From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirsky <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Dave Hansen <dave.hansen@intel.com>,
Borislav Petkov <bpetkov@suse.de>,
Greg KH <gregkh@linuxfoundation.org>,
keescook@google.com, hughd@google.com,
Brian Gerst <brgerst@gmail.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Rik van Riel <riel@redhat.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
David Laight <David.Laight@aculab.com>,
Eduardo Valentin <eduval@amazon.com>,
aliguori@amazon.com, Will Deacon <will.deacon@arm.com>,
daniel.gruss@iaik.tugraz.at, Ingo Molnar <mingo@kernel.org>,
Borislav Petkov <bp@suse.de>,
Dave Hansen <dave.hansen@linux.intel.com>
Subject: [patch 06/60] x86/entry/64: Allocate and enable the SYSENTER stack
Date: Mon, 04 Dec 2017 15:07:12 +0100 [thread overview]
Message-ID: <20171204150605.312726423@linutronix.de> (raw)
In-Reply-To: 20171204140706.296109558@linutronix.de
[-- Attachment #1: x86-entry-64--Allocate_and_enable_the_SYSENTER_stack.patch --]
[-- Type: text/plain, Size: 4793 bytes --]
From: Andy Lutomirski <luto@kernel.org>
This will simplify future changes that want scratch variables early in
the SYSENTER handler -- they'll be able to spill registers to the
stack. It also lets us get rid of a SWAPGS_UNSAFE_STACK user.
This does not depend on CONFIG_IA32_EMULATION=y because we'll want the
stack space even without IA32 emulation.
As far as I can tell, the reason that this wasn't done from day 1 is
that we use IST for #DB and #BP, which is IMO rather nasty and causes
a lot more problems than it solves. But, since #DB uses IST, we don't
actually need a real stack for SYSENTER (because SYSENTER with TF set
will invoke #DB on the IST stack rather than the SYSENTER stack).
I want to remove IST usage from these vectors some day, and this patch
is a prerequisite for that as well.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/c37d6e68a73e1b5b1203e0e95b488fa8092b3cfb.1511497875.git.luto@kernel.org
---
arch/x86/entry/entry_64_compat.S | 2 +-
arch/x86/include/asm/processor.h | 3 ---
arch/x86/kernel/asm-offsets.c | 5 +++++
arch/x86/kernel/asm-offsets_32.c | 5 -----
arch/x86/kernel/cpu/common.c | 4 +++-
arch/x86/kernel/process.c | 2 --
arch/x86/kernel/traps.c | 3 +--
7 files changed, 10 insertions(+), 14 deletions(-)
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -48,7 +48,7 @@
*/
ENTRY(entry_SYSENTER_compat)
/* Interrupts are off on entry. */
- SWAPGS_UNSAFE_STACK
+ SWAPGS
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
/*
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -340,14 +340,11 @@ struct tss_struct {
*/
unsigned long io_bitmap[IO_BITMAP_LONGS + 1];
-#ifdef CONFIG_X86_32
/*
* Space for the temporary SYSENTER stack.
*/
unsigned long SYSENTER_stack_canary;
unsigned long SYSENTER_stack[64];
-#endif
-
} ____cacheline_aligned;
DECLARE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss);
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -93,4 +93,9 @@ void common(void) {
BLANK();
DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
+
+ /* Offset from cpu_tss to SYSENTER_stack */
+ OFFSET(CPU_TSS_SYSENTER_stack, tss_struct, SYSENTER_stack);
+ /* Size of SYSENTER_stack */
+ DEFINE(SIZEOF_SYSENTER_stack, sizeof(((struct tss_struct *)0)->SYSENTER_stack));
}
--- a/arch/x86/kernel/asm-offsets_32.c
+++ b/arch/x86/kernel/asm-offsets_32.c
@@ -50,11 +50,6 @@ void foo(void)
DEFINE(TSS_sysenter_sp0, offsetof(struct tss_struct, x86_tss.sp0) -
offsetofend(struct tss_struct, SYSENTER_stack));
- /* Offset from cpu_tss to SYSENTER_stack */
- OFFSET(CPU_TSS_SYSENTER_stack, tss_struct, SYSENTER_stack);
- /* Size of SYSENTER_stack */
- DEFINE(SIZEOF_SYSENTER_stack, sizeof(((struct tss_struct *)0)->SYSENTER_stack));
-
#ifdef CONFIG_CC_STACKPROTECTOR
BLANK();
OFFSET(stack_canary_offset, stack_canary, canary);
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1386,7 +1386,9 @@ void syscall_init(void)
* AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
*/
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
- wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
+ wrmsrl_safe(MSR_IA32_SYSENTER_ESP,
+ (unsigned long)this_cpu_ptr(&cpu_tss) +
+ offsetofend(struct tss_struct, SYSENTER_stack));
wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
#else
wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -71,9 +71,7 @@
*/
.io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 },
#endif
-#ifdef CONFIG_X86_32
.SYSENTER_stack_canary = STACK_END_MAGIC,
-#endif
};
EXPORT_PER_CPU_SYMBOL(cpu_tss);
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -800,14 +800,13 @@ dotraplinkage void do_debug(struct pt_re
debug_stack_usage_dec();
exit:
-#if defined(CONFIG_X86_32)
/*
* This is the most likely code path that involves non-trivial use
* of the SYSENTER stack. Check that we haven't overrun it.
