On Mon, Nov 08, 2021 at 03:19:21PM +0000, Pavel Begunkov wrote: > On 11/8/21 13:49, Dan Carpenter wrote: > > Hello Pavel Begunkov, > > > > The patch caa8fe6e86fd: "io_uring: return iovec from > > __io_import_iovec" from Oct 15, 2021, leads to the following Smatch > > static checker warning: > > > > fs/io_uring.c:3218 __io_import_iovec() > > warn: passing zero to 'ERR_PTR' > > > [...] > > 3188 > > 3189 BUILD_BUG_ON(ERR_PTR(0) != NULL); > > > > This is super paranoid. :P > > A bit, but gives an idea about assumptions > > > 3209 ret = import_single_range(rw, buf, sqe_len, s->fast_iov, iter); > > 3210 return ERR_PTR(ret); > > if (ret) > return ERR_PTR(ret); > return NULL; > > How about this? I have some hope in compilers, should be > optimised out The code is fine, but it's hard to know when it's going to return NULL vs a valid pointer. It just needs a comment. regards, dan carpenter
