lkml.org 
[lkml]   [2016]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:core/urgent] objtool: Fix STACK_FRAME_NON_STANDARD macro checking for function symbols
Commit-ID:  0ea5ad869c85ac604f3e022bf2c5bef54838433b
Gitweb: http://git.kernel.org/tip/0ea5ad869c85ac604f3e022bf2c5bef54838433b
Author: Josh Poimboeuf <jpoimboe@redhat.com>
AuthorDate: Wed, 15 Jun 2016 15:45:58 -0500
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 10 Jul 2016 17:15:58 +0200

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 e8a1e69..25d8031 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)
\
 
 \ /
  Last update: 2016-07-10 21:01    [W:0.064 / U:6.760 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site