The patch titled
Subject: selftests/mm: report errno when things fail in gup_longterm
has been added to the -mm mm-unstable branch. Its filename is
selftests-mm-report-errno-when-things-fail-in-gup_longterm.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-report-errno-when-things-fail-in-gup_longterm.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Brendan Jackman <jackmanb@xxxxxxxxxx>
Subject: selftests/mm: report errno when things fail in gup_longterm
Date: Fri, 21 Feb 2025 18:25:40 +0000
Patch series "selftests/mm: Some cleanups from trying to run them", v2.
I never had much luck running mm selftests so I spent a couple of hours
digging into why.
Looks like most of the reason is missing SKIP checks, so this series is
just adding a bunch of those that I found. I did not do anything like all
of them, just the ones I spotted in gup_longterm, gup_test, mmap,
userfaultfd and memfd_secret.
It's a bit unfortunate to have to skip those tests when ftruncate() fails,
but I don't have time to dig deep enough into it to actually make them
pass - I observed these issues on both 9p and virtiofs. Probably it
requires digging into the filesystem implementation
(An alternative might just be to mount a tmpfs in the test script).
I am also seeing some failures to allocate hugetlb pages in uffd-mp-mremap
that I have not had time to fully understand, you can see those here:
https://gist.github.com/bjackman/af74c3a6e60975e6ff0d760cba1e05d2#file-userfaultfd-log
This patch (of 9):
Just reporting failure doesn't tell you what went wrong. This can fail in
different ways so report errno to help the reader get started debugging.
Link: https://lkml.kernel.org/r/20250221-mm-selftests-v2-0-28c4d66383c5@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20250221-mm-selftests-v2-1-28c4d66383c5@xxxxxxxxxx
Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
Cc: Dev Jain <dev.jain@xxxxxxx>
Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Mateusz Guzik <mjguzik@xxxxxxxxx>
Cc: Shuah Khan (Samsung OSG) <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/mm/gup_longterm.c | 37 +++++++++++---------
1 file changed, 21 insertions(+), 16 deletions(-)
--- a/tools/testing/selftests/mm/gup_longterm.c~selftests-mm-report-errno-when-things-fail-in-gup_longterm
+++ a/tools/testing/selftests/mm/gup_longterm.c
@@ -96,13 +96,13 @@ static void do_test(int fd, size_t size,
int ret;
if (ftruncate(fd, size)) {
- ksft_test_result_fail("ftruncate() failed\n");
+ ksft_test_result_fail("ftruncate() failed (%s)\n", strerror(errno));
return;
}
if (fallocate(fd, 0, 0, size)) {
if (size == pagesize)
- ksft_test_result_fail("fallocate() failed\n");
+ ksft_test_result_fail("fallocate() failed (%s)\n", strerror(errno));
else
ksft_test_result_skip("need more free huge pages\n");
return;
@@ -112,7 +112,7 @@ static void do_test(int fd, size_t size,
shared ? MAP_SHARED : MAP_PRIVATE, fd, 0);
if (mem == MAP_FAILED) {
if (size == pagesize || shared)
- ksft_test_result_fail("mmap() failed\n");
+ ksft_test_result_fail("mmap() failed (%s)\n", strerror(errno));
else
ksft_test_result_skip("need more free huge pages\n");
return;
@@ -130,7 +130,7 @@ static void do_test(int fd, size_t size,
*/
ret = mprotect(mem, size, PROT_READ);
if (ret) {
- ksft_test_result_fail("mprotect() failed\n");
+ ksft_test_result_fail("mprotect() failed (%s)\n", strerror(errno));
goto munmap;
}
/* FALLTHROUGH */
@@ -165,18 +165,20 @@ static void do_test(int fd, size_t size,
args.flags |= rw ? PIN_LONGTERM_TEST_FLAG_USE_WRITE : 0;
ret = ioctl(gup_fd, PIN_LONGTERM_TEST_START, &args);
if (ret && errno == EINVAL) {
