ftrace: Make recordmcount.c handle __fentry__

Steven Rostedt · rostedt · commit 48bb5dc6cd9d · 2012-08-23T11:24:43.000-04:00
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>
diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
@@ -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;
