32_SPEC_CTRL		0x00000048 /* Speculation Control */
+#define SPEC_CTRL_IBRS			(1 << 0)   /* Indirect Branch Restricted Speculation */
+#define SPEC_CTRL_STIBP			(1 << 1)   /* Single Thread Indirect Branch Predictors */
+
+#define MSR_IA32_PRED_CMD		0x00000049 /* Prediction Command */
+#define PRED_CMD_IBPB			(1 << 0)   /* Indirect Branch Prediction Barrier */
+
 #define MSR_PPIN_CTL			0x0000004e
 #define MSR_PPIN			0x0000004f
 
@@ -57,6 +64,11 @@
 #define SNB_C3_AUTO_UNDEMOTE		(1UL << 28)
 
 #define MSR_MTRRcap			0x000000fe
+
+#define MSR_IA32_ARCH_CAPABILITIES	0x0000010a
+#define ARCH_CAP_RDCL_NO		(1 << 0)   /* Not susceptible to Meltdown */
+#define ARCH_CAP_IBRS_ALL		(1 << 1)   /* Enhanced IBRS support */
+
 #define MSR_IA32_BBL_CR_CTL		0x00000119
 #define MSR_IA32_BBL_CR_CTL3		0x0000011e
 

[PATCH 4.14 12/64] x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit fec9434a12f38d3aeafeb75711b71d8a1fdef621

Also, for CPUs which don't speculate at all, don't report that they're
vulnerable to the Spectre variants either.

Leave the cpu_no_meltdown[] match table with just X86_VENDOR_AMD in it
for now, even though that could be done with a simple comparison, on the
assumption that we'll have more to add.

Based on suggestions from Dave Hansen and Alan Cox.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-6-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/common.c |   48 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 5 deletions(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -47,6 +47,8 @@
 #include <asm/pat.h>
 #include <asm/microcode.h>
 #include <asm/microcode_intel.h>
+#include <asm/intel-family.h>
+#include <asm/cpu_device_id.h>
 
 #ifdef CONFIG_X86_LOCAL_APIC
 #include <asm/uv/uv.h>
@@ -853,6 +855,41 @@ static void identify_cpu_without_cpuid(s
 #endif
 }
 
+static const __initdata struct x86_cpu_id cpu_no_speculation[] = {
+	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_CEDARVIEW,	X86_FEATURE_ANY },
+	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_CLOVERVIEW,	X86_FEATURE_ANY },
+	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_LINCROFT,	X86_FEATURE_ANY },
+	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_PENWELL,	X86_FEATURE_ANY },
+	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_PINEVIEW,	X86_FEATURE_ANY },
+	{ X86_VENDOR_CENTAUR,	5 },
+	{ X86_VENDOR_INTEL,	5 },
+	{ X86_VENDOR_NSC,	5 },
+	{ X86_VENDOR_ANY,	4 },
+	{}
+};
+
+static const __initdata struct x86_cpu_id cpu_no_meltdown[] = {
+	{ X86_VENDOR_AMD },
+	{}
+};
+
+static bool __init cpu_vulnerable_to_meltdown(struct cpuinfo_x86 *c)
+{
+	u64 ia32_cap = 0;
+
+	if (x86_match_cpu(cpu_no_meltdown))
+		return false;
+
+	if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
+		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
+
+	/* Rogue Data Cache Load? No! */
+	if (ia32_cap & ARCH_CAP_RDCL_NO)
+		return false;
+
+	return true;
+}
+
 /*
  * Do minimum CPU detection early.
  * Fields really needed: vendor, cpuid_level, family, model, mask,
@@ -900,11 +937,12 @@ static void __init early_identify_cpu(st
 
 	setup_force_cpu_cap(X86_FEATURE_ALWAYS);
 
-	if (c->x86_vendor != X86_VENDOR_AMD)
-		setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
-
-	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
-	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+	if (!x86_match_cpu(cpu_no_speculation)) {
+		if (cpu_vulnerable_to_meltdown(c))
+			setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
+		setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+		setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+	}
 
 	fpu__init_system(c);
 

[PATCH 4.14 13/64] x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit a5b2966364538a0e68c9fa29bc0a3a1651799035

This doesn't refuse to load the affected microcodes; it just refuses to
use the Spectre v2 mitigation features if they're detected, by clearing
the appropriate feature bits.

The AMD CPUID bits are handled here too, because hypervisors *may* have
been exposing those bits even on Intel chips, for fine-grained control
of what's available.

It is non-trivial to use x86_match_cpu() for this table because that
doesn't handle steppings. And the approach taken in commit bd9240a18
almost made me lose my lunch.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-7-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/intel.c |   66 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -102,6 +102,59 @@ static void probe_xeon_phi_r3mwait(struc
 		ELF_HWCAP2 |= HWCAP2_RING3MWAIT;
 }
 
+/*
+ * Early microcode releases for the Spectre v2 mitigation were broken.
+ * Information taken from;
+ * - https://newsroom.intel.com/wp-content/uploads/sites/11/2018/01/microcode-update-guidance.pdf
+ * - https://kb.vmware.com/s/article/52345
+ * - Microcode revisions observed in the wild
+ * - Release note from 20180108 microcode release
+ */
+struct sku_microcode {
+	u8 model;
+	u8 stepping;
+	u32 microcode;
+};
+static const struct sku_microcode spectre_bad_microcodes[] = {
+	{ INTEL_FAM6_KABYLAKE_DESKTOP,	0x0B,	0x84 },
+	{ INTEL_FAM6_KABYLAKE_DESKTOP,	0x0A,	0x84 },
+	{ INTEL_FAM6_KABYLAKE_DESKTOP,	0x09,	0x84 },
+	{ INTEL_FAM6_KABYLAKE_MOBILE,	0x0A,	0x84 },
+	{ INTEL_FAM6_KABYLAKE_MOBILE,	0x09,	0x84 },
+	{ INTEL_FAM6_SKYLAKE_X,		0x03,	0x0100013e },
+	{ INTEL_FAM6_SKYLAKE_X,		0x04,	0x0200003c },
+	{ INTEL_FAM6_SKYLAKE_MOBILE,	0x03,	0xc2 },
+	{ INTEL_FAM6_SKYLAKE_DESKTOP,	0x03,	0xc2 },
+	{ INTEL_FAM6_BROADWELL_CORE,	0x04,	0x28 },
+	{ INTEL_FAM6_BROADWELL_GT3E,	0x01,	0x1b },
+	{ INTEL_FAM6_BROADWELL_XEON_D,	0x02,	0x14 },
+	{ INTEL_FAM6_BROADWELL_XEON_D,	0x03,	0x07000011 },
+	{ INTEL_FAM6_BROADWELL_X,	0x01,	0x0b000025 },
+	{ INTEL_FAM6_HASWELL_ULT,	0x01,	0x21 },
+	{ INTEL_FAM6_HASWELL_GT3E,	0x01,	0x18 },
+	{ INTEL_FAM6_HASWELL_CORE,	0x03,	0x23 },
+	{ INTEL_FAM6_HASWELL_X,		0x02,	0x3b },
+	{ INTEL_FAM6_HASWELL_X,		0x04,	0x10 },
+	{ INTEL_FAM6_IVYBRIDGE_X,	0x04,	0x42a },
+	/* Updated in the 20180108 release; blacklist until we know otherwise */
+	{ INTEL_FAM6_ATOM_GEMINI_LAKE,	0x01,	0x22 },
+	/* Observed in the wild */
+	{ INTEL_FAM6_SANDYBRIDGE_X,	0x06,	0x61b },
+	{ INTEL_FAM6_SANDYBRIDGE_X,	0x07,	0x712 },
+};
+
+static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) {
+		if (c->x86_model == spectre_bad_microcodes[i].model &&
+		    c->x86_mask == spectre_bad_microcodes[i].stepping)
+			return (c->microcode <= spectre_bad_microcodes[i].microcode);
+	}
+	return false;
+}
+
 static void early_init_intel(struct cpuinfo_x86 *c)
 {
 	u64 misc_enable;
@@ -122,6 +175,19 @@ static void early_init_intel(struct cpui
 	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
 		c->microcode = intel_get_microcode_revision();
 
+	if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
+	     cpu_has(c, X86_FEATURE_STIBP) ||
+	     cpu_has(c, X86_FEATURE_AMD_SPEC_CTRL) ||
+	     cpu_has(c, X86_FEATURE_AMD_PRED_CMD) ||
+	     cpu_has(c, X86_FEATURE_AMD_STIBP)) && bad_spectre_microcode(c)) {
+		pr_warn("Intel Spectre v2 broken microcode detected; disabling SPEC_CTRL\n");
+		clear_cpu_cap(c, X86_FEATURE_SPEC_CTRL);
+		clear_cpu_cap(c, X86_FEATURE_STIBP);
+		clear_cpu_cap(c, X86_FEATURE_AMD_SPEC_CTRL);
+		clear_cpu_cap(c, X86_FEATURE_AMD_PRED_CMD);
+		clear_cpu_cap(c, X86_FEATURE_AMD_STIBP);
+	}
+
 	/*
 	 * Atom erratum AAE44/AAF40/AAG38/AAH41:
 	 *

[PATCH 4.14 14/64] x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit 20ffa1caecca4db8f79fe665acdeaa5af815a24d

Expose indirect_branch_prediction_barrier() for use in subsequent patches.

[ tglx: Add IBPB status to spectre_v2 sysfs file ]

Co-developed-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: dave.hansen@intel.com
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-8-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/cpufeatures.h   |    2 ++
 arch/x86/include/asm/nospec-branch.h |   13 +++++++++++++
 arch/x86/kernel/cpu/bugs.c           |   10 +++++++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -210,6 +210,8 @@
 #define X86_FEATURE_MBA			( 7*32+18) /* Memory Bandwidth Allocation */
 #define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* Fill RSB on context switches */
 
+#define X86_FEATURE_IBPB		( 7*32+21) /* Indirect Branch Prediction Barrier enabled*/
+
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW		( 8*32+ 0) /* Intel TPR Shadow */
 #define X86_FEATURE_VNMI		( 8*32+ 1) /* Intel Virtual NMI */
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -218,5 +218,18 @@ static inline void vmexit_fill_RSB(void)
 #endif
 }
 
+static inline void indirect_branch_prediction_barrier(void)
+{
+	asm volatile(ALTERNATIVE("",
+				 "movl %[msr], %%ecx\n\t"
+				 "movl %[val], %%eax\n\t"
+				 "movl $0, %%edx\n\t"
+				 "wrmsr",
+				 X86_FEATURE_IBPB)
+		     : : [msr] "i" (MSR_IA32_PRED_CMD),
+			 [val] "i" (PRED_CMD_IBPB)
+		     : "eax", "ecx", "edx", "memory");
+}
+
 #endif /* __ASSEMBLY__ */
 #endif /* __NOSPEC_BRANCH_H__ */
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -263,6 +263,13 @@ retpoline_auto:
 		setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
 		pr_info("Filling RSB on context switch\n");
 	}
+
+	/* Initialize Indirect Branch Prediction Barrier if supported */
+	if (boot_cpu_has(X86_FEATURE_SPEC_CTRL) ||
+	    boot_cpu_has(X86_FEATURE_AMD_PRED_CMD)) {
+		setup_force_cpu_cap(X86_FEATURE_IBPB);
+		pr_info("Enabling Indirect Branch Prediction Barrier\n");
+	}
 }
 
 #undef pr_fmt
@@ -292,7 +299,8 @@ ssize_t cpu_show_spectre_v2(struct devic
 	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
 		return sprintf(buf, "Not affected\n");
 
-	return sprintf(buf, "%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+	return sprintf(buf, "%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+		       boot_cpu_has(X86_FEATURE_IBPB) ? ", IPBP" : "",
 		       spectre_v2_bad_module ? " - vulnerable module loaded" : "");
 }
 #endif

[PATCH 4.14 15/64] x86/alternative: Print unadorned pointers

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Borislav Petkov bp@suse.de

commit 0e6c16c652cadaffd25a6bb326ec10da5bcec6b4

After commit ad67b74d2469 ("printk: hash addresses printed with %p")
pointers are being hashed when printed. However, this makes the alternative
debug output completely useless. Switch to %px in order to see the
unadorned kernel pointers.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: riel@redhat.com
Cc: ak@linux.intel.com
Cc: peterz@infradead.org
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: jikos@kernel.org
Cc: luto@amacapital.net
Cc: dave.hansen@intel.com
Cc: torvalds@linux-foundation.org
Cc: keescook@google.com
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Cc: pjt@google.com
Link: https://lkml.kernel.org/r/20180126121139.31959-2-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/alternative.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -298,7 +298,7 @@ recompute_jump(struct alt_instr *a, u8 *
 	tgt_rip  = next_rip + o_dspl;
 	n_dspl = tgt_rip - orig_insn;
 
-	DPRINTK("target RIP: %p, new_displ: 0x%x", tgt_rip, n_dspl);
+	DPRINTK("target RIP: %px, new_displ: 0x%x", tgt_rip, n_dspl);
 
 	if (tgt_rip - orig_insn >= 0) {
 		if (n_dspl - 2 <= 127)
@@ -355,7 +355,7 @@ static void __init_or_module noinline op
 	add_nops(instr + (a->instrlen - a->padlen), a->padlen);
 	local_irq_restore(flags);
 
-	DUMP_BYTES(instr, a->instrlen, "%p: [%d:%d) optimized NOPs: ",
+	DUMP_BYTES(instr, a->instrlen, "%px: [%d:%d) optimized NOPs: ",
 		   instr, a->instrlen - a->padlen, a->padlen);
 }
 
@@ -376,7 +376,7 @@ void __init_or_module noinline apply_alt
 	u8 *instr, *replacement;
 	u8 insnbuf[MAX_PATCH_LEN];
 
-	DPRINTK("alt table %p -> %p", start, end);
+	DPRINTK("alt table %px, -> %px", start, end);
 	/*
 	 * The scan order should be from start to end. A later scanned
 	 * alternative code can overwrite previously scanned alternative code.
@@ -400,14 +400,14 @@ void __init_or_module noinline apply_alt
 			continue;
 		}
 
-		DPRINTK("feat: %d*32+%d, old: (%p, len: %d), repl: (%p, len: %d), pad: %d",
+		DPRINTK("feat: %d*32+%d, old: (%px len: %d), repl: (%px, len: %d), pad: %d",
 			a->cpuid >> 5,
 			a->cpuid & 0x1f,
 			instr, a->instrlen,
 			replacement, a->replacementlen, a->padlen);
 
-		DUMP_BYTES(instr, a->instrlen, "%p: old_insn: ", instr);
-		DUMP_BYTES(replacement, a->replacementlen, "%p: rpl_insn: ", replacement);
+		DUMP_BYTES(instr, a->instrlen, "%px: old_insn: ", instr);
+		DUMP_BYTES(replacement, a->replacementlen, "%px: rpl_insn: ", replacement);
 
 		memcpy(insnbuf, replacement, a->replacementlen);
 		insnbuf_sz = a->replacementlen;
@@ -433,7 +433,7 @@ void __init_or_module noinline apply_alt
 				 a->instrlen - a->replacementlen);
 			insnbuf_sz += a->instrlen - a->replacementlen;
 		}
-		DUMP_BYTES(insnbuf, insnbuf_sz, "%p: final_insn: ", instr);
+		DUMP_BYTES(insnbuf, insnbuf_sz, "%px: final_insn: ", instr);
 
 		text_poke_early(instr, insnbuf, insnbuf_sz);
 	}

[PATCH 4.14 16/64] x86/nospec: Fix header guards names

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Borislav Petkov bp@suse.de

commit 7a32fc51ca938e67974cbb9db31e1a43f98345a9

... to adhere to the _ASM_X86_ naming scheme.

No functional change.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: riel@redhat.com
Cc: ak@linux.intel.com
Cc: peterz@infradead.org
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: jikos@kernel.org
Cc: luto@amacapital.net
Cc: dave.hansen@intel.com
Cc: torvalds@linux-foundation.org
Cc: keescook@google.com
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Cc: pjt@google.com
Link: https://lkml.kernel.org/r/20180126121139.31959-3-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/nospec-branch.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 
-#ifndef __NOSPEC_BRANCH_H__
-#define __NOSPEC_BRANCH_H__
+#ifndef _ASM_X86_NOSPEC_BRANCH_H_
+#define _ASM_X86_NOSPEC_BRANCH_H_
 
 #include <asm/alternative.h>
 #include <asm/alternative-asm.h>
@@ -232,4 +232,4 @@ static inline void indirect_branch_predi
 }
 
 #endif /* __ASSEMBLY__ */
-#endif /* __NOSPEC_BRANCH_H__ */
+#endif /* _ASM_X86_NOSPEC_BRANCH_H_ */

[PATCH 4.14 17/64] x86/bugs: Drop one "mitigation" from dmesg

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Borislav Petkov bp@suse.de

commit 55fa19d3e51f33d9cd4056d25836d93abf9438db

Make

[    0.031118] Spectre V2 mitigation: Mitigation: Full generic retpoline

into

[    0.031118] Spectre V2: Mitigation: Full generic retpoline

to reduce the mitigation mitigations strings.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: riel@redhat.com
Cc: ak@linux.intel.com
Cc: peterz@infradead.org
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: jikos@kernel.org
Cc: luto@amacapital.net
Cc: dave.hansen@intel.com
Cc: torvalds@linux-foundation.org
Cc: keescook@google.com
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: tim.c.chen@linux.intel.com
Cc: pjt@google.com
Link: https://lkml.kernel.org/r/20180126121139.31959-5-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/bugs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -91,7 +91,7 @@ static const char *spectre_v2_strings[]
 };
 
 #undef pr_fmt
-#define pr_fmt(fmt)     "Spectre V2 mitigation: " fmt
+#define pr_fmt(fmt)     "Spectre V2 : " fmt
 
 static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE;
 static bool spectre_v2_bad_module;

[PATCH 4.14 18/64] x86/cpu/bugs: Make retpoline module warning conditional

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner tglx@linutronix.de

commit e383095c7fe8d218e00ec0f83e4b95ed4e627b02

If sysfs is disabled and RETPOLINE not defined:

arch/x86/kernel/cpu/bugs.c:97:13: warning: ‘spectre_v2_bad_module’ defined but not used
[-Wunused-variable]
 static bool spectre_v2_bad_module;

Hide it.

Fixes: caf7501a1b4e ("module/retpoline: Warn about missing retpoline in module")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/cpu/bugs.c |   14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -94,9 +94,10 @@ static const char *spectre_v2_strings[]
 #define pr_fmt(fmt)     "Spectre V2 : " fmt
 
 static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE;
-static bool spectre_v2_bad_module;
 
 #ifdef RETPOLINE
+static bool spectre_v2_bad_module;
+
 bool retpoline_module_ok(bool has_retpoline)
 {
 	if (spectre_v2_enabled == SPECTRE_V2_NONE || has_retpoline)
@@ -106,6 +107,13 @@ bool retpoline_module_ok(bool has_retpol
 	spectre_v2_bad_module = true;
 	return false;
 }
+
+static inline const char *spectre_v2_module_string(void)
+{
+	return spectre_v2_bad_module ? " - vulnerable module loaded" : "";
+}
+#else
+static inline const char *spectre_v2_module_string(void) { return ""; }
 #endif
 
 static void __init spec2_print_if_insecure(const char *reason)
@@ -300,7 +308,7 @@ ssize_t cpu_show_spectre_v2(struct devic
 		return sprintf(buf, "Not affected\n");
 
 	return sprintf(buf, "%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
-		       boot_cpu_has(X86_FEATURE_IBPB) ? ", IPBP" : "",
-		       spectre_v2_bad_module ? " - vulnerable module loaded" : "");
+		       boot_cpu_has(X86_FEATURE_IBPB) ? ", IBPB" : "",
+		       spectre_v2_module_string());
 }
 #endif

[PATCH 4.14 19/64] x86/cpufeatures: Clean up Spectre v2 related CPUID flags

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit 2961298efe1ea1b6fc0d7ee8b76018fa6c0bcef2

We want to expose the hardware features simply in /proc/cpuinfo as "ibrs",
"ibpb" and "stibp". Since AMD has separate CPUID bits for those, use them
as the user-visible bits.

When the Intel SPEC_CTRL bit is set which indicates both IBRS and IBPB
capability, set those (AMD) bits accordingly. Likewise if the Intel STIBP
bit is set, set the AMD STIBP that's used for the generic hardware
capability.

Hide the rest from /proc/cpuinfo by putting "" in the comments. Including
RETPOLINE and RETPOLINE_AMD which shouldn't be visible there. There are
patches to make the sysfs vulnerabilities information non-readable by
non-root, and the same should apply to all information about which
mitigations are actually in use. Those *shouldn't* appear in /proc/cpuinfo.

The feature bit for whether IBPB is actually used, which is needed for
ALTERNATIVEs, is renamed to X86_FEATURE_USE_IBPB.

Originally-by: Borislav Petkov <bp@suse.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1517070274-12128-2-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/cpufeatures.h   |   18 +++++++++---------
 arch/x86/include/asm/nospec-branch.h |    2 +-
 arch/x86/kernel/cpu/bugs.c           |    7 +++----
 arch/x86/kernel/cpu/intel.c          |   31 +++++++++++++++++++++----------
 4 files changed, 34 insertions(+), 24 deletions(-)

--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -203,14 +203,14 @@
 #define X86_FEATURE_PROC_FEEDBACK	( 7*32+ 9) /* AMD ProcFeedbackInterface */
 #define X86_FEATURE_SME			( 7*32+10) /* AMD Secure Memory Encryption */
 #define X86_FEATURE_PTI			( 7*32+11) /* Kernel Page Table Isolation enabled */
-#define X86_FEATURE_RETPOLINE		( 7*32+12) /* Generic Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_RETPOLINE_AMD	( 7*32+13) /* AMD Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE		( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_AMD	( 7*32+13) /* "" AMD Retpoline mitigation for Spectre variant 2 */
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
 
 #define X86_FEATURE_MBA			( 7*32+18) /* Memory Bandwidth Allocation */
-#define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* Fill RSB on context switches */
+#define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* "" Fill RSB on context switches */
 
-#define X86_FEATURE_IBPB		( 7*32+21) /* Indirect Branch Prediction Barrier enabled*/
+#define X86_FEATURE_USE_IBPB		( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW		( 8*32+ 0) /* Intel TPR Shadow */
@@ -271,9 +271,9 @@
 #define X86_FEATURE_CLZERO		(13*32+ 0) /* CLZERO instruction */
 #define X86_FEATURE_IRPERF		(13*32+ 1) /* Instructions Retired Count */
 #define X86_FEATURE_XSAVEERPTR		(13*32+ 2) /* Always save/restore FP error pointers */
-#define X86_FEATURE_AMD_PRED_CMD	(13*32+12) /* Prediction Command MSR (AMD) */
-#define X86_FEATURE_AMD_SPEC_CTRL	(13*32+14) /* Speculation Control MSR only (AMD) */
-#define X86_FEATURE_AMD_STIBP		(13*32+15) /* Single Thread Indirect Branch Predictors (AMD) */
+#define X86_FEATURE_IBPB		(13*32+12) /* Indirect Branch Prediction Barrier */
+#define X86_FEATURE_IBRS		(13*32+14) /* Indirect Branch Restricted Speculation */
+#define X86_FEATURE_STIBP		(13*32+15) /* Single Thread Indirect Branch Predictors */
 
 /* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
 #define X86_FEATURE_DTHERM		(14*32+ 0) /* Digital Thermal Sensor */
@@ -325,8 +325,8 @@
 /* Intel-defined CPU features, CPUID level 0x00000007:0 (EDX), word 18 */
 #define X86_FEATURE_AVX512_4VNNIW	(18*32+ 2) /* AVX-512 Neural Network Instructions */
 #define X86_FEATURE_AVX512_4FMAPS	(18*32+ 3) /* AVX-512 Multiply Accumulation Single precision */
-#define X86_FEATURE_SPEC_CTRL		(18*32+26) /* Speculation Control (IBRS + IBPB) */
-#define X86_FEATURE_STIBP		(18*32+27) /* Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_SPEC_CTRL		(18*32+26) /* "" Speculation Control (IBRS + IBPB) */
+#define X86_FEATURE_INTEL_STIBP		(18*32+27) /* "" Single Thread Indirect Branch Predictors */
 #define X86_FEATURE_ARCH_CAPABILITIES	(18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
 
 /*
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -225,7 +225,7 @@ static inline void indirect_branch_predi
 				 "movl %[val], %%eax\n\t"
 				 "movl $0, %%edx\n\t"
 				 "wrmsr",
-				 X86_FEATURE_IBPB)
+				 X86_FEATURE_USE_IBPB)
 		     : : [msr] "i" (MSR_IA32_PRED_CMD),
 			 [val] "i" (PRED_CMD_IBPB)
 		     : "eax", "ecx", "edx", "memory");
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -273,9 +273,8 @@ retpoline_auto:
 	}
 
 	/* Initialize Indirect Branch Prediction Barrier if supported */
-	if (boot_cpu_has(X86_FEATURE_SPEC_CTRL) ||
-	    boot_cpu_has(X86_FEATURE_AMD_PRED_CMD)) {
-		setup_force_cpu_cap(X86_FEATURE_IBPB);
+	if (boot_cpu_has(X86_FEATURE_IBPB)) {
+		setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
 		pr_info("Enabling Indirect Branch Prediction Barrier\n");
 	}
 }
@@ -308,7 +307,7 @@ ssize_t cpu_show_spectre_v2(struct devic
 		return sprintf(buf, "Not affected\n");
 
 	return sprintf(buf, "%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
-		       boot_cpu_has(X86_FEATURE_IBPB) ? ", IBPB" : "",
+		       boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
 		       spectre_v2_module_string());
 }
 #endif
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -175,17 +175,28 @@ static void early_init_intel(struct cpui
 	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
 		c->microcode = intel_get_microcode_revision();
 
-	if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
-	     cpu_has(c, X86_FEATURE_STIBP) ||
-	     cpu_has(c, X86_FEATURE_AMD_SPEC_CTRL) ||
-	     cpu_has(c, X86_FEATURE_AMD_PRED_CMD) ||
-	     cpu_has(c, X86_FEATURE_AMD_STIBP)) && bad_spectre_microcode(c)) {
-		pr_warn("Intel Spectre v2 broken microcode detected; disabling SPEC_CTRL\n");
-		clear_cpu_cap(c, X86_FEATURE_SPEC_CTRL);
+	/*
+	 * The Intel SPEC_CTRL CPUID bit implies IBRS and IBPB support,
+	 * and they also have a different bit for STIBP support. Also,
+	 * a hypervisor might have set the individual AMD bits even on
+	 * Intel CPUs, for finer-grained selection of what's available.
+	 */
+	if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
+		set_cpu_cap(c, X86_FEATURE_IBRS);
+		set_cpu_cap(c, X86_FEATURE_IBPB);
+	}
+	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
+		set_cpu_cap(c, X86_FEATURE_STIBP);
+
+	/* Now if any of them are set, check the blacklist and clear the lot */
+	if ((cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
+	     cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
+		pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n");
+		clear_cpu_cap(c, X86_FEATURE_IBRS);
+		clear_cpu_cap(c, X86_FEATURE_IBPB);
 		clear_cpu_cap(c, X86_FEATURE_STIBP);
-		clear_cpu_cap(c, X86_FEATURE_AMD_SPEC_CTRL);
-		clear_cpu_cap(c, X86_FEATURE_AMD_PRED_CMD);
-		clear_cpu_cap(c, X86_FEATURE_AMD_STIBP);
+		clear_cpu_cap(c, X86_FEATURE_SPEC_CTRL);
+		clear_cpu_cap(c, X86_FEATURE_INTEL_STIBP);
 	}
 
 	/*

[PATCH 4.14 20/64] x86/retpoline: Simplify vmexit_fill_RSB()

