From: Hongfu Li <[email protected]> The test creates a non-anonymous VMA (ptr_not_anon) via mmap() with MAP_PRIVATE but without MAP_ANONYMOUS, using fd=0 (stdin) as the file descriptor. This always fails because fd=0 is not a regular file, and the failure was hidden because ASSERT_NE() incorrectly checked for NULL instead of MAP_FAILED.
Fix by using mkstemp() + ftruncate() to create a real temporary file, then mapping it with MAP_PRIVATE to obtain a genuine file-backed VMA. Also fix the mmap() error checks to use MAP_FAILED instead of NULL, and pass fd=-1 for the anonymous mapping for clarity. The temp file is unlinked immediately so it does not persist on disk. Signed-off-by: Hongfu Li <[email protected]> --- .../selftests/prctl/set-anon-vma-name-test.c | 21 ++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/prctl/set-anon-vma-name-test.c b/tools/testing/selftests/prctl/set-anon-vma-name-test.c index ac6721b184a6..5f9589534da8 100644 --- a/tools/testing/selftests/prctl/set-anon-vma-name-test.c +++ b/tools/testing/selftests/prctl/set-anon-vma-name-test.c @@ -4,11 +4,13 @@ */ #include <errno.h> +#include <fcntl.h> #include <sys/prctl.h> #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #include <string.h> +#include <unistd.h> #include "kselftest_harness.h" @@ -73,15 +75,24 @@ int was_renaming_successful(char *target_name, unsigned long ptr) FIXTURE(vma) { void *ptr_anon, *ptr_not_anon; + int fd_not_anon; }; FIXTURE_SETUP(vma) { + char template[] = "./set-anon-vma-test-XXXXXX"; + self->ptr_anon = mmap(NULL, AREA_SIZE, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); - ASSERT_NE(self->ptr_anon, NULL); + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(self->ptr_anon, MAP_FAILED); + + self->fd_not_anon = mkstemp(template); + ASSERT_NE(self->fd_not_anon, -1); + unlink(template); + ASSERT_EQ(ftruncate(self->fd_not_anon, AREA_SIZE), 0); self->ptr_not_anon = mmap(NULL, AREA_SIZE, PROT_READ | PROT_WRITE, - MAP_PRIVATE, 0, 0); - ASSERT_NE(self->ptr_not_anon, NULL); + MAP_PRIVATE, self->fd_not_anon, 0); + ASSERT_NE(self->ptr_not_anon, MAP_FAILED); + close(self->fd_not_anon); } FIXTURE_TEARDOWN(vma) { @@ -98,7 +109,7 @@ TEST_F(vma, renaming) { EXPECT_EQ(rename_vma((unsigned long)self->ptr_anon, AREA_SIZE, BAD_NAME), -EINVAL); TH_LOG("Try to rename non-anonymous VMA"); - EXPECT_EQ(rename_vma((unsigned long) self->ptr_not_anon, AREA_SIZE, GOOD_NAME), -EINVAL); + EXPECT_EQ(rename_vma((unsigned long) self->ptr_not_anon, AREA_SIZE, GOOD_NAME), -EBADF); } TEST_HARNESS_MAIN -- 2.54.0
