Re: [PATCH 1/1] script/sorttable: fix some initialization problems

[Nathan Chancellor <nathan@kernel.org>]

On Mon, Jan 17, 2022 at 02:23:44PM +0800, Yinan Liu wrote:
> elf_mcount_loc and mcount_sort_thread definitions are not
> initialized immediately within the function, which can cause
> the judgment logic to use uninitialized values when the
> initialization logic of subsequent code fails.
> 
> Link: https://lkml.kernel.org/r/20211212113358.34208-2-yinan@linux.alibaba.com
> 
> Fixes:72b3942a173c (scripts: ftrace - move the sort-processing in ftrace_init)

This should be:

Fixes: 72b3942a173c ("scripts: ftrace - move the sort-processing in ftrace_init")

You can add an alias to always get the format right, like:

$ git config --global alias.fixes 'show -s --format="Fixes: %h (\"%s\")"'

$ git fixes 72b3942a173c387b27860ba1069636726e208777
Fixes: 72b3942a173c ("scripts: ftrace - move the sort-processing in ftrace_init")

> Signed-off-by: Yinan Liu <yinan@linux.alibaba.com>

This resolves the warnings I reported and does not introduce any new
ones. It seems reasonable to me.

Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  scripts/sorttable.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/sorttable.h b/scripts/sorttable.h
> index 1e8b77928fa4..13ae3262ec96 100644
> --- a/scripts/sorttable.h
> +++ b/scripts/sorttable.h
> @@ -199,6 +199,8 @@ static int compare_extable(const void *a, const void *b)
>  	return 0;
>  }
>  #ifdef MCOUNT_SORT_ENABLED
> +pthread_t mcount_sort_thread;
> +
>  struct elf_mcount_loc {
>  	Elf_Ehdr *ehdr;
>  	Elf_Shdr *init_data_sec;
> @@ -282,10 +284,9 @@ static int do_sort(Elf_Ehdr *ehdr,
>  	unsigned int shnum;
>  	unsigned int shstrndx;
>  #ifdef MCOUNT_SORT_ENABLED
> -	struct elf_mcount_loc mstruct;
> +	struct elf_mcount_loc mstruct = {NULL, NULL, 0, 0};

Wonder if this would be better using either '= {}' or '= {0}'?

>  	uint_t _start_mcount_loc = 0;
>  	uint_t _stop_mcount_loc = 0;
> -	pthread_t mcount_sort_thread;
>  #endif
>  #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
>  	unsigned int orc_ip_size = 0;
> -- 
> 2.19.1.6.gb485710b
> 
>