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Borislav Petkov bp@alien8.de

commit 1dde7415e99933bb7293d6b2843752cbdb43ec11

Simplify it to call an asm-function instead of pasting 41 insn bytes at
every call site. Also, add alignment to the macro as suggested here:

  https://support.google.com/faqs/answer/7625886

[dwmw2: Clean up comments, let it clobber %ebx and just tell the compiler]

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1517070274-12128-3-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/entry/entry_32.S             |    3 -
 arch/x86/entry/entry_64.S             |    3 -
 arch/x86/include/asm/asm-prototypes.h |    3 +
 arch/x86/include/asm/nospec-branch.h  |   70 +++-------------------------------
 arch/x86/lib/Makefile                 |    1 
 arch/x86/lib/retpoline.S              |   56 +++++++++++++++++++++++++++
 6 files changed, 71 insertions(+), 65 deletions(-)

--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -252,7 +252,8 @@ ENTRY(__switch_to_asm)
 	 * exist, overwrite the RSB with entries which capture
 	 * speculative execution to prevent attack.
 	 */
-	FILL_RETURN_BUFFER %ebx, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
+	/* Clobbers %ebx */
+	FILL_RETURN_BUFFER RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
 #endif
 
 	/* restore callee-saved registers */
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -495,7 +495,8 @@ ENTRY(__switch_to_asm)
 	 * exist, overwrite the RSB with entries which capture
 	 * speculative execution to prevent attack.
 	 */
-	FILL_RETURN_BUFFER %r12, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
+	/* Clobbers %rbx */
+	FILL_RETURN_BUFFER RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
 #endif
 
 	/* restore callee-saved registers */
--- a/arch/x86/include/asm/asm-prototypes.h
+++ b/arch/x86/include/asm/asm-prototypes.h
@@ -38,4 +38,7 @@ INDIRECT_THUNK(dx)
 INDIRECT_THUNK(si)
 INDIRECT_THUNK(di)
 INDIRECT_THUNK(bp)
+asmlinkage void __fill_rsb(void);
+asmlinkage void __clear_rsb(void);
+
 #endif /* CONFIG_RETPOLINE */
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -7,50 +7,6 @@
 #include <asm/alternative-asm.h>
 #include <asm/cpufeatures.h>
 
-/*
- * Fill the CPU return stack buffer.
- *
- * Each entry in the RSB, if used for a speculative 'ret', contains an
- * infinite 'pause; lfence; jmp' loop to capture speculative execution.
- *
- * This is required in various cases for retpoline and IBRS-based
- * mitigations for the Spectre variant 2 vulnerability. Sometimes to
- * eliminate potentially bogus entries from the RSB, and sometimes
- * purely to ensure that it doesn't get empty, which on some CPUs would
- * allow predictions from other (unwanted!) sources to be used.
- *
- * We define a CPP macro such that it can be used from both .S files and
- * inline assembly. It's possible to do a .macro and then include that
- * from C via asm(".include <asm/nospec-branch.h>") but let's not go there.
- */
-
-#define RSB_CLEAR_LOOPS		32	/* To forcibly overwrite all entries */
-#define RSB_FILL_LOOPS		16	/* To avoid underflow */
-
-/*
- * Google experimented with loop-unrolling and this turned out to be
- * the optimal version — two calls, each with their own speculation
- * trap should their return address end up getting used, in a loop.
- */
-#define __FILL_RETURN_BUFFER(reg, nr, sp)	\
-	mov	$(nr/2), reg;			\
-771:						\
-	call	772f;				\
-773:	/* speculation trap */			\
-	pause;					\
-	lfence;					\
-	jmp	773b;				\
-772:						\
-	call	774f;				\
-775:	/* speculation trap */			\
-	pause;					\
-	lfence;					\
-	jmp	775b;				\
-774:						\
-	dec	reg;				\
-	jnz	771b;				\
-	add	$(BITS_PER_LONG/8) * nr, sp;
-
 #ifdef __ASSEMBLY__
 
 /*
@@ -121,17 +77,10 @@
 #endif
 .endm
 
- /*
-  * A simpler FILL_RETURN_BUFFER macro. Don't make people use the CPP
-  * monstrosity above, manually.
-  */
-.macro FILL_RETURN_BUFFER reg:req nr:req ftr:req
+/* This clobbers the BX register */
+.macro FILL_RETURN_BUFFER nr:req ftr:req
 #ifdef CONFIG_RETPOLINE
-	ANNOTATE_NOSPEC_ALTERNATIVE
-	ALTERNATIVE "jmp .Lskip_rsb_\@",				\
-		__stringify(__FILL_RETURN_BUFFER(\reg,\nr,%_ASM_SP))	\
-		\ftr
-.Lskip_rsb_\@:
+	ALTERNATIVE "", "call __clear_rsb", \ftr
 #endif
 .endm
 
@@ -206,15 +155,10 @@ extern char __indirect_thunk_end[];
 static inline void vmexit_fill_RSB(void)
 {
 #ifdef CONFIG_RETPOLINE
-	unsigned long loops;
-
-	asm volatile (ANNOTATE_NOSPEC_ALTERNATIVE
-		      ALTERNATIVE("jmp 910f",
-				  __stringify(__FILL_RETURN_BUFFER(%0, RSB_CLEAR_LOOPS, %1)),
-				  X86_FEATURE_RETPOLINE)
-		      "910:"
-		      : "=r" (loops), ASM_CALL_CONSTRAINT
-		      : : "memory" );
+	alternative_input("",
+			  "call __fill_rsb",
+			  X86_FEATURE_RETPOLINE,
+			  ASM_NO_INPUT_CLOBBER(_ASM_BX, "memory"));
 #endif
 }
 
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -27,6 +27,7 @@ lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) +=
 lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o
 lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
 lib-$(CONFIG_RETPOLINE) += retpoline.o
+OBJECT_FILES_NON_STANDARD_retpoline.o :=y
 
 obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o
 
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -7,6 +7,7 @@
 #include <asm/alternative-asm.h>
 #include <asm/export.h>
 #include <asm/nospec-branch.h>
+#include <asm/bitsperlong.h>
 
 .macro THUNK reg
 	.section .text.__x86.indirect_thunk
@@ -46,3 +47,58 @@ GENERATE_THUNK(r13)
 GENERATE_THUNK(r14)
 GENERATE_THUNK(r15)
 #endif
+
+/*
+ * Fill the CPU return stack buffer.
+ *
+ * Each entry in the RSB, if used for a speculative 'ret', contains an
+ * infinite 'pause; lfence; jmp' loop to capture speculative execution.
+ *
+ * This is required in various cases for retpoline and IBRS-based
+ * mitigations for the Spectre variant 2 vulnerability. Sometimes to
+ * eliminate potentially bogus entries from the RSB, and sometimes
+ * purely to ensure that it doesn't get empty, which on some CPUs would
+ * allow predictions from other (unwanted!) sources to be used.
+ *
+ * Google experimented with loop-unrolling and this turned out to be
+ * the optimal version - two calls, each with their own speculation
+ * trap should their return address end up getting used, in a loop.
+ */
+.macro STUFF_RSB nr:req sp:req
+	mov	$(\nr / 2), %_ASM_BX
+	.align 16
+771:
+	call	772f
+773:						/* speculation trap */
+	pause
+	lfence
+	jmp	773b
+	.align 16
+772:
+	call	774f
+775:						/* speculation trap */
+	pause
+	lfence
+	jmp	775b
+	.align 16
+774:
+	dec	%_ASM_BX
+	jnz	771b
+	add	$((BITS_PER_LONG/8) * \nr), \sp
+.endm
+
+#define RSB_FILL_LOOPS		16	/* To avoid underflow */
+
+ENTRY(__fill_rsb)
+	STUFF_RSB RSB_FILL_LOOPS, %_ASM_SP
+	ret
+END(__fill_rsb)
+EXPORT_SYMBOL_GPL(__fill_rsb)
+
+#define RSB_CLEAR_LOOPS		32	/* To forcibly overwrite all entries */
+
+ENTRY(__clear_rsb)
+	STUFF_RSB RSB_CLEAR_LOOPS, %_ASM_SP
+	ret
+END(__clear_rsb)
+EXPORT_SYMBOL_GPL(__clear_rsb)

[PATCH 4.14 21/64] x86/speculation: Simplify indirect_branch_prediction_barrier()

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Borislav Petkov bp@suse.de

commit 64e16720ea0879f8ab4547e3b9758936d483909b

Make it all a function which does the WRMSR instead of having a hairy
inline asm.

[dwmw2: export it, fix CONFIG_RETPOLINE issues]

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1517070274-12128-4-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/nospec-branch.h |   13 ++++---------
 arch/x86/include/asm/processor.h     |    3 +++
 arch/x86/kernel/cpu/bugs.c           |    6 ++++++
 3 files changed, 13 insertions(+), 9 deletions(-)

--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -164,15 +164,10 @@ static inline void vmexit_fill_RSB(void)
 
 static inline void indirect_branch_prediction_barrier(void)
 {
-	asm volatile(ALTERNATIVE("",
-				 "movl %[msr], %%ecx\n\t"
-				 "movl %[val], %%eax\n\t"
-				 "movl $0, %%edx\n\t"
-				 "wrmsr",
-				 X86_FEATURE_USE_IBPB)
-		     : : [msr] "i" (MSR_IA32_PRED_CMD),
-			 [val] "i" (PRED_CMD_IBPB)
-		     : "eax", "ecx", "edx", "memory");
+	alternative_input("",
+			  "call __ibp_barrier",
+			  X86_FEATURE_USE_IBPB,
+			  ASM_NO_INPUT_CLOBBER("eax", "ecx", "edx", "memory"));
 }
 
 #endif /* __ASSEMBLY__ */
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -970,4 +970,7 @@ bool xen_set_default_idle(void);
 
 void stop_this_cpu(void *dummy);
 void df_debug(struct pt_regs *regs, long error_code);
+
+void __ibp_barrier(void);
+
 #endif /* _ASM_X86_PROCESSOR_H */
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -311,3 +311,9 @@ ssize_t cpu_show_spectre_v2(struct devic
 		       spectre_v2_module_string());
 }
 #endif
+
+void __ibp_barrier(void)
+{
+	__wrmsr(MSR_IA32_PRED_CMD, PRED_CMD_IBPB, 0);
+}
+EXPORT_SYMBOL_GPL(__ibp_barrier);

[PATCH 4.14 22/64] auxdisplay: img-ascii-lcd: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jesse Chan <jc@linux.com>

commit 09c479f7f1fbfaf848e5813996793966cd50be81 upstream.

This change resolves a new compile-time warning
when built as a loadable module:

WARNING: modpost: missing MODULE_LICENSE() in drivers/auxdisplay/img-ascii-lcd.o
see include/linux/module.h for more information

This adds the license as "GPL", which matches the header of the file.

MODULE_DESCRIPTION and MODULE_AUTHOR are also added.

Signed-off-by: Jesse Chan <jc@linux.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/auxdisplay/img-ascii-lcd.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/auxdisplay/img-ascii-lcd.c
+++ b/drivers/auxdisplay/img-ascii-lcd.c
@@ -443,3 +443,7 @@ static struct platform_driver img_ascii_
 	.remove	= img_ascii_lcd_remove,
 };
 module_platform_driver(img_ascii_lcd_driver);
+
+MODULE_DESCRIPTION("Imagination Technologies ASCII LCD Display");
+MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");
+MODULE_LICENSE("GPL");

[PATCH 4.14 23/64] iio: adc/accel: Fix up module licenses

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Linus Walleij <linus.walleij@linaro.org>

commit 9a0ebbc93547d88f422905c34dcceebe928f3e9e upstream.

The module license checker complains about these two so just fix
it up. They are both GPLv2, both written by me or using code
I extracted while refactoring from the GPLv2 drivers.

Cc: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iio/accel/kxsd9-i2c.c      |    3 +++
 drivers/iio/adc/qcom-vadc-common.c |    4 ++++
 2 files changed, 7 insertions(+)

--- a/drivers/iio/accel/kxsd9-i2c.c
+++ b/drivers/iio/accel/kxsd9-i2c.c
@@ -63,3 +63,6 @@ static struct i2c_driver kxsd9_i2c_drive
 	.id_table	= kxsd9_i2c_id,
 };
 module_i2c_driver(kxsd9_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("KXSD9 accelerometer I2C interface");
--- a/drivers/iio/adc/qcom-vadc-common.c
+++ b/drivers/iio/adc/qcom-vadc-common.c
@@ -5,6 +5,7 @@
 #include <linux/math64.h>
 #include <linux/log2.h>
 #include <linux/err.h>
+#include <linux/module.h>
 
 #include "qcom-vadc-common.h"
 
@@ -229,3 +230,6 @@ int qcom_vadc_decimation_from_dt(u32 val
 	return __ffs64(value / VADC_DECIMATION_MIN);
 }
 EXPORT_SYMBOL(qcom_vadc_decimation_from_dt);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm ADC common functionality");

[PATCH 4.14 24/64] pinctrl: pxa: pxa2xx: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jesse Chan <jc@linux.com>

commit 0b9335cbd38e3bd2025bcc23b5758df4ac035f75 upstream.

This change resolves a new compile-time warning
when built as a loadable module:

WARNING: modpost: missing MODULE_LICENSE() in drivers/pinctrl/pxa/pinctrl-pxa2xx.o
see include/linux/module.h for more information

This adds the license as "GPL v2", which matches the header of the file.

MODULE_DESCRIPTION and MODULE_AUTHOR are also added.

Signed-off-by: Jesse Chan <jc@linux.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/pinctrl/pxa/pinctrl-pxa2xx.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/pinctrl/pxa/pinctrl-pxa2xx.c
+++ b/drivers/pinctrl/pxa/pinctrl-pxa2xx.c
@@ -436,3 +436,7 @@ int pxa2xx_pinctrl_exit(struct platform_
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pxa2xx_pinctrl_exit);
+
+MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
+MODULE_DESCRIPTION("Marvell PXA2xx pinctrl driver");
+MODULE_LICENSE("GPL v2");

[PATCH 4.14 25/64] ASoC: pcm512x: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jesse Chan <jc@linux.com>

commit 0cab20cec0b663b7be8e2be5998d5a4113647f86 upstream.

This change resolves a new compile-time warning
when built as a loadable module:

WARNING: modpost: missing MODULE_LICENSE() in sound/soc/codecs/snd-soc-pcm512x-spi.o
see include/linux/module.h for more information

This adds the license as "GPL v2", which matches the header of the file.

MODULE_DESCRIPTION and MODULE_AUTHOR are also added.

Signed-off-by: Jesse Chan <jc@linux.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 sound/soc/codecs/pcm512x-spi.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/sound/soc/codecs/pcm512x-spi.c
+++ b/sound/soc/codecs/pcm512x-spi.c
@@ -70,3 +70,7 @@ static struct spi_driver pcm512x_spi_dri
 };
 
 module_spi_driver(pcm512x_spi_driver);
+
+MODULE_DESCRIPTION("ASoC PCM512x codec driver - SPI");
+MODULE_AUTHOR("Mark Brown <broonie@kernel.org>");
+MODULE_LICENSE("GPL v2");

[PATCH 4.14 26/64] KVM: nVMX: Eliminate vmcs02 pool

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jim Mattson jmattson@google.com

commit de3a0021a60635de96aa92713c1a31a96747d72c

The potential performance advantages of a vmcs02 pool have never been
realized. To simplify the code, eliminate the pool. Instead, a single
vmcs02 is allocated per VCPU when the VCPU enters VMX operation.

Cc: stable@vger.kernel.org       # prereq for Spectre mitigation
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
Reviewed-by: Ameya More <ameya.more@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/vmx.c |  146 ++++++++---------------------------------------------
 1 file changed, 23 insertions(+), 123 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -182,7 +182,6 @@ module_param(ple_window_max, int, S_IRUG
 extern const ulong vmx_return;
 
 #define NR_AUTOLOAD_MSRS 8
-#define VMCS02_POOL_SIZE 1
 
 struct vmcs {
 	u32 revision_id;
@@ -223,7 +222,7 @@ struct shared_msr_entry {
  * stored in guest memory specified by VMPTRLD, but is opaque to the guest,
  * which must access it using VMREAD/VMWRITE/VMCLEAR instructions.
  * More than one of these structures may exist, if L1 runs multiple L2 guests.
- * nested_vmx_run() will use the data here to build a vmcs02: a VMCS for the
+ * nested_vmx_run() will use the data here to build the vmcs02: a VMCS for the
  * underlying hardware which will be used to run L2.
  * This structure is packed to ensure that its layout is identical across
  * machines (necessary for live migration).
@@ -406,13 +405,6 @@ struct __packed vmcs12 {
  */
 #define VMCS12_SIZE 0x1000
 
-/* Used to remember the last vmcs02 used for some recently used vmcs12s */
-struct vmcs02_list {
-	struct list_head list;
-	gpa_t vmptr;
-	struct loaded_vmcs vmcs02;
-};
-
 /*
  * The nested_vmx structure is part of vcpu_vmx, and holds information we need
  * for correct emulation of VMX (i.e., nested VMX) on this vcpu.
@@ -437,15 +429,15 @@ struct nested_vmx {
 	 */
 	bool sync_shadow_vmcs;
 
-	/* vmcs02_list cache of VMCSs recently used to run L2 guests */
-	struct list_head vmcs02_pool;
-	int vmcs02_num;
 	bool change_vmcs01_virtual_x2apic_mode;
 	/* L2 must run next, and mustn't decide to exit to L1. */
 	bool nested_run_pending;
+
+	struct loaded_vmcs vmcs02;
+
 	/*
-	 * Guest pages referred to in vmcs02 with host-physical pointers, so
-	 * we must keep them pinned while L2 runs.
+	 * Guest pages referred to in the vmcs02 with host-physical
+	 * pointers, so we must keep them pinned while L2 runs.
 	 */
 	struct page *apic_access_page;
 	struct page *virtual_apic_page;
@@ -6964,94 +6956,6 @@ static int handle_monitor(struct kvm_vcp
 }
 
 /*
- * To run an L2 guest, we need a vmcs02 based on the L1-specified vmcs12.
- * We could reuse a single VMCS for all the L2 guests, but we also want the
- * option to allocate a separate vmcs02 for each separate loaded vmcs12 - this
- * allows keeping them loaded on the processor, and in the future will allow
- * optimizations where prepare_vmcs02 doesn't need to set all the fields on
- * every entry if they never change.
- * So we keep, in vmx->nested.vmcs02_pool, a cache of size VMCS02_POOL_SIZE
- * (>=0) with a vmcs02 for each recently loaded vmcs12s, most recent first.
- *
- * The following functions allocate and free a vmcs02 in this pool.
- */
-
-/* Get a VMCS from the pool to use as vmcs02 for the current vmcs12. */
-static struct loaded_vmcs *nested_get_current_vmcs02(struct vcpu_vmx *vmx)
-{
-	struct vmcs02_list *item;
-	list_for_each_entry(item, &vmx->nested.vmcs02_pool, list)
-		if (item->vmptr == vmx->nested.current_vmptr) {
-			list_move(&item->list, &vmx->nested.vmcs02_pool);
-			return &item->vmcs02;
-		}
-
-	if (vmx->nested.vmcs02_num >= max(VMCS02_POOL_SIZE, 1)) {
-		/* Recycle the least recently used VMCS. */
-		item = list_last_entry(&vmx->nested.vmcs02_pool,
-				       struct vmcs02_list, list);
-		item->vmptr = vmx->nested.current_vmptr;
-		list_move(&item->list, &vmx->nested.vmcs02_pool);
-		return &item->vmcs02;
-	}
-
-	/* Create a new VMCS */
-	item = kzalloc(sizeof(struct vmcs02_list), GFP_KERNEL);
-	if (!item)
-		return NULL;
-	item->vmcs02.vmcs = alloc_vmcs();
-	item->vmcs02.shadow_vmcs = NULL;
-	if (!item->vmcs02.vmcs) {
-		kfree(item);
-		return NULL;
-	}
-	loaded_vmcs_init(&item->vmcs02);
-	item->vmptr = vmx->nested.current_vmptr;
-	list_add(&(item->list), &(vmx->nested.vmcs02_pool));
-	vmx->nested.vmcs02_num++;
-	return &item->vmcs02;
-}
-
-/* Free and remove from pool a vmcs02 saved for a vmcs12 (if there is one) */
-static void nested_free_vmcs02(struct vcpu_vmx *vmx, gpa_t vmptr)
-{
-	struct vmcs02_list *item;
-	list_for_each_entry(item, &vmx->nested.vmcs02_pool, list)
-		if (item->vmptr == vmptr) {
-			free_loaded_vmcs(&item->vmcs02);
-			list_del(&item->list);
-			kfree(item);
-			vmx->nested.vmcs02_num--;
-			return;
-		}
-}
-
-/*
- * Free all VMCSs saved for this vcpu, except the one pointed by
- * vmx->loaded_vmcs. We must be running L1, so vmx->loaded_vmcs
- * must be &vmx->vmcs01.
- */
-static void nested_free_all_saved_vmcss(struct vcpu_vmx *vmx)
-{
-	struct vmcs02_list *item, *n;
-
-	WARN_ON(vmx->loaded_vmcs != &vmx->vmcs01);
-	list_for_each_entry_safe(item, n, &vmx->nested.vmcs02_pool, list) {
-		/*
-		 * Something will leak if the above WARN triggers.  Better than
-		 * a use-after-free.
-		 */
-		if (vmx->loaded_vmcs == &item->vmcs02)
-			continue;
-
-		free_loaded_vmcs(&item->vmcs02);
-		list_del(&item->list);
-		kfree(item);
-		vmx->nested.vmcs02_num--;
-	}
-}
-
-/*
  * The following 3 functions, nested_vmx_succeed()/failValid()/failInvalid(),
  * set the success or error code of an emulated VMX instruction, as specified
  * by Vol 2B, VMX Instruction Reference, "Conventions".
@@ -7232,6 +7136,12 @@ static int enter_vmx_operation(struct kv
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct vmcs *shadow_vmcs;
 
+	vmx->nested.vmcs02.vmcs = alloc_vmcs();
+	vmx->nested.vmcs02.shadow_vmcs = NULL;
+	if (!vmx->nested.vmcs02.vmcs)
+		goto out_vmcs02;
+	loaded_vmcs_init(&vmx->nested.vmcs02);
+
 	if (cpu_has_vmx_msr_bitmap()) {
 		vmx->nested.msr_bitmap =
 				(unsigned long *)__get_free_page(GFP_KERNEL);
@@ -7254,9 +7164,6 @@ static int enter_vmx_operation(struct kv
 		vmx->vmcs01.shadow_vmcs = shadow_vmcs;
 	}
 
-	INIT_LIST_HEAD(&(vmx->nested.vmcs02_pool));
-	vmx->nested.vmcs02_num = 0;
-
 	hrtimer_init(&vmx->nested.preemption_timer, CLOCK_MONOTONIC,
 		     HRTIMER_MODE_REL_PINNED);
 	vmx->nested.preemption_timer.function = vmx_preemption_timer_fn;
@@ -7271,6 +7178,9 @@ out_cached_vmcs12:
 	free_page((unsigned long)vmx->nested.msr_bitmap);
 
 out_msr_bitmap:
+	free_loaded_vmcs(&vmx->nested.vmcs02);
+
+out_vmcs02:
 	return -ENOMEM;
 }
 
@@ -7423,7 +7333,7 @@ static void free_nested(struct vcpu_vmx
 		vmx->vmcs01.shadow_vmcs = NULL;
 	}
 	kfree(vmx->nested.cached_vmcs12);
-	/* Unpin physical memory we referred to in current vmcs02 */
+	/* Unpin physical memory we referred to in the vmcs02 */
 	if (vmx->nested.apic_access_page) {
 		kvm_release_page_dirty(vmx->nested.apic_access_page);
 		vmx->nested.apic_access_page = NULL;
@@ -7439,7 +7349,7 @@ static void free_nested(struct vcpu_vmx
 		vmx->nested.pi_desc = NULL;
 	}
 
-	nested_free_all_saved_vmcss(vmx);
+	free_loaded_vmcs(&vmx->nested.vmcs02);
 }
 
 /* Emulate the VMXOFF instruction */
@@ -7482,8 +7392,6 @@ static int handle_vmclear(struct kvm_vcp
 			vmptr + offsetof(struct vmcs12, launch_state),
 			&zero, sizeof(zero));
 
-	nested_free_vmcs02(vmx, vmptr);
-
 	nested_vmx_succeed(vcpu);
 	return kvm_skip_emulated_instruction(vcpu);
 }
@@ -8395,10 +8303,11 @@ static bool nested_vmx_exit_reflected(st
 
 	/*
 	 * The host physical addresses of some pages of guest memory
-	 * are loaded into VMCS02 (e.g. L1's Virtual APIC Page). The CPU
-	 * may write to these pages via their host physical address while
-	 * L2 is running, bypassing any address-translation-based dirty
-	 * tracking (e.g. EPT write protection).
+	 * are loaded into the vmcs02 (e.g. vmcs12's Virtual APIC
+	 * Page). The CPU may write to these pages via their host
+	 * physical address while L2 is running, bypassing any
+	 * address-translation-based dirty tracking (e.g. EPT write
+	 * protection).
 	 *
 	 * Mark them dirty on every exit from L2 to prevent them from
 	 * getting out of sync with dirty tracking.
@@ -10894,20 +10803,15 @@ static int enter_vmx_non_root_mode(struc
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
-	struct loaded_vmcs *vmcs02;
 	u32 msr_entry_idx;
 	u32 exit_qual;
 
-	vmcs02 = nested_get_current_vmcs02(vmx);
-	if (!vmcs02)
-		return -ENOMEM;
-
 	enter_guest_mode(vcpu);
 
 	if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
 		vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
 
-	vmx_switch_vmcs(vcpu, vmcs02);
+	vmx_switch_vmcs(vcpu, &vmx->nested.vmcs02);
 	vmx_segment_cache_clear(vmx);
 
 	if (prepare_vmcs02(vcpu, vmcs12, from_vmentry, &exit_qual)) {
@@ -11522,10 +11426,6 @@ static void nested_vmx_vmexit(struct kvm
 	vm_exit_controls_reset_shadow(vmx);
 	vmx_segment_cache_clear(vmx);
 
-	/* if no vmcs02 cache requested, remove the one we used */
-	if (VMCS02_POOL_SIZE == 0)
-		nested_free_vmcs02(vmx, vmx->nested.current_vmptr);
-
 	/* Update any VMCS fields that might have changed while L2 ran */
 	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
 	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.nr);

[PATCH 4.14 27/64] KVM: VMX: introduce alloc_loaded_vmcs

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Paolo Bonzini pbonzini@redhat.com

commit f21f165ef922c2146cc5bdc620f542953c41714b

Group together the calls to alloc_vmcs and loaded_vmcs_init.  Soon we'll also
allocate an MSR bitmap there.

