* [PATCH -tip v4 1/4] x86/asm: Allow to pass macros to __ASM_FORM()
2019-09-06 13:13 [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
@ 2019-09-06 13:13 ` Masami Hiramatsu
2019-10-18 12:48 ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2019-09-06 13:13 ` [PATCH -tip v4 2/4] x86: xen: kvm: Gather the definition of emulate prefixes Masami Hiramatsu
` (3 subsequent siblings)
4 siblings, 1 reply; 13+ messages in thread
From: Masami Hiramatsu @ 2019-09-06 13:13 UTC (permalink / raw)
To: Ingo Molnar
Cc: Josh Poimboeuf, Andrew Cooper, Peter Zijlstra, Randy Dunlap,
Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
Use __stringify() at __ASM_FORM() so that user can pass
code including macros to __ASM_FORM().
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
arch/x86/include/asm/asm.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 3ff577c0b102..1b563f9167ea 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -7,9 +7,11 @@
# define __ASM_FORM_RAW(x) x
# define __ASM_FORM_COMMA(x) x,
#else
-# define __ASM_FORM(x) " " #x " "
-# define __ASM_FORM_RAW(x) #x
-# define __ASM_FORM_COMMA(x) " " #x ","
+#include <linux/stringify.h>
+
+# define __ASM_FORM(x) " " __stringify(x) " "
+# define __ASM_FORM_RAW(x) __stringify(x)
+# define __ASM_FORM_COMMA(x) " " __stringify(x) ","
#endif
#ifndef __x86_64__
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip: x86/core] x86/asm: Allow to pass macros to __ASM_FORM()
2019-09-06 13:13 ` [PATCH -tip v4 1/4] x86/asm: Allow to pass macros to __ASM_FORM() Masami Hiramatsu
@ 2019-10-18 12:48 ` tip-bot2 for Masami Hiramatsu
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot2 for Masami Hiramatsu @ 2019-10-18 12:48 UTC (permalink / raw)
To: linux-tip-commits
Cc: Masami Hiramatsu, Peter Zijlstra (Intel),
Juergen Gross, x86, Boris Ostrovsky, Ingo Molnar,
Stefano Stabellini, Andrew Cooper, Borislav Petkov, xen-devel,
Randy Dunlap, Josh Poimboeuf, linux-kernel
The following commit has been merged into the x86/core branch of tip:
Commit-ID: f7919fd943abf0c77aed4441ea9897a323d132f5
Gitweb: https://git.kernel.org/tip/f7919fd943abf0c77aed4441ea9897a323d132f5
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Fri, 06 Sep 2019 22:13:48 +09:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 17 Oct 2019 21:31:57 +02:00
x86/asm: Allow to pass macros to __ASM_FORM()
Use __stringify() at __ASM_FORM() so that user can pass
code including macros to __ASM_FORM().
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/156777562873.25081.2288083344657460959.stgit@devnote2
---
arch/x86/include/asm/asm.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 3ff577c..1b563f9 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -7,9 +7,11 @@
# define __ASM_FORM_RAW(x) x
# define __ASM_FORM_COMMA(x) x,
#else
-# define __ASM_FORM(x) " " #x " "
-# define __ASM_FORM_RAW(x) #x
-# define __ASM_FORM_COMMA(x) " " #x ","
+#include <linux/stringify.h>
+
+# define __ASM_FORM(x) " " __stringify(x) " "
+# define __ASM_FORM_RAW(x) __stringify(x)
+# define __ASM_FORM_COMMA(x) " " __stringify(x) ","
#endif
#ifndef __x86_64__
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH -tip v4 2/4] x86: xen: kvm: Gather the definition of emulate prefixes
2019-09-06 13:13 [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
2019-09-06 13:13 ` [PATCH -tip v4 1/4] x86/asm: Allow to pass macros to __ASM_FORM() Masami Hiramatsu
@ 2019-09-06 13:13 ` Masami Hiramatsu
2019-10-18 12:48 ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2019-09-06 13:14 ` [PATCH -tip v4 3/4] x86: xen: insn: Decode Xen and KVM emulate-prefix signature Masami Hiramatsu
` (2 subsequent siblings)
4 siblings, 1 reply; 13+ messages in thread
From: Masami Hiramatsu @ 2019-09-06 13:13 UTC (permalink / raw)
To: Ingo Molnar
Cc: Josh Poimboeuf, Andrew Cooper, Peter Zijlstra, Randy Dunlap,
Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
Gather the emulate prefixes, which forcibly make the following
instruction emulated on virtualization, in one place.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
arch/x86/include/asm/emulate_prefix.h | 14 ++++++++++++++
arch/x86/include/asm/xen/interface.h | 11 ++++-------
arch/x86/kvm/x86.c | 4 +++-
3 files changed, 21 insertions(+), 8 deletions(-)
create mode 100644 arch/x86/include/asm/emulate_prefix.h
diff --git a/arch/x86/include/asm/emulate_prefix.h b/arch/x86/include/asm/emulate_prefix.h
new file mode 100644
index 000000000000..70f5b98a5286
--- /dev/null
+++ b/arch/x86/include/asm/emulate_prefix.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_EMULATE_PREFIX_H
+#define _ASM_X86_EMULATE_PREFIX_H
+
+/*
+ * Virt escape sequences to trigger instruction emulation;
+ * ideally these would decode to 'whole' instruction and not destroy
+ * the instruction stream; sadly this is not true for the 'kvm' one :/
+ */
+
+#define __XEN_EMULATE_PREFIX 0x0f,0x0b,0x78,0x65,0x6e /* ud2 ; .ascii "xen" */
+#define __KVM_EMULATE_PREFIX 0x0f,0x0b,0x6b,0x76,0x6d /* ud2 ; .ascii "kvm" */
+
+#endif
diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h
index 62ca03ef5c65..9139b3e86316 100644
--- a/arch/x86/include/asm/xen/interface.h
+++ b/arch/x86/include/asm/xen/interface.h
@@ -379,12 +379,9 @@ struct xen_pmu_arch {
* Prefix forces emulation of some non-trapping instructions.
