perf record: Add a fallback to the reference relocation symbol

Usually "_text" is enough, but I received reports that its not always
available, so fallback to "_stext" for the symbol we use to check if we
need to apply any relocation to all the symbols in the kernel symtab,
for when, for instance, kexec is being used.

Reported-by: Darren Hart <dvhltc@us.ibm.com>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3b8b6387c47ca4de49873990b2c47216c8309aaf..f1411e9cdf47eb5355090119604419883ef160a0 100644 (file)
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -563,6 +563,9 @@ static int __cmd_record(int argc, const char **argv)
 
        err = event__synthesize_kernel_mmap(process_synthesized_event,
                                            session, "_text");
+       if (err < 0)
+               err = event__synthesize_kernel_mmap(process_synthesized_event,
+                                                   session, "_stext");
        if (err < 0) {
                pr_err("Couldn't record kernel reference relocation symbol.\n");
                return err;