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> --- 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 */ -- 2.34.1