* Currently only CPUID.
*/
-#ifdef __ASSEMBLY__
-#define XEN_EMULATE_PREFIX .byte 0x0f,0x0b,0x78,0x65,0x6e ;
-#define XEN_CPUID XEN_EMULATE_PREFIX cpuid
-#else
-#define XEN_EMULATE_PREFIX ".byte 0x0f,0x0b,0x78,0x65,0x6e ; "
-#define XEN_CPUID XEN_EMULATE_PREFIX "cpuid"
-#endif
+#include <asm/emulate_prefix.h>
+
+#define XEN_EMULATE_PREFIX __ASM_FORM(.byte __XEN_EMULATE_PREFIX ;)
+#define XEN_CPUID XEN_EMULATE_PREFIX __ASM_FORM(cpuid)
#endif /* _ASM_X86_XEN_INTERFACE_H */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 290c3c3efb87..5f8b0a60f48b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -68,6 +68,7 @@
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
#include <asm/intel_pt.h>
+#include <asm/emulate_prefix.h>
#include <clocksource/hyperv_timer.h>
#define CREATE_TRACE_POINTS
@@ -5319,6 +5320,7 @@ EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
int handle_ud(struct kvm_vcpu *vcpu)
{
+ static const char kvm_emulate_prefix[] = { __KVM_EMULATE_PREFIX };
int emul_type = EMULTYPE_TRAP_UD;
enum emulation_result er;
char sig[5]; /* ud2; .ascii "kvm" */
@@ -5327,7 +5329,7 @@ int handle_ud(struct kvm_vcpu *vcpu)
if (force_emulation_prefix &&
kvm_read_guest_virt(vcpu, kvm_get_linear_rip(vcpu),
sig, sizeof(sig), &e) == 0 &&
- memcmp(sig, "\xf\xbkvm", sizeof(sig)) == 0) {
+ memcmp(sig, kvm_emulate_prefix, sizeof(sig)) == 0) {
kvm_rip_write(vcpu, kvm_rip_read(vcpu) + sizeof(sig));
emul_type = 0;
}
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip: x86/core] x86: xen: kvm: Gather the definition of emulate prefixes
2019-09-06 13:13 ` [PATCH -tip v4 2/4] x86: xen: kvm: Gather the definition of emulate prefixes Masami Hiramatsu
@ 2019-10-18 12:48 ` tip-bot2 for Masami Hiramatsu
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot2 for Masami Hiramatsu @ 2019-10-18 12:48 UTC (permalink / raw)
To: linux-tip-commits
Cc: Peter Zijlstra, Masami Hiramatsu, Juergen Gross, x86,
Ingo Molnar, Boris Ostrovsky, Andrew Cooper, Stefano Stabellini,
Borislav Petkov, xen-devel, Randy Dunlap, Josh Poimboeuf,
linux-kernel
The following commit has been merged into the x86/core branch of tip:
Commit-ID: b3dc0695fa40c3b280230fb6fb7fb7a94ce28bf4
Gitweb: https://git.kernel.org/tip/b3dc0695fa40c3b280230fb6fb7fb7a94ce28bf4
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Fri, 06 Sep 2019 22:13:59 +09:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 17 Oct 2019 21:31:57 +02:00
x86: xen: kvm: Gather the definition of emulate prefixes
Gather the emulate prefixes, which forcibly make the following
instruction emulated on virtualization, in one place.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/156777563917.25081.7286628561790289995.stgit@devnote2
---
arch/x86/include/asm/emulate_prefix.h | 14 ++++++++++++++
arch/x86/include/asm/xen/interface.h | 11 ++++-------
arch/x86/kvm/x86.c | 4 +++-
3 files changed, 21 insertions(+), 8 deletions(-)
create mode 100644 arch/x86/include/asm/emulate_prefix.h
diff --git a/arch/x86/include/asm/emulate_prefix.h b/arch/x86/include/asm/emulate_prefix.h
new file mode 100644
index 0000000..70f5b98
--- /dev/null
+++ b/arch/x86/include/asm/emulate_prefix.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_EMULATE_PREFIX_H
+#define _ASM_X86_EMULATE_PREFIX_H
+
+/*
+ * Virt escape sequences to trigger instruction emulation;
+ * ideally these would decode to 'whole' instruction and not destroy
+ * the instruction stream; sadly this is not true for the 'kvm' one :/
+ */
+
+#define __XEN_EMULATE_PREFIX 0x0f,0x0b,0x78,0x65,0x6e /* ud2 ; .ascii "xen" */
+#define __KVM_EMULATE_PREFIX 0x0f,0x0b,0x6b,0x76,0x6d /* ud2 ; .ascii "kvm" */
+
+#endif
diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h
index 62ca03e..9139b3e 100644
--- a/arch/x86/include/asm/xen/interface.h
+++ b/arch/x86/include/asm/xen/interface.h
@@ -379,12 +379,9 @@ struct xen_pmu_arch {
* Prefix forces emulation of some non-trapping instructions.
