[PATCH] tracing: prevent PROFILE_ALL_BRANCHES when FORTIFY_SOURCE=y

From: Randy Dunlap
Date: Mon Jan 15 2018 - 14:07:36 EST


From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

I regularly get 50 MB - 60 MB files during kernel randconfig builds.
These large files mostly contain (many repeats of; e.g., 124,594):

In file included from ../include/linux/string.h:6:0,
from ../include/linux/uuid.h:20,
from ../include/linux/mod_devicetable.h:13,
from ../scripts/mod/devicetable-offsets.c:3:
../include/linux/compiler.h:64:4: warning: '______f' is static but declared in inline function 'strcpy' which is not static [enabled by default]
______f = { \
^
../include/linux/compiler.h:56:23: note: in expansion of macro '__trace_if'
^
../include/linux/string.h:425:2: note: in expansion of macro 'if'
if (p_size == (size_t)-1 && q_size == (size_t)-1)
^

This only happens when CONFIG_FORTIFY_SOURCE=y and
CONFIG_PROFILE_ALL_BRANCHES=y, so prevent PROFILE_ALL_BRANCHES if
FORTIFY_SOURCE=y.

Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- orig/kernel/trace/Kconfig
+++ next/kernel/trace/Kconfig
@@ -355,7 +355,7 @@ config PROFILE_ANNOTATED_BRANCHES
on if you need to profile the system's use of these macros.

config PROFILE_ALL_BRANCHES
- bool "Profile all if conditionals"
+ bool "Profile all if conditionals" if !FORTIFY_SOURCE
select TRACE_BRANCH_PROFILING
help
This tracer profiles all branch conditions. Every if ()