*/
WARN(this_cpu_read(cpu_tss.SYSENTER_stack_canary) != STACK_END_MAGIC,
"Overran or corrupted SYSENTER stack\n");
-#endif
+
ist_exit(regs);
}
NOKPROBE_SYMBOL(do_debug);
next prev parent reply other threads:[~2017-12-04 17:07 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-04 14:07 [patch 00/60] x86/kpti: Kernel Page Table Isolation (was KAISER) Thomas Gleixner
2017-12-04 14:07 ` [patch 01/60] x86/entry/64/paravirt: Use paravirt-safe macro to access eflags Thomas Gleixner
2017-12-05 12:17 ` Juergen Gross
2017-12-04 14:07 ` [patch 02/60] x86/unwinder/orc: Dont bail on stack overflow Thomas Gleixner
2017-12-04 20:31 ` Andy Lutomirski
2017-12-04 21:31 ` Thomas Gleixner
2017-12-04 14:07 ` [patch 03/60] x86/unwinder: Handle stack overflows more gracefully Thomas Gleixner
2017-12-04 14:07 ` [patch 04/60] x86/irq: Remove an old outdated comment about context tracking races Thomas Gleixner
2017-12-04 14:07 ` [patch 05/60] x86/irq/64: Print the offending IP in the stack overflow warning Thomas Gleixner
2017-12-04 14:07 ` Thomas Gleixner [this message]
2017-12-04 14:07 ` [patch 07/60] x86/dumpstack: Add get_stack_info() support for the SYSENTER stack Thomas Gleixner
2017-12-04 14:07 ` [patch 08/60] x86/entry/gdt: Put per-CPU GDT remaps in ascending order Thomas Gleixner
2017-12-04 14:07 ` [patch 09/60] x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area Thomas Gleixner
2017-12-04 14:07 ` [patch 10/60] x86/kasan/64: Teach KASAN about the cpu_entry_area Thomas Gleixner
2017-12-04 14:07 ` [patch 11/60] x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss Thomas Gleixner
2017-12-04 14:07 ` [patch 12/60] x86/dumpstack: Handle stack overflow on all stacks Thomas Gleixner
2017-12-04 14:07 ` [patch 13/60] x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct Thomas Gleixner
2017-12-04 14:07 ` [patch 14/60] x86/entry: Remap the TSS into the CPU entry area Thomas Gleixner
2017-12-04 18:20 ` Borislav Petkov
2017-12-04 14:07 ` [patch 15/60] x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 Thomas Gleixner
2017-12-04 14:07 ` [patch 16/60] x86/espfix/64: Stop assuming that pt_regs is on the entry stack Thomas Gleixner
2017-12-04 14:07 ` [patch 17/60] x86/entry/64: Use a per-CPU trampoline stack for IDT entries Thomas Gleixner
2017-12-04 14:07 ` [patch 18/60] x86/entry/64: Return to userspace from the trampoline stack Thomas Gleixner
2017-12-04 14:07 ` [patch 19/60] x86/entry/64: Create a per-CPU SYSCALL entry trampoline Thomas Gleixner
2017-12-04 22:30 ` Andy Lutomirski
2017-12-04 14:07 ` [patch 20/60] x86/entry/64: Move the IST stacks into struct cpu_entry_area Thomas Gleixner
2017-12-04 14:07 ` [patch 21/60] x86/entry/64: Remove the SYSENTER stack canary Thomas Gleixner
2017-12-04 14:07 ` [patch 22/60] x86/entry: Clean up the SYSENTER_stack code Thomas Gleixner