* Currently only CPUID.
*/
-#ifdef __ASSEMBLY__
-#define XEN_EMULATE_PREFIX .byte 0x0f,0x0b,0x78,0x65,0x6e ;
-#define XEN_CPUID XEN_EMULATE_PREFIX cpuid
-#else
-#define XEN_EMULATE_PREFIX ".byte 0x0f,0x0b,0x78,0x65,0x6e ; "
-#define XEN_CPUID XEN_EMULATE_PREFIX "cpuid"
-#endif
+#include <asm/emulate_prefix.h>
+
+#define XEN_EMULATE_PREFIX __ASM_FORM(.byte __XEN_EMULATE_PREFIX ;)
+#define XEN_CPUID XEN_EMULATE_PREFIX __ASM_FORM(cpuid)
#endif /* _ASM_X86_XEN_INTERFACE_H */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 661e2bf..777574f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -68,6 +68,7 @@
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
#include <asm/intel_pt.h>
+#include <asm/emulate_prefix.h>
#include <clocksource/hyperv_timer.h>
#define CREATE_TRACE_POINTS
@@ -5446,6 +5447,7 @@ EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
int handle_ud(struct kvm_vcpu *vcpu)
{
+ static const char kvm_emulate_prefix[] = { __KVM_EMULATE_PREFIX };
int emul_type = EMULTYPE_TRAP_UD;
char sig[5]; /* ud2; .ascii "kvm" */
struct x86_exception e;
@@ -5453,7 +5455,7 @@ int handle_ud(struct kvm_vcpu *vcpu)
if (force_emulation_prefix &&
kvm_read_guest_virt(vcpu, kvm_get_linear_rip(vcpu),
sig, sizeof(sig), &e) == 0 &&
- memcmp(sig, "\xf\xbkvm", sizeof(sig)) == 0) {
+ memcmp(sig, kvm_emulate_prefix, sizeof(sig)) == 0) {
kvm_rip_write(vcpu, kvm_rip_read(vcpu) + sizeof(sig));
emul_type = EMULTYPE_TRAP_UD_FORCED;
}
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH -tip v4 3/4] x86: xen: insn: Decode Xen and KVM emulate-prefix signature
2019-09-06 13:13 [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
2019-09-06 13:13 ` [PATCH -tip v4 1/4] x86/asm: Allow to pass macros to __ASM_FORM() Masami Hiramatsu
2019-09-06 13:13 ` [PATCH -tip v4 2/4] x86: xen: kvm: Gather the definition of emulate prefixes Masami Hiramatsu
@ 2019-09-06 13:14 ` Masami Hiramatsu
2019-10-18 12:48 ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2019-09-06 13:14 ` [PATCH -tip v4 4/4] x86: kprobes: Prohibit probing on instruction which has emulate prefix Masami Hiramatsu
2019-09-17 6:14 ` [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
4 siblings, 1 reply; 13+ messages in thread
From: Masami Hiramatsu @ 2019-09-06 13:14 UTC (permalink / raw)
To: Ingo Molnar
Cc: Josh Poimboeuf, Andrew Cooper, Peter Zijlstra, Randy Dunlap,
Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
Decode Xen and KVM's emulate-prefix signature by x86 insn decoder.
It is called "prefix" but actually not x86 instruction prefix, so
this adds insn.emulate_prefix_size field instead of reusing
insn.prefixes.
If x86 decoder finds a special sequence of instructions of
XEN_EMULATE_PREFIX and 'ud2a; .ascii "kvm"', it just counts the
length, set insn.emulate_prefix_size and fold it with the next
instruction. In other words, the signature and the next instruction
is treated as a single instruction.
