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authorFrederic Weisbecker <fweisbec@gmail.com>2010-05-20 07:47:21 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2010-06-08 23:31:27 +0200
commitb0f82b81fe6bbcf78d478071f33e44554726bc81 (patch)
tree6305c095b927f956a791b9dce687cb94a21718e6 /arch/x86
parentc9cf4dbb4d9ca715d8fedf13301a53296429abc6 (diff)
perf: Drop the skip argument from perf_arch_fetch_regs_caller
Drop this argument now that we always want to rewind only to the state of the first caller. It means frame pointers are not necessary anymore to reliably get the source of an event. But this also means we need this helper to be a macro now, as an inline function is not an option since we need to know when to provide a default implentation. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/perf_event.h13
-rw-r--r--arch/x86/include/asm/stacktrace.h7
-rw-r--r--arch/x86/kernel/cpu/perf_event.c16
3 files changed, 15 insertions, 21 deletions
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 254883d0c7e0..02de29830ffe 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -140,6 +140,19 @@ extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
extern unsigned long perf_misc_flags(struct pt_regs *regs);
#define perf_misc_flags(regs) perf_misc_flags(regs)
+#include <asm/stacktrace.h>
+
+/*
+ * We abuse bit 3 from flags to pass exact information, see perf_misc_flags
+ * and the comment with PERF_EFLAGS_EXACT.
+ */
+#define perf_arch_fetch_caller_regs(regs, __ip) { \
+ (regs)->ip = (__ip); \
+ (regs)->bp = caller_frame_pointer(); \
+ (regs)->cs = __KERNEL_CS; \
+ regs->flags = 0; \
+}
+
#else
static inline void init_hw_perf_events(void) { }
static inline void perf_events_lapic_init(void) { }
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index a957463d3c7a..2b16a2ad23dc 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -78,17 +78,14 @@ struct stack_frame_ia32 {
u32 return_address;
};
-static inline unsigned long rewind_frame_pointer(int n)
+static inline unsigned long caller_frame_pointer(void)
{
struct stack_frame *frame;
get_bp(frame);
#ifdef CONFIG_FRAME_POINTER
- while (n--) {
- if (probe_kernel_address(&frame->next_frame, frame))
- break;
- }
+ frame = frame->next_frame;
#endif
return (unsigned long)frame;
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 9632fb61e8f9..2c075fe573d0 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1706,22 +1706,6 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
return entry;
}
-void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip)
-{
- regs->ip = ip;
- /*
- * perf_arch_fetch_caller_regs adds another call, we need to increment
- * the skip level
- */
- regs->bp = rewind_frame_pointer(skip + 1);
- regs->cs = __KERNEL_CS;
- /*
- * We abuse bit 3 to pass exact information, see perf_misc_flags
- * and the comment with PERF_EFLAGS_EXACT.
- */
- regs->flags = 0;
-}
-
unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
unsigned long ip;