Cc: stable@vger.kernel.org       # prereq for Spectre mitigation
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/vmx.c |   36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3814,11 +3814,6 @@ static struct vmcs *alloc_vmcs_cpu(int c
 	return vmcs;
 }
 
-static struct vmcs *alloc_vmcs(void)
-{
-	return alloc_vmcs_cpu(raw_smp_processor_id());
-}
-
 static void free_vmcs(struct vmcs *vmcs)
 {
 	free_pages((unsigned long)vmcs, vmcs_config.order);
@@ -3837,6 +3832,22 @@ static void free_loaded_vmcs(struct load
 	WARN_ON(loaded_vmcs->shadow_vmcs != NULL);
 }
 
+static struct vmcs *alloc_vmcs(void)
+{
+	return alloc_vmcs_cpu(raw_smp_processor_id());
+}
+
+static int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
+{
+	loaded_vmcs->vmcs = alloc_vmcs();
+	if (!loaded_vmcs->vmcs)
+		return -ENOMEM;
+
+	loaded_vmcs->shadow_vmcs = NULL;
+	loaded_vmcs_init(loaded_vmcs);
+	return 0;
+}
+
 static void free_kvm_area(void)
 {
 	int cpu;
@@ -7135,12 +7146,11 @@ static int enter_vmx_operation(struct kv
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct vmcs *shadow_vmcs;
+	int r;
 
-	vmx->nested.vmcs02.vmcs = alloc_vmcs();
-	vmx->nested.vmcs02.shadow_vmcs = NULL;
-	if (!vmx->nested.vmcs02.vmcs)
+	r = alloc_loaded_vmcs(&vmx->nested.vmcs02);
+	if (r < 0)
 		goto out_vmcs02;
-	loaded_vmcs_init(&vmx->nested.vmcs02);
 
 	if (cpu_has_vmx_msr_bitmap()) {
 		vmx->nested.msr_bitmap =
@@ -9535,13 +9545,11 @@ static struct kvm_vcpu *vmx_create_vcpu(
 	if (!vmx->guest_msrs)
 		goto free_pml;
 
-	vmx->loaded_vmcs = &vmx->vmcs01;
-	vmx->loaded_vmcs->vmcs = alloc_vmcs();
-	vmx->loaded_vmcs->shadow_vmcs = NULL;
-	if (!vmx->loaded_vmcs->vmcs)
+	err = alloc_loaded_vmcs(&vmx->vmcs01);
+	if (err < 0)
 		goto free_msrs;
-	loaded_vmcs_init(vmx->loaded_vmcs);
 
+	vmx->loaded_vmcs = &vmx->vmcs01;
 	cpu = get_cpu();
 	vmx_vcpu_load(&vmx->vcpu, cpu);
 	vmx->vcpu.cpu = cpu;

[PATCH 4.14 28/64] objtool: Improve retpoline alternative handling

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Josh Poimboeuf jpoimboe@redhat.com

commit a845c7cf4b4cb5e9e3b2823867892b27646f3a98

Currently objtool requires all retpolines to be:

  a) patched in with alternatives; and

  b) annotated with ANNOTATE_NOSPEC_ALTERNATIVE.

If you forget to do both of the above, objtool segfaults trying to
dereference a NULL 'insn->call_dest' pointer.

Avoid that situation and print a more helpful error message:

  quirks.o: warning: objtool: efi_delete_dummy_variable()+0x99: unsupported intra-function call
  quirks.o: warning: objtool: If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.

Future improvements can be made to make objtool smarter with respect to
retpolines, but this is a good incremental improvement for now.

Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/819e50b6d9c2e1a22e34c1a636c0b2057cc8c6e5.1517284349.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/objtool/check.c |   36 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 20 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -543,18 +543,14 @@ static int add_call_destinations(struct
 			dest_off = insn->offset + insn->len + insn->immediate;
 			insn->call_dest = find_symbol_by_offset(insn->sec,
 								dest_off);
-			/*
-			 * FIXME: Thanks to retpolines, it's now considered
-			 * normal for a function to call within itself.  So
-			 * disable this warning for now.
-			 */
-#if 0
-			if (!insn->call_dest) {
-				WARN_FUNC("can't find call dest symbol at offset 0x%lx",
-					  insn->sec, insn->offset, dest_off);
+
+			if (!insn->call_dest && !insn->ignore) {
+				WARN_FUNC("unsupported intra-function call",
+					  insn->sec, insn->offset);
+				WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.");
 				return -1;
 			}
-#endif
+
 		} else if (rela->sym->type == STT_SECTION) {
 			insn->call_dest = find_symbol_by_offset(rela->sym->sec,
 								rela->addend+4);
@@ -648,6 +644,8 @@ static int handle_group_alt(struct objto
 
 		last_new_insn = insn;
 
+		insn->ignore = orig_insn->ignore_alts;
+
 		if (insn->type != INSN_JUMP_CONDITIONAL &&
 		    insn->type != INSN_JUMP_UNCONDITIONAL)
 			continue;
@@ -729,10 +727,6 @@ static int add_special_section_alts(stru
 			goto out;
 		}
 
-		/* Ignore retpoline alternatives. */
-		if (orig_insn->ignore_alts)
-			continue;
-
 		new_insn = NULL;
 		if (!special_alt->group || special_alt->new_len) {
 			new_insn = find_insn(file, special_alt->new_sec,
@@ -1089,11 +1083,11 @@ static int decode_sections(struct objtoo
 	if (ret)
 		return ret;
 
-	ret = add_call_destinations(file);
+	ret = add_special_section_alts(file);
 	if (ret)
 		return ret;
 
-	ret = add_special_section_alts(file);
+	ret = add_call_destinations(file);
 	if (ret)
 		return ret;
 
@@ -1720,10 +1714,12 @@ static int validate_branch(struct objtoo
 
 		insn->visited = true;
 
-		list_for_each_entry(alt, &insn->alts, list) {
-			ret = validate_branch(file, alt->insn, state);
-			if (ret)
-				return 1;
+		if (!insn->ignore_alts) {
+			list_for_each_entry(alt, &insn->alts, list) {
+				ret = validate_branch(file, alt->insn, state);
+				if (ret)
+					return 1;
+			}
 		}
 
 		switch (insn->type) {

[PATCH 4.14 29/64] objtool: Add support for alternatives at the end of a section

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Josh Poimboeuf jpoimboe@redhat.com

commit 17bc33914bcc98ba3c6b426fd1c49587a25c0597

Now that the previous patch gave objtool the ability to read retpoline
alternatives, it shows a new warning:

  arch/x86/entry/entry_64.o: warning: objtool: .entry_trampoline: don't know how to handle alternatives at end of section

This is due to the JMP_NOSPEC in entry_SYSCALL_64_trampoline().

Previously, objtool ignored this situation because it wasn't needed, and
it would have required a bit of extra code.  Now that this case exists,
add proper support for it.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2a30a3c2158af47d891a76e69bb1ef347e0443fd.1517284349.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/objtool/check.c |   53 +++++++++++++++++++++++++++++---------------------
 1 file changed, 31 insertions(+), 22 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -594,7 +594,7 @@ static int handle_group_alt(struct objto
 			    struct instruction *orig_insn,
 			    struct instruction **new_insn)
 {
-	struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump;
+	struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
 	unsigned long dest_off;
 
 	last_orig_insn = NULL;
@@ -610,28 +610,30 @@ static int handle_group_alt(struct objto
 		last_orig_insn = insn;
 	}
 
-	if (!next_insn_same_sec(file, last_orig_insn)) {
-		WARN("%s: don't know how to handle alternatives at end of section",
-		     special_alt->orig_sec->name);
-		return -1;
-	}
-
-	fake_jump = malloc(sizeof(*fake_jump));
-	if (!fake_jump) {
-		WARN("malloc failed");
-		return -1;
+	if (next_insn_same_sec(file, last_orig_insn)) {
+		fake_jump = malloc(sizeof(*fake_jump));
+		if (!fake_jump) {
+			WARN("malloc failed");
+			return -1;
+		}
+		memset(fake_jump, 0, sizeof(*fake_jump));
+		INIT_LIST_HEAD(&fake_jump->alts);
+		clear_insn_state(&fake_jump->state);
+
+		fake_jump->sec = special_alt->new_sec;
+		fake_jump->offset = -1;
+		fake_jump->type = INSN_JUMP_UNCONDITIONAL;
+		fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
+		fake_jump->ignore = true;
 	}
-	memset(fake_jump, 0, sizeof(*fake_jump));
-	INIT_LIST_HEAD(&fake_jump->alts);
-	clear_insn_state(&fake_jump->state);
-
-	fake_jump->sec = special_alt->new_sec;
-	fake_jump->offset = -1;
-	fake_jump->type = INSN_JUMP_UNCONDITIONAL;
-	fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
-	fake_jump->ignore = true;
 
 	if (!special_alt->new_len) {
+		if (!fake_jump) {
+			WARN("%s: empty alternative at end of section",
+			     special_alt->orig_sec->name);
+			return -1;
+		}
+
 		*new_insn = fake_jump;
 		return 0;
 	}
@@ -654,8 +656,14 @@ static int handle_group_alt(struct objto
 			continue;
 
 		dest_off = insn->offset + insn->len + insn->immediate;
-		if (dest_off == special_alt->new_off + special_alt->new_len)
+		if (dest_off == special_alt->new_off + special_alt->new_len) {
+			if (!fake_jump) {
+				WARN("%s: alternative jump to end of section",
+				     special_alt->orig_sec->name);
+				return -1;
+			}
 			insn->jump_dest = fake_jump;
+		}
 
 		if (!insn->jump_dest) {
 			WARN_FUNC("can't find alternative jump destination",
@@ -670,7 +678,8 @@ static int handle_group_alt(struct objto
 		return -1;
 	}
 
-	list_add(&fake_jump->list, &last_new_insn->list);
+	if (fake_jump)
+		list_add(&fake_jump->list, &last_new_insn->list);
 
 	return 0;
 }

[PATCH 4.14 30/64] objtool: Warn on stripped section symbol

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Josh Poimboeuf jpoimboe@redhat.com

commit 830c1e3d16b2c1733cd1ec9c8f4d47a398ae31bc

With the following fix:

  2a0098d70640 ("objtool: Fix seg fault with gold linker")

... a seg fault was avoided, but the original seg fault condition in
objtool wasn't fixed.  Replace the seg fault with an error message.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/dc4585a70d6b975c99fc51d1957ccdde7bd52f3a.1517284349.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/objtool/orc_gen.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -98,6 +98,11 @@ static int create_orc_entry(struct secti
 	struct orc_entry *orc;
 	struct rela *rela;
 
+	if (!insn_sec->sym) {
+		WARN("missing symbol for section %s", insn_sec->name);
+		return -1;
+	}
+
 	/* populate ORC data */
 	orc = (struct orc_entry *)u_sec->data->d_buf + idx;
 	memcpy(orc, o, sizeof(*orc));

[PATCH 4.14 31/64] x86/mm: Fix overlap of i386 CPU_ENTRY_AREA with FIX_BTMAP

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: William Grant <william.grant@canonical.com>

commit 55f49fcb879fbeebf2a8c1ac7c9e6d90df55f798

Since commit 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the
fixmap"), i386's CPU_ENTRY_AREA has been mapped to the memory area just
below FIXADDR_START. But already immediately before FIXADDR_START is the
FIX_BTMAP area, which means that early_ioremap can collide with the entry
area.

It's especially bad on PAE where FIX_BTMAP_BEGIN gets aligned to exactly
match CPU_ENTRY_AREA_BASE, so the first early_ioremap slot clobbers the
IDT and causes interrupts during early boot to reset the system.

The overlap wasn't a problem before the CPU entry area was introduced,
as the fixmap has classically been preceded by the pkmap or vmalloc
areas, neither of which is used until early_ioremap is out of the
picture.

Relocate CPU_ENTRY_AREA to below FIX_BTMAP, not just below the permanent
fixmap area.

Fixes: commit 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap")
Signed-off-by: William Grant <william.grant@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/7041d181-a019-e8b9-4e4e-48215f841e2c@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/fixmap.h           |    6 ++++--
 arch/x86/include/asm/pgtable_32_types.h |    5 +++--
 2 files changed, 7 insertions(+), 4 deletions(-)

--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -137,8 +137,10 @@ enum fixed_addresses {
 
 extern void reserve_top_address(unsigned long reserve);
 
-#define FIXADDR_SIZE	(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
-#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_SIZE		(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_TOT_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_TOT_START	(FIXADDR_TOP - FIXADDR_TOT_SIZE)
 
 extern int fixmaps_set;
 
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h
@@ -44,8 +44,9 @@ extern bool __vmalloc_start_set; /* set
  */
 #define CPU_ENTRY_AREA_PAGES	(NR_CPUS * 40)
 
-#define CPU_ENTRY_AREA_BASE				\
-	((FIXADDR_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1)) & PMD_MASK)
+#define CPU_ENTRY_AREA_BASE						\
+	((FIXADDR_TOT_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1))   \
+	 & PMD_MASK)
 
 #define PKMAP_BASE		\
 	((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK)

[PATCH 4.14 32/64] x86/spectre: Check CONFIG_RETPOLINE in command line parser

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dou Liyang <douly.fnst@cn.fujitsu.com>

commit 9471eee9186a46893726e22ebb54cade3f9bc043

The spectre_v2 option 'auto' does not check whether CONFIG_RETPOLINE is
enabled. As a consequence it fails to emit the appropriate warning and sets
feature flags which have no effect at all.

Add the missing IS_ENABLED() check.

Fixes: da285121560e ("x86/spectre: Add boot time option to select Spectre v2 mitigation")
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: peterz@infradead.org
Cc: Tomohiro <misono.tomohiro@jp.fujitsu.com>
Cc: dave.hansen@intel.com
Cc: bp@alien8.de
Cc: arjan@linux.intel.com
Cc: dwmw@amazon.co.uk
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/f5892721-7528-3647-08fb-f8d10e65ad87@cn.fujitsu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/bugs.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -213,10 +213,10 @@ static void __init spectre_v2_select_mit
 		return;
 
 	case SPECTRE_V2_CMD_FORCE:
-		/* FALLTRHU */
 	case SPECTRE_V2_CMD_AUTO:
-		goto retpoline_auto;
-
+		if (IS_ENABLED(CONFIG_RETPOLINE))
+			goto retpoline_auto;
+		break;
 	case SPECTRE_V2_CMD_RETPOLINE_AMD:
 		if (IS_ENABLED(CONFIG_RETPOLINE))
 			goto retpoline_amd;

[PATCH 4.14 33/64] x86/entry/64: Remove the SYSCALL64 fast path

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski luto@kernel.org

commit 21d375b6b34ff511a507de27bf316b3dde6938d9

The SYCALLL64 fast path was a nice, if small, optimization back in the good
old days when syscalls were actually reasonably fast.  Now there is PTI to
slow everything down, and indirect branches are verboten, making everything
messier.  The retpoline code in the fast path is particularly nasty.

Just get rid of the fast path. The slow path is barely slower.

[ tglx: Split out the 'push all extra regs' part ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Link: https://lkml.kernel.org/r/462dff8d4d64dfbfc851fbf3130641809d980ecd.1517164461.git.luto@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/entry/entry_64.S   |  117 --------------------------------------------
 arch/x86/entry/syscall_64.c |    7 --
 2 files changed, 2 insertions(+), 122 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -237,86 +237,11 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 
 	TRACE_IRQS_OFF
 
-	/*
-	 * If we need to do entry work or if we guess we'll need to do
-	 * exit work, go straight to the slow path.
-	 */
-	movq	PER_CPU_VAR(current_task), %r11
-	testl	$_TIF_WORK_SYSCALL_ENTRY|_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
-	jnz	entry_SYSCALL64_slow_path
-
-entry_SYSCALL_64_fastpath:
-	/*
-	 * Easy case: enable interrupts and issue the syscall.  If the syscall
-	 * needs pt_regs, we'll call a stub that disables interrupts again
-	 * and jumps to the slow path.
-	 */
-	TRACE_IRQS_ON
-	ENABLE_INTERRUPTS(CLBR_NONE)
-#if __SYSCALL_MASK == ~0
-	cmpq	$__NR_syscall_max, %rax
-#else
-	andl	$__SYSCALL_MASK, %eax
-	cmpl	$__NR_syscall_max, %eax
-#endif
-	ja	1f				/* return -ENOSYS (already in pt_regs->ax) */
-	movq	%r10, %rcx
-
-	/*
-	 * This call instruction is handled specially in stub_ptregs_64.
-	 * It might end up jumping to the slow path.  If it jumps, RAX
-	 * and all argument registers are clobbered.
-	 */
-#ifdef CONFIG_RETPOLINE
-	movq	sys_call_table(, %rax, 8), %rax
-	call	__x86_indirect_thunk_rax
-#else
-	call	*sys_call_table(, %rax, 8)
-#endif
-.Lentry_SYSCALL_64_after_fastpath_call:
-
-	movq	%rax, RAX(%rsp)
-1:
-
-	/*
-	 * If we get here, then we know that pt_regs is clean for SYSRET64.
-	 * If we see that no exit work is required (which we are required
-	 * to check with IRQs off), then we can go straight to SYSRET64.
-	 */
-	DISABLE_INTERRUPTS(CLBR_ANY)
-	TRACE_IRQS_OFF
-	movq	PER_CPU_VAR(current_task), %r11
-	testl	$_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
-	jnz	1f
-
-	LOCKDEP_SYS_EXIT
-	TRACE_IRQS_ON		/* user mode is traced as IRQs on */
-	movq	RIP(%rsp), %rcx
-	movq	EFLAGS(%rsp), %r11
-	addq	$6*8, %rsp	/* skip extra regs -- they were preserved */
-	UNWIND_HINT_EMPTY
-	jmp	.Lpop_c_regs_except_rcx_r11_and_sysret
-
-1:
-	/*
-	 * The fast path looked good when we started, but something changed
-	 * along the way and we need to switch to the slow path.  Calling
-	 * raise(3) will trigger this, for example.  IRQs are off.
-	 */
-	TRACE_IRQS_ON
-	ENABLE_INTERRUPTS(CLBR_ANY)
-	SAVE_EXTRA_REGS
-	movq	%rsp, %rdi
-	call	syscall_return_slowpath	/* returns with IRQs disabled */
-	jmp	return_from_SYSCALL_64
-
-entry_SYSCALL64_slow_path:
 	/* IRQs are off. */
 	SAVE_EXTRA_REGS
 	movq	%rsp, %rdi
 	call	do_syscall_64		/* returns with IRQs disabled */
 
-return_from_SYSCALL_64:
 	TRACE_IRQS_IRETQ		/* we're about to change IF */
 
 	/*
@@ -389,7 +314,6 @@ syscall_return_via_sysret:
 	/* rcx and r11 are already restored (see code above) */
 	UNWIND_HINT_EMPTY
 	POP_EXTRA_REGS
-.Lpop_c_regs_except_rcx_r11_and_sysret:
 	popq	%rsi	/* skip r11 */
 	popq	%r10
 	popq	%r9
@@ -420,47 +344,6 @@ syscall_return_via_sysret:
 	USERGS_SYSRET64
 END(entry_SYSCALL_64)
 
-ENTRY(stub_ptregs_64)
-	/*
-	 * Syscalls marked as needing ptregs land here.
-	 * If we are on the fast path, we need to save the extra regs,
-	 * which we achieve by trying again on the slow path.  If we are on
-	 * the slow path, the extra regs are already saved.
-	 *
-	 * RAX stores a pointer to the C function implementing the syscall.
-	 * IRQs are on.
-	 */
-	cmpq	$.Lentry_SYSCALL_64_after_fastpath_call, (%rsp)
-	jne	1f
-
-	/*
-	 * Called from fast path -- disable IRQs again, pop return address
-	 * and jump to slow path
-	 */
-	DISABLE_INTERRUPTS(CLBR_ANY)
-	TRACE_IRQS_OFF
-	popq	%rax
-	UNWIND_HINT_REGS extra=0
-	jmp	entry_SYSCALL64_slow_path
-
-1:
-	JMP_NOSPEC %rax				/* Called from C */
-END(stub_ptregs_64)
-
-.macro ptregs_stub func
-ENTRY(ptregs_\func)
-	UNWIND_HINT_FUNC
-	leaq	\func(%rip), %rax
-	jmp	stub_ptregs_64
-END(ptregs_\func)
-.endm
-
-/* Instantiate ptregs_stub for each ptregs-using syscall */
-#define __SYSCALL_64_QUAL_(sym)
-#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_stub sym
-#define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym)
-#include <asm/syscalls_64.h>
-
 /*
  * %rdi: prev task
  * %rsi: next task
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,11 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_64_QUAL_(sym) sym
-#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_##sym
-
-#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long __SYSCALL_64_QUAL_##qual(sym)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
 
-#define __SYSCALL_64(nr, sym, qual) [nr] = __SYSCALL_64_QUAL_##qual(sym),
+#define __SYSCALL_64(nr, sym, qual) [nr] = sym,
 
 extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 

[PATCH 4.14 34/64] x86/entry/64: Push extra regs right away

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski luto@kernel.org

commit d1f7732009e0549eedf8ea1db948dc37be77fd46

With the fast path removed there is no point in splitting the push of the
normal and the extra register set. Just push the extra regs right away.

[ tglx: Split out from 'x86/entry/64: Remove the SYSCALL64 fast path' ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Link: https://lkml.kernel.org/r/462dff8d4d64dfbfc851fbf3130641809d980ecd.1517164461.git.luto@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/entry/entry_64.S |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -232,13 +232,17 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 	pushq	%r9				/* pt_regs->r9 */
 	pushq	%r10				/* pt_regs->r10 */
 	pushq	%r11				/* pt_regs->r11 */
-	sub	$(6*8), %rsp			/* pt_regs->bp, bx, r12-15 not saved */
-	UNWIND_HINT_REGS extra=0
+	pushq	%rbx				/* pt_regs->rbx */
+	pushq	%rbp				/* pt_regs->rbp */
+	pushq	%r12				/* pt_regs->r12 */
+	pushq	%r13				/* pt_regs->r13 */
+	pushq	%r14				/* pt_regs->r14 */
+	pushq	%r15				/* pt_regs->r15 */
+	UNWIND_HINT_REGS
 
 	TRACE_IRQS_OFF
 
 	/* IRQs are off. */
-	SAVE_EXTRA_REGS
 	movq	%rsp, %rdi
 	call	do_syscall_64		/* returns with IRQs disabled */
 

[PATCH 4.14 35/64] x86/asm: Move status from thread_struct to thread_info

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski luto@kernel.org

commit 37a8f7c38339b22b69876d6f5a0ab851565284e3

The TS_COMPAT bit is very hot and is accessed from code paths that mostly
also touch thread_info::flags.  Move it into struct thread_info to improve
cache locality.

The only reason it was in thread_struct is that there was a brief period
during which arch-specific fields were not allowed in struct thread_info.

Linus suggested further changing:

  ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);

to:

  if (unlikely(ti->status & (TS_COMPAT|TS_I386_REGS_POKED)))
          ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);

on the theory that frequently dirtying the cacheline even in pure 64-bit
code that never needs to modify status hurts performance.  That could be a
reasonable followup patch, but I suspect it matters less on top of this
patch.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Link: https://lkml.kernel.org/r/03148bcc1b217100e6e8ecf6a5468c45cf4304b6.1517164461.git.luto@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/entry/common.c            |    4 ++--
 arch/x86/include/asm/processor.h   |    2 --
 arch/x86/include/asm/syscall.h     |    6 +++---
 arch/x86/include/asm/thread_info.h |    3 ++-
 arch/x86/kernel/process_64.c       |    4 ++--
 arch/x86/kernel/ptrace.c           |    2 +-
 arch/x86/kernel/signal.c           |    2 +-
 7 files changed, 11 insertions(+), 12 deletions(-)

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -208,7 +208,7 @@ __visible inline void prepare_exit_to_us
 	 * special case only applies after poking regs and before the
 	 * very next return to user mode.
 	 */
-	current->thread.status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
+	ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
 #endif
 
 	user_enter_irqoff();
@@ -306,7 +306,7 @@ static __always_inline void do_syscall_3
 	unsigned int nr = (unsigned int)regs->orig_ax;
 
 #ifdef CONFIG_IA32_EMULATION
-	current->thread.status |= TS_COMPAT;
+	ti->status |= TS_COMPAT;
 #endif
 
 	if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) {
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -459,8 +459,6 @@ struct thread_struct {
 	unsigned short		gsindex;
 #endif
 
-	u32			status;		/* thread synchronous flags */
-
 #ifdef CONFIG_X86_64
 	unsigned long		fsbase;
 	unsigned long		gsbase;
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -60,7 +60,7 @@ static inline long syscall_get_error(str
 	 * TS_COMPAT is set for 32-bit syscall entries and then
 	 * remains set until we return to user mode.
 	 */
-	if (task->thread.status & (TS_COMPAT|TS_I386_REGS_POKED))
+	if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
 		/*
 		 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
 		 * and will match correctly in comparisons.
@@ -116,7 +116,7 @@ static inline void syscall_get_arguments
 					 unsigned long *args)
 {
 # ifdef CONFIG_IA32_EMULATION
-	if (task->thread.status & TS_COMPAT)
+	if (task->thread_info.status & TS_COMPAT)
 		switch (i) {
 		case 0:
 			if (!n--) break;
@@ -177,7 +177,7 @@ static inline void syscall_set_arguments
 					 const unsigned long *args)
 {
 # ifdef CONFIG_IA32_EMULATION
-	if (task->thread.status & TS_COMPAT)
+	if (task->thread_info.status & TS_COMPAT)
 		switch (i) {
 		case 0:
 			if (!n--) break;
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -55,6 +55,7 @@ struct task_struct;
 
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
+	u32			status;		/* thread synchronous flags */
 };
 
 #define INIT_THREAD_INFO(tsk)			\
@@ -221,7 +222,7 @@ static inline int arch_within_stack_fram
 #define in_ia32_syscall() true
 #else
 #define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \
-			   current->thread.status & TS_COMPAT)
+			   current_thread_info()->status & TS_COMPAT)
 #endif
 
 /*
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -557,7 +557,7 @@ static void __set_personality_x32(void)
 	 * Pretend to come from a x32 execve.
 	 */
 	task_pt_regs(current)->orig_ax = __NR_x32_execve | __X32_SYSCALL_BIT;
-	current->thread.status &= ~TS_COMPAT;
+	current_thread_info()->status &= ~TS_COMPAT;
 #endif
 }
 
@@ -571,7 +571,7 @@ static void __set_personality_ia32(void)
 	current->personality |= force_personality32;
 	/* Prepare the first "return" to user space */
 	task_pt_regs(current)->orig_ax = __NR_ia32_execve;
-	current->thread.status |= TS_COMPAT;
+	current_thread_info()->status |= TS_COMPAT;
 #endif
 }
 
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -935,7 +935,7 @@ static int putreg32(struct task_struct *
 		 */
 		regs->orig_ax = value;
 		if (syscall_get_nr(child, regs) >= 0)
-			child->thread.status |= TS_I386_REGS_POKED;
+			child->thread_info.status |= TS_I386_REGS_POKED;
 		break;
 
 	case offsetof(struct user32, regs.eflags):
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -787,7 +787,7 @@ static inline unsigned long get_nr_resta
 	 * than the tracee.
 	 */
 #ifdef CONFIG_IA32_EMULATION
-	if (current->thread.status & (TS_COMPAT|TS_I386_REGS_POKED))
+	if (current_thread_info()->status & (TS_COMPAT|TS_I386_REGS_POKED))
 		return __NR_ia32_restart_syscall;
 #endif
 #ifdef CONFIG_X86_X32_ABI

[PATCH 4.14 36/64] Documentation: Document array_index_nospec

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mark Rutland mark.rutland@arm.com

commit f84a56f73dddaeac1dba8045b007f742f61cd2da

Document the rationale and usage of the new array_index_nospec() helper.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: linux-arch@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: gregkh@linuxfoundation.org
Cc: kernel-hardening@lists.openwall.com
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727413645.33451.15878817161436755393.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 Documentation/speculation.txt |   90 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

--- /dev/null
+++ b/Documentation/speculation.txt
@@ -0,0 +1,90 @@
+This document explains potential effects of speculation, and how undesirable
+effects can be mitigated portably using common APIs.
+
+===========
+Speculation
+===========
+
+To improve performance and minimize average latencies, many contemporary CPUs
+employ speculative execution techniques such as branch prediction, performing
+work which may be discarded at a later stage.
+
+Typically speculative execution cannot be observed from architectural state,
+such as the contents of registers. However, in some cases it is possible to
+observe its impact on microarchitectural state, such as the presence or
+absence of data in caches. Such state may form side-channels which can be
+observed to extract secret information.
+
+For example, in the presence of branch prediction, it is possible for bounds
+checks to be ignored by code which is speculatively executed. Consider the
+following code:
+
+	int load_array(int *array, unsigned int index)
+	{
+		if (index >= MAX_ARRAY_ELEMS)
+			return 0;
+		else
+			return array[index];
+	}
+
+Which, on arm64, may be compiled to an assembly sequence such as:
+
+	CMP	<index>, #MAX_ARRAY_ELEMS
+	B.LT	less
+	MOV	<returnval>, #0
+	RET
+  less:
+	LDR	<returnval>, [<array>, <index>]
+	RET
+
+It is possible that a CPU mis-predicts the conditional branch, and
+speculatively loads array[index], even if index >= MAX_ARRAY_ELEMS. This
+value will subsequently be discarded, but the speculated load may affect
+microarchitectural state which can be subsequently measured.
+
+More complex sequences involving multiple dependent memory accesses may
+result in sensitive information being leaked. Consider the following
+code, building on the prior example:
+
+	int load_dependent_arrays(int *arr1, int *arr2, int index)
+	{
+		int val1, val2,
+
+		val1 = load_array(arr1, index);
+		val2 = load_array(arr2, val1);
+
+		return val2;
+	}
+
+Under speculation, the first call to load_array() may return the value
+of an out-of-bounds address, while the second call will influence
+microarchitectural state dependent on this value. This may provide an
+arbitrary read primitive.
+
+====================================
+Mitigating speculation side-channels
+====================================
+
+The kernel provides a generic API to ensure that bounds checks are
+respected even under speculation. Architectures which are affected by
+speculation-based side-channels are expected to implement these
+primitives.
+
+The array_index_nospec() helper in <linux/nospec.h> can be used to
+prevent information from being leaked via side-channels.
+
+A call to array_index_nospec(index, size) returns a sanitized index
+value that is bounded to [0, size) even under cpu speculation
+conditions.
+
+This can be used to protect the earlier load_array() example:
+
+	int load_array(int *array, unsigned int index)
+	{
+		if (index >= MAX_ARRAY_ELEMS)
+			return 0;
+		else {
+			index = array_index_nospec(index, MAX_ARRAY_ELEMS);
+			return array[index];
+		}
+	}

[PATCH 4.14 37/64] array_index_nospec: Sanitize speculative array de-references

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit f3804203306e098dae9ca51540fcd5eb700d7f40

array_index_nospec() is proposed as a generic mechanism to mitigate
against Spectre-variant-1 attacks, i.e. an attack that bypasses boundary
checks via speculative execution. The array_index_nospec()
implementation is expected to be safe for current generation CPUs across
multiple architectures (ARM, x86).

