Re: [PATCH] tracing: prevent PROFILE_ALL_BRANCHES when FORTIFY_SOURCE=y

From: Steven Rostedt
Date: Mon Jan 15 2018 - 14:10:56 EST


On Mon, 15 Jan 2018 11:07:27 -0800
Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:

> 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>

I'm actually working on a patch that I need to send to Linus before
4.15 is released. Want me to add this one too? Or do you have your own
branch to push to mainline with?

-- Steve

> ---
> 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 ()