On 3 Jul 2025, at 4:38, David Hildenbrand wrote:
> On 03.07.25 08:06, Aboorva Devarajan wrote:
>> Gracefully skip test if userfaultfd is not supported (ENOSYS) or not
>> permitted (EPERM), instead of failing. This avoids misleading failures
>> with clear skip messages.
>> --------------
>> Before Patch
>> --------------
>> ~ running ./hugepage-mremap
>> ...
>> ~ Bail out! userfaultfd: Function not implemented
>> ~ Planned tests != run tests (1 != 0)
>> ~ Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0
>> ~ [FAIL]
>> not ok 4 hugepage-mremap # exit=1
>>
>> --------------
>> After Patch
>> --------------
>> ~ running ./hugepage-mremap
>> ...
>> ~ ok 2 # SKIP userfaultfd is not supported/not enabled.
>> ~ 1 skipped test(s) detected.
>> ~ Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
>> ~ [SKIP]
>> ok 4 hugepage-mremap # SKIP
>>
>> Signed-off-by: Aboorva Devarajan <aboor...@linux.ibm.com>
>> ---
>> tools/testing/selftests/mm/hugepage-mremap.c | 16 +++++++++++++---
>> 1 file changed, 13 insertions(+), 3 deletions(-)
>>
>> diff --git a/tools/testing/selftests/mm/hugepage-mremap.c
>> b/tools/testing/selftests/mm/hugepage-mremap.c
>> index c463d1c09c9b..1a0e6dd87578 100644
>> --- a/tools/testing/selftests/mm/hugepage-mremap.c
>> +++ b/tools/testing/selftests/mm/hugepage-mremap.c
>> @@ -65,10 +65,20 @@ static void register_region_with_uffd(char *addr, size_t
>> len)
>> struct uffdio_api uffdio_api;
>> /* Create and enable userfaultfd object. */
>> -
>> uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
>> - if (uffd == -1)
>> - ksft_exit_fail_msg("userfaultfd: %s\n", strerror(errno));
>> + if (uffd == -1) {
>> + switch (errno) {
>> + case EPERM:
>> + ksft_exit_skip("No userfaultfd permissions, try running
>> as root.\n");
>
> "Insufficient permissions, try ..." ?
>
>> + break;
>> + case ENOSYS:
>> + ksft_exit_skip("userfaultfd is not supported/not
>> enabled.\n");
>> + break;
>
> Note that we have in tools/testing/selftests/mm/config
>
> CONFIG_USERFAULTFD=y
I added the same fix to guard-regions.c since I did not know the config
file existed.
And from git history, I learnt that I could use the command below to merge
these config to my local config:
“./scripts/kconfig/merge_config.sh .config tools/testing/selftests/xxx/config”
Reviewed-by: Zi Yan <z...@nvidia.com>
Best Regards,
Yan, Zi
