Messages in this thread | | | Date | Wed, 20 Jun 2012 14:27:42 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v2][GIT PULL][v3.5] ftrace: Make all inline tags also include notrace |
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* Steven Rostedt <rostedt@goodmis.org> wrote:
> 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
Pulled, thanks Steve!
Ingo
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