From: Peter Collingbourne <pcc@google.com> stable inclusion from stable-5.10.54 commit 1077e2b15283dff2f8c7dcc2ad934bccb8c617ad bugzilla: 175586 https://gitee.com/openeuler/kernel/issues/I4DVDU Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 0db282ba2c12c1515d490d14a1ff696643ab0f1b upstream. This test passes pointers obtained from anon_allocate_area to the userfaultfd and mremap APIs. This causes a problem if the system allocator returns tagged pointers because with the tagged address ABI the kernel rejects tagged addresses passed to these APIs, which would end up causing the test to fail. To make this test compatible with such system allocators, stop using the system allocator to allocate memory in anon_allocate_area, and instead just use mmap. Link: https://lkml.kernel.org/r/20210714195437.118982-3-pcc@google.com Link: https://linux-review.googlesource.com/id/Icac91064fcd923f77a83e8e133f8631c5b... Fixes: c47174fc362a ("userfaultfd: selftest") Co-developed-by: Lokesh Gidra <lokeshgidra@google.com> Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alistair Delva <adelva@google.com> Cc: William McVicker <willmcvicker@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Mitch Phillips <mitchp@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: <stable@vger.kernel.org> [5.4] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- tools/testing/selftests/vm/userfaultfd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index c4425597769a..b1be8df80611 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -180,8 +180,10 @@ static int anon_release_pages(char *rel_area) static void anon_allocate_area(void **alloc_area) { - if (posix_memalign(alloc_area, page_size, nr_pages * page_size)) { - fprintf(stderr, "out of memory\n"); + *alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + if (*alloc_area == MAP_FAILED) + fprintf(stderr, "mmap of anonymous memory failed"); *alloc_area = NULL; } } -- 2.20.1