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[PATCH -tip v6 06/22] [BUGFIX] x86: Prohibit probing on memcpy/memset
- From: Masami Hiramatsu <masami dot hiramatsu dot pt at hitachi dot com>
- To: Ingo Molnar <mingo at kernel dot org>
- Cc: linux-arch at vger dot kernel dot org, Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Sandeepa Prabhu <sandeepa dot prabhu at linaro dot org>, x86 at kernel dot org, lkml <linux-kernel at vger dot kernel dot org>, "Steven Rostedt (Red Hat)" <rostedt at goodmis dot org>, Ingo Molnar <mingo at redhat dot com>, systemtap at sourceware dot org, "H. Peter Anvin" <hpa at zytor dot com>, Thomas Gleixner <tglx at linutronix dot de>, "David S. Miller" <davem at davemloft dot net>
- Date: Thu, 19 Dec 2013 09:04:09 +0000
- Subject: [PATCH -tip v6 06/22] [BUGFIX] x86: Prohibit probing on memcpy/memset
- Authentication-results: sourceware.org; auth=none
- References: <20131219090353 dot 14309 dot 15496 dot stgit at kbuild-fedora dot novalocal>
memcpy/memset functions are fundamental functions and
those are involved in kprobe's exception handling.
Prohibit probing on them to avoid kernel crash.
BTW, perf bench also includes some assembly files
and _ASM_NOKPROBE causes a build error. This includes
some fixes for that too.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
arch/x86/include/asm/string_32.h | 6 +++---
arch/x86/lib/memcpy_32.c | 2 ++
arch/x86/lib/memcpy_64.S | 4 ++++
arch/x86/lib/memset_64.S | 3 +++
tools/perf/bench/mem-memcpy-x86-64-asm.S | 1 +
tools/perf/bench/mem-memset-x86-64-asm.S | 1 +
6 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h
index 3d3e835..3227294 100644
--- a/arch/x86/include/asm/string_32.h
+++ b/arch/x86/include/asm/string_32.h
@@ -151,14 +151,14 @@ static __always_inline void *__constant_memcpy(void *to, const void *from,
* This CPU favours 3DNow strongly (eg AMD Athlon)
*/
-static inline void *__constant_memcpy3d(void *to, const void *from, size_t len)
+static nokprobe_inline void *__constant_memcpy3d(void *to, const void *from, size_t len)
{
if (len < 512)
return __constant_memcpy(to, from, len);
return _mmx_memcpy(to, from, len);
}
-static inline void *__memcpy3d(void *to, const void *from, size_t len)
+static nokprobe_inline void *__memcpy3d(void *to, const void *from, size_t len)
{
if (len < 512)
return __memcpy(to, from, len);
@@ -204,7 +204,7 @@ void *memmove(void *dest, const void *src, size_t n);
#define __HAVE_ARCH_MEMCHR
extern void *memchr(const void *cs, int c, size_t count);
-static inline void *__memset_generic(void *s, char c, size_t count)
+static nokprobe_inline void *__memset_generic(void *s, char c, size_t count)
{
int d0, d1;
asm volatile("rep\n\t"
diff --git a/arch/x86/lib/memcpy_32.c b/arch/x86/lib/memcpy_32.c
index e78761d..dabf966 100644
--- a/arch/x86/lib/memcpy_32.c
+++ b/arch/x86/lib/memcpy_32.c
@@ -1,5 +1,6 @@
#include <linux/string.h>
#include <linux/module.h>
+#include <linux/kprobes.h> /* for NOKPROBE_SYMBOL */
#undef memcpy
#undef memset
@@ -13,6 +14,7 @@ void *memcpy(void *to, const void *from, size_t n)
#endif
}
EXPORT_SYMBOL(memcpy);
+NOKPROBE_SYMBOL(memcpy);
void *memset(void *s, int c, size_t count)
{
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 56313a3..80adbf5 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -2,6 +2,7 @@
#include <linux/linkage.h>
+#include <asm/asm.h>
#include <asm/cpufeature.h>
#include <asm/dwarf2.h>
#include <asm/alternative-asm.h>
@@ -184,6 +185,9 @@ ENTRY(memcpy)
ENDPROC(memcpy)
ENDPROC(__memcpy)
+_ASM_NOKPROBE(memcpy)
+_ASM_NOKPROBE(__memcpy)
+
/*
* Some CPUs are adding enhanced REP MOVSB/STOSB feature
* If the feature is supported, memcpy_c_e() is the first choice.
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index 2dcb380..a62849d 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -135,6 +135,9 @@ ENTRY(__memset)
ENDPROC(memset)
ENDPROC(__memset)
+_ASM_NOKPROBE(memset)
+_ASM_NOKPROBE(__memset)
+
/* Some CPUs support enhanced REP MOVSB/STOSB feature.
* It is recommended to use this when possible.
*
diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S
index fcd9cf0..d3d2d41 100644
--- a/tools/perf/bench/mem-memcpy-x86-64-asm.S
+++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S
@@ -3,6 +3,7 @@
#define globl p2align 4; .globl
#define Lmemcpy_c globl memcpy_c; memcpy_c
#define Lmemcpy_c_e globl memcpy_c_e; memcpy_c_e
+#define _ASM_NOKPROBE(a)
#include "../../../arch/x86/lib/memcpy_64.S"
/*
* We need to provide note.GNU-stack section, saying that we want
diff --git a/tools/perf/bench/mem-memset-x86-64-asm.S b/tools/perf/bench/mem-memset-x86-64-asm.S
index 9e5af89..c9cbb29 100644
--- a/tools/perf/bench/mem-memset-x86-64-asm.S
+++ b/tools/perf/bench/mem-memset-x86-64-asm.S
@@ -3,6 +3,7 @@
#define globl p2align 4; .globl
#define Lmemset_c globl memset_c; memset_c
#define Lmemset_c_e globl memset_c_e; memset_c_e
+#define _ASM_NOKPROBE(a)
#include "../../../arch/x86/lib/memset_64.S"
/*