2017-12-04 19:41 ` Borislav Petkov
2017-12-04 14:07 ` [patch 23/60] x86/entry/64: Make cpu_entry_area.tss read-only Thomas Gleixner
2017-12-04 20:25 ` Borislav Petkov
2017-12-04 14:07 ` [patch 24/60] x86/paravirt: Dont patch flush_tlb_single Thomas Gleixner
2017-12-05 12:18 ` Juergen Gross
2017-12-04 14:07 ` [patch 25/60] x86/paravirt: Provide a way to check for hypervisors Thomas Gleixner
2017-12-05 12:19 ` Juergen Gross
2017-12-04 14:07 ` [patch 26/60] x86/cpufeature: Make cpu bugs sticky Thomas Gleixner
2017-12-04 22:39 ` Borislav Petkov
2017-12-04 14:07 ` [patch 27/60] x86/cpufeatures: Add X86_BUG_CPU_INSECURE Thomas Gleixner
2017-12-04 23:18 ` Borislav Petkov
2017-12-04 14:07 ` [patch 28/60] x86/mm/kpti: Disable global pages if KERNEL_PAGE_TABLE_ISOLATION=y Thomas Gleixner
2017-12-05 14:34 ` Borislav Petkov
2017-12-04 14:07 ` [patch 29/60] x86/mm/kpti: Prepare the x86/entry assembly code for entry/exit CR3 switching Thomas Gleixner
2017-12-04 14:07 ` [patch 30/60] x86/mm/kpti: Add infrastructure for page table isolation Thomas Gleixner
2017-12-05 15:20 ` Borislav Petkov
2017-12-04 14:07 ` [patch 31/60] x86/mm/kpti: Add mapping helper functions Thomas Gleixner
2017-12-04 22:27 ` Andy Lutomirski
2017-12-05 16:01 ` Borislav Petkov
2017-12-07 8:33 ` Borislav Petkov
2017-12-04 14:07 ` [patch 32/60] x86/mm/kpti: Allow NX poison to be set in p4d/pgd Thomas Gleixner
2017-12-05 17:09 ` Borislav Petkov
2017-12-04 14:07 ` [patch 33/60] x86/mm/kpti: Allocate a separate user PGD Thomas Gleixner
2017-12-05 18:33 ` Borislav Petkov
2017-12-06 20:56 ` Ingo Molnar
2017-12-04 14:07 ` [patch 34/60] x86/mm/kpti: Populate " Thomas Gleixner
2017-12-05 19:17 ` Borislav Petkov
2017-12-04 14:07 ` [patch 35/60] x86/espfix: Ensure that ESPFIX is visible in " Thomas Gleixner
2017-12-04 22:28 ` Andy Lutomirski
2017-12-04 14:07 ` [patch 36/60] x86/mm/kpti: Add functions to clone kernel PMDs Thomas Gleixner
2017-12-06 15:39 ` Borislav Petkov
2017-12-04 14:07 ` [patch 37/60] x86mm//kpti: Force entry through trampoline when KPTI active Thomas Gleixner
2017-12-06 16:01 ` Borislav Petkov
2017-12-04 14:07 ` [patch 38/60] x86/fixmap: Move cpu entry area into a separate PMD Thomas Gleixner
2017-12-06 18:57 ` Borislav Petkov
2017-12-04 14:07 ` [patch 39/60] x86/mm/kpti: Share cpu_entry_area PMDs Thomas Gleixner
2017-12-06 21:18 ` Borislav Petkov
2017-12-04 14:07 ` [patch 40/60] x86: PMD align entry text Thomas Gleixner
2017-12-07 8:07 ` Borislav Petkov
2017-12-04 14:07 ` [patch 41/60] x86/mm/kpti: Share entry text PMD Thomas Gleixner
2017-12-07 8:24 ` Borislav Petkov
2017-12-04 14:07 ` [patch 42/60] x86/fixmap: Move IDT fixmap into the cpu_entry_area range Thomas Gleixner
2017-12-04 14:07 ` [patch 43/60] x86/fixmap: Add debugstore entries to cpu_entry_area Thomas Gleixner