Reported-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
Changes in v4:
- Use asm/emulate_prefix.h instead of xen/prefix.h
- Fix to add emulate_prefix.h to the checkist of perf.
---
arch/x86/include/asm/insn.h | 6 +++++
arch/x86/lib/insn.c | 34 +++++++++++++++++++++++++++
tools/arch/x86/include/asm/emulate_prefix.h | 14 +++++++++++
tools/arch/x86/include/asm/insn.h | 6 +++++
tools/arch/x86/lib/insn.c | 34 +++++++++++++++++++++++++++
tools/objtool/sync-check.sh | 3 ++
| 3 ++
7 files changed, 98 insertions(+), 2 deletions(-)
create mode 100644 tools/arch/x86/include/asm/emulate_prefix.h
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index 154f27be8bfc..5c1ae3eff9d4 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -45,6 +45,7 @@ struct insn {
struct insn_field immediate2; /* for 64bit imm or seg16 */
};
+ int emulate_prefix_size;
insn_attr_t attr;
unsigned char opnd_bytes;
unsigned char addr_bytes;
@@ -128,6 +129,11 @@ static inline int insn_is_evex(struct insn *insn)
return (insn->vex_prefix.nbytes == 4);
}
+static inline int insn_has_emulate_prefix(struct insn *insn)
+{
+ return !!insn->emulate_prefix_size;
+}
+
/* Ensure this instruction is decoded completely */
static inline int insn_complete(struct insn *insn)
{
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 0b5862ba6a75..404279563891 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -13,6 +13,8 @@
#include <asm/inat.h>
#include <asm/insn.h>
+#include <asm/emulate_prefix.h>
+
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
@@ -58,6 +60,36 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
insn->addr_bytes = 4;
}
+static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
+static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
+
+static int __insn_get_emulate_prefix(struct insn *insn,
+ const insn_byte_t *prefix, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
+ goto err_out;
+ }
+
+ insn->emulate_prefix_size = len;
+ insn->next_byte += len;
+
+ return 1;
+
+err_out:
+ return 0;
+}
+
+static void insn_get_emulate_prefix(struct insn *insn)
+{
+ if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
+ return;
+
+ __insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
+}
+
/**
* insn_get_prefixes - scan x86 instruction prefix bytes
* @insn: &struct insn containing instruction
@@ -76,6 +108,8 @@ void insn_get_prefixes(struct insn *insn)
if (prefixes->got)
return;
+ insn_get_emulate_prefix(insn);
+
nb = 0;
lb = 0;
b = peek_next(insn_byte_t, insn);
diff --git a/tools/arch/x86/include/asm/emulate_prefix.h b/tools/arch/x86/include/asm/emulate_prefix.h
new file mode 100644
index 000000000000..70f5b98a5286
--- /dev/null
+++ b/tools/arch/x86/include/asm/emulate_prefix.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_EMULATE_PREFIX_H
+#define _ASM_X86_EMULATE_PREFIX_H
+
+/*
+ * Virt escape sequences to trigger instruction emulation;
+ * ideally these would decode to 'whole' instruction and not destroy
+ * the instruction stream; sadly this is not true for the 'kvm' one :/
+ */
+
+#define __XEN_EMULATE_PREFIX 0x0f,0x0b,0x78,0x65,0x6e /* ud2 ; .ascii "xen" */
+#define __KVM_EMULATE_PREFIX 0x0f,0x0b,0x6b,0x76,0x6d /* ud2 ; .ascii "kvm" */
+
+#endif
diff --git a/tools/arch/x86/include/asm/insn.h b/tools/arch/x86/include/asm/insn.h
index 37a4c390750b..568854b14d0a 100644
--- a/tools/arch/x86/include/asm/insn.h
+++ b/tools/arch/x86/include/asm/insn.h
@@ -45,6 +45,7 @@ struct insn {
struct insn_field immediate2; /* for 64bit imm or seg16 */
};
+ int emulate_prefix_size;
insn_attr_t attr;
unsigned char opnd_bytes;
unsigned char addr_bytes;
@@ -128,6 +129,11 @@ static inline int insn_is_evex(struct insn *insn)
return (insn->vex_prefix.nbytes == 4);
}
+static inline int insn_has_emulate_prefix(struct insn *insn)
+{
+ return !!insn->emulate_prefix_size;
+}
+
/* Ensure this instruction is decoded completely */
static inline int insn_complete(struct insn *insn)