- ksft_test_result_skip("PIN_LONGTERM_TEST_START failed\n");
+ ksft_test_result_skip("PIN_LONGTERM_TEST_START failed (EINVAL)n");
break;
} else if (ret && errno == EFAULT) {
ksft_test_result(!should_work, "Should have failed\n");
break;
} else if (ret) {
- ksft_test_result_fail("PIN_LONGTERM_TEST_START failed\n");
+ ksft_test_result_fail("PIN_LONGTERM_TEST_START failed (%s)\n",
+ strerror(errno));
break;
}
if (ioctl(gup_fd, PIN_LONGTERM_TEST_STOP))
- ksft_print_msg("[INFO] PIN_LONGTERM_TEST_STOP failed\n");
+ ksft_print_msg("[INFO] PIN_LONGTERM_TEST_STOP failed (%s)\n",
+ strerror(errno));
/*
* TODO: if the kernel ever supports long-term R/W pinning on
@@ -202,7 +204,8 @@ static void do_test(int fd, size_t size,
/* Skip on errors, as we might just lack kernel support. */
ret = io_uring_queue_init(1, &ring, 0);
if (ret < 0) {
- ksft_test_result_skip("io_uring_queue_init() failed\n");
+ ksft_test_result_skip("io_uring_queue_init() failed (%s)\n",
+ strerror(errno));
break;
}
/*
@@ -215,13 +218,15 @@ static void do_test(int fd, size_t size,
/* Only new kernels return EFAULT. */
if (ret && (errno == ENOSPC || errno == EOPNOTSUPP ||
errno == EFAULT)) {
- ksft_test_result(!should_work, "Should have failed\n");
+ ksft_test_result(!should_work, "Should have failed (%s)\n",
+ strerror(errno));
} else if (ret) {
/*
* We might just lack support or have insufficient
* MEMLOCK limits.
*/
- ksft_test_result_skip("io_uring_register_buffers() failed\n");
+ ksft_test_result_skip("io_uring_register_buffers() failed (%s)\n",
+ strerror(errno));
} else {
ksft_test_result(should_work, "Should have worked\n");
io_uring_unregister_buffers(&ring);
@@ -249,7 +254,7 @@ static void run_with_memfd(test_fn fn, c
fd = memfd_create("test", 0);
if (fd < 0) {
- ksft_test_result_fail("memfd_create() failed\n");
+ ksft_test_result_fail("memfd_create() failed (%s)\n", strerror(errno));
return;
}
@@ -266,13 +271,13 @@ static void run_with_tmpfile(test_fn fn,
file = tmpfile();
if (!file) {
- ksft_test_result_fail("tmpfile() failed\n");
+ ksft_test_result_fail("tmpfile() failed (%s)\n", strerror(errno));
return;
}
fd = fileno(file);
if (fd < 0) {
- ksft_test_result_fail("fileno() failed\n");
+ ksft_test_result_fail("fileno() failed (%s)\n", strerror(errno));
goto close;
}
@@ -290,12 +295,12 @@ static void run_with_local_tmpfile(test_
fd = mkstemp(filename);
if (fd < 0) {
- ksft_test_result_fail("mkstemp() failed\n");
+ ksft_test_result_fail("mkstemp() failed (%s)\n", strerror(errno));
return;
}
if (unlink(filename)) {
- ksft_test_result_fail("unlink() failed\n");
+ ksft_test_result_fail("unlink() failed (%s)\n", strerror(errno));
goto close;
}
@@ -317,7 +322,7 @@ static void run_with_memfd_hugetlb(test_
fd = memfd_create("test", flags);
if (fd < 0) {
- ksft_test_result_skip("memfd_create() failed\n");
+ ksft_test_result_skip("memfd_create() failed (%s)\n", strerror(errno));
return;
}
_
Patches currently in -mm which might be from jackmanb@xxxxxxxxxx are
mm-mmu_gather-update-comment-on-rcu-freeing.patch
selftests-mm-report-errno-when-things-fail-in-gup_longterm.patch
selftests-mm-fix-assumption-that-sudo-is-present.patch
selftests-mm-skip-uffd-stress-if-userfaultfd-not-available.patch
selftests-mm-skip-uffd-wp-mremap-if-userfaultfd-not-available.patch
selftests-mm-uffd-rename-nr_cpus-nr_threads.patch
selftests-mm-print-some-details-when-uffd-stress-gets-bad-params.patch
selftests-mm-dont-fail-uffd-stress-if-too-many-cpus.patch
selftests-mm-skip-map_populate-on-weird-filesystems.patch
selftests-mm-skip-gup_longerm-tests-on-weird-filesystems.patch