Based on an original implementation by Linus Torvalds, tweaked to remove
speculative flows by Alexei Starovoitov, and tweaked again by Linus to
introduce an x86 assembly implementation for the mask generation.

Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Co-developed-by: Alexei Starovoitov <ast@kernel.org>
Suggested-by: Cyril Novikov <cnovikov@lynx.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727414229.33451.18411580953862676575.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 include/linux/nospec.h |   72 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

--- /dev/null
+++ b/include/linux/nospec.h
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright(c) 2018 Linus Torvalds. All rights reserved.
+// Copyright(c) 2018 Alexei Starovoitov. All rights reserved.
+// Copyright(c) 2018 Intel Corporation. All rights reserved.
+
+#ifndef _LINUX_NOSPEC_H
+#define _LINUX_NOSPEC_H
+
+/**
+ * array_index_mask_nospec() - generate a ~0 mask when index < size, 0 otherwise
+ * @index: array element index
+ * @size: number of elements in array
+ *
+ * When @index is out of bounds (@index >= @size), the sign bit will be
+ * set.  Extend the sign bit to all bits and invert, giving a result of
+ * zero for an out of bounds index, or ~0 if within bounds [0, @size).
+ */
+#ifndef array_index_mask_nospec
+static inline unsigned long array_index_mask_nospec(unsigned long index,
+						    unsigned long size)
+{
+	/*
+	 * Warn developers about inappropriate array_index_nospec() usage.
+	 *
+	 * Even if the CPU speculates past the WARN_ONCE branch, the
+	 * sign bit of @index is taken into account when generating the
+	 * mask.
+	 *
+	 * This warning is compiled out when the compiler can infer that
+	 * @index and @size are less than LONG_MAX.
+	 */
+	if (WARN_ONCE(index > LONG_MAX || size > LONG_MAX,
+			"array_index_nospec() limited to range of [0, LONG_MAX]\n"))
+		return 0;
+
+	/*
+	 * Always calculate and emit the mask even if the compiler
+	 * thinks the mask is not needed. The compiler does not take
+	 * into account the value of @index under speculation.
+	 */
+	OPTIMIZER_HIDE_VAR(index);
+	return ~(long)(index | (size - 1UL - index)) >> (BITS_PER_LONG - 1);
+}
+#endif
+
+/*
+ * array_index_nospec - sanitize an array index after a bounds check
+ *
+ * For a code sequence like:
+ *
+ *     if (index < size) {
+ *         index = array_index_nospec(index, size);
+ *         val = array[index];
+ *     }
+ *
+ * ...if the CPU speculates past the bounds check then
+ * array_index_nospec() will clamp the index within the range of [0,
+ * size).
+ */
+#define array_index_nospec(index, size)					\
+({									\
+	typeof(index) _i = (index);					\
+	typeof(size) _s = (size);					\
+	unsigned long _mask = array_index_mask_nospec(_i, _s);		\
+									\
+	BUILD_BUG_ON(sizeof(_i) > sizeof(long));			\
+	BUILD_BUG_ON(sizeof(_s) > sizeof(long));			\
+									\
+	_i &= _mask;							\
+	_i;								\
+})
+#endif /* _LINUX_NOSPEC_H */

[PATCH 4.14 38/64] x86: Implement array_index_mask_nospec

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit babdde2698d482b6c0de1eab4f697cf5856c5859

array_index_nospec() uses a mask to sanitize user controllable array
indexes, i.e. generate a 0 mask if 'index' >= 'size', and a ~0 mask
otherwise. While the default array_index_mask_nospec() handles the
carry-bit from the (index - size) result in software.

The x86 array_index_mask_nospec() does the same, but the carry-bit is
handled in the processor CF flag without conditional instructions in the
control flow.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727414808.33451.1873237130672785331.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/barrier.h |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -24,6 +24,30 @@
 #define wmb()	asm volatile("sfence" ::: "memory")
 #endif
 
+/**
+ * array_index_mask_nospec() - generate a mask that is ~0UL when the
+ * 	bounds check succeeds and 0 otherwise
+ * @index: array element index
+ * @size: number of elements in array
+ *
+ * Returns:
+ *     0 - (index < size)
+ */
+static inline unsigned long array_index_mask_nospec(unsigned long index,
+		unsigned long size)
+{
+	unsigned long mask;
+
+	asm ("cmp %1,%2; sbb %0,%0;"
+			:"=r" (mask)
+			:"r"(size),"r" (index)
+			:"cc");
+	return mask;
+}
+
+/* Override the default implementation from linux/nospec.h. */
+#define array_index_mask_nospec array_index_mask_nospec
+
 #ifdef CONFIG_X86_PPRO_FENCE
 #define dma_rmb()	rmb()
 #else

[PATCH 4.14 39/64] x86: Introduce barrier_nospec

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit b3d7ad85b80bbc404635dca80f5b129f6242bc7a

Rename the open coded form of this instruction sequence from
rdtsc_ordered() into a generic barrier primitive, barrier_nospec().

One of the mitigations for Spectre variant1 vulnerabilities is to fence
speculative execution after successfully validating a bounds check. I.e.
force the result of a bounds check to resolve in the instruction pipeline
to ensure speculative execution honors that result before potentially
operating on out-of-bounds data.

No functional changes.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Andi Kleen <ak@linux.intel.com>
Suggested-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727415361.33451.9049453007262764675.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/barrier.h |    4 ++++
 arch/x86/include/asm/msr.h     |    3 +--
 2 files changed, 5 insertions(+), 2 deletions(-)

--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -48,6 +48,10 @@ static inline unsigned long array_index_
 /* Override the default implementation from linux/nospec.h. */
 #define array_index_mask_nospec array_index_mask_nospec
 
+/* Prevent speculative execution past this barrier. */
+#define barrier_nospec() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \
+					   "lfence", X86_FEATURE_LFENCE_RDTSC)
+
 #ifdef CONFIG_X86_PPRO_FENCE
 #define dma_rmb()	rmb()
 #else
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -214,8 +214,7 @@ static __always_inline unsigned long lon
 	 * that some other imaginary CPU is updating continuously with a
 	 * time stamp.
 	 */
-	alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC,
-			  "lfence", X86_FEATURE_LFENCE_RDTSC);
+	barrier_nospec();
 	return rdtsc();
 }
 

[PATCH 4.14 40/64] x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit b3bbfb3fb5d25776b8e3f361d2eedaabb0b496cd

For __get_user() paths, do not allow the kernel to speculate on the value
of a user controlled pointer. In addition to the 'stac' instruction for
Supervisor Mode Access Protection (SMAP), a barrier_nospec() causes the
access_ok() result to resolve in the pipeline before the CPU might take any
speculative action on the pointer value. Given the cost of 'stac' the
speculation barrier is placed after 'stac' to hopefully overlap the cost of
disabling SMAP with the cost of flushing the instruction pipeline.

Since __get_user is a major kernel interface that deals with user
controlled pointers, the __uaccess_begin_nospec() mechanism will prevent
speculative execution past an access_ok() permission check. While
speculative execution past access_ok() is not enough to lead to a kernel
memory leak, it is a necessary precondition.

To be clear, __uaccess_begin_nospec() is addressing a class of potential
problems near __get_user() usages.

Note, that while the barrier_nospec() in __uaccess_begin_nospec() is used
to protect __get_user(), pointer masking similar to array_index_nospec()
will be used for get_user() since it incorporates a bounds check near the
usage.

uaccess_try_nospec provides the same mechanism for get_user_try.

No functional changes.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Andi Kleen <ak@linux.intel.com>
Suggested-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727415922.33451.5796614273104346583.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/uaccess.h |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -124,6 +124,11 @@ extern int __get_user_bad(void);
 
 #define __uaccess_begin() stac()
 #define __uaccess_end()   clac()
+#define __uaccess_begin_nospec()	\
+({					\
+	stac();				\
+	barrier_nospec();		\
+})
 
 /*
  * This is a type: either unsigned long, if the argument fits into
@@ -487,6 +492,10 @@ struct __large_struct { unsigned long bu
 	__uaccess_begin();						\
 	barrier();
 
+#define uaccess_try_nospec do {						\
+	current->thread.uaccess_err = 0;				\
+	__uaccess_begin_nospec();					\
+
 #define uaccess_catch(err)						\
 	__uaccess_end();						\
 	(err) |= (current->thread.uaccess_err ? -EFAULT : 0);		\

[PATCH 4.14 41/64] x86/usercopy: Replace open coded stac/clac with __uaccess_{begin, end}

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit b5c4ae4f35325d520b230bab6eb3310613b72ac1

In preparation for converting some __uaccess_begin() instances to
__uacess_begin_nospec(), make sure all 'from user' uaccess paths are
using the _begin(), _end() helpers rather than open-coded stac() and
clac().

No functional changes.

Suggested-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727416438.33451.17309465232057176966.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/lib/usercopy_32.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -331,12 +331,12 @@ do {									\
 
 unsigned long __copy_user_ll(void *to, const void *from, unsigned long n)
 {
-	stac();
+	__uaccess_begin();
 	if (movsl_is_ok(to, from, n))
 		__copy_user(to, from, n);
 	else
 		n = __copy_user_intel(to, from, n);
-	clac();
+	__uaccess_end();
 	return n;
 }
 EXPORT_SYMBOL(__copy_user_ll);
@@ -344,7 +344,7 @@ EXPORT_SYMBOL(__copy_user_ll);
 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
 					unsigned long n)
 {
-	stac();
+	__uaccess_begin();
 #ifdef CONFIG_X86_INTEL_USERCOPY
 	if (n > 64 && static_cpu_has(X86_FEATURE_XMM2))
 		n = __copy_user_intel_nocache(to, from, n);
@@ -353,7 +353,7 @@ unsigned long __copy_from_user_ll_nocach
 #else
 	__copy_user(to, from, n);
 #endif
-	clac();
+	__uaccess_end();
 	return n;
 }
 EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);

[PATCH 4.14 42/64] x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit 304ec1b050310548db33063e567123fae8fd0301

Quoting Linus:

    I do think that it would be a good idea to very expressly document
    the fact that it's not that the user access itself is unsafe. I do
    agree that things like "get_user()" want to be protected, but not
    because of any direct bugs or problems with get_user() and friends,
    but simply because get_user() is an excellent source of a pointer
    that is obviously controlled from a potentially attacking user
    space. So it's a prime candidate for then finding _subsequent_
    accesses that can then be used to perturb the cache.

__uaccess_begin_nospec() covers __get_user() and copy_from_iter() where the
limit check is far away from the user pointer de-reference. In those cases
a barrier_nospec() prevents speculation with a potential pointer to
privileged memory. uaccess_try_nospec covers get_user_try.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727416953.33451.10508284228526170604.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/uaccess.h    |    6 +++---
 arch/x86/include/asm/uaccess_32.h |    6 +++---
 arch/x86/include/asm/uaccess_64.h |   12 ++++++------
 arch/x86/lib/usercopy_32.c        |    4 ++--
 4 files changed, 14 insertions(+), 14 deletions(-)

--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -450,7 +450,7 @@ do {									\
 ({									\
 	int __gu_err;							\
 	__inttype(*(ptr)) __gu_val;					\
-	__uaccess_begin();						\
+	__uaccess_begin_nospec();					\
 	__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT);	\
 	__uaccess_end();						\
 	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
@@ -557,7 +557,7 @@ struct __large_struct { unsigned long bu
  *	get_user_ex(...);
  * } get_user_catch(err)
  */
-#define get_user_try		uaccess_try
+#define get_user_try		uaccess_try_nospec
 #define get_user_catch(err)	uaccess_catch(err)
 
 #define get_user_ex(x, ptr)	do {					\
@@ -591,7 +591,7 @@ extern void __cmpxchg_wrong_size(void)
 	__typeof__(ptr) __uval = (uval);				\
 	__typeof__(*(ptr)) __old = (old);				\
 	__typeof__(*(ptr)) __new = (new);				\
-	__uaccess_begin();						\
+	__uaccess_begin_nospec();					\
 	switch (size) {							\
 	case 1:								\
 	{								\
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -29,21 +29,21 @@ raw_copy_from_user(void *to, const void
 		switch (n) {
 		case 1:
 			ret = 0;
-			__uaccess_begin();
+			__uaccess_begin_nospec();
 			__get_user_asm_nozero(*(u8 *)to, from, ret,
 					      "b", "b", "=q", 1);
 			__uaccess_end();
 			return ret;
 		case 2:
 			ret = 0;
-			__uaccess_begin();
+			__uaccess_begin_nospec();
 			__get_user_asm_nozero(*(u16 *)to, from, ret,
 					      "w", "w", "=r", 2);
 			__uaccess_end();
 			return ret;
 		case 4:
 			ret = 0;
-			__uaccess_begin();
+			__uaccess_begin_nospec();
 			__get_user_asm_nozero(*(u32 *)to, from, ret,
 					      "l", "k", "=r", 4);
 			__uaccess_end();
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -55,31 +55,31 @@ raw_copy_from_user(void *dst, const void
 		return copy_user_generic(dst, (__force void *)src, size);
 	switch (size) {
 	case 1:
-		__uaccess_begin();
+		__uaccess_begin_nospec();
 		__get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src,
 			      ret, "b", "b", "=q", 1);
 		__uaccess_end();
 		return ret;
 	case 2:
-		__uaccess_begin();
+		__uaccess_begin_nospec();
 		__get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src,
 			      ret, "w", "w", "=r", 2);
 		__uaccess_end();
 		return ret;
 	case 4:
-		__uaccess_begin();
+		__uaccess_begin_nospec();
 		__get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src,
 			      ret, "l", "k", "=r", 4);
 		__uaccess_end();
 		return ret;
 	case 8:
-		__uaccess_begin();
+		__uaccess_begin_nospec();
 		__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
 			      ret, "q", "", "=r", 8);
 		__uaccess_end();
 		return ret;
 	case 10:
-		__uaccess_begin();
+		__uaccess_begin_nospec();
 		__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
 			       ret, "q", "", "=r", 10);
 		if (likely(!ret))
@@ -89,7 +89,7 @@ raw_copy_from_user(void *dst, const void
 		__uaccess_end();
 		return ret;
 	case 16:
-		__uaccess_begin();
+		__uaccess_begin_nospec();
 		__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
 			       ret, "q", "", "=r", 16);
 		if (likely(!ret))
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -331,7 +331,7 @@ do {									\
 
 unsigned long __copy_user_ll(void *to, const void *from, unsigned long n)
 {
-	__uaccess_begin();
+	__uaccess_begin_nospec();
 	if (movsl_is_ok(to, from, n))
 		__copy_user(to, from, n);
 	else
@@ -344,7 +344,7 @@ EXPORT_SYMBOL(__copy_user_ll);
 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
 					unsigned long n)
 {
-	__uaccess_begin();
+	__uaccess_begin_nospec();
 #ifdef CONFIG_X86_INTEL_USERCOPY
 	if (n > 64 && static_cpu_has(X86_FEATURE_XMM2))
 		n = __copy_user_intel_nocache(to, from, n);

[PATCH 4.14 43/64] x86/get_user: Use pointer masking to limit speculation

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit c7f631cb07e7da06ac1d231ca178452339e32a94

Quoting Linus:

    I do think that it would be a good idea to very expressly document
    the fact that it's not that the user access itself is unsafe. I do
    agree that things like "get_user()" want to be protected, but not
    because of any direct bugs or problems with get_user() and friends,
    but simply because get_user() is an excellent source of a pointer
    that is obviously controlled from a potentially attacking user
    space. So it's a prime candidate for then finding _subsequent_
    accesses that can then be used to perturb the cache.

Unlike the __get_user() case get_user() includes the address limit check
near the pointer de-reference. With that locality the speculation can be
mitigated with pointer narrowing rather than a barrier, i.e.
array_index_nospec(). Where the narrowing is performed by:

	cmp %limit, %ptr
	sbb %mask, %mask
	and %mask, %ptr

With respect to speculation the value of %ptr is either less than %limit
or NULL.

Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727417469.33451.11804043010080838495.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/lib/getuser.S |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -40,6 +40,8 @@ ENTRY(__get_user_1)
 	mov PER_CPU_VAR(current_task), %_ASM_DX
 	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
+	sbb %_ASM_DX, %_ASM_DX		/* array_index_mask_nospec() */
+	and %_ASM_DX, %_ASM_AX
 	ASM_STAC
 1:	movzbl (%_ASM_AX),%edx
 	xor %eax,%eax
@@ -54,6 +56,8 @@ ENTRY(__get_user_2)
 	mov PER_CPU_VAR(current_task), %_ASM_DX
 	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
+	sbb %_ASM_DX, %_ASM_DX		/* array_index_mask_nospec() */
+	and %_ASM_DX, %_ASM_AX
 	ASM_STAC
 2:	movzwl -1(%_ASM_AX),%edx
 	xor %eax,%eax
@@ -68,6 +72,8 @@ ENTRY(__get_user_4)
 	mov PER_CPU_VAR(current_task), %_ASM_DX
 	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
+	sbb %_ASM_DX, %_ASM_DX		/* array_index_mask_nospec() */
+	and %_ASM_DX, %_ASM_AX
 	ASM_STAC
 3:	movl -3(%_ASM_AX),%edx
 	xor %eax,%eax
@@ -83,6 +89,8 @@ ENTRY(__get_user_8)
 	mov PER_CPU_VAR(current_task), %_ASM_DX
 	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
+	sbb %_ASM_DX, %_ASM_DX		/* array_index_mask_nospec() */
+	and %_ASM_DX, %_ASM_AX
 	ASM_STAC
 4:	movq -7(%_ASM_AX),%rdx
 	xor %eax,%eax
@@ -94,6 +102,8 @@ ENTRY(__get_user_8)
 	mov PER_CPU_VAR(current_task), %_ASM_DX
 	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user_8
+	sbb %_ASM_DX, %_ASM_DX		/* array_index_mask_nospec() */
+	and %_ASM_DX, %_ASM_AX
 	ASM_STAC
 4:	movl -7(%_ASM_AX),%edx
 5:	movl -3(%_ASM_AX),%ecx

[PATCH 4.14 44/64] x86/syscall: Sanitize syscall table de-references under speculation

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit 2fbd7af5af8665d18bcefae3e9700be07e22b681

The syscall table base is a user controlled function pointer in kernel
space. Use array_index_nospec() to prevent any out of bounds speculation.

While retpoline prevents speculating into a userspace directed target it
does not stop the pointer de-reference, the concern is leaking memory
relative to the syscall table base, by observing instruction cache
behavior.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727417984.33451.1216731042505722161.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/entry/common.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -21,6 +21,7 @@
 #include <linux/export.h>
 #include <linux/context_tracking.h>
 #include <linux/user-return-notifier.h>
+#include <linux/nospec.h>
 #include <linux/uprobes.h>
 #include <linux/livepatch.h>
 #include <linux/syscalls.h>
@@ -284,7 +285,8 @@ __visible void do_syscall_64(struct pt_r
 	 * regs->orig_ax, which changes the behavior of some syscalls.
 	 */
 	if (likely((nr & __SYSCALL_MASK) < NR_syscalls)) {
-		regs->ax = sys_call_table[nr & __SYSCALL_MASK](
+		nr = array_index_nospec(nr & __SYSCALL_MASK, NR_syscalls);
+		regs->ax = sys_call_table[nr](
 			regs->di, regs->si, regs->dx,
 			regs->r10, regs->r8, regs->r9);
 	}
@@ -320,6 +322,7 @@ static __always_inline void do_syscall_3
 	}
 
 	if (likely(nr < IA32_NR_syscalls)) {
+		nr = array_index_nospec(nr, IA32_NR_syscalls);
 		/*
 		 * It's possible that a 32-bit syscall implementation
 		 * takes a 64-bit parameter but nonetheless assumes that

[PATCH 4.14 45/64] vfs, fdtable: Prevent bounds-check bypass via speculative execution

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit 56c30ba7b348b90484969054d561f711ba196507

'fd' is a user controlled value that is used as a data dependency to
read from the 'fdt->fd' array.  In order to avoid potential leaks of
kernel memory values, block speculative execution of the instruction
stream that could issue reads based on an invalid 'file *' returned from
__fcheck_files.

Co-developed-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727418500.33451.17392199002892248656.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 include/linux/fdtable.h |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -10,6 +10,7 @@
 #include <linux/compiler.h>
 #include <linux/spinlock.h>
 #include <linux/rcupdate.h>
+#include <linux/nospec.h>
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/fs.h>
@@ -82,8 +83,10 @@ static inline struct file *__fcheck_file
 {
 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);
 
-	if (fd < fdt->max_fds)
+	if (fd < fdt->max_fds) {
+		fd = array_index_nospec(fd, fdt->max_fds);
 		return rcu_dereference_raw(fdt->fd[fd]);
+	}
 	return NULL;
 }
 

[PATCH 4.14 46/64] nl80211: Sanitize array index in parse_txq_params

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit 259d8c1e984318497c84eef547bbb6b1d9f4eb05

Wireless drivers rely on parse_txq_params to validate that txq_params->ac
is less than NL80211_NUM_ACS by the time the low-level driver's ->conf_tx()
handler is called. Use a new helper, array_index_nospec(), to sanitize
txq_params->ac with respect to speculation. I.e. ensure that any
speculation into ->conf_tx() handlers is done with a value of
txq_params->ac that is within the bounds of [0, NL80211_NUM_ACS).

Reported-by: Christian Lamparter <chunkeey@gmail.com>
Reported-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: linux-wireless@vger.kernel.org
Cc: torvalds@linux-foundation.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727419584.33451.7700736761686184303.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 net/wireless/nl80211.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -16,6 +16,7 @@
 #include <linux/nl80211.h>
 #include <linux/rtnetlink.h>
 #include <linux/netlink.h>
+#include <linux/nospec.h>
 #include <linux/etherdevice.h>
 #include <net/net_namespace.h>
 #include <net/genetlink.h>
@@ -2056,20 +2057,22 @@ static const struct nla_policy txq_param
 static int parse_txq_params(struct nlattr *tb[],
 			    struct ieee80211_txq_params *txq_params)
 {
+	u8 ac;
+
 	if (!tb[NL80211_TXQ_ATTR_AC] || !tb[NL80211_TXQ_ATTR_TXOP] ||
 	    !tb[NL80211_TXQ_ATTR_CWMIN] || !tb[NL80211_TXQ_ATTR_CWMAX] ||
 	    !tb[NL80211_TXQ_ATTR_AIFS])
 		return -EINVAL;
 
-	txq_params->ac = nla_get_u8(tb[NL80211_TXQ_ATTR_AC]);
+	ac = nla_get_u8(tb[NL80211_TXQ_ATTR_AC]);
 	txq_params->txop = nla_get_u16(tb[NL80211_TXQ_ATTR_TXOP]);
 	txq_params->cwmin = nla_get_u16(tb[NL80211_TXQ_ATTR_CWMIN]);
 	txq_params->cwmax = nla_get_u16(tb[NL80211_TXQ_ATTR_CWMAX]);
 	txq_params->aifs = nla_get_u8(tb[NL80211_TXQ_ATTR_AIFS]);
 
-	if (txq_params->ac >= NL80211_NUM_ACS)
+	if (ac >= NL80211_NUM_ACS)
 		return -EINVAL;
-
+	txq_params->ac = array_index_nospec(ac, NL80211_NUM_ACS);
 	return 0;
 }
 

[PATCH 4.14 47/64] x86/spectre: Report get_user mitigation for spectre_v1

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit edfbae53dab8348fca778531be9f4855d2ca0360

Reflect the presence of get_user(), __get_user(), and 'syscall' protections
in sysfs. The expectation is that new and better tooling will allow the
kernel to grow more usages of array_index_nospec(), for now, only claim
mitigation for __user pointer de-references.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727420158.33451.11658324346540434635.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/bugs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -297,7 +297,7 @@ ssize_t cpu_show_spectre_v1(struct devic
 {
 	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1))
 		return sprintf(buf, "Not affected\n");
-	return sprintf(buf, "Vulnerable\n");
+	return sprintf(buf, "Mitigation: __user pointer sanitization\n");
 }
 
 ssize_t cpu_show_spectre_v2(struct device *dev,

[PATCH 4.14 48/64] x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable"

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Colin Ian King colin.king@canonical.com

commit e698dcdfcda41efd0984de539767b4cddd235f1e

Trivial fix to spelling mistake in pr_err error message text.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: kernel-janitors@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180130193218.9271-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/cpu/bugs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -103,7 +103,7 @@ bool retpoline_module_ok(bool has_retpol
 	if (spectre_v2_enabled == SPECTRE_V2_NONE || has_retpoline)
 		return true;
 
-	pr_err("System may be vunerable to spectre v2\n");
+	pr_err("System may be vulnerable to spectre v2\n");
 	spectre_v2_bad_module = true;
 	return false;
 }

[PATCH 4.14 48/64] x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable"

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Colin Ian King colin.king@canonical.com

commit e698dcdfcda41efd0984de539767b4cddd235f1e

Trivial fix to spelling mistake in pr_err error message text.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: kernel-janitors@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180130193218.9271-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/cpu/bugs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -103,7 +103,7 @@ bool retpoline_module_ok(bool has_retpol
 	if (spectre_v2_enabled = SPECTRE_V2_NONE || has_retpoline)
 		return true;
 
-	pr_err("System may be vunerable to spectre v2\n");
+	pr_err("System may be vulnerable to spectre v2\n");
 	spectre_v2_bad_module = true;
 	return false;
 }

[PATCH 4.14 49/64] x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit 7fcae1118f5fd44a862aa5c3525248e35ee67c3b

Despite the fact that all the other code there seems to be doing it, just
using set_cpu_cap() in early_intel_init() doesn't actually work.