{
diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c
index 79e048f1d902..0151dfc6da61 100644
--- a/tools/arch/x86/lib/insn.c
+++ b/tools/arch/x86/lib/insn.c
@@ -13,6 +13,8 @@
#include "../include/asm/inat.h"
#include "../include/asm/insn.h"
+#include "../include/asm/emulate_prefix.h"
+
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
@@ -58,6 +60,36 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
insn->addr_bytes = 4;
}
+static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
+static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
+
+static int __insn_get_emulate_prefix(struct insn *insn,
+ const insn_byte_t *prefix, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
+ goto err_out;
+ }
+
+ insn->emulate_prefix_size = len;
+ insn->next_byte += len;
+
+ return 1;
+
+err_out:
+ return 0;
+}
+
+static void insn_get_emulate_prefix(struct insn *insn)
+{
+ if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
+ return;
+
+ __insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
+}
+
/**
* insn_get_prefixes - scan x86 instruction prefix bytes
* @insn: &struct insn containing instruction
@@ -76,6 +108,8 @@ void insn_get_prefixes(struct insn *insn)
if (prefixes->got)
return;
+ insn_get_emulate_prefix(insn);
+
nb = 0;
lb = 0;
b = peek_next(insn_byte_t, insn);
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index 0a832e265a50..9bd04bbed01e 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -4,6 +4,7 @@
FILES='
arch/x86/include/asm/inat_types.h
arch/x86/include/asm/orc_types.h
+arch/x86/include/asm/emulate_prefix.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
'
@@ -46,6 +47,6 @@ done
check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
-check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]"'
+check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'
cd -
--git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
index e2e0f06c97d0..988b1879ec98 100755
--- a/tools/perf/check-headers.sh
+++ b/tools/perf/check-headers.sh
@@ -27,6 +27,7 @@ arch/x86/include/asm/disabled-features.h
arch/x86/include/asm/required-features.h
arch/x86/include/asm/cpufeatures.h
arch/x86/include/asm/inat_types.h
+arch/x86/include/asm/emulate_prefix.h
arch/x86/include/uapi/asm/prctl.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
@@ -115,7 +116,7 @@ check lib/ctype.c '-I "^EXPORT_SYMBOL" -I "^#include <linux/export.h>" -B
check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
-check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]"'
+check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'
# diff non-symmetric files
check_2 tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip: x86/core] x86: xen: insn: Decode Xen and KVM emulate-prefix signature
2019-09-06 13:14 ` [PATCH -tip v4 3/4] x86: xen: insn: Decode Xen and KVM emulate-prefix signature Masami Hiramatsu
@ 2019-10-18 12:48 ` tip-bot2 for Masami Hiramatsu
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot2 for Masami Hiramatsu @ 2019-10-18 12:48 UTC (permalink / raw)
To: linux-tip-commits
Cc: Masami Hiramatsu, Peter Zijlstra (Intel),
Josh Poimboeuf, Juergen Gross, x86, Boris Ostrovsky, Ingo Molnar,
Stefano Stabellini, Andrew Cooper, Borislav Petkov, xen-devel,
Randy Dunlap, linux-kernel
The following commit has been merged into the x86/core branch of tip:
Commit-ID: 4d65adfcd1196818659d3bd9b42dccab291e1751
Gitweb: https://git.kernel.org/tip/4d65adfcd1196818659d3bd9b42dccab291e1751
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Fri, 06 Sep 2019 22:14:10 +09:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 17 Oct 2019 21:31:57 +02:00
x86: xen: insn: Decode Xen and KVM emulate-prefix signature
Decode Xen and KVM's emulate-prefix signature by x86 insn decoder.
It is called "prefix" but actually not x86 instruction prefix, so
this adds insn.emulate_prefix_size field instead of reusing
insn.prefixes.
