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| author | Ingo Molnar <mingo@elte.hu> | 2008-11-12 13:17:38 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-12 13:26:38 +0100 |
| commit | 2b7d0390a6d6d595f43ea3806639664afe5b9ebe (patch) | |
| tree | 661cd33467685dd268e35d7e4dc1dbf2aa83d994 | |
| parent | f88c4ae9f8c3939bee4337c75c7a673b5de7a8a7 (diff) | |
| download | linux-stable-2b7d0390a6d6d595f43ea3806639664afe5b9ebe.tar.gz linux-stable-2b7d0390a6d6d595f43ea3806639664afe5b9ebe.tar.bz2 linux-stable-2b7d0390a6d6d595f43ea3806639664afe5b9ebe.zip | |
tracing: branch tracer, fix vdso crash
Impact: fix bootup crash
the branch tracer missed arch/x86/vdso/vclock_gettime.c from
disabling tracing, which caused such bootup crashes:
[ 201.840097] init[1]: segfault at 7fffed3fe7c0 ip 00007fffed3fea2e sp 000077
also clean up the ugly ifdefs in arch/x86/kernel/vsyscall_64.c by
creating DISABLE_UNLIKELY_PROFILE facility for code to turn off
instrumentation on a per file basis.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/vsyscall_64.c | 9 | ||||
| -rw-r--r-- | arch/x86/vdso/vclock_gettime.c | 3 | ||||
| -rw-r--r-- | include/linux/compiler.h | 6 |
3 files changed, 10 insertions, 8 deletions
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 2f90202e59b3..ece02932ea57 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -17,13 +17,8 @@ * want per guest time just set the kernel.vsyscall64 sysctl to 0. */ -/* Protect userspace from profiling */ -#ifdef CONFIG_TRACE_UNLIKELY_PROFILE -# undef likely -# undef unlikely -# define likely(x) likely_notrace(x) -# define unlikely(x) unlikely_notrace(x) -#endif +/* Disable profiling for userspace code: */ +#define DISABLE_UNLIKELY_PROFILE #include <linux/time.h> #include <linux/init.h> diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 1ef0f90813d6..6e667631e7dc 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -9,6 +9,9 @@ * Also alternative() doesn't work. */ +/* Disable profiling for userspace code: */ +#define DISABLE_UNLIKELY_PROFILE + #include <linux/kernel.h> #include <linux/posix-timers.h> #include <linux/time.h> diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 935e30cfaf3c..63b7d9089d6e 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -59,7 +59,11 @@ extern void __chk_io_ptr(const volatile void __iomem *); * specific implementations come from the above header files */ -#ifdef CONFIG_TRACE_UNLIKELY_PROFILE +/* + * Note: DISABLE_UNLIKELY_PROFILE can be used by special lowlevel code + * to disable branch tracing on a per file basis. + */ +#if defined(CONFIG_TRACE_UNLIKELY_PROFILE) && !defined(DISABLE_UNLIKELY_PROFILE) struct ftrace_likely_data { const char *func; const char *file; |