On Tue, 2019-07-30 at 14:39 +0800, Chuhong Yuan wrote: > Kees Cook <keescook@xxxxxxxxxxxx> 于2019年7月30日周二 下午12:26写道： > > On Mon, Jul 29, 2019 at 11:13:46PM +0800, Chuhong Yuan wrote: > > > strncmp(str, const, len) is error-prone. > > > We had better use newly introduced > > > str_has_prefix() instead of it. > > > > Wait, stop. :) After Laura called my attention to your conversion series, > > mpe pointed out that str_has_prefix() is almost redundant to strstarts() > > (from 2009), and the latter has many more users. Let's fix strstarts() > > match str_has_prefix()'s return behavior (all the existing callers are > > doing boolean tests, so the change in return value won't matter), and > > then we can continue with this replacement. (And add some documentation > > to Documenation/process/deprecated.rst along with a checkpatch.pl test > > maybe too?) > > > > Thanks for your advice! > Does that mean replacing strstarts()'s implementation with > str_has_prefix()'s and then use strstarts() to substitute > strncmp? > > I am not very clear about how to add the test into checkpatch.pl. > Should I write a check for this pattern or directly add strncmp into > deprecated_apis? After Nitin's patch gets applied: (which btw wasn't cc'd to lkml) (sorry about the bad link, something about it hits some spam filter) open wall . com/lists/kernel-hardening/2019/07/28/1 Add it to deprecated_string_apis And we've had this sort of discussion before: https://lore.kernel.org/patchwork/patch/1026598/ I believe I'm still in favor of global conversion of strstarts to str_has_prefix.