If x86 decoder finds a special sequence of instructions of
XEN_EMULATE_PREFIX and 'ud2a; .ascii "kvm"', it just counts the
length, set insn.emulate_prefix_size and fold it with the next
instruction. In other words, the signature and the next instruction
is treated as a single instruction.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lkml.kernel.org/r/156777564986.25081.4964537658500952557.stgit@devnote2
---
arch/x86/include/asm/insn.h | 6 ++++-
arch/x86/lib/insn.c | 34 ++++++++++++++++++++-
tools/arch/x86/include/asm/emulate_prefix.h | 14 ++++++++-
tools/arch/x86/include/asm/insn.h | 6 ++++-
tools/arch/x86/lib/insn.c | 34 ++++++++++++++++++++-
tools/objtool/sync-check.sh | 3 +-
| 3 +-
7 files changed, 98 insertions(+), 2 deletions(-)
create mode 100644 tools/arch/x86/include/asm/emulate_prefix.h
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index 154f27b..5c1ae3e 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -45,6 +45,7 @@ struct insn {
struct insn_field immediate2; /* for 64bit imm or seg16 */
};
+ int emulate_prefix_size;
insn_attr_t attr;
unsigned char opnd_bytes;
unsigned char addr_bytes;
@@ -128,6 +129,11 @@ static inline int insn_is_evex(struct insn *insn)
return (insn->vex_prefix.nbytes == 4);
}
+static inline int insn_has_emulate_prefix(struct insn *insn)
+{
+ return !!insn->emulate_prefix_size;
+}
+
/* Ensure this instruction is decoded completely */
static inline int insn_complete(struct insn *insn)
{
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 0b5862b..4042795 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -13,6 +13,8 @@
#include <asm/inat.h>
#include <asm/insn.h>
+#include <asm/emulate_prefix.h>
+
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
@@ -58,6 +60,36 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
insn->addr_bytes = 4;
}
+static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
+static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
+
+static int __insn_get_emulate_prefix(struct insn *insn,
+ const insn_byte_t *prefix, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
+ goto err_out;
+ }
+
+ insn->emulate_prefix_size = len;
+ insn->next_byte += len;
+
+ return 1;
+
+err_out:
+ return 0;
+}
+
+static void insn_get_emulate_prefix(struct insn *insn)
+{
+ if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
+ return;
+
+ __insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
+}
+
/**
* insn_get_prefixes - scan x86 instruction prefix bytes
* @insn: &struct insn containing instruction
@@ -76,6 +108,8 @@ void insn_get_prefixes(struct insn *insn)
if (prefixes->got)
return;
+ insn_get_emulate_prefix(insn);
+
nb = 0;
lb = 0;
b = peek_next(insn_byte_t, insn);
diff --git a/tools/arch/x86/include/asm/emulate_prefix.h b/tools/arch/x86/include/asm/emulate_prefix.h
new file mode 100644
index 0000000..70f5b98
--- /dev/null
+++ b/tools/arch/x86/include/asm/emulate_prefix.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_EMULATE_PREFIX_H
+#define _ASM_X86_EMULATE_PREFIX_H
+
+/*
+ * Virt escape sequences to trigger instruction emulation;
+ * ideally these would decode to 'whole' instruction and not destroy
+ * the instruction stream; sadly this is not true for the 'kvm' one :/
+ */
+
+#define __XEN_EMULATE_PREFIX 0x0f,0x0b,0x78,0x65,0x6e /* ud2 ; .ascii "xen" */
+#define __KVM_EMULATE_PREFIX 0x0f,0x0b,0x6b,0x76,0x6d /* ud2 ; .ascii "kvm" */
+
+#endif
diff --git a/tools/arch/x86/include/asm/insn.h b/tools/arch/x86/include/asm/insn.h
index 37a4c39..568854b 100644
--- a/tools/arch/x86/include/asm/insn.h
+++ b/tools/arch/x86/include/asm/insn.h
@@ -45,6 +45,7 @@ struct insn {
struct insn_field immediate2; /* for 64bit imm or seg16 */
};
+ int emulate_prefix_size;
insn_attr_t attr;
unsigned char opnd_bytes;
unsigned char addr_bytes;
@@ -128,6 +129,11 @@ static inline int insn_is_evex(struct insn *insn)
return (insn->vex_prefix.nbytes == 4);
}
+static inline int insn_has_emulate_prefix(struct insn *insn)
+{
+ return !!insn->emulate_prefix_size;
+}
+
/* Ensure this instruction is decoded completely */
static inline int insn_complete(struct insn *insn)
{
diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c
index 79e048f..0151dfc 100644
--- a/tools/arch/x86/lib/insn.c
+++ b/tools/arch/x86/lib/insn.c
@@ -13,6 +13,8 @@
#include "../include/asm/inat.h"
#include "../include/asm/insn.h"
+#include "../include/asm/emulate_prefix.h"
+
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
@@ -58,6 +60,36 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
insn->addr_bytes = 4;
}
+static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
+static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
+
+static int __insn_get_emulate_prefix(struct insn *insn,
+ const insn_byte_t *prefix, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
+ goto err_out;
+ }
+
+ insn->emulate_prefix_size = len;
+ insn->next_byte += len;
+
+ return 1;
+
+err_out:
+ return 0;
+}
+
+static void insn_get_emulate_prefix(struct insn *insn)
+{
+ if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
+ return;
+
+ __insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
+}
+
/**
* insn_get_prefixes - scan x86 instruction prefix bytes
* @insn: &struct insn containing instruction
@@ -76,6 +108,8 @@ void insn_get_prefixes(struct insn *insn)
if (prefixes->got)
return;
+ insn_get_emulate_prefix(insn);
+
nb = 0;
lb = 0;
b = peek_next(insn_byte_t, insn);
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index 0a832e2..9bd04bb 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -4,6 +4,7 @@
FILES='
arch/x86/include/asm/inat_types.h
arch/x86/include/asm/orc_types.h
+arch/x86/include/asm/emulate_prefix.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
'
@@ -46,6 +47,6 @@ done
check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
-check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]"'
+check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'
cd -
--git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
index cea13cb..499235a 100755
--- a/tools/perf/check-headers.sh
+++ b/tools/perf/check-headers.sh
@@ -28,6 +28,7 @@ arch/x86/include/asm/disabled-features.h
arch/x86/include/asm/required-features.h
arch/x86/include/asm/cpufeatures.h
arch/x86/include/asm/inat_types.h
+arch/x86/include/asm/emulate_prefix.h
arch/x86/include/uapi/asm/prctl.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
@@ -116,7 +117,7 @@ check lib/ctype.c '-I "^EXPORT_SYMBOL" -I "^#include <linux/export.h>" -B
check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
-check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]"'
+check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'
# diff non-symmetric files
check_2 tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH -tip v4 4/4] x86: kprobes: Prohibit probing on instruction which has emulate prefix
2019-09-06 13:13 [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
` (2 preceding siblings ...)
