ftrace: Make recordmcount.c handle __fentry__

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.

Link: http://lkml.kernel.org/r/20120807194058.990674363@goodmis.org

Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: John Reiser <jreiser@bitwagon.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt 2011-02-09 13:13:23 -05:00 committed by Steven Rostedt
parent a0e0fac633
commit 48bb5dc6cd

View File

@ -261,11 +261,13 @@ static unsigned get_mcountsym(Elf_Sym const *const sym0,
&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 (strcmp(mcount, symname) == 0 ||
(altmcount && strcmp(altmcount, symname) == 0))
(altmcount && strcmp(altmcount, symname) == 0) ||
(strcmp(fentry, symname) == 0))
mcountsym = Elf_r_sym(relp);
return mcountsym;