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>
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index fb6c91e..bea785c 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -905,8 +905,10 @@
extern void __perf_sw_event(u32, u64, int, struct pt_regs *, u64);
-extern void
-perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip);
+#ifndef perf_arch_fetch_caller_regs
+static inline void
+perf_arch_fetch_caller_regs(struct regs *regs, unsigned long ip) { }
+#endif
/*
* Take a snapshot of the regs. Skip ip and frame pointer to
@@ -916,31 +918,11 @@
* - bp for callchains
* - eflags, for future purposes, just in case
*/
-static inline void perf_fetch_caller_regs(struct pt_regs *regs, int skip)
+static inline void perf_fetch_caller_regs(struct pt_regs *regs)
{
- unsigned long ip;
-
memset(regs, 0, sizeof(*regs));
- switch (skip) {
- case 1 :
- ip = CALLER_ADDR0;
- break;
- case 2 :
- ip = CALLER_ADDR1;
- break;
- case 3 :
- ip = CALLER_ADDR2;
- break;
- case 4:
- ip = CALLER_ADDR3;
- break;
- /* No need to support further for now */
- default:
- ip = 0;
- }
-
- return perf_arch_fetch_caller_regs(regs, ip, skip);
+ perf_arch_fetch_caller_regs(regs, CALLER_ADDR0);
}
static inline void
@@ -950,7 +932,7 @@
struct pt_regs hot_regs;
if (!regs) {
- perf_fetch_caller_regs(&hot_regs, 1);
+ perf_fetch_caller_regs(&hot_regs);
regs = &hot_regs;
}
__perf_sw_event(event_id, nr, nmi, regs, addr);