2017-12-07 9:55 ` Borislav Petkov
2017-12-04 14:07 ` [patch 44/60] x86/events/intel/ds: Map debug buffers in fixmap Thomas Gleixner
2017-12-04 14:07 ` [patch 45/60] x86/fixmap: Add ldt entries to user shared fixmap Thomas Gleixner
2017-12-04 14:07 ` [patch 46/60] x86/ldt: Rename ldt_struct->entries member Thomas Gleixner
2017-12-04 14:07 ` [patch 47/60] x86/ldt: Map LDT entries into fixmap Thomas Gleixner
2017-12-04 22:33 ` Andy Lutomirski
2017-12-04 22:51 ` Thomas Gleixner
2017-12-04 14:07 ` [patch 48/60] x86/mm: Move the CR3 construction functions to tlbflush.h Thomas Gleixner
2017-12-04 14:07 ` [patch 49/60] x86/mm: Remove hard-coded ASID limit checks Thomas Gleixner
2017-12-04 14:07 ` [patch 50/60] x86/mm: Put MMU to hardware ASID translation in one place Thomas Gleixner
2017-12-04 14:07 ` [patch 51/60] x86/mm: Allow flushing for future ASID switches Thomas Gleixner
2017-12-04 22:22 ` Andy Lutomirski
2017-12-04 22:34 ` Dave Hansen
2017-12-04 22:36 ` Andy Lutomirski
2017-12-04 22:47 ` Peter Zijlstra
2017-12-04 22:54 ` Andy Lutomirski
2017-12-04 23:06 ` Peter Zijlstra
2017-12-04 14:07 ` [patch 52/60] x86/mm: Abstract switching CR3 Thomas Gleixner
2017-12-04 14:07 ` [patch 53/60] x86/mm: Use/Fix PCID to optimize user/kernel switches Thomas Gleixner
2017-12-05 21:46 ` Andy Lutomirski
2017-12-05 22:05 ` Peter Zijlstra
2017-12-05 22:08 ` Dave Hansen
2017-12-04 14:08 ` [patch 54/60] x86/mm: Optimize RESTORE_CR3 Thomas Gleixner
2017-12-04 14:08 ` [patch 55/60] x86/mm: Use INVPCID for __native_flush_tlb_single() Thomas Gleixner
2017-12-04 22:25 ` Andy Lutomirski
2017-12-04 22:51 ` Peter Zijlstra
2017-12-05 13:51 ` Dave Hansen
2017-12-05 14:08 ` Peter Zijlstra
2017-12-04 14:08 ` [patch 56/60] x86/mm/kpti: Disable native VSYSCALL Thomas Gleixner
2017-12-04 22:33 ` Andy Lutomirski
2017-12-04 14:08 ` [patch 57/60] x86/mm/kpti: Add Kconfig Thomas Gleixner
2017-12-04 16:54 ` Andy Lutomirski
2017-12-04 16:57 ` Thomas Gleixner
2017-12-05 9:34 ` Thomas Gleixner
2017-12-04 14:08 ` [patch 58/60] x86/mm/debug_pagetables: Add page table directory Thomas Gleixner
2017-12-04 14:08 ` [patch 59/60] x86/mm/dump_pagetables: Check user space page table for WX pages Thomas Gleixner
2017-12-04 14:08 ` [patch 60/60] x86/mm/debug_pagetables: Allow dumping current pagetables Thomas Gleixner
2017-12-04 18:02 ` [patch 00/60] x86/kpti: Kernel Page Table Isolation (was KAISER) Linus Torvalds
2017-12-04 18:18 ` Thomas Gleixner
2017-12-04 18:21 ` Boris Ostrovsky
2017-12-04 18:28 ` Linus Torvalds
2017-12-05 21:49 ` Andy Lutomirski
2017-12-05 21:57 ` Dave Hansen
2017-12-05 23:19 ` Andy Lutomirski
2018-01-19 20:56 ` Andrew Morton
2018-01-19 21:06 ` Dave Hansen
2018-01-20 19:59 ` Thomas Gleixner
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