On Tue, Oct 10, 2023 at 06:04:42PM -0400, Alexander Aring wrote:
> From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
>
> 8 is not the maximum size of the suffix used when creating debugfs files.
>
> Let the compiler compute the correct size, and only give a hint about the
> longest possible string that is used.
>
> When building with W=1, this fixes the following warnings:
>
> fs/dlm/debug_fs.c: In function ‘dlm_create_debug_file’:
> fs/dlm/debug_fs.c:1020:58: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=]
> 1020 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_waiters", ls->ls_name);
> | ^
> fs/dlm/debug_fs.c:1020:9: note: ‘snprintf’ output between 9 and 73 bytes into a destination of size 72
> 1020 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_waiters", ls->ls_name);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/dlm/debug_fs.c:1031:50: error: ‘_queued_asts’ directive output may be truncated writing 12 bytes into a region of size between 8 and 72 [-Werror=format-truncation=]
> 1031 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_queued_asts", ls->ls_name);
> | ^~~~~~~~~~~~
> fs/dlm/debug_fs.c:1031:9: note: ‘snprintf’ output between 13 and 77 bytes into a destination of size 72
> 1031 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_queued_asts", ls->ls_name);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Fixes: 541adb0d4d10b ("fs: dlm: debugfs for queued callbacks")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
> ---
> fs/dlm/debug_fs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
> index e9726c6cbdf2..c93359ceaae6 100644
> --- a/fs/dlm/debug_fs.c
> +++ b/fs/dlm/debug_fs.c
> @@ -973,7 +973,8 @@ void dlm_delete_debug_comms_file(void *ctx)
>
> void dlm_create_debug_file(struct dlm_ls *ls)
> {
> - char name[DLM_LOCKSPACE_LEN + 8];
> + /* Reserve enough space for the longest file name */
> + char name[DLM_LOCKSPACE_LEN + sizeof("_queued_asts")];
>
> /* format 1 */
>
> --
> 2.39.3
>
<formletter>
This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.
</formletter>
