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ftrace: Make all inline tags also include notrace

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Commit 5963e317b1 ("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 45959ee7aa ("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>
This commit is contained in:
Steven Rostedt 2012-06-14 10:54:28 -04:00
parent a702704682
commit 93b3cca1cc
1 changed files with 3 additions and 3 deletions
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6
include/linux/compiler-gcc.h
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@ -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