For CPUs with PKU support, setup_pku() calls get_cpu_cap() after
c->c_init() has set those feature bits. That resets those bits back to what
was queried from the hardware.

Turning the bits off for bad microcode is easy to fix. That can just use
setup_clear_cpu_cap() to force them off for all CPUs.

I was less keen on forcing the feature bits *on* that way, just in case
of inconsistencies. I appreciate that the kernel is going to get this
utterly wrong if CPU features are not consistent, because it has already
applied alternatives by the time secondary CPUs are brought up.

But at least if setup_force_cpu_cap() isn't being used, we might have a
chance of *detecting* the lack of the corresponding bit and either
panicking or refusing to bring the offending CPU online.

So ensure that the appropriate feature bits are set within get_cpu_cap()
regardless of how many extra times it's called.

Fixes: 2961298e ("x86/cpufeatures: Clean up Spectre v2 related CPUID flags")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: karahmed@amazon.de
Cc: peterz@infradead.org
Cc: bp@alien8.de
Link: https://lkml.kernel.org/r/1517322623-15261-1-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/common.c |   21 +++++++++++++++++++++
 arch/x86/kernel/cpu/intel.c  |   27 ++++++++-------------------
 2 files changed, 29 insertions(+), 19 deletions(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -726,6 +726,26 @@ static void apply_forced_caps(struct cpu
 	}
 }
 
+static void init_speculation_control(struct cpuinfo_x86 *c)
+{
+	/*
+	 * The Intel SPEC_CTRL CPUID bit implies IBRS and IBPB support,
+	 * and they also have a different bit for STIBP support. Also,
+	 * a hypervisor might have set the individual AMD bits even on
+	 * Intel CPUs, for finer-grained selection of what's available.
+	 *
+	 * We use the AMD bits in 0x8000_0008 EBX as the generic hardware
+	 * features, which are visible in /proc/cpuinfo and used by the
+	 * kernel. So set those accordingly from the Intel bits.
+	 */
+	if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
+		set_cpu_cap(c, X86_FEATURE_IBRS);
+		set_cpu_cap(c, X86_FEATURE_IBPB);
+	}
+	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
+		set_cpu_cap(c, X86_FEATURE_STIBP);
+}
+
 void get_cpu_cap(struct cpuinfo_x86 *c)
 {
 	u32 eax, ebx, ecx, edx;
@@ -820,6 +840,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 		c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
 
 	init_scattered_cpuid_features(c);
+	init_speculation_control(c);
 
 	/*
 	 * Clear/Set all flags overridden by options, after probe.
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -175,28 +175,17 @@ static void early_init_intel(struct cpui
 	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
 		c->microcode = intel_get_microcode_revision();
 
-	/*
-	 * The Intel SPEC_CTRL CPUID bit implies IBRS and IBPB support,
-	 * and they also have a different bit for STIBP support. Also,
-	 * a hypervisor might have set the individual AMD bits even on
-	 * Intel CPUs, for finer-grained selection of what's available.
-	 */
-	if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
-		set_cpu_cap(c, X86_FEATURE_IBRS);
-		set_cpu_cap(c, X86_FEATURE_IBPB);
-	}
-	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
-		set_cpu_cap(c, X86_FEATURE_STIBP);
-
 	/* Now if any of them are set, check the blacklist and clear the lot */
-	if ((cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
+	if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
+	     cpu_has(c, X86_FEATURE_INTEL_STIBP) ||
+	     cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
 	     cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
 		pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n");
-		clear_cpu_cap(c, X86_FEATURE_IBRS);
-		clear_cpu_cap(c, X86_FEATURE_IBPB);
-		clear_cpu_cap(c, X86_FEATURE_STIBP);
-		clear_cpu_cap(c, X86_FEATURE_SPEC_CTRL);
-		clear_cpu_cap(c, X86_FEATURE_INTEL_STIBP);
+		setup_clear_cpu_cap(X86_FEATURE_IBRS);
+		setup_clear_cpu_cap(X86_FEATURE_IBPB);
+		setup_clear_cpu_cap(X86_FEATURE_STIBP);
+		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
+		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
 	}
 
 	/*

[PATCH 4.14 50/64] x86/speculation: Use Indirect Branch Prediction Barrier in context switch

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tim Chen tim.c.chen@linux.intel.com

commit 18bf3c3ea8ece8f03b6fc58508f2dfd23c7711c7

Flush indirect branches when switching into a process that marked itself
non dumpable. This protects high value processes like gpg better,
without having too high performance overhead.

If done naïvely, we could switch to a kernel idle thread and then back
to the original process, such as:

    process A -> idle -> process A

In such scenario, we do not have to do IBPB here even though the process
is non-dumpable, as we are switching back to the same process after a
hiatus.

To avoid the redundant IBPB, which is expensive, we track the last mm
user context ID. The cost is to have an extra u64 mm context id to track
the last mm we were using before switching to the init_mm used by idle.
Avoiding the extra IBPB is probably worth the extra memory for this
common scenario.

For those cases where tlb_defer_switch_to_init_mm() returns true (non
PCID), lazy tlb will defer switch to init_mm, so we will not be changing
the mm for the process A -> idle -> process A switch. So IBPB will be
skipped for this case.

Thanks to the reviewers and Andy Lutomirski for the suggestion of
using ctx_id which got rid of the problem of mm pointer recycling.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: linux@dominikbrodowski.net
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: pbonzini@redhat.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1517263487-3708-1-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/tlbflush.h |    2 ++
 arch/x86/mm/tlb.c               |   33 ++++++++++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -174,6 +174,8 @@ struct tlb_state {
 	struct mm_struct *loaded_mm;
 	u16 loaded_mm_asid;
 	u16 next_asid;
+	/* last user mm's ctx id */
+	u64 last_ctx_id;
 
 	/*
 	 * We can be in one of several states:
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -6,13 +6,14 @@
 #include <linux/interrupt.h>
 #include <linux/export.h>
 #include <linux/cpu.h>
+#include <linux/debugfs.h>
 
 #include <asm/tlbflush.h>
 #include <asm/mmu_context.h>
+#include <asm/nospec-branch.h>
 #include <asm/cache.h>
 #include <asm/apic.h>
 #include <asm/uv/uv.h>
-#include <linux/debugfs.h>
 
 /*
  *	TLB flushing, formerly SMP-only
@@ -247,6 +248,27 @@ void switch_mm_irqs_off(struct mm_struct
 	} else {
 		u16 new_asid;
 		bool need_flush;
+		u64 last_ctx_id = this_cpu_read(cpu_tlbstate.last_ctx_id);
+
+		/*
+		 * Avoid user/user BTB poisoning by flushing the branch
+		 * predictor when switching between processes. This stops
+		 * one process from doing Spectre-v2 attacks on another.
+		 *
+		 * As an optimization, flush indirect branches only when
+		 * switching into processes that disable dumping. This
+		 * protects high value processes like gpg, without having
+		 * too high performance overhead. IBPB is *expensive*!
+		 *
+		 * This will not flush branches when switching into kernel
+		 * threads. It will also not flush if we switch to idle
+		 * thread and back to the same process. It will flush if we
+		 * switch to a different non-dumpable process.
+		 */
+		if (tsk && tsk->mm &&
+		    tsk->mm->context.ctx_id != last_ctx_id &&
+		    get_dumpable(tsk->mm) != SUID_DUMP_USER)
+			indirect_branch_prediction_barrier();
 
 		if (IS_ENABLED(CONFIG_VMAP_STACK)) {
 			/*
@@ -292,6 +314,14 @@ void switch_mm_irqs_off(struct mm_struct
 			trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, 0);
 		}
 
+		/*
+		 * Record last user mm's context id, so we can avoid
+		 * flushing branch buffer with IBPB if we switch back
+		 * to the same user.
+		 */
+		if (next != &init_mm)
+			this_cpu_write(cpu_tlbstate.last_ctx_id, next->context.ctx_id);
+
 		this_cpu_write(cpu_tlbstate.loaded_mm, next);
 		this_cpu_write(cpu_tlbstate.loaded_mm_asid, new_asid);
 	}
@@ -369,6 +399,7 @@ void initialize_tlbstate_and_flush(void)
 	write_cr3(build_cr3(mm->pgd, 0));
 
 	/* Reinitialize tlbstate. */
+	this_cpu_write(cpu_tlbstate.last_ctx_id, mm->context.ctx_id);
 	this_cpu_write(cpu_tlbstate.loaded_mm_asid, 0);
 	this_cpu_write(cpu_tlbstate.next_asid, 1);
 	this_cpu_write(cpu_tlbstate.ctxs[0].ctx_id, mm->context.ctx_id);

[PATCH 4.14 51/64] x86/paravirt: Remove noreplace-paravirt cmdline option

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Josh Poimboeuf jpoimboe@redhat.com

commit 12c69f1e94c89d40696e83804dd2f0965b5250cd

The 'noreplace-paravirt' option disables paravirt patching, leaving the
original pv indirect calls in place.

That's highly incompatible with retpolines, unless we want to uglify
paravirt even further and convert the paravirt calls to retpolines.

As far as I can tell, the option doesn't seem to be useful for much
other than introducing surprising corner cases and making the kernel
vulnerable to Spectre v2.  It was probably a debug option from the early
paravirt days.  So just remove it.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: https://lkml.kernel.org/r/20180131041333.2x6blhxirc2kclrq@treble
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 Documentation/admin-guide/kernel-parameters.txt |    2 --
 arch/x86/kernel/alternative.c                   |   14 --------------
 2 files changed, 16 deletions(-)

--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2718,8 +2718,6 @@
 	norandmaps	Don't use address space randomization.  Equivalent to
 			echo 0 > /proc/sys/kernel/randomize_va_space
 
-	noreplace-paravirt	[X86,IA-64,PV_OPS] Don't patch paravirt_ops
-
 	noreplace-smp	[X86-32,SMP] Don't replace SMP instructions
 			with UP alternatives
 
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -46,17 +46,6 @@ static int __init setup_noreplace_smp(ch
 }
 __setup("noreplace-smp", setup_noreplace_smp);
 
-#ifdef CONFIG_PARAVIRT
-static int __initdata_or_module noreplace_paravirt = 0;
-
-static int __init setup_noreplace_paravirt(char *str)
-{
-	noreplace_paravirt = 1;
-	return 1;
-}
-__setup("noreplace-paravirt", setup_noreplace_paravirt);
-#endif
-
 #define DPRINTK(fmt, args...)						\
 do {									\
 	if (debug_alternative)						\
@@ -599,9 +588,6 @@ void __init_or_module apply_paravirt(str
 	struct paravirt_patch_site *p;
 	char insnbuf[MAX_PATCH_LEN];
 
-	if (noreplace_paravirt)
-		return;
-
 	for (p = start; p < end; p++) {
 		unsigned int used;
 

[PATCH 4.14 52/64] KVM: VMX: make MSR bitmaps per-VCPU

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Paolo Bonzini pbonzini@redhat.com

commit 904e14fb7cb96401a7dc803ca2863fd5ba32ffe6

Place the MSR bitmap in struct loaded_vmcs, and update it in place
every time the x2apic or APICv state can change.  This is rare and
the loop can handle 64 MSRs per iteration, in a similar fashion as
nested_vmx_prepare_msr_bitmap.

This prepares for choosing, on a per-VM basis, whether to intercept
the SPEC_CTRL and PRED_CMD MSRs.

Cc: stable@vger.kernel.org       # prereq for Spectre mitigation
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/vmx.c |  276 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 150 insertions(+), 126 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -108,6 +108,14 @@ static u64 __read_mostly host_xss;
 static bool __read_mostly enable_pml = 1;
 module_param_named(pml, enable_pml, bool, S_IRUGO);
 
+#define MSR_TYPE_R	1
+#define MSR_TYPE_W	2
+#define MSR_TYPE_RW	3
+
+#define MSR_BITMAP_MODE_X2APIC		1
+#define MSR_BITMAP_MODE_X2APIC_APICV	2
+#define MSR_BITMAP_MODE_LM		4
+
 #define KVM_VMX_TSC_MULTIPLIER_MAX     0xffffffffffffffffULL
 
 /* Guest_tsc -> host_tsc conversion requires 64-bit division.  */
@@ -206,6 +214,7 @@ struct loaded_vmcs {
 	int soft_vnmi_blocked;
 	ktime_t entry_time;
 	s64 vnmi_blocked_time;
+	unsigned long *msr_bitmap;
 	struct list_head loaded_vmcss_on_cpu_link;
 };
 
@@ -446,8 +455,6 @@ struct nested_vmx {
 	bool pi_pending;
 	u16 posted_intr_nv;
 
-	unsigned long *msr_bitmap;
-
 	struct hrtimer preemption_timer;
 	bool preemption_timer_expired;
 
@@ -562,6 +569,7 @@ struct vcpu_vmx {
 	struct kvm_vcpu       vcpu;
 	unsigned long         host_rsp;
 	u8                    fail;
+	u8		      msr_bitmap_mode;
 	u32                   exit_intr_info;
 	u32                   idt_vectoring_info;
 	ulong                 rflags;
@@ -919,6 +927,7 @@ static bool vmx_get_nmi_mask(struct kvm_
 static void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked);
 static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 *vmcs12,
 					    u16 error_code);
+static void vmx_update_msr_bitmap(struct kvm_vcpu *vcpu);
 
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -938,12 +947,6 @@ static DEFINE_PER_CPU(spinlock_t, blocke
 enum {
 	VMX_IO_BITMAP_A,
 	VMX_IO_BITMAP_B,
-	VMX_MSR_BITMAP_LEGACY,
-	VMX_MSR_BITMAP_LONGMODE,
-	VMX_MSR_BITMAP_LEGACY_X2APIC_APICV,
-	VMX_MSR_BITMAP_LONGMODE_X2APIC_APICV,
-	VMX_MSR_BITMAP_LEGACY_X2APIC,
-	VMX_MSR_BITMAP_LONGMODE_X2APIC,
 	VMX_VMREAD_BITMAP,
 	VMX_VMWRITE_BITMAP,
 	VMX_BITMAP_NR
@@ -953,12 +956,6 @@ static unsigned long *vmx_bitmap[VMX_BIT
 
 #define vmx_io_bitmap_a                      (vmx_bitmap[VMX_IO_BITMAP_A])
 #define vmx_io_bitmap_b                      (vmx_bitmap[VMX_IO_BITMAP_B])
-#define vmx_msr_bitmap_legacy                (vmx_bitmap[VMX_MSR_BITMAP_LEGACY])
-#define vmx_msr_bitmap_longmode              (vmx_bitmap[VMX_MSR_BITMAP_LONGMODE])
-#define vmx_msr_bitmap_legacy_x2apic_apicv   (vmx_bitmap[VMX_MSR_BITMAP_LEGACY_X2APIC_APICV])
-#define vmx_msr_bitmap_longmode_x2apic_apicv (vmx_bitmap[VMX_MSR_BITMAP_LONGMODE_X2APIC_APICV])
-#define vmx_msr_bitmap_legacy_x2apic         (vmx_bitmap[VMX_MSR_BITMAP_LEGACY_X2APIC])
-#define vmx_msr_bitmap_longmode_x2apic       (vmx_bitmap[VMX_MSR_BITMAP_LONGMODE_X2APIC])
 #define vmx_vmread_bitmap                    (vmx_bitmap[VMX_VMREAD_BITMAP])
 #define vmx_vmwrite_bitmap                   (vmx_bitmap[VMX_VMWRITE_BITMAP])
 
@@ -2559,36 +2556,6 @@ static void move_msr_up(struct vcpu_vmx
 	vmx->guest_msrs[from] = tmp;
 }
 
-static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu)
-{
-	unsigned long *msr_bitmap;
-
-	if (is_guest_mode(vcpu))
-		msr_bitmap = to_vmx(vcpu)->nested.msr_bitmap;
-	else if (cpu_has_secondary_exec_ctrls() &&
-		 (vmcs_read32(SECONDARY_VM_EXEC_CONTROL) &
-		  SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE)) {
-		if (enable_apicv && kvm_vcpu_apicv_active(vcpu)) {
-			if (is_long_mode(vcpu))
-				msr_bitmap = vmx_msr_bitmap_longmode_x2apic_apicv;
-			else
-				msr_bitmap = vmx_msr_bitmap_legacy_x2apic_apicv;
-		} else {
-			if (is_long_mode(vcpu))
-				msr_bitmap = vmx_msr_bitmap_longmode_x2apic;
-			else
-				msr_bitmap = vmx_msr_bitmap_legacy_x2apic;
-		}
-	} else {
-		if (is_long_mode(vcpu))
-			msr_bitmap = vmx_msr_bitmap_longmode;
-		else
-			msr_bitmap = vmx_msr_bitmap_legacy;
-	}
-
-	vmcs_write64(MSR_BITMAP, __pa(msr_bitmap));
-}
-
 /*
  * Set up the vmcs to automatically save and restore system
  * msrs.  Don't touch the 64-bit msrs if the guest is in legacy
@@ -2629,7 +2596,7 @@ static void setup_msrs(struct vcpu_vmx *
 	vmx->save_nmsrs = save_nmsrs;
 
 	if (cpu_has_vmx_msr_bitmap())
-		vmx_set_msr_bitmap(&vmx->vcpu);
+		vmx_update_msr_bitmap(&vmx->vcpu);
 }
 
 /*
@@ -3829,6 +3796,8 @@ static void free_loaded_vmcs(struct load
 	loaded_vmcs_clear(loaded_vmcs);
 	free_vmcs(loaded_vmcs->vmcs);
 	loaded_vmcs->vmcs = NULL;
+	if (loaded_vmcs->msr_bitmap)
+		free_page((unsigned long)loaded_vmcs->msr_bitmap);
 	WARN_ON(loaded_vmcs->shadow_vmcs != NULL);
 }
 
@@ -3845,7 +3814,18 @@ static int alloc_loaded_vmcs(struct load
 
 	loaded_vmcs->shadow_vmcs = NULL;
 	loaded_vmcs_init(loaded_vmcs);
+
+	if (cpu_has_vmx_msr_bitmap()) {
+		loaded_vmcs->msr_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL);
+		if (!loaded_vmcs->msr_bitmap)
+			goto out_vmcs;
+		memset(loaded_vmcs->msr_bitmap, 0xff, PAGE_SIZE);
+	}
 	return 0;
+
+out_vmcs:
+	free_loaded_vmcs(loaded_vmcs);
+	return -ENOMEM;
 }
 
 static void free_kvm_area(void)
@@ -4920,10 +4900,8 @@ static void free_vpid(int vpid)
 	spin_unlock(&vmx_vpid_lock);
 }
 
-#define MSR_TYPE_R	1
-#define MSR_TYPE_W	2
-static void __vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
-						u32 msr, int type)
+static void __always_inline vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
+							  u32 msr, int type)
 {
 	int f = sizeof(unsigned long);
 
@@ -4957,6 +4935,50 @@ static void __vmx_disable_intercept_for_
 	}
 }
 
+static void __always_inline vmx_enable_intercept_for_msr(unsigned long *msr_bitmap,
+							 u32 msr, int type)
+{
+	int f = sizeof(unsigned long);
+
+	if (!cpu_has_vmx_msr_bitmap())
+		return;
+
+	/*
+	 * See Intel PRM Vol. 3, 20.6.9 (MSR-Bitmap Address). Early manuals
+	 * have the write-low and read-high bitmap offsets the wrong way round.
+	 * We can control MSRs 0x00000000-0x00001fff and 0xc0000000-0xc0001fff.
+	 */
+	if (msr <= 0x1fff) {
+		if (type & MSR_TYPE_R)
+			/* read-low */
+			__set_bit(msr, msr_bitmap + 0x000 / f);
+
+		if (type & MSR_TYPE_W)
+			/* write-low */
+			__set_bit(msr, msr_bitmap + 0x800 / f);
+
+	} else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
+		msr &= 0x1fff;
+		if (type & MSR_TYPE_R)
+			/* read-high */
+			__set_bit(msr, msr_bitmap + 0x400 / f);
+
+		if (type & MSR_TYPE_W)
+			/* write-high */
+			__set_bit(msr, msr_bitmap + 0xc00 / f);
+
+	}
+}
+
+static void __always_inline vmx_set_intercept_for_msr(unsigned long *msr_bitmap,
+			     			      u32 msr, int type, bool value)
+{
+	if (value)
+		vmx_enable_intercept_for_msr(msr_bitmap, msr, type);
+	else
+		vmx_disable_intercept_for_msr(msr_bitmap, msr, type);
+}
+
 /*
  * If a msr is allowed by L0, we should check whether it is allowed by L1.
  * The corresponding bit will be cleared unless both of L0 and L1 allow it.
@@ -5003,28 +5025,68 @@ static void nested_vmx_disable_intercept
 	}
 }
 
-static void vmx_disable_intercept_for_msr(u32 msr, bool longmode_only)
+static u8 vmx_msr_bitmap_mode(struct kvm_vcpu *vcpu)
 {
-	if (!longmode_only)
-		__vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy,
-						msr, MSR_TYPE_R | MSR_TYPE_W);
-	__vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode,
-						msr, MSR_TYPE_R | MSR_TYPE_W);
-}
-
-static void vmx_disable_intercept_msr_x2apic(u32 msr, int type, bool apicv_active)
-{
-	if (apicv_active) {
-		__vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv,
-				msr, type);
-		__vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv,
-				msr, type);
-	} else {
-		__vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
-				msr, type);
-		__vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
-				msr, type);
+	u8 mode = 0;
+
+	if (cpu_has_secondary_exec_ctrls() &&
+	    (vmcs_read32(SECONDARY_VM_EXEC_CONTROL) &
+	     SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE)) {
+		mode |= MSR_BITMAP_MODE_X2APIC;
+		if (enable_apicv && kvm_vcpu_apicv_active(vcpu))
+			mode |= MSR_BITMAP_MODE_X2APIC_APICV;
+	}
+
+	if (is_long_mode(vcpu))
+		mode |= MSR_BITMAP_MODE_LM;
+
+	return mode;
+}
+
+#define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4))
+
+static void vmx_update_msr_bitmap_x2apic(unsigned long *msr_bitmap,
+					 u8 mode)
+{
+	int msr;
+
+	for (msr = 0x800; msr <= 0x8ff; msr += BITS_PER_LONG) {
+		unsigned word = msr / BITS_PER_LONG;
+		msr_bitmap[word] = (mode & MSR_BITMAP_MODE_X2APIC_APICV) ? 0 : ~0;
+		msr_bitmap[word + (0x800 / sizeof(long))] = ~0;
 	}
+
+	if (mode & MSR_BITMAP_MODE_X2APIC) {
+		/*
+		 * TPR reads and writes can be virtualized even if virtual interrupt
+		 * delivery is not in use.
+		 */
+		vmx_disable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_TASKPRI), MSR_TYPE_RW);
+		if (mode & MSR_BITMAP_MODE_X2APIC_APICV) {
+			vmx_enable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_TMCCT), MSR_TYPE_R);
+			vmx_disable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_EOI), MSR_TYPE_W);
+			vmx_disable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_SELF_IPI), MSR_TYPE_W);
+		}
+	}
+}
+
+static void vmx_update_msr_bitmap(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	unsigned long *msr_bitmap = vmx->vmcs01.msr_bitmap;
+	u8 mode = vmx_msr_bitmap_mode(vcpu);
+	u8 changed = mode ^ vmx->msr_bitmap_mode;
+
+	if (!changed)
+		return;
+
+	vmx_set_intercept_for_msr(msr_bitmap, MSR_KERNEL_GS_BASE, MSR_TYPE_RW,
+				  !(mode & MSR_BITMAP_MODE_LM));
+
+	if (changed & (MSR_BITMAP_MODE_X2APIC | MSR_BITMAP_MODE_X2APIC_APICV))
+		vmx_update_msr_bitmap_x2apic(msr_bitmap, mode);
+
+	vmx->msr_bitmap_mode = mode;
 }
 
 static bool vmx_get_enable_apicv(struct kvm_vcpu *vcpu)
@@ -5272,7 +5334,7 @@ static void vmx_refresh_apicv_exec_ctrl(
 	}
 
 	if (cpu_has_vmx_msr_bitmap())
-		vmx_set_msr_bitmap(vcpu);
+		vmx_update_msr_bitmap(vcpu);
 }
 
 static u32 vmx_exec_control(struct vcpu_vmx *vmx)
@@ -5459,7 +5521,7 @@ static int vmx_vcpu_setup(struct vcpu_vm
 		vmcs_write64(VMWRITE_BITMAP, __pa(vmx_vmwrite_bitmap));
 	}
 	if (cpu_has_vmx_msr_bitmap())
-		vmcs_write64(MSR_BITMAP, __pa(vmx_msr_bitmap_legacy));
+		vmcs_write64(MSR_BITMAP, __pa(vmx->vmcs01.msr_bitmap));
 
 	vmcs_write64(VMCS_LINK_POINTER, -1ull); /* 22.3.1.5 */
 
@@ -6742,7 +6804,7 @@ void vmx_enable_tdp(void)
 
 static __init int hardware_setup(void)
 {
-	int r = -ENOMEM, i, msr;
+	int r = -ENOMEM, i;
 
 	rdmsrl_safe(MSR_EFER, &host_efer);
 
@@ -6763,9 +6825,6 @@ static __init int hardware_setup(void)
 
 	memset(vmx_io_bitmap_b, 0xff, PAGE_SIZE);
 
-	memset(vmx_msr_bitmap_legacy, 0xff, PAGE_SIZE);
-	memset(vmx_msr_bitmap_longmode, 0xff, PAGE_SIZE);
-
 	if (setup_vmcs_config(&vmcs_config) < 0) {
 		r = -EIO;
 		goto out;
@@ -6828,42 +6887,8 @@ static __init int hardware_setup(void)
 		kvm_tsc_scaling_ratio_frac_bits = 48;
 	}
 
-	vmx_disable_intercept_for_msr(MSR_FS_BASE, false);
-	vmx_disable_intercept_for_msr(MSR_GS_BASE, false);
-	vmx_disable_intercept_for_msr(MSR_KERNEL_GS_BASE, true);
-	vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_CS, false);
-	vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_ESP, false);
-	vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP, false);
-
-	memcpy(vmx_msr_bitmap_legacy_x2apic_apicv,
-			vmx_msr_bitmap_legacy, PAGE_SIZE);
-	memcpy(vmx_msr_bitmap_longmode_x2apic_apicv,
-			vmx_msr_bitmap_longmode, PAGE_SIZE);
-	memcpy(vmx_msr_bitmap_legacy_x2apic,
-			vmx_msr_bitmap_legacy, PAGE_SIZE);
-	memcpy(vmx_msr_bitmap_longmode_x2apic,
-			vmx_msr_bitmap_longmode, PAGE_SIZE);
-
 	set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */
 
-	for (msr = 0x800; msr <= 0x8ff; msr++) {
-		if (msr == 0x839 /* TMCCT */)
-			continue;
-		vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
-	}
-
-	/*
-	 * TPR reads and writes can be virtualized even if virtual interrupt
-	 * delivery is not in use.
-	 */
-	vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
-	vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
-
-	/* EOI */
-	vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
-	/* SELF-IPI */
-	vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);
-
 	if (enable_ept)
 		vmx_enable_tdp();
 	else
@@ -7152,13 +7177,6 @@ static int enter_vmx_operation(struct kv
 	if (r < 0)
 		goto out_vmcs02;
 
