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

[Steven Rostedt <rostedt@goodmis.org>]

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

> From: Randy Dunlap <rdunlap@infradead.org>
> 
> 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@infradead.org>
> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

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 ()