On Thu, Dec 14, 2023 at 03:19:30PM +0500, Muhammad Usama Anjum wrote: > The "locked-in-memory size" limit per process can be non-multiple of > page_size. The mmap() fails if we try to allocate locked-in-memory > with same size as the allowed limit if it isn't multiple of the > page_size because mmap() rounds off the memory size to be allocated > to next multiple of page_size. > > Fix this by flooring the length to be allocated with mmap() to the > previous multiple of the page_size. > > Fixes: 76fe17ef588a ("secretmem: test: add basic selftest for memfd_secret(2)") > Reported-by: "kernelci.org bot" <bot@xxxxxxxxxxxx> > Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx> > --- > tools/testing/selftests/mm/memfd_secret.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/tools/testing/selftests/mm/memfd_secret.c b/tools/testing/selftests/mm/memfd_secret.c > index 957b9e18c729..9b298f6a04b3 100644 > --- a/tools/testing/selftests/mm/memfd_secret.c > +++ b/tools/testing/selftests/mm/memfd_secret.c > @@ -62,6 +62,9 @@ static void test_mlock_limit(int fd) > char *mem; > > len = mlock_limit_cur; > + if (len % page_size != 0) > + len = (len/page_size) * page_size; > + With mlock limit smaller than a page we get zero length here and mmap will fail with -EINVAL because of it. In this case I think we can just skip the first mmap and only check that mmaping more than mlock limit fails. > mem = mmap(NULL, len, prot, mode, fd, 0); > if (mem == MAP_FAILED) { > fail("unable to mmap secret memory\n"); > -- > 2.42.0 > -- Sincerely yours, Mike.