-	if (cpu_has_vmx_msr_bitmap()) {
-		vmx->nested.msr_bitmap =
-				(unsigned long *)__get_free_page(GFP_KERNEL);
-		if (!vmx->nested.msr_bitmap)
-			goto out_msr_bitmap;
-	}
-
 	vmx->nested.cached_vmcs12 = kmalloc(VMCS12_SIZE, GFP_KERNEL);
 	if (!vmx->nested.cached_vmcs12)
 		goto out_cached_vmcs12;
@@ -7185,9 +7203,6 @@ out_shadow_vmcs:
 	kfree(vmx->nested.cached_vmcs12);
 
 out_cached_vmcs12:
-	free_page((unsigned long)vmx->nested.msr_bitmap);
-
-out_msr_bitmap:
 	free_loaded_vmcs(&vmx->nested.vmcs02);
 
 out_vmcs02:
@@ -7332,10 +7347,6 @@ static void free_nested(struct vcpu_vmx
 	free_vpid(vmx->nested.vpid02);
 	vmx->nested.posted_intr_nv = -1;
 	vmx->nested.current_vmptr = -1ull;
-	if (vmx->nested.msr_bitmap) {
-		free_page((unsigned long)vmx->nested.msr_bitmap);
-		vmx->nested.msr_bitmap = NULL;
-	}
 	if (enable_shadow_vmcs) {
 		vmx_disable_shadow_vmcs(vmx);
 		vmcs_clear(vmx->vmcs01.shadow_vmcs);
@@ -8851,7 +8862,7 @@ static void vmx_set_virtual_x2apic_mode(
 	}
 	vmcs_write32(SECONDARY_VM_EXEC_CONTROL, sec_exec_control);
 
-	vmx_set_msr_bitmap(vcpu);
+	vmx_update_msr_bitmap(vcpu);
 }
 
 static void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu, hpa_t hpa)
@@ -9513,6 +9524,7 @@ static struct kvm_vcpu *vmx_create_vcpu(
 {
 	int err;
 	struct vcpu_vmx *vmx = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
+	unsigned long *msr_bitmap;
 	int cpu;
 
 	if (!vmx)
@@ -9549,6 +9561,15 @@ static struct kvm_vcpu *vmx_create_vcpu(
 	if (err < 0)
 		goto free_msrs;
 
+	msr_bitmap = vmx->vmcs01.msr_bitmap;
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_FS_BASE, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_GS_BASE, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_KERNEL_GS_BASE, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_CS, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_ESP, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_EIP, MSR_TYPE_RW);
+	vmx->msr_bitmap_mode = 0;
+
 	vmx->loaded_vmcs = &vmx->vmcs01;
 	cpu = get_cpu();
 	vmx_vcpu_load(&vmx->vcpu, cpu);
@@ -10018,7 +10039,7 @@ static inline bool nested_vmx_merge_msr_
 	int msr;
 	struct page *page;
 	unsigned long *msr_bitmap_l1;
-	unsigned long *msr_bitmap_l0 = to_vmx(vcpu)->nested.msr_bitmap;
+	unsigned long *msr_bitmap_l0 = to_vmx(vcpu)->nested.vmcs02.msr_bitmap;
 
 	/* This shortcut is ok because we support only x2APIC MSRs so far. */
 	if (!nested_cpu_has_virt_x2apic_mode(vmcs12))
@@ -10595,6 +10616,9 @@ static int prepare_vmcs02(struct kvm_vcp
 	if (kvm_has_tsc_control)
 		decache_tsc_multiplier(vmx);
 
+	if (cpu_has_vmx_msr_bitmap())
+		vmcs_write64(MSR_BITMAP, __pa(vmx->nested.vmcs02.msr_bitmap));
+
 	if (enable_vpid) {
 		/*
 		 * There is no direct mapping between vpid02 and vpid12, the
@@ -11388,7 +11412,7 @@ static void load_vmcs12_host_state(struc
 	vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
 
 	if (cpu_has_vmx_msr_bitmap())
-		vmx_set_msr_bitmap(vcpu);
+		vmx_update_msr_bitmap(vcpu);
 
 	if (nested_vmx_load_msr(vcpu, vmcs12->vm_exit_msr_load_addr,
 				vmcs12->vm_exit_msr_load_count))

[PATCH 4.14 53/64] x86/kvm: Update spectre-v1 mitigation

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams dan.j.williams@intel.com

commit 085331dfc6bbe3501fb936e657331ca943827600

Commit 75f139aaf896 "KVM: x86: Add memory barrier on vmcs field lookup"
added a raw 'asm("lfence");' to prevent a bounds check bypass of
'vmcs_field_to_offset_table'.

The lfence can be avoided in this path by using the array_index_nospec()
helper designed for these types of fixes.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Honig <ahonig@google.com>
Cc: kvm@vger.kernel.org
Cc: Jim Mattson <jmattson@google.com>
Link: https://lkml.kernel.org/r/151744959670.6342.3001723920950249067.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/vmx.c |   20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -34,6 +34,7 @@
 #include <linux/tboot.h>
 #include <linux/hrtimer.h>
 #include <linux/frame.h>
+#include <linux/nospec.h>
 #include "kvm_cache_regs.h"
 #include "x86.h"
 
@@ -887,21 +888,18 @@ static const unsigned short vmcs_field_t
 
 static inline short vmcs_field_to_offset(unsigned long field)
 {
-	BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX);
+	const size_t size = ARRAY_SIZE(vmcs_field_to_offset_table);
+	unsigned short offset;
 
-	if (field >= ARRAY_SIZE(vmcs_field_to_offset_table))
+	BUILD_BUG_ON(size > SHRT_MAX);
+	if (field >= size)
 		return -ENOENT;
 
-	/*
-	 * FIXME: Mitigation for CVE-2017-5753.  To be replaced with a
-	 * generic mechanism.
-	 */
-	asm("lfence");
-
-	if (vmcs_field_to_offset_table[field] == 0)
+	field = array_index_nospec(field, size);
+	offset = vmcs_field_to_offset_table[field];
+	if (offset == 0)
 		return -ENOENT;
-
-	return vmcs_field_to_offset_table[field];
+	return offset;
 }
 
 static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)

[PATCH 4.14 54/64] x86/retpoline: Avoid retpolines for built-in __init functions

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse dwmw@amazon.co.uk

commit 66f793099a636862a71c59d4a6ba91387b155e0c

There's no point in building init code with retpolines, since it runs before
any potentially hostile userspace does. And before the retpoline is actually
ALTERNATIVEd into place, for much of it.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: karahmed@amazon.de
Cc: peterz@infradead.org
Cc: bp@alien8.de
Link: https://lkml.kernel.org/r/1517484441-1420-2-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 include/linux/init.h |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -5,6 +5,13 @@
 #include <linux/compiler.h>
 #include <linux/types.h>
 
+/* Built-in __init functions needn't be compiled with retpoline */
+#if defined(RETPOLINE) && !defined(MODULE)
+#define __noretpoline __attribute__((indirect_branch("keep")))
+#else
+#define __noretpoline
+#endif
+
 /* These macros are used to mark some functions or 
  * initialized data (doesn't apply to uninitialized data)
  * as `initialization' functions. The kernel can take this
@@ -40,7 +47,7 @@
 
 /* These are for everybody (although not all archs will actually
    discard it in modules) */
-#define __init		__section(.init.text) __cold __inittrace __latent_entropy
+#define __init		__section(.init.text) __cold __inittrace __latent_entropy __noretpoline
 #define __initdata	__section(.init.data)
 #define __initconst	__section(.init.rodata)
 #define __exitdata	__section(.exit.data)

[PATCH 4.14 55/64] x86/spectre: Simplify spectre_v2 command line parsing

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit 9005c6834c0ffdfe46afa76656bd9276cca864f6

[dwmw2: Use ARRAY_SIZE]

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: bp@alien8.de
Link: https://lkml.kernel.org/r/1517484441-1420-3-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/bugs.c |   84 +++++++++++++++++++++++++++++----------------
 1 file changed, 55 insertions(+), 29 deletions(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -119,13 +119,13 @@ static inline const char *spectre_v2_mod
 static void __init spec2_print_if_insecure(const char *reason)
 {
 	if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
-		pr_info("%s\n", reason);
+		pr_info("%s selected on command line.\n", reason);
 }
 
 static void __init spec2_print_if_secure(const char *reason)
 {
 	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
-		pr_info("%s\n", reason);
+		pr_info("%s selected on command line.\n", reason);
 }
 
 static inline bool retp_compiler(void)
@@ -140,42 +140,68 @@ static inline bool match_option(const ch
 	return len == arglen && !strncmp(arg, opt, len);
 }
 
+static const struct {
+	const char *option;
+	enum spectre_v2_mitigation_cmd cmd;
+	bool secure;
+} mitigation_options[] = {
+	{ "off",               SPECTRE_V2_CMD_NONE,              false },
+	{ "on",                SPECTRE_V2_CMD_FORCE,             true },
+	{ "retpoline",         SPECTRE_V2_CMD_RETPOLINE,         false },
+	{ "retpoline,amd",     SPECTRE_V2_CMD_RETPOLINE_AMD,     false },
+	{ "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false },
+	{ "auto",              SPECTRE_V2_CMD_AUTO,              false },
+};
+
 static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
 {
 	char arg[20];
-	int ret;
+	int ret, i;
+	enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO;
+
+	if (cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
+		return SPECTRE_V2_CMD_NONE;
+	else {
+		ret = cmdline_find_option(boot_command_line, "spectre_v2", arg,
+					  sizeof(arg));
+		if (ret < 0)
+			return SPECTRE_V2_CMD_AUTO;
 
-	ret = cmdline_find_option(boot_command_line, "spectre_v2", arg,
-				  sizeof(arg));
-	if (ret > 0)  {
-		if (match_option(arg, ret, "off")) {
-			goto disable;
-		} else if (match_option(arg, ret, "on")) {
-			spec2_print_if_secure("force enabled on command line.");
-			return SPECTRE_V2_CMD_FORCE;
-		} else if (match_option(arg, ret, "retpoline")) {
-			spec2_print_if_insecure("retpoline selected on command line.");
-			return SPECTRE_V2_CMD_RETPOLINE;
-		} else if (match_option(arg, ret, "retpoline,amd")) {
-			if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
-				pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n");
-				return SPECTRE_V2_CMD_AUTO;
-			}
-			spec2_print_if_insecure("AMD retpoline selected on command line.");
-			return SPECTRE_V2_CMD_RETPOLINE_AMD;
-		} else if (match_option(arg, ret, "retpoline,generic")) {
-			spec2_print_if_insecure("generic retpoline selected on command line.");
-			return SPECTRE_V2_CMD_RETPOLINE_GENERIC;
-		} else if (match_option(arg, ret, "auto")) {
+		for (i = 0; i < ARRAY_SIZE(mitigation_options); i++) {
+			if (!match_option(arg, ret, mitigation_options[i].option))
+				continue;
+			cmd = mitigation_options[i].cmd;
+			break;
+		}
+
+		if (i >= ARRAY_SIZE(mitigation_options)) {
+			pr_err("unknown option (%s). Switching to AUTO select\n",
+			       mitigation_options[i].option);
 			return SPECTRE_V2_CMD_AUTO;
 		}
 	}
 
-	if (!cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
+	if ((cmd == SPECTRE_V2_CMD_RETPOLINE ||
+	     cmd == SPECTRE_V2_CMD_RETPOLINE_AMD ||
+	     cmd == SPECTRE_V2_CMD_RETPOLINE_GENERIC) &&
+	    !IS_ENABLED(CONFIG_RETPOLINE)) {
+		pr_err("%s selected but not compiled in. Switching to AUTO select\n",
+		       mitigation_options[i].option);
 		return SPECTRE_V2_CMD_AUTO;
-disable:
-	spec2_print_if_insecure("disabled on command line.");
-	return SPECTRE_V2_CMD_NONE;
+	}
+
+	if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD &&
+	    boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
+		pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n");
+		return SPECTRE_V2_CMD_AUTO;
+	}
+
+	if (mitigation_options[i].secure)
+		spec2_print_if_secure(mitigation_options[i].option);
+	else
+		spec2_print_if_insecure(mitigation_options[i].option);
+
+	return cmd;
 }
 
 /* Check for Skylake-like CPUs (for RSB handling) */

[PATCH 4.14 56/64] x86/pti: Mark constant arrays as __initconst

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann arnd@arndb.de

commit 4bf5d56d429cbc96c23d809a08f63cd29e1a702e

I'm seeing build failures from the two newly introduced arrays that
are marked 'const' and '__initdata', which are mutually exclusive:

arch/x86/kernel/cpu/common.c:882:43: error: 'cpu_no_speculation' causes a section type conflict with 'e820_table_firmware_init'
arch/x86/kernel/cpu/common.c:895:43: error: 'cpu_no_meltdown' causes a section type conflict with 'e820_table_firmware_init'

The correct annotation is __initconst.

Fixes: fec9434a12f3 ("x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180202213959.611210-1-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kernel/cpu/common.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -876,7 +876,7 @@ static void identify_cpu_without_cpuid(s
 #endif
 }
 
-static const __initdata struct x86_cpu_id cpu_no_speculation[] = {
+static const __initconst struct x86_cpu_id cpu_no_speculation[] = {
 	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_CEDARVIEW,	X86_FEATURE_ANY },
 	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_CLOVERVIEW,	X86_FEATURE_ANY },
 	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_LINCROFT,	X86_FEATURE_ANY },
@@ -889,7 +889,7 @@ static const __initdata struct x86_cpu_i
 	{}
 };
 
-static const __initdata struct x86_cpu_id cpu_no_meltdown[] = {
+static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
 	{ X86_VENDOR_AMD },
 	{}
 };

[PATCH 4.14 57/64] x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Darren Kenny darren.kenny@oracle.com

commit af189c95a371b59f493dbe0f50c0a09724868881

Fixes: 117cc7a908c83 ("x86/retpoline: Fill return stack buffer on vmexit")
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180202191220.blvgkgutojecxr3b@starbug-vm.ie.oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/include/asm/nospec-branch.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -150,7 +150,7 @@ extern char __indirect_thunk_end[];
  * On VMEXIT we must ensure that no RSB predictions learned in the guest
  * can be followed in the host, by overwriting the RSB completely. Both
  * retpoline and IBRS mitigations for Spectre v2 need this; only on future
- * CPUs with IBRS_ATT *might* it be avoided.
+ * CPUs with IBRS_ALL *might* it be avoided.
  */
 static inline void vmexit_fill_RSB(void)
 {

[PATCH 4.14 58/64] KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit b7b27aa011a1df42728d1768fc181d9ce69e6911

[dwmw2: Stop using KF() for bits in it, too]
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Link: https://lkml.kernel.org/r/1517522386-18410-2-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/cpuid.c |    8 +++-----
 arch/x86/kvm/cpuid.h |    1 +
 2 files changed, 4 insertions(+), 5 deletions(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -67,9 +67,7 @@ u64 kvm_supported_xcr0(void)
 
 #define F(x) bit(X86_FEATURE_##x)
 
-/* These are scattered features in cpufeatures.h. */
-#define KVM_CPUID_BIT_AVX512_4VNNIW     2
-#define KVM_CPUID_BIT_AVX512_4FMAPS     3
+/* For scattered features from cpufeatures.h; we currently expose none */
 #define KF(x) bit(KVM_CPUID_BIT_##x)
 
 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
@@ -392,7 +390,7 @@ static inline int __do_cpuid_ent(struct
 
 	/* cpuid 7.0.edx*/
 	const u32 kvm_cpuid_7_0_edx_x86_features =
-		KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS);
+		F(AVX512_4VNNIW) | F(AVX512_4FMAPS);
 
 	/* all calls to cpuid_count() should be made on the same cpu */
 	get_cpu();
@@ -477,7 +475,7 @@ static inline int __do_cpuid_ent(struct
 			if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
 				entry->ecx &= ~F(PKU);
 			entry->edx &= kvm_cpuid_7_0_edx_x86_features;
-			entry->edx &= get_scattered_cpuid_leaf(7, 0, CPUID_EDX);
+			cpuid_mask(&entry->edx, CPUID_7_EDX);
 		} else {
 			entry->ebx = 0;
 			entry->ecx = 0;
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -54,6 +54,7 @@ static const struct cpuid_reg reverse_cp
 	[CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
 	[CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
 	[CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
+	[CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
 };
 
 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned x86_feature)

[PATCH 4.14 59/64] KVM/x86: Add IBPB support

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ashok Raj ashok.raj@intel.com

commit 15d45071523d89b3fb7372e2135fbd72f6af9506

The Indirect Branch Predictor Barrier (IBPB) is an indirect branch
control mechanism. It keeps earlier branches from influencing
later ones.

Unlike IBRS and STIBP, IBPB does not define a new mode of operation.
It's a command that ensures predicted branch targets aren't used after
the barrier. Although IBRS and IBPB are enumerated by the same CPUID
enumeration, IBPB is very different.

IBPB helps mitigate against three potential attacks:

* Mitigate guests from being attacked by other guests.
  - This is addressed by issing IBPB when we do a guest switch.

* Mitigate attacks from guest/ring3->host/ring3.
  These would require a IBPB during context switch in host, or after
  VMEXIT. The host process has two ways to mitigate
  - Either it can be compiled with retpoline
  - If its going through context switch, and has set !dumpable then
    there is a IBPB in that path.
    (Tim's patch: https://patchwork.kernel.org/patch/10192871)
  - The case where after a VMEXIT you return back to Qemu might make
    Qemu attackable from guest when Qemu isn't compiled with retpoline.
  There are issues reported when doing IBPB on every VMEXIT that resulted
  in some tsc calibration woes in guest.

* Mitigate guest/ring0->host/ring0 attacks.
  When host kernel is using retpoline it is safe against these attacks.
  If host kernel isn't using retpoline we might need to do a IBPB flush on
  every VMEXIT.

Even when using retpoline for indirect calls, in certain conditions 'ret'
can use the BTB on Skylake-era CPUs. There are other mitigations
available like RSB stuffing/clearing.

* IBPB is issued only for SVM during svm_free_vcpu().
  VMX has a vmclear and SVM doesn't.  Follow discussion here:
  https://lkml.org/lkml/2018/1/15/146

Please refer to the following spec for more details on the enumeration
and control.

Refer here to get documentation about mitigations.

https://software.intel.com/en-us/side-channel-security-support

[peterz: rebase and changelog rewrite]
[karahmed: - rebase
           - vmx: expose PRED_CMD if guest has it in CPUID
           - svm: only pass through IBPB if guest has it in CPUID
           - vmx: support !cpu_has_vmx_msr_bitmap()]
           - vmx: support nested]
[dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS)
        PRED_CMD is a write-only MSR]

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: kvm@vger.kernel.org
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1515720739-43819-6-git-send-email-ashok.raj@intel.com
Link: https://lkml.kernel.org/r/1517522386-18410-3-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/cpuid.c |   11 ++++++-
 arch/x86/kvm/svm.c   |   28 +++++++++++++++++
 arch/x86/kvm/vmx.c   |   80 +++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 116 insertions(+), 3 deletions(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -365,6 +365,10 @@ static inline int __do_cpuid_ent(struct
 		F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
 		0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
 
+	/* cpuid 0x80000008.ebx */
+	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
+		F(IBPB);
+
 	/* cpuid 0xC0000001.edx */
 	const u32 kvm_cpuid_C000_0001_edx_x86_features =
 		F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
@@ -625,7 +629,12 @@ static inline int __do_cpuid_ent(struct
 		if (!g_phys_as)
 			g_phys_as = phys_as;
 		entry->eax = g_phys_as | (virt_as << 8);
-		entry->ebx = entry->edx = 0;
+		entry->edx = 0;
+		/* IBPB isn't necessarily present in hardware cpuid */
+		if (boot_cpu_has(X86_FEATURE_IBPB))
+			entry->ebx |= F(IBPB);
+		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
+		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
 		break;
 	}
 	case 0x80000019:
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -249,6 +249,7 @@ static const struct svm_direct_access_ms
 	{ .index = MSR_CSTAR,				.always = true  },
 	{ .index = MSR_SYSCALL_MASK,			.always = true  },
 #endif
+	{ .index = MSR_IA32_PRED_CMD,			.always = false },
 	{ .index = MSR_IA32_LASTBRANCHFROMIP,		.always = false },
 	{ .index = MSR_IA32_LASTBRANCHTOIP,		.always = false },
 	{ .index = MSR_IA32_LASTINTFROMIP,		.always = false },
@@ -529,6 +530,7 @@ struct svm_cpu_data {
 	struct kvm_ldttss_desc *tss_desc;
 
 	struct page *save_area;
+	struct vmcb *current_vmcb;
 };
 
 static DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
@@ -1706,11 +1708,17 @@ static void svm_free_vcpu(struct kvm_vcp
 	__free_pages(virt_to_page(svm->nested.msrpm), MSRPM_ALLOC_ORDER);
 	kvm_vcpu_uninit(vcpu);
 	kmem_cache_free(kvm_vcpu_cache, svm);
+	/*
+	 * The vmcb page can be recycled, causing a false negative in
+	 * svm_vcpu_load(). So do a full IBPB now.
+	 */
+	indirect_branch_prediction_barrier();
 }
 
 static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
+	struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
 	int i;
 
 	if (unlikely(cpu != vcpu->cpu)) {
@@ -1739,6 +1747,10 @@ static void svm_vcpu_load(struct kvm_vcp
 	if (static_cpu_has(X86_FEATURE_RDTSCP))
 		wrmsrl(MSR_TSC_AUX, svm->tsc_aux);
 
+	if (sd->current_vmcb != svm->vmcb) {
+		sd->current_vmcb = svm->vmcb;
+		indirect_branch_prediction_barrier();
+	}
 	avic_vcpu_load(vcpu, cpu);
 }
 
@@ -3670,6 +3682,22 @@ static int svm_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr);
 		break;
+	case MSR_IA32_PRED_CMD:
+		if (!msr->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB))
+			return 1;
+
+		if (data & ~PRED_CMD_IBPB)
+			return 1;
+
+		if (!data)
+			break;
+
+		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
+		if (is_guest_mode(vcpu))
+			break;
+		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD, 0, 1);
+		break;
 	case MSR_STAR:
 		svm->vmcb->save.star = data;
 		break;
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -582,6 +582,7 @@ struct vcpu_vmx {
 	u64 		      msr_host_kernel_gs_base;
 	u64 		      msr_guest_kernel_gs_base;
 #endif
+
 	u32 vm_entry_controls_shadow;
 	u32 vm_exit_controls_shadow;
 	u32 secondary_exec_control;
@@ -926,6 +927,8 @@ static void vmx_set_nmi_mask(struct kvm_
 static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 *vmcs12,
 					    u16 error_code);
 static void vmx_update_msr_bitmap(struct kvm_vcpu *vcpu);
+static void __always_inline vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
+							  u32 msr, int type);
 
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -1900,6 +1903,29 @@ static void update_exception_bitmap(stru
 	vmcs_write32(EXCEPTION_BITMAP, eb);
 }
 
+/*
+ * Check if MSR is intercepted for L01 MSR bitmap.
+ */
+static bool msr_write_intercepted_l01(struct kvm_vcpu *vcpu, u32 msr)
+{
+	unsigned long *msr_bitmap;
+	int f = sizeof(unsigned long);
+
+	if (!cpu_has_vmx_msr_bitmap())
+		return true;
+
+	msr_bitmap = to_vmx(vcpu)->vmcs01.msr_bitmap;
+
+	if (msr <= 0x1fff) {
+		return !!test_bit(msr, msr_bitmap + 0x800 / f);
+	} else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
+		msr &= 0x1fff;
+		return !!test_bit(msr, msr_bitmap + 0xc00 / f);
+	}
+
+	return true;
+}
+
 static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
 		unsigned long entry, unsigned long exit)
 {
@@ -2278,6 +2304,7 @@ static void vmx_vcpu_load(struct kvm_vcp
 	if (per_cpu(current_vmcs, cpu) != vmx->loaded_vmcs->vmcs) {
 		per_cpu(current_vmcs, cpu) = vmx->loaded_vmcs->vmcs;
 		vmcs_load(vmx->loaded_vmcs->vmcs);
+		indirect_branch_prediction_barrier();
 	}
 
 	if (!already_loaded) {
@@ -3337,6 +3364,34 @@ static int vmx_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr_info);
 		break;
+	case MSR_IA32_PRED_CMD:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB) &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
+			return 1;
+
+		if (data & ~PRED_CMD_IBPB)
+			return 1;
+
+		if (!data)
+			break;
+
+		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
+
+		/*
+		 * For non-nested:
+		 * When it's written (to non-zero) for the first time, pass
+		 * it through.
+		 *
+		 * For nested:
+		 * The handling of the MSR bitmap for L2 guests is done in
+		 * nested_vmx_merge_msr_bitmap. We should not touch the
+		 * vmcs02.msr_bitmap here since it gets completely overwritten
+		 * in the merging.
+		 */
+		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD,
+					      MSR_TYPE_W);
+		break;
 	case MSR_IA32_CR_PAT:
 		if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
 			if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
@@ -10038,9 +10093,23 @@ static inline bool nested_vmx_merge_msr_
 	struct page *page;
 	unsigned long *msr_bitmap_l1;
 	unsigned long *msr_bitmap_l0 = to_vmx(vcpu)->nested.vmcs02.msr_bitmap;
+	/*
+	 * pred_cmd is trying to verify two things:
+	 *
+	 * 1. L0 gave a permission to L1 to actually passthrough the MSR. This
+	 *    ensures that we do not accidentally generate an L02 MSR bitmap
+	 *    from the L12 MSR bitmap that is too permissive.
+	 * 2. That L1 or L2s have actually used the MSR. This avoids
+	 *    unnecessarily merging of the bitmap if the MSR is unused. This
+	 *    works properly because we only update the L01 MSR bitmap lazily.
+	 *    So even if L0 should pass L1 these MSRs, the L01 bitmap is only
+	 *    updated to reflect this when L1 (or its L2s) actually write to
+	 *    the MSR.
+	 */
+	bool pred_cmd = msr_write_intercepted_l01(vcpu, MSR_IA32_PRED_CMD);
 
-	/* This shortcut is ok because we support only x2APIC MSRs so far. */
-	if (!nested_cpu_has_virt_x2apic_mode(vmcs12))
+	if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
+	    !pred_cmd)
 		return false;
 
 	page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->msr_bitmap);
@@ -10073,6 +10142,13 @@ static inline bool nested_vmx_merge_msr_
 				MSR_TYPE_W);
 		}
 	}
+
+	if (pred_cmd)
+		nested_vmx_disable_intercept_for_msr(
+					msr_bitmap_l1, msr_bitmap_l0,
+					MSR_IA32_PRED_CMD,
+					MSR_TYPE_W);
+
 	kunmap(page);
 	kvm_release_page_clean(page);
 

[PATCH 4.14 59/64] KVM/x86: Add IBPB support

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ashok Raj ashok.raj@intel.com

commit 15d45071523d89b3fb7372e2135fbd72f6af9506

The Indirect Branch Predictor Barrier (IBPB) is an indirect branch
control mechanism. It keeps earlier branches from influencing
later ones.

Unlike IBRS and STIBP, IBPB does not define a new mode of operation.
It's a command that ensures predicted branch targets aren't used after
the barrier. Although IBRS and IBPB are enumerated by the same CPUID
enumeration, IBPB is very different.

IBPB helps mitigate against three potential attacks:

* Mitigate guests from being attacked by other guests.
  - This is addressed by issing IBPB when we do a guest switch.

* Mitigate attacks from guest/ring3->host/ring3.
  These would require a IBPB during context switch in host, or after
  VMEXIT. The host process has two ways to mitigate
  - Either it can be compiled with retpoline
  - If its going through context switch, and has set !dumpable then
    there is a IBPB in that path.
    (Tim's patch: https://patchwork.kernel.org/patch/10192871)
  - The case where after a VMEXIT you return back to Qemu might make
    Qemu attackable from guest when Qemu isn't compiled with retpoline.
  There are issues reported when doing IBPB on every VMEXIT that resulted
  in some tsc calibration woes in guest.

