gcc-8 warns about using strncpy() with the source size as the limit: fs/exec.c:1223:32: error: argument to 'sizeof' in 'strncpy' call is the same expression as the source; did you mean to use the size of the destination? [-Werror=sizeof-pointer-memaccess]
This is indeed slightly suspicious, as it protects us from source arguments without NUL-termination, but does not guarantee that the destination is terminated. This changes it to strlcpy with a hardcoded length, to guarantee a properly terminated string. Since we already use strlcpy() for __set_task_comm(), the source should always be terminated properly, so this patch won't change the behavior, but make it a bit more robust. Signed-off-by: Arnd Bergmann <[email protected]> --- fs/exec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 6be2aa0ab26f..3e8012afe440 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1218,9 +1218,9 @@ static int de_thread(struct task_struct *tsk) char *get_task_comm(char *buf, struct task_struct *tsk) { - /* buf must be at least sizeof(tsk->comm) in size */ + /* buf must be at least TASK_COMM_LEN in size */ task_lock(tsk); - strncpy(buf, tsk->comm, sizeof(tsk->comm)); + strlcpy(buf, tsk->comm, TASK_COMM_LEN); task_unlock(tsk); return buf; } -- 2.9.0
