lkml.org 
[lkml]   [2012]   [Jun]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH v2][GIT PULL][v3.5] ftrace: Make all inline tags also include notrace
From
Date

Ingo,

I updated the change log as you recommended, there was no code change.

-- Steve

Please pull the latest tip/perf/urgent-2 tree, which can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
tip/perf/urgent-2

Head SHA1: 93b3cca1ccd30b1ad290951a3fc7c10c73db7313


Steven Rostedt (1):
ftrace: Make all inline tags also include notrace

----
include/linux/compiler-gcc.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
---------------------------
commit 93b3cca1ccd30b1ad290951a3fc7c10c73db7313
Author: Steven Rostedt <rostedt@goodmis.org>
Date: Thu Jun 14 10:54:28 2012 -0400

ftrace: Make all inline tags also include notrace

Commit 5963e317b1e9d2a ("ftrace/x86: Do not change stacks in DEBUG when
calling lockdep") prevented lockdep calls from the int3 breakpoint handler
from reseting the stack if a function that was called was in the process
of being converted for tracing and had a breakpoint on it. The idea is,
before calling the lockdep code, do a load_idt() to the special IDT that
kept the breakpoint stack from reseting. This worked well as a quick fix
for this kernel release, until a certain config caused a lockup in the
function tracer start up tests.

Investigating it, I found that the load_idt that was used to prevent
the int3 from changing stacks was itself being traced!

Even though the config had CONFIG_OPTIMIZE_INLINING disabled, and
all 'inline' tags were set to always inline, there were still cases that
it did not inline! This was caused by CONFIG_PARAVIRT_GUEST, where it
would add a pointer to the native_load_idt() which made that function
to be traced.

Commit 45959ee7aa645815a ("ftrace: Do not function trace inlined functions")
only touched the 'inline' tags when CONFIG_OPMITIZE_INLINING was enabled.
PARAVIRT_GUEST shows that this was not enough and we need to also
mark always_inline with notrace as well.

Reported-by: Fengguang Wu <wfg@linux.intel.com>
Tested-by: Fengguang Wu <wfg@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index e5834aa..6a6d7ae 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -47,9 +47,9 @@
*/
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
!defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
-# define inline inline __attribute__((always_inline))
-# define __inline__ __inline__ __attribute__((always_inline))
-# define __inline __inline __attribute__((always_inline))
+# define inline inline __attribute__((always_inline)) notrace
+# define __inline__ __inline__ __attribute__((always_inline)) notrace
+# define __inline __inline __attribute__((always_inline)) notrace
#else
/* A lot of inline functions can cause havoc with function tracing */
# define inline inline notrace



\
 
 \ /
  Last update: 2012-06-18 16:41    [W:0.058 / U:0.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site