* Mitigate guest/ring0->host/ring0 attacks.
  When host kernel is using retpoline it is safe against these attacks.
  If host kernel isn't using retpoline we might need to do a IBPB flush on
  every VMEXIT.

Even when using retpoline for indirect calls, in certain conditions 'ret'
can use the BTB on Skylake-era CPUs. There are other mitigations
available like RSB stuffing/clearing.

* IBPB is issued only for SVM during svm_free_vcpu().
  VMX has a vmclear and SVM doesn't.  Follow discussion here:
  https://lkml.org/lkml/2018/1/15/146

Please refer to the following spec for more details on the enumeration
and control.

Refer here to get documentation about mitigations.

https://software.intel.com/en-us/side-channel-security-support

[peterz: rebase and changelog rewrite]
[karahmed: - rebase
           - vmx: expose PRED_CMD if guest has it in CPUID
           - svm: only pass through IBPB if guest has it in CPUID
           - vmx: support !cpu_has_vmx_msr_bitmap()]
           - vmx: support nested]
[dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS)
        PRED_CMD is a write-only MSR]

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: kvm@vger.kernel.org
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1515720739-43819-6-git-send-email-ashok.raj@intel.com
Link: https://lkml.kernel.org/r/1517522386-18410-3-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/cpuid.c |   11 ++++++-
 arch/x86/kvm/svm.c   |   28 +++++++++++++++++
 arch/x86/kvm/vmx.c   |   80 +++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 116 insertions(+), 3 deletions(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -365,6 +365,10 @@ static inline int __do_cpuid_ent(struct
 		F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
 		0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
 
+	/* cpuid 0x80000008.ebx */
+	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
+		F(IBPB);
+
 	/* cpuid 0xC0000001.edx */
 	const u32 kvm_cpuid_C000_0001_edx_x86_features =
 		F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
@@ -625,7 +629,12 @@ static inline int __do_cpuid_ent(struct
 		if (!g_phys_as)
 			g_phys_as = phys_as;
 		entry->eax = g_phys_as | (virt_as << 8);
-		entry->ebx = entry->edx = 0;
+		entry->edx = 0;
+		/* IBPB isn't necessarily present in hardware cpuid */
+		if (boot_cpu_has(X86_FEATURE_IBPB))
+			entry->ebx |= F(IBPB);
+		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
+		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
 		break;
 	}
 	case 0x80000019:
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -249,6 +249,7 @@ static const struct svm_direct_access_ms
 	{ .index = MSR_CSTAR,				.always = true  },
 	{ .index = MSR_SYSCALL_MASK,			.always = true  },
 #endif
+	{ .index = MSR_IA32_PRED_CMD,			.always = false },
 	{ .index = MSR_IA32_LASTBRANCHFROMIP,		.always = false },
 	{ .index = MSR_IA32_LASTBRANCHTOIP,		.always = false },
 	{ .index = MSR_IA32_LASTINTFROMIP,		.always = false },
@@ -529,6 +530,7 @@ struct svm_cpu_data {
 	struct kvm_ldttss_desc *tss_desc;
 
 	struct page *save_area;
+	struct vmcb *current_vmcb;
 };
 
 static DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
@@ -1706,11 +1708,17 @@ static void svm_free_vcpu(struct kvm_vcp
 	__free_pages(virt_to_page(svm->nested.msrpm), MSRPM_ALLOC_ORDER);
 	kvm_vcpu_uninit(vcpu);
 	kmem_cache_free(kvm_vcpu_cache, svm);
+	/*
+	 * The vmcb page can be recycled, causing a false negative in
+	 * svm_vcpu_load(). So do a full IBPB now.
+	 */
+	indirect_branch_prediction_barrier();
 }
 
 static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
+	struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
 	int i;
 
 	if (unlikely(cpu != vcpu->cpu)) {
@@ -1739,6 +1747,10 @@ static void svm_vcpu_load(struct kvm_vcp
 	if (static_cpu_has(X86_FEATURE_RDTSCP))
 		wrmsrl(MSR_TSC_AUX, svm->tsc_aux);
 
+	if (sd->current_vmcb != svm->vmcb) {
+		sd->current_vmcb = svm->vmcb;
+		indirect_branch_prediction_barrier();
+	}
 	avic_vcpu_load(vcpu, cpu);
 }
 
@@ -3670,6 +3682,22 @@ static int svm_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr);
 		break;
+	case MSR_IA32_PRED_CMD:
+		if (!msr->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB))
+			return 1;
+
+		if (data & ~PRED_CMD_IBPB)
+			return 1;
+
+		if (!data)
+			break;
+
+		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
+		if (is_guest_mode(vcpu))
+			break;
+		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD, 0, 1);
+		break;
 	case MSR_STAR:
 		svm->vmcb->save.star = data;
 		break;
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -582,6 +582,7 @@ struct vcpu_vmx {
 	u64 		      msr_host_kernel_gs_base;
 	u64 		      msr_guest_kernel_gs_base;
 #endif
+
 	u32 vm_entry_controls_shadow;
 	u32 vm_exit_controls_shadow;
 	u32 secondary_exec_control;
@@ -926,6 +927,8 @@ static void vmx_set_nmi_mask(struct kvm_
 static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 *vmcs12,
 					    u16 error_code);
 static void vmx_update_msr_bitmap(struct kvm_vcpu *vcpu);
+static void __always_inline vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
+							  u32 msr, int type);
 
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -1900,6 +1903,29 @@ static void update_exception_bitmap(stru
 	vmcs_write32(EXCEPTION_BITMAP, eb);
 }
 
+/*
+ * Check if MSR is intercepted for L01 MSR bitmap.
+ */
+static bool msr_write_intercepted_l01(struct kvm_vcpu *vcpu, u32 msr)
+{
+	unsigned long *msr_bitmap;
+	int f = sizeof(unsigned long);
+
+	if (!cpu_has_vmx_msr_bitmap())
+		return true;
+
+	msr_bitmap = to_vmx(vcpu)->vmcs01.msr_bitmap;
+
+	if (msr <= 0x1fff) {
+		return !!test_bit(msr, msr_bitmap + 0x800 / f);
+	} else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
+		msr &= 0x1fff;
+		return !!test_bit(msr, msr_bitmap + 0xc00 / f);
+	}
+
+	return true;
+}
+
 static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
 		unsigned long entry, unsigned long exit)
 {
@@ -2278,6 +2304,7 @@ static void vmx_vcpu_load(struct kvm_vcp
 	if (per_cpu(current_vmcs, cpu) != vmx->loaded_vmcs->vmcs) {
 		per_cpu(current_vmcs, cpu) = vmx->loaded_vmcs->vmcs;
 		vmcs_load(vmx->loaded_vmcs->vmcs);
+		indirect_branch_prediction_barrier();
 	}
 
 	if (!already_loaded) {
@@ -3337,6 +3364,34 @@ static int vmx_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr_info);
 		break;
+	case MSR_IA32_PRED_CMD:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB) &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
+			return 1;
+
+		if (data & ~PRED_CMD_IBPB)
+			return 1;
+
+		if (!data)
+			break;
+
+		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
+
+		/*
+		 * For non-nested:
+		 * When it's written (to non-zero) for the first time, pass
+		 * it through.
+		 *
+		 * For nested:
+		 * The handling of the MSR bitmap for L2 guests is done in
+		 * nested_vmx_merge_msr_bitmap. We should not touch the
+		 * vmcs02.msr_bitmap here since it gets completely overwritten
+		 * in the merging.
+		 */
+		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD,
+					      MSR_TYPE_W);
+		break;
 	case MSR_IA32_CR_PAT:
 		if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
 			if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
@@ -10038,9 +10093,23 @@ static inline bool nested_vmx_merge_msr_
 	struct page *page;
 	unsigned long *msr_bitmap_l1;
 	unsigned long *msr_bitmap_l0 = to_vmx(vcpu)->nested.vmcs02.msr_bitmap;
+	/*
+	 * pred_cmd is trying to verify two things:
+	 *
+	 * 1. L0 gave a permission to L1 to actually passthrough the MSR. This
+	 *    ensures that we do not accidentally generate an L02 MSR bitmap
+	 *    from the L12 MSR bitmap that is too permissive.
+	 * 2. That L1 or L2s have actually used the MSR. This avoids
+	 *    unnecessarily merging of the bitmap if the MSR is unused. This
+	 *    works properly because we only update the L01 MSR bitmap lazily.
+	 *    So even if L0 should pass L1 these MSRs, the L01 bitmap is only
+	 *    updated to reflect this when L1 (or its L2s) actually write to
+	 *    the MSR.
+	 */
+	bool pred_cmd = msr_write_intercepted_l01(vcpu, MSR_IA32_PRED_CMD);
 
-	/* This shortcut is ok because we support only x2APIC MSRs so far. */
-	if (!nested_cpu_has_virt_x2apic_mode(vmcs12))
+	if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
+	    !pred_cmd)
 		return false;
 
 	page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->msr_bitmap);
@@ -10073,6 +10142,13 @@ static inline bool nested_vmx_merge_msr_
 				MSR_TYPE_W);
 		}
 	}
+
+	if (pred_cmd)
+		nested_vmx_disable_intercept_for_msr(
+					msr_bitmap_l1, msr_bitmap_l0,
+					MSR_IA32_PRED_CMD,
+					MSR_TYPE_W);
+
 	kunmap(page);
 	kvm_release_page_clean(page);
 

[PATCH 4.14 60/64] KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit 28c1c9fabf48d6ad596273a11c46e0d0da3e14cd

Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO
(bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the
contents will come directly from the hardware, but user-space can still
override it.

[dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional]

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: kvm@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/cpuid.c |    2 +-
 arch/x86/kvm/vmx.c   |   15 +++++++++++++++
 arch/x86/kvm/x86.c   |    1 +
 3 files changed, 17 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -394,7 +394,7 @@ static inline int __do_cpuid_ent(struct
 
 	/* cpuid 7.0.edx*/
 	const u32 kvm_cpuid_7_0_edx_x86_features =
-		F(AVX512_4VNNIW) | F(AVX512_4FMAPS);
+		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(ARCH_CAPABILITIES);
 
 	/* all calls to cpuid_count() should be made on the same cpu */
 	get_cpu();
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -583,6 +583,8 @@ struct vcpu_vmx {
 	u64 		      msr_guest_kernel_gs_base;
 #endif
 
+	u64 		      arch_capabilities;
+
 	u32 vm_entry_controls_shadow;
 	u32 vm_exit_controls_shadow;
 	u32 secondary_exec_control;
@@ -3257,6 +3259,12 @@ static int vmx_get_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		msr_info->data = guest_read_tsc(vcpu);
 		break;
+	case MSR_IA32_ARCH_CAPABILITIES:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
+			return 1;
+		msr_info->data = to_vmx(vcpu)->arch_capabilities;
+		break;
 	case MSR_IA32_SYSENTER_CS:
 		msr_info->data = vmcs_read32(GUEST_SYSENTER_CS);
 		break;
@@ -3392,6 +3400,11 @@ static int vmx_set_msr(struct kvm_vcpu *
 		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD,
 					      MSR_TYPE_W);
 		break;
+	case MSR_IA32_ARCH_CAPABILITIES:
+		if (!msr_info->host_initiated)
+			return 1;
+		vmx->arch_capabilities = data;
+		break;
 	case MSR_IA32_CR_PAT:
 		if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
 			if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
@@ -5652,6 +5665,8 @@ static int vmx_vcpu_setup(struct vcpu_vm
 		++vmx->nmsrs;
 	}
 
+	if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
+		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, vmx->arch_capabilities);
 
 	vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);
 
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1006,6 +1006,7 @@ static u32 msrs_to_save[] = {
 #endif
 	MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
 	MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
+	MSR_IA32_ARCH_CAPABILITIES
 };
 
 static unsigned num_msrs_to_save;

[PATCH 4.14 60/64] KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit 28c1c9fabf48d6ad596273a11c46e0d0da3e14cd

Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO
(bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the
contents will come directly from the hardware, but user-space can still
override it.

[dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional]

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: kvm@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/cpuid.c |    2 +-
 arch/x86/kvm/vmx.c   |   15 +++++++++++++++
 arch/x86/kvm/x86.c   |    1 +
 3 files changed, 17 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -394,7 +394,7 @@ static inline int __do_cpuid_ent(struct
 
 	/* cpuid 7.0.edx*/
 	const u32 kvm_cpuid_7_0_edx_x86_features =
-		F(AVX512_4VNNIW) | F(AVX512_4FMAPS);
+		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(ARCH_CAPABILITIES);
 
 	/* all calls to cpuid_count() should be made on the same cpu */
 	get_cpu();
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -583,6 +583,8 @@ struct vcpu_vmx {
 	u64 		      msr_guest_kernel_gs_base;
 #endif
 
+	u64 		      arch_capabilities;
+
 	u32 vm_entry_controls_shadow;
 	u32 vm_exit_controls_shadow;
 	u32 secondary_exec_control;
@@ -3257,6 +3259,12 @@ static int vmx_get_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		msr_info->data = guest_read_tsc(vcpu);
 		break;
+	case MSR_IA32_ARCH_CAPABILITIES:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
+			return 1;
+		msr_info->data = to_vmx(vcpu)->arch_capabilities;
+		break;
 	case MSR_IA32_SYSENTER_CS:
 		msr_info->data = vmcs_read32(GUEST_SYSENTER_CS);
 		break;
@@ -3392,6 +3400,11 @@ static int vmx_set_msr(struct kvm_vcpu *
 		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD,
 					      MSR_TYPE_W);
 		break;
+	case MSR_IA32_ARCH_CAPABILITIES:
+		if (!msr_info->host_initiated)
+			return 1;
+		vmx->arch_capabilities = data;
+		break;
 	case MSR_IA32_CR_PAT:
 		if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
 			if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
@@ -5652,6 +5665,8 @@ static int vmx_vcpu_setup(struct vcpu_vm
 		++vmx->nmsrs;
 	}
 
+	if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
+		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, vmx->arch_capabilities);
 
 	vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);
 
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1006,6 +1006,7 @@ static u32 msrs_to_save[] = {
 #endif
 	MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
 	MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
+	MSR_IA32_ARCH_CAPABILITIES
 };
 
 static unsigned num_msrs_to_save;

[PATCH 4.14 61/64] KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit d28b387fb74da95d69d2615732f50cceb38e9a4d

[ Based on a patch from Ashok Raj <ashok.raj@intel.com> ]

Add direct access to MSR_IA32_SPEC_CTRL for guests. This is needed for
guests that will only mitigate Spectre V2 through IBRS+IBPB and will not
be using a retpoline+IBPB based approach.

To avoid the overhead of saving and restoring the MSR_IA32_SPEC_CTRL for
guests that do not actually use the MSR, only start saving and restoring
when a non-zero is written to it.

No attempt is made to handle STIBP here, intentionally. Filtering STIBP
may be added in a future patch, which may require trapping all writes
if we don't want to pass it through directly to the guest.

[dwmw2: Clean up CPUID bits, save/restore manually, handle reset]

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: kvm@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/1517522386-18410-5-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/cpuid.c |    9 ++--
 arch/x86/kvm/vmx.c   |  105 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 arch/x86/kvm/x86.c   |    2 
 3 files changed, 110 insertions(+), 6 deletions(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -367,7 +367,7 @@ static inline int __do_cpuid_ent(struct
 
 	/* cpuid 0x80000008.ebx */
 	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
-		F(IBPB);
+		F(IBPB) | F(IBRS);
 
 	/* cpuid 0xC0000001.edx */
 	const u32 kvm_cpuid_C000_0001_edx_x86_features =
@@ -394,7 +394,8 @@ static inline int __do_cpuid_ent(struct
 
 	/* cpuid 7.0.edx*/
 	const u32 kvm_cpuid_7_0_edx_x86_features =
-		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(ARCH_CAPABILITIES);
+		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
+		F(ARCH_CAPABILITIES);
 
 	/* all calls to cpuid_count() should be made on the same cpu */
 	get_cpu();
@@ -630,9 +631,11 @@ static inline int __do_cpuid_ent(struct
 			g_phys_as = phys_as;
 		entry->eax = g_phys_as | (virt_as << 8);
 		entry->edx = 0;
-		/* IBPB isn't necessarily present in hardware cpuid */
+		/* IBRS and IBPB aren't necessarily present in hardware cpuid */
 		if (boot_cpu_has(X86_FEATURE_IBPB))
 			entry->ebx |= F(IBPB);
+		if (boot_cpu_has(X86_FEATURE_IBRS))
+			entry->ebx |= F(IBRS);
 		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
 		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
 		break;
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -584,6 +584,7 @@ struct vcpu_vmx {
 #endif
 
 	u64 		      arch_capabilities;
+	u64 		      spec_ctrl;
 
 	u32 vm_entry_controls_shadow;
 	u32 vm_exit_controls_shadow;
@@ -1906,6 +1907,29 @@ static void update_exception_bitmap(stru
 }
 
 /*
+ * Check if MSR is intercepted for currently loaded MSR bitmap.
+ */
+static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr)
+{
+	unsigned long *msr_bitmap;
+	int f = sizeof(unsigned long);
+
+	if (!cpu_has_vmx_msr_bitmap())
+		return true;
+
+	msr_bitmap = to_vmx(vcpu)->loaded_vmcs->msr_bitmap;
+
+	if (msr <= 0x1fff) {
+		return !!test_bit(msr, msr_bitmap + 0x800 / f);
+	} else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
+		msr &= 0x1fff;
+		return !!test_bit(msr, msr_bitmap + 0xc00 / f);
+	}
+
+	return true;
+}
+
+/*
  * Check if MSR is intercepted for L01 MSR bitmap.
  */
 static bool msr_write_intercepted_l01(struct kvm_vcpu *vcpu, u32 msr)
@@ -3259,6 +3283,14 @@ static int vmx_get_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		msr_info->data = guest_read_tsc(vcpu);
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
+			return 1;
+
+		msr_info->data = to_vmx(vcpu)->spec_ctrl;
+		break;
 	case MSR_IA32_ARCH_CAPABILITIES:
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
@@ -3372,6 +3404,37 @@ static int vmx_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr_info);
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
+			return 1;
+
+		/* The STIBP bit doesn't fault even if it's not advertised */
+		if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP))
+			return 1;
+
+		vmx->spec_ctrl = data;
+
+		if (!data)
+			break;
+
+		/*
+		 * For non-nested:
+		 * When it's written (to non-zero) for the first time, pass
+		 * it through.
+		 *
+		 * For nested:
+		 * The handling of the MSR bitmap for L2 guests is done in
+		 * nested_vmx_merge_msr_bitmap. We should not touch the
+		 * vmcs02.msr_bitmap here since it gets completely overwritten
+		 * in the merging. We update the vmcs01 here for L1 as well
+		 * since it will end up touching the MSR anyway now.
+		 */
+		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap,
+					      MSR_IA32_SPEC_CTRL,
+					      MSR_TYPE_RW);
+		break;
 	case MSR_IA32_PRED_CMD:
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB) &&
@@ -5697,6 +5760,7 @@ static void vmx_vcpu_reset(struct kvm_vc
 	u64 cr0;
 
 	vmx->rmode.vm86_active = 0;
+	vmx->spec_ctrl = 0;
 
 	vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val();
 	kvm_set_cr8(vcpu, 0);
@@ -9360,6 +9424,15 @@ static void __noclone vmx_vcpu_run(struc
 
 	vmx_arm_hv_timer(vcpu);
 
+	/*
+	 * If this vCPU has touched SPEC_CTRL, restore the guest's value if
+	 * it's non-zero. Since vmentry is serialising on affected CPUs, there
+	 * is no need to worry about the conditional branch over the wrmsr
+	 * being speculatively taken.
+	 */
+	if (vmx->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl);
+
 	vmx->__launched = vmx->loaded_vmcs->launched;
 	asm(
 		/* Store host registers */
@@ -9478,6 +9551,27 @@ static void __noclone vmx_vcpu_run(struc
 #endif
 	      );
 
+	/*
+	 * We do not use IBRS in the kernel. If this vCPU has used the
+	 * SPEC_CTRL MSR it may have left it on; save the value and
+	 * turn it off. This is much more efficient than blindly adding
+	 * it to the atomic save/restore list. Especially as the former
+	 * (Saving guest MSRs on vmexit) doesn't even exist in KVM.
+	 *
+	 * For non-nested case:
+	 * If the L01 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 *
+	 * For nested case:
+	 * If the L02 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 */
+	if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL))
+		rdmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl);
+
+	if (vmx->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+
 	/* Eliminate branch target predictions from guest mode */
 	vmexit_fill_RSB();
 
@@ -10109,7 +10203,7 @@ static inline bool nested_vmx_merge_msr_
 	unsigned long *msr_bitmap_l1;
 	unsigned long *msr_bitmap_l0 = to_vmx(vcpu)->nested.vmcs02.msr_bitmap;
 	/*
-	 * pred_cmd is trying to verify two things:
+	 * pred_cmd & spec_ctrl are trying to verify two things:
 	 *
 	 * 1. L0 gave a permission to L1 to actually passthrough the MSR. This
 	 *    ensures that we do not accidentally generate an L02 MSR bitmap
@@ -10122,9 +10216,10 @@ static inline bool nested_vmx_merge_msr_
 	 *    the MSR.
 	 */
 	bool pred_cmd = msr_write_intercepted_l01(vcpu, MSR_IA32_PRED_CMD);
+	bool spec_ctrl = msr_write_intercepted_l01(vcpu, MSR_IA32_SPEC_CTRL);
 
 	if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
-	    !pred_cmd)
+	    !pred_cmd && !spec_ctrl)
 		return false;
 
 	page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->msr_bitmap);
@@ -10158,6 +10253,12 @@ static inline bool nested_vmx_merge_msr_
 		}
 	}
 
+	if (spec_ctrl)
+		nested_vmx_disable_intercept_for_msr(
+					msr_bitmap_l1, msr_bitmap_l0,
+					MSR_IA32_SPEC_CTRL,
+					MSR_TYPE_R | MSR_TYPE_W);
+
 	if (pred_cmd)
 		nested_vmx_disable_intercept_for_msr(
 					msr_bitmap_l1, msr_bitmap_l0,
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1006,7 +1006,7 @@ static u32 msrs_to_save[] = {
 #endif
 	MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
 	MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
-	MSR_IA32_ARCH_CAPABILITIES
+	MSR_IA32_SPEC_CTRL, MSR_IA32_ARCH_CAPABILITIES
 };
 
 static unsigned num_msrs_to_save;

[PATCH 4.14 61/64] KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit d28b387fb74da95d69d2615732f50cceb38e9a4d

[ Based on a patch from Ashok Raj <ashok.raj@intel.com> ]

Add direct access to MSR_IA32_SPEC_CTRL for guests. This is needed for
guests that will only mitigate Spectre V2 through IBRS+IBPB and will not
be using a retpoline+IBPB based approach.

To avoid the overhead of saving and restoring the MSR_IA32_SPEC_CTRL for
guests that do not actually use the MSR, only start saving and restoring
when a non-zero is written to it.

No attempt is made to handle STIBP here, intentionally. Filtering STIBP
may be added in a future patch, which may require trapping all writes
if we don't want to pass it through directly to the guest.

[dwmw2: Clean up CPUID bits, save/restore manually, handle reset]

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: kvm@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/1517522386-18410-5-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/cpuid.c |    9 ++--
 arch/x86/kvm/vmx.c   |  105 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 arch/x86/kvm/x86.c   |    2 
 3 files changed, 110 insertions(+), 6 deletions(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -367,7 +367,7 @@ static inline int __do_cpuid_ent(struct
 
 	/* cpuid 0x80000008.ebx */
 	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
-		F(IBPB);
+		F(IBPB) | F(IBRS);
 
 	/* cpuid 0xC0000001.edx */
 	const u32 kvm_cpuid_C000_0001_edx_x86_features =
@@ -394,7 +394,8 @@ static inline int __do_cpuid_ent(struct
 
 	/* cpuid 7.0.edx*/
 	const u32 kvm_cpuid_7_0_edx_x86_features =
-		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(ARCH_CAPABILITIES);
+		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
+		F(ARCH_CAPABILITIES);
 
 	/* all calls to cpuid_count() should be made on the same cpu */
 	get_cpu();
@@ -630,9 +631,11 @@ static inline int __do_cpuid_ent(struct
 			g_phys_as = phys_as;
 		entry->eax = g_phys_as | (virt_as << 8);
 		entry->edx = 0;
-		/* IBPB isn't necessarily present in hardware cpuid */
+		/* IBRS and IBPB aren't necessarily present in hardware cpuid */
 		if (boot_cpu_has(X86_FEATURE_IBPB))
 			entry->ebx |= F(IBPB);
+		if (boot_cpu_has(X86_FEATURE_IBRS))
+			entry->ebx |= F(IBRS);
 		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
 		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
 		break;
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -584,6 +584,7 @@ struct vcpu_vmx {
 #endif
 
 	u64 		      arch_capabilities;
+	u64 		      spec_ctrl;
 
 	u32 vm_entry_controls_shadow;
 	u32 vm_exit_controls_shadow;
@@ -1906,6 +1907,29 @@ static void update_exception_bitmap(stru
 }
 
 /*
+ * Check if MSR is intercepted for currently loaded MSR bitmap.
+ */
+static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr)
+{
+	unsigned long *msr_bitmap;
+	int f = sizeof(unsigned long);
+
+	if (!cpu_has_vmx_msr_bitmap())
+		return true;
+
+	msr_bitmap = to_vmx(vcpu)->loaded_vmcs->msr_bitmap;
+
+	if (msr <= 0x1fff) {
+		return !!test_bit(msr, msr_bitmap + 0x800 / f);
+	} else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
+		msr &= 0x1fff;
+		return !!test_bit(msr, msr_bitmap + 0xc00 / f);
+	}
+
+	return true;
+}
+
+/*
  * Check if MSR is intercepted for L01 MSR bitmap.
  */
 static bool msr_write_intercepted_l01(struct kvm_vcpu *vcpu, u32 msr)
@@ -3259,6 +3283,14 @@ static int vmx_get_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		msr_info->data = guest_read_tsc(vcpu);
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
+			return 1;
+
+		msr_info->data = to_vmx(vcpu)->spec_ctrl;
+		break;
 	case MSR_IA32_ARCH_CAPABILITIES:
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
@@ -3372,6 +3404,37 @@ static int vmx_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr_info);
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
+			return 1;
+
+		/* The STIBP bit doesn't fault even if it's not advertised */
+		if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP))
+			return 1;
+
+		vmx->spec_ctrl = data;
+
+		if (!data)
+			break;
+
+		/*
+		 * For non-nested:
+		 * When it's written (to non-zero) for the first time, pass
+		 * it through.
+		 *
+		 * For nested:
+		 * The handling of the MSR bitmap for L2 guests is done in
+		 * nested_vmx_merge_msr_bitmap. We should not touch the
+		 * vmcs02.msr_bitmap here since it gets completely overwritten
+		 * in the merging. We update the vmcs01 here for L1 as well
+		 * since it will end up touching the MSR anyway now.
+		 */
+		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap,
+					      MSR_IA32_SPEC_CTRL,
+					      MSR_TYPE_RW);
+		break;
 	case MSR_IA32_PRED_CMD:
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB) &&
@@ -5697,6 +5760,7 @@ static void vmx_vcpu_reset(struct kvm_vc
 	u64 cr0;
 
 	vmx->rmode.vm86_active = 0;
+	vmx->spec_ctrl = 0;
 
 	vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val();
 	kvm_set_cr8(vcpu, 0);
@@ -9360,6 +9424,15 @@ static void __noclone vmx_vcpu_run(struc
 
 	vmx_arm_hv_timer(vcpu);
 
+	/*
+	 * If this vCPU has touched SPEC_CTRL, restore the guest's value if
+	 * it's non-zero. Since vmentry is serialising on affected CPUs, there
+	 * is no need to worry about the conditional branch over the wrmsr
+	 * being speculatively taken.
+	 */
+	if (vmx->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl);
+
 	vmx->__launched = vmx->loaded_vmcs->launched;
 	asm(
 		/* Store host registers */
@@ -9478,6 +9551,27 @@ static void __noclone vmx_vcpu_run(struc
 #endif
 	      );
 
+	/*
+	 * We do not use IBRS in the kernel. If this vCPU has used the
+	 * SPEC_CTRL MSR it may have left it on; save the value and
+	 * turn it off. This is much more efficient than blindly adding
+	 * it to the atomic save/restore list. Especially as the former
+	 * (Saving guest MSRs on vmexit) doesn't even exist in KVM.
+	 *
+	 * For non-nested case:
+	 * If the L01 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 *
+	 * For nested case:
+	 * If the L02 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 */
+	if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL))
+		rdmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl);
+
+	if (vmx->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+
 	/* Eliminate branch target predictions from guest mode */
 	vmexit_fill_RSB();
 
@@ -10109,7 +10203,7 @@ static inline bool nested_vmx_merge_msr_
 	unsigned long *msr_bitmap_l1;
 	unsigned long *msr_bitmap_l0 = to_vmx(vcpu)->nested.vmcs02.msr_bitmap;
 	/*
-	 * pred_cmd is trying to verify two things:
+	 * pred_cmd & spec_ctrl are trying to verify two things:
 	 *
 	 * 1. L0 gave a permission to L1 to actually passthrough the MSR. This
 	 *    ensures that we do not accidentally generate an L02 MSR bitmap
@@ -10122,9 +10216,10 @@ static inline bool nested_vmx_merge_msr_
 	 *    the MSR.
 	 */
 	bool pred_cmd = msr_write_intercepted_l01(vcpu, MSR_IA32_PRED_CMD);
+	bool spec_ctrl = msr_write_intercepted_l01(vcpu, MSR_IA32_SPEC_CTRL);
 
 	if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
-	    !pred_cmd)
+	    !pred_cmd && !spec_ctrl)
 		return false;
 
 	page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->msr_bitmap);
@@ -10158,6 +10253,12 @@ static inline bool nested_vmx_merge_msr_
 		}
 	}
 
+	if (spec_ctrl)
+		nested_vmx_disable_intercept_for_msr(
+					msr_bitmap_l1, msr_bitmap_l0,
+					MSR_IA32_SPEC_CTRL,
+					MSR_TYPE_R | MSR_TYPE_W);
+
 	if (pred_cmd)
 		nested_vmx_disable_intercept_for_msr(
 					msr_bitmap_l1, msr_bitmap_l0,
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1006,7 +1006,7 @@ static u32 msrs_to_save[] = {
 #endif
 	MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
 	MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
-	MSR_IA32_ARCH_CAPABILITIES
+	MSR_IA32_SPEC_CTRL, MSR_IA32_ARCH_CAPABILITIES
 };
 
 static unsigned num_msrs_to_save;

[PATCH 4.14 62/64] KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit b2ac58f90540e39324e7a29a7ad471407ae0bf48

[ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ]

... basically doing exactly what we do for VMX:

- Passthrough SPEC_CTRL to guests (if enabled in guest CPUID)
- Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest
  actually used it.

