On Mon, 30 Sep 2024 17:03:45 -0700 Justin Stitt <[email protected]> wrote:
> strncpy() is deprecated for use on NUL-terminated destination strings [1] and > as such we should prefer more robust and less ambiguous string interfaces. > > We expect the @pattern and @num_buf strings to be NUL-terminated, as > evidenced by their manual NUL-byte assignments immediately following > each copy. > > Switch to using strscpy which guarantees NUL-termination for the > destination buffer -- eschewing manual NUL-byte assignments. strscpy > does not NUL-pad so to keep this behavior zero-allocate @num_buf. @pred > is already zero-allocated before the copies. > pred = kzalloc(sizeof(*pred), GFP_KERNEL); > > This should result in no behavioral changes whilst helping towards the > goal of [2] -- with the ultimate goal of removing strncpy in favor of > less ambiguous and more robust alternatives. > > Link: > https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings > [1] > Link: https://github.com/KSPP/linux/issues/90 [2] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html > Cc: Kees Cook <[email protected]> > Cc: [email protected] > Signed-off-by: Justin Stitt <[email protected]> So this breaks my tests. This is why I have trouble with taking changes like this :-( Before this patch, his worked: # echo 'common_pid != 0 && common_pid != 120 && common_pid != 1253 && common_pid != 17 && common_pid != 394 && common_pid != 81 && common_pid != 87' > /sys/kernel/tracing/events/sched/sched_switch/filter But now it gives an error of: -bash: echo: write error: Invalid argument I have to drop this. -- Steve
