From 5150537319a8de01fcc2cf2b6f0fc65b70d3f809 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@redhat.com>
Date: Wed, 15 Jun 2016 15:45:58 -0500
Subject: [PATCH] objtool: Fix STACK_FRAME_NON_STANDARD macro checking for
function symbols
Mathieu Desnoyers reported that the STACK_FRAME_NON_STANDARD macro
wasn't working with the lttng_filter_interpret_bytecode() function in
the lttng-modules code.
Usually the relocation created by STACK_FRAME_NON_STANDARD creates a
reference to a section symbol like this:
Offset Type Value Addend Name
000000000000000000 X86_64_64 000000000000000000 +3136 .text
But in this case it created a reference to a function symbol:
Offset Type Value Addend Name
000000000000000000 X86_64_64 0x00000000000003a0 +0 lttng_filter_interpret_bytecode
To be honest I have no idea what causes gcc to decide to do one over the
other. But both are valid ELF, so add support for the function symbol.
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lttng-dev@lists.lttng.org
Link: http://lkml.kernel.org/r/9cee42843bc6d94e990a152e4e0319cfdf6756ef.1466023450.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
tools/objtool/builtin-check.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index e8a1e69eb92c5..25d803148f5c6 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -122,10 +122,14 @@ static bool ignore_func(struct objtool_file *file, struct symbol *func)
/* check for STACK_FRAME_NON_STANDARD */
if (file->whitelist && file->whitelist->rela)
- list_for_each_entry(rela, &file->whitelist->rela->rela_list, list)
- if (rela->sym->sec == func->sec &&
+ list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) {
+ if (rela->sym->type == STT_SECTION &&
+ rela->sym->sec == func->sec &&
rela->addend == func->offset)
return true;
+ if (rela->sym->type == STT_FUNC && rela->sym == func)
+ return true;
+ }
/* check if it has a context switching instruction */
func_for_each_insn(file, func, insn)
--
2.39.5