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: kvm@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/1517669783-20732-1-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/svm.c |   88 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -184,6 +184,8 @@ struct vcpu_svm {
 		u64 gs_base;
 	} host;
 
+	u64 spec_ctrl;
+
 	u32 *msrpm;
 
 	ulong nmi_iret_rip;
@@ -249,6 +251,7 @@ static const struct svm_direct_access_ms
 	{ .index = MSR_CSTAR,				.always = true  },
 	{ .index = MSR_SYSCALL_MASK,			.always = true  },
 #endif
+	{ .index = MSR_IA32_SPEC_CTRL,			.always = false },
 	{ .index = MSR_IA32_PRED_CMD,			.always = false },
 	{ .index = MSR_IA32_LASTBRANCHFROMIP,		.always = false },
 	{ .index = MSR_IA32_LASTBRANCHTOIP,		.always = false },
@@ -882,6 +885,25 @@ static bool valid_msr_intercept(u32 inde
 	return false;
 }
 
+static bool msr_write_intercepted(struct kvm_vcpu *vcpu, unsigned msr)
+{
+	u8 bit_write;
+	unsigned long tmp;
+	u32 offset;
+	u32 *msrpm;
+
+	msrpm = is_guest_mode(vcpu) ? to_svm(vcpu)->nested.msrpm:
+				      to_svm(vcpu)->msrpm;
+
+	offset    = svm_msrpm_offset(msr);
+	bit_write = 2 * (msr & 0x0f) + 1;
+	tmp       = msrpm[offset];
+
+	BUG_ON(offset == MSR_INVALID);
+
+	return !!test_bit(bit_write,  &tmp);
+}
+
 static void set_msr_interception(u32 *msrpm, unsigned msr,
 				 int read, int write)
 {
@@ -1587,6 +1609,8 @@ static void svm_vcpu_reset(struct kvm_vc
 	u32 dummy;
 	u32 eax = 1;
 
+	svm->spec_ctrl = 0;
+
 	if (!init_event) {
 		svm->vcpu.arch.apic_base = APIC_DEFAULT_PHYS_BASE |
 					   MSR_IA32_APICBASE_ENABLE;
@@ -3591,6 +3615,13 @@ static int svm_get_msr(struct kvm_vcpu *
 	case MSR_VM_CR:
 		msr_info->data = svm->nested.vm_cr_msr;
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+			return 1;
+
+		msr_info->data = svm->spec_ctrl;
+		break;
 	case MSR_IA32_UCODE_REV:
 		msr_info->data = 0x01000065;
 		break;
@@ -3682,6 +3713,33 @@ static int svm_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr);
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+			return 1;
+
+		/* The STIBP bit doesn't fault even if it's not advertised */
+		if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP))
+			return 1;
+
+		svm->spec_ctrl = data;
+
+		if (!data)
+			break;
+
+		/*
+		 * For non-nested:
+		 * When it's written (to non-zero) for the first time, pass
+		 * it through.
+		 *
+		 * For nested:
+		 * The handling of the MSR bitmap for L2 guests is done in
+		 * nested_svm_vmrun_msrpm.
+		 * We update the L1 MSR bit as well since it will end up
+		 * touching the MSR anyway now.
+		 */
+		set_msr_interception(svm->msrpm, MSR_IA32_SPEC_CTRL, 1, 1);
+		break;
 	case MSR_IA32_PRED_CMD:
 		if (!msr->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB))
@@ -4950,6 +5008,15 @@ static void svm_vcpu_run(struct kvm_vcpu
 
 	local_irq_enable();
 
+	/*
+	 * If this vCPU has touched SPEC_CTRL, restore the guest's value if
+	 * it's non-zero. Since vmentry is serialising on affected CPUs, there
+	 * is no need to worry about the conditional branch over the wrmsr
+	 * being speculatively taken.
+	 */
+	if (svm->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl);
+
 	asm volatile (
 		"push %%" _ASM_BP "; \n\t"
 		"mov %c[rbx](%[svm]), %%" _ASM_BX " \n\t"
@@ -5042,6 +5109,27 @@ static void svm_vcpu_run(struct kvm_vcpu
 #endif
 		);
 
+	/*
+	 * We do not use IBRS in the kernel. If this vCPU has used the
+	 * SPEC_CTRL MSR it may have left it on; save the value and
+	 * turn it off. This is much more efficient than blindly adding
+	 * it to the atomic save/restore list. Especially as the former
+	 * (Saving guest MSRs on vmexit) doesn't even exist in KVM.
+	 *
+	 * For non-nested case:
+	 * If the L01 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 *
+	 * For nested case:
+	 * If the L02 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 */
+	if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL))
+		rdmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl);
+
+	if (svm->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+
 	/* Eliminate branch target predictions from guest mode */
 	vmexit_fill_RSB();
 

[PATCH 4.14 62/64] KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed karahmed@amazon.de

commit b2ac58f90540e39324e7a29a7ad471407ae0bf48

[ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ]

... basically doing exactly what we do for VMX:

- Passthrough SPEC_CTRL to guests (if enabled in guest CPUID)
- Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest
  actually used it.

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: kvm@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/1517669783-20732-1-git-send-email-karahmed@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 arch/x86/kvm/svm.c |   88 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -184,6 +184,8 @@ struct vcpu_svm {
 		u64 gs_base;
 	} host;
 
+	u64 spec_ctrl;
+
 	u32 *msrpm;
 
 	ulong nmi_iret_rip;
@@ -249,6 +251,7 @@ static const struct svm_direct_access_ms
 	{ .index = MSR_CSTAR,				.always = true  },
 	{ .index = MSR_SYSCALL_MASK,			.always = true  },
 #endif
+	{ .index = MSR_IA32_SPEC_CTRL,			.always = false },
 	{ .index = MSR_IA32_PRED_CMD,			.always = false },
 	{ .index = MSR_IA32_LASTBRANCHFROMIP,		.always = false },
 	{ .index = MSR_IA32_LASTBRANCHTOIP,		.always = false },
@@ -882,6 +885,25 @@ static bool valid_msr_intercept(u32 inde
 	return false;
 }
 
+static bool msr_write_intercepted(struct kvm_vcpu *vcpu, unsigned msr)
+{
+	u8 bit_write;
+	unsigned long tmp;
+	u32 offset;
+	u32 *msrpm;
+
+	msrpm = is_guest_mode(vcpu) ? to_svm(vcpu)->nested.msrpm:
+				      to_svm(vcpu)->msrpm;
+
+	offset    = svm_msrpm_offset(msr);
+	bit_write = 2 * (msr & 0x0f) + 1;
+	tmp       = msrpm[offset];
+
+	BUG_ON(offset == MSR_INVALID);
+
+	return !!test_bit(bit_write,  &tmp);
+}
+
 static void set_msr_interception(u32 *msrpm, unsigned msr,
 				 int read, int write)
 {
@@ -1587,6 +1609,8 @@ static void svm_vcpu_reset(struct kvm_vc
 	u32 dummy;
 	u32 eax = 1;
 
+	svm->spec_ctrl = 0;
+
 	if (!init_event) {
 		svm->vcpu.arch.apic_base = APIC_DEFAULT_PHYS_BASE |
 					   MSR_IA32_APICBASE_ENABLE;
@@ -3591,6 +3615,13 @@ static int svm_get_msr(struct kvm_vcpu *
 	case MSR_VM_CR:
 		msr_info->data = svm->nested.vm_cr_msr;
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+			return 1;
+
+		msr_info->data = svm->spec_ctrl;
+		break;
 	case MSR_IA32_UCODE_REV:
 		msr_info->data = 0x01000065;
 		break;
@@ -3682,6 +3713,33 @@ static int svm_set_msr(struct kvm_vcpu *
 	case MSR_IA32_TSC:
 		kvm_write_tsc(vcpu, msr);
 		break;
+	case MSR_IA32_SPEC_CTRL:
+		if (!msr->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+			return 1;
+
+		/* The STIBP bit doesn't fault even if it's not advertised */
+		if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP))
+			return 1;
+
+		svm->spec_ctrl = data;
+
+		if (!data)
+			break;
+
+		/*
+		 * For non-nested:
+		 * When it's written (to non-zero) for the first time, pass
+		 * it through.
+		 *
+		 * For nested:
+		 * The handling of the MSR bitmap for L2 guests is done in
+		 * nested_svm_vmrun_msrpm.
+		 * We update the L1 MSR bit as well since it will end up
+		 * touching the MSR anyway now.
+		 */
+		set_msr_interception(svm->msrpm, MSR_IA32_SPEC_CTRL, 1, 1);
+		break;
 	case MSR_IA32_PRED_CMD:
 		if (!msr->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB))
@@ -4950,6 +5008,15 @@ static void svm_vcpu_run(struct kvm_vcpu
 
 	local_irq_enable();
 
+	/*
+	 * If this vCPU has touched SPEC_CTRL, restore the guest's value if
+	 * it's non-zero. Since vmentry is serialising on affected CPUs, there
+	 * is no need to worry about the conditional branch over the wrmsr
+	 * being speculatively taken.
+	 */
+	if (svm->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl);
+
 	asm volatile (
 		"push %%" _ASM_BP "; \n\t"
 		"mov %c[rbx](%[svm]), %%" _ASM_BX " \n\t"
@@ -5042,6 +5109,27 @@ static void svm_vcpu_run(struct kvm_vcpu
 #endif
 		);
 
+	/*
+	 * We do not use IBRS in the kernel. If this vCPU has used the
+	 * SPEC_CTRL MSR it may have left it on; save the value and
+	 * turn it off. This is much more efficient than blindly adding
+	 * it to the atomic save/restore list. Especially as the former
+	 * (Saving guest MSRs on vmexit) doesn't even exist in KVM.
+	 *
+	 * For non-nested case:
+	 * If the L01 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 *
+	 * For nested case:
+	 * If the L02 MSR bitmap does not intercept the MSR, then we need to
+	 * save it.
+	 */
+	if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL))
+		rdmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl);
+
+	if (svm->spec_ctrl)
+		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+
 	/* Eliminate branch target predictions from guest mode */
 	vmexit_fill_RSB();
 

[PATCH 4.14 63/64] serial: core: mark port as initialized after successful IRQ change

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

commit 44117a1d1732c513875d5a163f10d9adbe866c08 upstream.

setserial changes the IRQ via uart_set_info(). It invokes
uart_shutdown() which free the current used IRQ and clear
TTY_PORT_INITIALIZED. It will then update the IRQ number and invoke
uart_startup() before returning to the caller leaving
TTY_PORT_INITIALIZED cleared.

The next open will crash with
|  list_add double add: new=ffffffff839fcc98, prev=ffffffff839fcc98, next=ffffffff839fcc98.
since the close from the IOCTL won't free the IRQ (and clean the list)
due to the TTY_PORT_INITIALIZED check in uart_shutdown().

There is same pattern in uart_do_autoconfig() and I *think* it also
needs to set TTY_PORT_INITIALIZED there.
Is there a reason why uart_startup() does not set the flag by itself
after the IRQ has been acquired (since it is cleared in uart_shutdown)?

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/tty/serial/serial_core.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -987,6 +987,8 @@ static int uart_set_info(struct tty_stru
 		}
 	} else {
 		retval = uart_startup(tty, state, 1);
+		if (retval == 0)
+			tty_port_set_initialized(port, true);
 		if (retval > 0)
 			retval = 0;
 	}

[PATCH 4.14 64/64] fpga: region: release of_parse_phandle nodes after use

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ian Abbott <abbotti@mev.co.uk>

commit 0f5eb1545907edeea7672a9c1652c4231150ff22 upstream.

Both fpga_region_get_manager() and fpga_region_get_bridges() call
of_parse_phandle(), but nothing calls of_node_put() on the returned
struct device_node pointers.  Make sure to do that to stop their
reference counters getting out of whack.

Fixes: 0fa20cdfcc1f ("fpga: fpga-region: device tree control for FPGA")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 drivers/fpga/fpga-region.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -147,6 +147,7 @@ static struct fpga_manager *fpga_region_
 			mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
 			if (mgr_node) {
 				mgr = of_fpga_mgr_get(mgr_node);
+				of_node_put(mgr_node);
 				of_node_put(np);
 				return mgr;
 			}
@@ -192,10 +193,13 @@ static int fpga_region_get_bridges(struc
 		parent_br = region_np->parent;
 
 	/* If overlay has a list of bridges, use it. */
-	if (of_parse_phandle(overlay, "fpga-bridges", 0))
+	br = of_parse_phandle(overlay, "fpga-bridges", 0);
+	if (br) {
+		of_node_put(br);
 		np = overlay;
-	else
+	} else {
 		np = region_np;
+	}
 
 	for (i = 0; ; i++) {
 		br = of_parse_phandle(np, "fpga-bridges", i);
@@ -203,12 +207,15 @@ static int fpga_region_get_bridges(struc
 			break;
 
 		/* If parent bridge is in list, skip it. */
-		if (br == parent_br)
+		if (br == parent_br) {
+			of_node_put(br);
 			continue;
+		}
 
 		/* If node is a bridge, get it and add to list */
 		ret = fpga_bridge_get_to_list(br, region->info,
 					      &region->bridge_list);
+		of_node_put(br);
 
 		/* If any of the bridges are in use, give up */
 		if (ret == -EBUSY) {

Re: [PATCH 4.14 00/64] 4.14.18-stable review

[Shuah Khan]

On 02/05/2018 11:22 AM, Greg Kroah-Hartman wrote:
> This is the start of the stable review cycle for the 4.14.18 release.
> There are 64 patches in this series, all will be posted as a response
> to this one.  If anyone has any issues with these being applied, please
> let me know.
> 
> Responses should be made by Wed Feb  7 18:21:22 UTC 2018.
> Anything received after that time might be too late.
> 
> The whole patch series can be found in one patch at:
> 	kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.14.18-rc1.gz
> or in the git tree and branch at:
>   git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.14.y
> and the diffstat can be found below.
> 
> thanks,
> 
> greg k-h
> 

Compiled and booted on my test system. No dmesg regressions.

thanks,
-- Shuah

Re: [PATCH 4.14 00/64] 4.14.18-stable review

[Dan Rue]

On Mon, Feb 05, 2018 at 10:22:19AM -0800, Greg Kroah-Hartman wrote:
> This is the start of the stable review cycle for the 4.14.18 release.
> There are 64 patches in this series, all will be posted as a response
> to this one.  If anyone has any issues with these being applied, please
> let me know.
> 
> Responses should be made by Wed Feb  7 18:21:22 UTC 2018.
> Anything received after that time might be too late.
> 
> The whole patch series can be found in one patch at:
> 	kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.14.18-rc1.gz
> or in the git tree and branch at:
>   git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.14.y
> and the diffstat can be found below.

Results from Linaro’s test farm.
No regressions on arm64, arm and x86_64.

Summary
------------------------------------------------------------------------

kernel: 4.14.18-rc1
git repo:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
git branch: linux-4.14.y
git commit: 161cd48d7ece18d8e7256f58ea7b48a417e7eade
git describe: v4.14.17-65-g161cd48d7ece
Test details:
https://qa-reports.linaro.org/lkft/linux-stable-rc-4.14-oe/build/v4.14.17-65-g161cd48d7ece


No regressions (compared to build v4.14.17)

Boards, architectures and test suites:
-------------------------------------

hi6220-hikey - arm64
* boot - pass: 20,
* kselftest - pass: 46, skip: 16,
* libhugetlbfs - pass: 90, skip: 1,
* ltp-cap_bounds-tests - pass: 2,
* ltp-containers-tests - pass: 64,
* ltp-fcntl-locktests-tests - pass: 2,
* ltp-filecaps-tests - pass: 2,
* ltp-fs-tests - pass: 60,
* ltp-fs_bind-tests - pass: 2,
* ltp-fs_perms_simple-tests - pass: 19,
* ltp-fsx-tests - pass: 2,
* ltp-hugetlb-tests - pass: 21, skip: 1,
* ltp-io-tests - pass: 3,
* ltp-ipc-tests - pass: 9,
* ltp-math-tests - pass: 11,
* ltp-nptl-tests - pass: 2,
* ltp-pty-tests - pass: 4,
* ltp-sched-tests - pass: 10,
* ltp-securebits-tests - pass: 4,
* ltp-syscalls-tests - pass: 984, skip: 121,
* ltp-timers-tests - pass: 12,

juno-r2 - arm64
* boot - pass: 20,
* kselftest - pass: 46, skip: 16,
* libhugetlbfs - pass: 90, skip: 1,
* ltp-cap_bounds-tests - pass: 2,
* ltp-containers-tests - pass: 64,
* ltp-fcntl-locktests-tests - pass: 2,
* ltp-filecaps-tests - pass: 2,
* ltp-fs-tests - pass: 60,
* ltp-fs_bind-tests - pass: 2,
* ltp-fs_perms_simple-tests - pass: 19,
* ltp-fsx-tests - pass: 2,
* ltp-io-tests - pass: 3,
* ltp-ipc-tests - pass: 9,
* ltp-math-tests - pass: 11,
* ltp-nptl-tests - pass: 2,
* ltp-pty-tests - pass: 4,
* ltp-sched-tests - pass: 10,
* ltp-securebits-tests - pass: 4,
* ltp-syscalls-tests - pass: 987, skip: 121,
* ltp-timers-tests - pass: 12,

x15 - arm
* boot - pass: 20,
* kselftest - pass: 43, skip: 18,
* libhugetlbfs - pass: 87, skip: 1,
* ltp-cap_bounds-tests - pass: 2,
* ltp-containers-tests - pass: 64,
* ltp-fcntl-locktests-tests - pass: 2,
* ltp-filecaps-tests - pass: 2,
* ltp-fs-tests - pass: 60,
* ltp-fs_bind-tests - pass: 2,
* ltp-fs_perms_simple-tests - pass: 19,
* ltp-fsx-tests - pass: 2,
* ltp-hugetlb-tests - pass: 20, skip: 2,
* ltp-io-tests - pass: 3,
* ltp-ipc-tests - pass: 9,
* ltp-math-tests - pass: 11,
* ltp-nptl-tests - pass: 2,
* ltp-pty-tests - pass: 4,
* ltp-sched-tests - pass: 13, skip: 1,
* ltp-securebits-tests - pass: 4,
* ltp-syscalls-tests - pass: 1038, skip: 66,
* ltp-timers-tests - pass: 12,

x86_64
* boot - pass: 20,
* kselftest - pass: 56, skip: 18, fail: 1
* libhugetlbfs - pass: 90, skip: 1,
* ltp-cap_bounds-tests - pass: 2,
* ltp-containers-tests - pass: 64,
* ltp-fcntl-locktests-tests - pass: 2,
* ltp-filecaps-tests - pass: 2,
* ltp-fs-tests - pass: 61, skip: 1,
* ltp-fs_bind-tests - pass: 2,
* ltp-fs_perms_simple-tests - pass: 19,
* ltp-fsx-tests - pass: 2,
* ltp-hugetlb-tests - pass: 22,
* ltp-io-tests - pass: 3,
* ltp-ipc-tests - pass: 9,
* ltp-math-tests - pass: 11,
* ltp-nptl-tests - pass: 2,
* ltp-pty-tests - pass: 4,
* ltp-sched-tests - pass: 9, skip: 1,
* ltp-securebits-tests - pass: 4,
* ltp-syscalls-tests - pass: 1016, skip: 116,
* ltp-timers-tests - pass: 12,


--
Linaro QA (beta)
https://qa-reports.linaro.org

Re: [PATCH 4.14 00/64] 4.14.18-stable review

[kernelci.org bot]

stable-rc/linux-4.14.y boot: 110 boots: 1 failed, 47 passed with 62 offline (v4.14.17-65-g161cd48d7ece)

Full Boot Summary: https://kernelci.org/boot/all/job/stable-rc/branch/linux-4.14.y/kernel/v4.14.17-65-g161cd48d7ece/
Full Build Summary: https://kernelci.org/build/stable-rc/branch/linux-4.14.y/kernel/v4.14.17-65-g161cd48d7ece/

Tree: stable-rc
Branch: linux-4.14.y
Git Describe: v4.14.17-65-g161cd48d7ece
Git Commit: 161cd48d7ece18d8e7256f58ea7b48a417e7eade
Git URL: http://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
Tested: 62 unique boards, 22 SoC families, 16 builds out of 185

Boot Regressions Detected:

arm:

    exynos_defconfig:
        exynos5250-snow:
            lab-collabora: new failure (last pass: v4.14.17)

Boot Failure Detected:

arm:

    exynos_defconfig
        exynos5250-snow: 1 failed lab

Offline Platforms:

arm:

    sunxi_defconfig:
        sun4i-a10-cubieboard: 1 offline lab
        sun5i-r8-chip: 1 offline lab
        sun7i-a20-bananapi: 1 offline lab
        sun7i-a20-cubietruck: 1 offline lab

    bcm2835_defconfig:
        bcm2835-rpi-b: 1 offline lab

    tegra_defconfig:
        tegra124-jetson-tk1: 1 offline lab
        tegra20-iris-512: 1 offline lab
        tegra30-beaver: 1 offline lab

    mvebu_v7_defconfig:
        armada-xp-openblocks-ax3-4: 1 offline lab

    multi_v7_defconfig:
        alpine-db: 1 offline lab
        armada-xp-openblocks-ax3-4: 1 offline lab
        at91-sama5d4_xplained: 1 offline lab
        exynos5250-arndale: 1 offline lab
        exynos5410-odroidxu: 1 offline lab
        exynos5420-arndale-octa: 1 offline lab
        exynos5422-odroidxu3: 1 offline lab
        imx6dl-wandboard_dual: 1 offline lab
        imx6dl-wandboard_solo: 1 offline lab
        meson8b-odroidc1: 1 offline lab
        omap3-beagle: 1 offline lab
        omap3-beagle-xm: 1 offline lab
        omap4-panda: 1 offline lab
        qcom-apq8064-cm-qs600: 1 offline lab
        qcom-apq8064-ifc6410: 1 offline lab
        socfpga_cyclone5_de0_sockit: 1 offline lab
        stih410-b2120: 1 offline lab
        stih410-b2120_rootfs:nfs: 1 offline lab
        sun4i-a10-cubieboard: 1 offline lab
        sun5i-r8-chip: 1 offline lab
        sun7i-a20-bananapi: 1 offline lab
        sun7i-a20-cubietruck: 1 offline lab
        tegra124-jetson-tk1: 1 offline lab
        tegra20-iris-512: 1 offline lab
        tegra30-beaver: 1 offline lab
        vf610-colibri-eval-v3: 1 offline lab
        zynq-zc702: 1 offline lab

    omap2plus_defconfig:
        omap3-beagle: 1 offline lab
        omap3-beagle-xm: 1 offline lab
        omap4-panda: 1 offline lab

    imx_v6_v7_defconfig:
        imx6dl-wandboard_dual: 1 offline lab
        imx6dl-wandboard_solo: 1 offline lab
        vf610-colibri-eval-v3: 1 offline lab

    davinci_all_defconfig:
        da850-lcdk: 1 offline lab
        dm365evm,legacy: 1 offline lab

    exynos_defconfig:
        exynos5250-arndale: 1 offline lab
        exynos5410-odroidxu: 1 offline lab
        exynos5420-arndale-octa: 1 offline lab
        exynos5422-odroidxu3: 1 offline lab

    qcom_defconfig:
        qcom-apq8064-cm-qs600: 1 offline lab
        qcom-apq8064-ifc6410: 1 offline lab

    sama5_defconfig:
        at91-sama5d4_xplained: 1 offline lab

arm64:

    defconfig:
        apq8016-sbc: 1 offline lab
        bcm2837-rpi-3-b: 1 offline lab
        juno-r2: 1 offline lab
        meson-gxbb-odroidc2: 1 offline lab
        meson-gxbb-p200: 1 offline lab
        meson-gxl-s905d-p230: 1 offline lab
        meson-gxl-s905x-khadas-vim: 1 offline lab
        meson-gxl-s905x-nexbox-a95x: 1 offline lab
        meson-gxl-s905x-p212: 1 offline lab
        rk3399-firefly: 1 offline lab
        sun50i-a64-pine64-plus: 1 offline lab

---
For more info write to <info@kernelci.org>

Re: [PATCH 4.14 00/64] 4.14.18-stable review

[Guenter Roeck]

On 02/05/2018 10:22 AM, Greg Kroah-Hartman wrote:
> This is the start of the stable review cycle for the 4.14.18 release.
> There are 64 patches in this series, all will be posted as a response
> to this one.  If anyone has any issues with these being applied, please
> let me know.
> 
> Responses should be made by Wed Feb  7 18:21:22 UTC 2018.
> Anything received after that time might be too late.
> 

Build results:
	total: 145 pass: 145 fail: 0
Qemu test results:
	total: 126 pass: 126 fail: 0

Details are available at http://kerneltests.org/builders.

Guenter