Am 08.04.25 um 13:54 schrieb Fedor Pchelkin: > If user can request an arbitrary size value then we should use __GFP_NOWARN > and back on the allocator to return NULL in case it doesn't even try to > satisfy an enormous memory allocation request (in which case it yells in > the log without __GFP_NOWARN being passed). Maybe that would be a more > appropriate thing here?
Using __GFP_NOWARN is most likely an incorrect approach as well, this might disable all warnings. E.g. also OOM if I'm not completely mistaken and we clearly do want those. > Please see: > https://lore.kernel.org/dm-devel/CAHk-=wi8zer6tnqo-bz+wxfpmv9spc-lxgrm_3pootzegjh...@mail.gmail.com/ Linus comment is about kvmalloc(), but the code here is using kvmalloc_array() which as far as I know is explicitly made to safely allocate arrays with parameters provided by userspace. So pre-checking those parameters in the caller once more is a bit questionable, especially since we need to spread that around to all callers of kvmalloc_array() which looks backwards considering the purpose of kvmalloc_array(). Maybe we should reduce the warning to info level for kvmalloc_array() since returning NULL when incorrect parameters are given can be perfectly handled by the caller. Regards, Christian.
