perf: Fix unexported generic perf_arch_fetch_caller_regs

perf_arch_fetch_caller_regs() is exported for the overriden x86
version, but not for the generic weak version.

As a general rule, weak functions should not have their symbol
exported in the same file they are defined.

So let's export it on trace_event_perf.c as it is used by trace
events only.

This fixes:

	ERROR: ".perf_arch_fetch_caller_regs" [fs/xfs/xfs.ko] undefined!
	ERROR: ".perf_arch_fetch_caller_regs" [arch/powerpc/platforms/cell/spufs/spufs.ko] undefined!

-v2: And also only build it if trace events are enabled.
-v3: Fix changelog mistake

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1268697902-9518-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 7645faea8e85e9d4f3c85326ddb6851bc1e0510e..60398a0d947c855fbc25687694bb6a2b41100a3d 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1702,6 +1702,7 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
        return entry;
 }
 
+#ifdef CONFIG_EVENT_TRACING
 void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip)
 {
        regs->ip = ip;
@@ -1713,4 +1714,4 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski
        regs->cs = __KERNEL_CS;
        local_save_flags(regs->flags);
 }
-EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs);
+#endif

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index fb3031cf9f173f18e081277453ee05f87ad70fc5..574ee58a3046a4bff950aa9051e73a2d5dfd7d8b 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2786,10 +2786,12 @@ __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
        return NULL;
 }
 
+#ifdef CONFIG_EVENT_TRACING
 __weak
 void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip)
 {
 }
+#endif
 
 /*
  * Output

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 0709e4f7511404e7fb84d6c6ab6da1b5b1560f51..7d79a10c3cde9962e63b498861babef6b57ff020 100644 (file)
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -12,6 +12,8 @@
 DEFINE_PER_CPU(struct pt_regs, perf_trace_regs);
 EXPORT_PER_CPU_SYMBOL_GPL(perf_trace_regs);
 
+EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs);
+
 static char *perf_trace_buf;
 static char *perf_trace_buf_nmi;