2019-09-06 13:14 ` [PATCH -tip v4 3/4] x86: xen: insn: Decode Xen and KVM emulate-prefix signature Masami Hiramatsu
@ 2019-09-06 13:14 ` Masami Hiramatsu
2019-10-18 12:48 ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2019-09-17 6:14 ` [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
4 siblings, 1 reply; 13+ messages in thread
From: Masami Hiramatsu @ 2019-09-06 13:14 UTC (permalink / raw)
To: Ingo Molnar
Cc: Josh Poimboeuf, Andrew Cooper, Peter Zijlstra, Randy Dunlap,
Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
Prohibit probing on instruction which has XEN_EMULATE_PREFIX
or KVM's emulate prefix. Since that prefix is a marker for Xen
and KVM, if we modify the marker by kprobe's int3, that doesn't
work as expected.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
arch/x86/kernel/kprobes/core.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 43fc13c831af..4f13af7cbcdb 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -351,6 +351,10 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn)
kernel_insn_init(insn, dest, MAX_INSN_SIZE);
insn_get_length(insn);
+ /* We can not probe force emulate prefixed instruction */
+ if (insn_has_emulate_prefix(insn))
+ return 0;
+
/* Another subsystem puts a breakpoint, failed to recover */
if (insn->opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
return 0;
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip: x86/core] x86: kprobes: Prohibit probing on instruction which has emulate prefix
2019-09-06 13:14 ` [PATCH -tip v4 4/4] x86: kprobes: Prohibit probing on instruction which has emulate prefix Masami Hiramatsu
@ 2019-10-18 12:48 ` tip-bot2 for Masami Hiramatsu
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot2 for Masami Hiramatsu @ 2019-10-18 12:48 UTC (permalink / raw)
To: linux-tip-commits
Cc: Masami Hiramatsu, Peter Zijlstra (Intel),
Juergen Gross, x86, Boris Ostrovsky, Ingo Molnar,
Stefano Stabellini, Andrew Cooper, Borislav Petkov, xen-devel,
Randy Dunlap, Josh Poimboeuf, linux-kernel
The following commit has been merged into the x86/core branch of tip:
Commit-ID: 004e8dce9c5595697951f7cd0e9f66b35c92265e
Gitweb: https://git.kernel.org/tip/004e8dce9c5595697951f7cd0e9f66b35c92265e
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Fri, 06 Sep 2019 22:14:20 +09:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 17 Oct 2019 21:31:57 +02:00
x86: kprobes: Prohibit probing on instruction which has emulate prefix
Prohibit probing on instruction which has XEN_EMULATE_PREFIX
or KVM's emulate prefix. Since that prefix is a marker for Xen
and KVM, if we modify the marker by kprobe's int3, that doesn't
work as expected.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/156777566048.25081.6296162369492175325.stgit@devnote2
---
arch/x86/kernel/kprobes/core.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 43fc13c..4f13af7 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -351,6 +351,10 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn)
kernel_insn_init(insn, dest, MAX_INSN_SIZE);
insn_get_length(insn);
+ /* We can not probe force emulate prefixed instruction */
+ if (insn_has_emulate_prefix(insn))
+ return 0;
+
/* Another subsystem puts a breakpoint, failed to recover */
if (insn->opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
return 0;
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes
2019-09-06 13:13 [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
` (3 preceding siblings ...)
2019-09-06 13:14 ` [PATCH -tip v4 4/4] x86: kprobes: Prohibit probing on instruction which has emulate prefix Masami Hiramatsu
@ 2019-09-17 6:14 ` Masami Hiramatsu
2019-10-09 12:31 ` Peter Zijlstra
4 siblings, 1 reply; 13+ messages in thread
From: Masami Hiramatsu @ 2019-09-17 6:14 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: Ingo Molnar, Josh Poimboeuf, Andrew Cooper, Peter Zijlstra,
Randy Dunlap, Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
Hi Peter,
Could you review this version?
Thank you,
On Fri, 6 Sep 2019 22:13:37 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:
> Hi,
>
> Here is the 4th version of patches to handle Xen/KVM emulate
> prefix by x86 instruction decoder.
