[RFC][PATCH 1/4] ftrace: Make recordmcount.c handle __fentry__

[Steven Rostedt <rostedt@goodmis.org>]

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From: Steven Rostedt <srostedt@redhat.com>

With gcc 4.6.0 the -mfentry feature places the function profiling
call at the start of the function. When this is used, the call is
to __fentry__ and not mcount.

Change recordmcount.c to record both callers to __fentry__ and
mcount.

Cc: John Reiser <jreiser@bitwagon.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 scripts/recordmcount.h |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
index baf187b..e75ff44 100644
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -276,11 +276,13 @@ static uint_t *sift_rel_mcount(uint_t *mlocp,
 				&sym0[Elf_r_sym(relp)];
 			char const *symname = &str0[w(symp->st_name)];
 			char const *mcount = '_' == gpfx ? "_mcount" : "mcount";
+			char const *fentry = "__fentry__";
 
 			if ('.' == symname[0])
 				++symname;  /* ppc64 hack */
 			if (0 == strcmp(mcount, symname) ||
-			    (altmcount && 0 == strcmp(altmcount, symname)))
+			    (altmcount && 0 == strcmp(altmcount, symname)) ||
+			    (0 == strcmp(fentry, symname)))
 				mcountsym = Elf_r_sym(relp);
 		}
 
-- 
1.7.2.3