On Fri, May 28, 2021 at 12:14:43AM +0900, Hyeonggon Yoo wrote: > Hello, I was compiling kernel with make CC=clang-10 W=1 -s > > there are some places that compiler complains about > pointer arithmetic like below.it says it's undefined behavior. > > is it just OK to use UBs like this (I hope it's not), > or am I missing something? > > fs/kernfs/file.c:128:15: warning: performing pointer arithmetic on > a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > return NULL + !*ppos; Should work just fine, what problems have you found with that code? Also happens in a few other places in the vfs layer. Tricky code, but it works as pointer math is valid C code :) thanks, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