>
> These patches allow x86 instruction decoder to decode
> Xen and KVM emulate prefix correctly, and prohibit kprobes to
> probe on it.
> Previous version is here;
>
> https://lkml.kernel.org/r/156773433821.31441.2905951246664148487.stgit@devnote2
>
> In this version, I added 2 patches, [1/4] fixes __ASM_FORM() to
> accept macros using __stringify(), [2/4] introduces new
> asm/emulate_prefix.h to initialize Xen and KVM emulate prefix
> at one place. [3/4] is updated to use new emulate_prefix.h and
> fix to add emulate_prefix.h to sync check list.
>
> This series can be applied on -tip master branch which
> has merged Josh's objtool/perf sharing common x86 insn
> decoder series.
>
> Thank you,
>
> ---
>
> Masami Hiramatsu (4):
> x86/asm: Allow to pass macros to __ASM_FORM()
> x86: xen: kvm: Gather the definition of emulate prefixes
> x86: xen: insn: Decode Xen and KVM emulate-prefix signature
> x86: kprobes: Prohibit probing on instruction which has emulate prefix
>
>
> arch/x86/include/asm/asm.h | 8 ++++--
> arch/x86/include/asm/emulate_prefix.h | 14 +++++++++++
> arch/x86/include/asm/insn.h | 6 +++++
> arch/x86/include/asm/xen/interface.h | 11 +++------
> arch/x86/kernel/kprobes/core.c | 4 +++
> arch/x86/kvm/x86.c | 4 ++-
> arch/x86/lib/insn.c | 34 +++++++++++++++++++++++++++
> tools/arch/x86/include/asm/emulate_prefix.h | 14 +++++++++++
> tools/arch/x86/include/asm/insn.h | 6 +++++
> tools/arch/x86/lib/insn.c | 34 +++++++++++++++++++++++++++
> tools/objtool/sync-check.sh | 3 ++
> tools/perf/check-headers.sh | 3 ++
> 12 files changed, 128 insertions(+), 13 deletions(-)
> create mode 100644 arch/x86/include/asm/emulate_prefix.h
> create mode 100644 tools/arch/x86/include/asm/emulate_prefix.h
>
> --
> Masami Hiramatsu (Linaro) <mhiramat@kernel.org>
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes
2019-09-17 6:14 ` [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes Masami Hiramatsu
@ 2019-10-09 12:31 ` Peter Zijlstra
2019-10-17 3:26 ` Masami Hiramatsu
0 siblings, 1 reply; 13+ messages in thread
From: Peter Zijlstra @ 2019-10-09 12:31 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: Ingo Molnar, Josh Poimboeuf, Andrew Cooper, Randy Dunlap,
Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
On Tue, Sep 17, 2019 at 03:14:03PM +0900, Masami Hiramatsu wrote:
> Hi Peter,
>
> Could you review this version?
These look good to me; shall I merge them or what was the plan?
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes
2019-10-09 12:31 ` Peter Zijlstra
@ 2019-10-17 3:26 ` Masami Hiramatsu
2019-10-17 7:29 ` Peter Zijlstra
0 siblings, 1 reply; 13+ messages in thread
From: Masami Hiramatsu @ 2019-10-17 3:26 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Ingo Molnar, Josh Poimboeuf, Andrew Cooper, Randy Dunlap,
Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
Hi Peter,
On Wed, 9 Oct 2019 14:31:06 +0200
Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, Sep 17, 2019 at 03:14:03PM +0900, Masami Hiramatsu wrote:
> > Hi Peter,
> >
> > Could you review this version?
>
> These look good to me; shall I merge them or what was the plan?
Thanks for the review, yes, could you merge this series to support emulated prefixes correctly?
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH -tip v4 0/4] x86: kprobes: Prohibit kprobes on Xen/KVM emulate prefixes
2019-10-17 3:26 ` Masami Hiramatsu
@ 2019-10-17 7:29 ` Peter Zijlstra
0 siblings, 0 replies; 13+ messages in thread
From: Peter Zijlstra @ 2019-10-17 7:29 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: Ingo Molnar, Josh Poimboeuf, Andrew Cooper, Randy Dunlap,
Borislav Petkov, Juergen Gross, Boris Ostrovsky,
Stefano Stabellini, x86, linux-kernel, xen-devel
On Thu, Oct 17, 2019 at 12:26:55PM +0900, Masami Hiramatsu wrote:
> Hi Peter,
>
> On Wed, 9 Oct 2019 14:31:06 +0200
> Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Tue, Sep 17, 2019 at 03:14:03PM +0900, Masami Hiramatsu wrote:
> > > Hi Peter,
> > >
> > > Could you review this version?
> >
> > These look good to me; shall I merge them or what was the plan?
>
> Thanks for the review, yes, could you merge this series to support emulated prefixes correctly?
OK, I'll get them merged.
^ permalink raw reply [flat|nested] 13+ messages in thread