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authorIngo Molnar <mingo@elte.hu>2008-11-12 13:17:38 +0100
committerIngo Molnar <mingo@elte.hu>2008-11-12 13:26:38 +0100
commit2b7d0390a6d6d595f43ea3806639664afe5b9ebe (patch)
tree661cd33467685dd268e35d7e4dc1dbf2aa83d994
parentf88c4ae9f8c3939bee4337c75c7a673b5de7a8a7 (diff)
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.c9
-rw-r--r--arch/x86/vdso/vclock_gettime.c3
-rw-r--r--include/linux/compiler.h6
3 files changed, 10 insertions, 8 deletions
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 2f90202e59b..ece02932ea5 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 1ef0f90813d..6e667631e7d 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 935e30cfaf3..63b7d9089d6 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;