Hi, Usama
在 2026/8/17 23:44, Usama Anjum 写道:
> On 15/08/2026 9:07 am, Song Hu wrote:
>> mremap_test calls ksft_set_plan() without ksft_print_header(), and its
>> get_mmap_min_addr() skip path uses a bare exit(KSFT_SKIP) that prints no
>> TAP line, so its output is not valid KTAP. Add the header and switch
>> the skip to ksft_exit_skip().
>>
>> Also fix two more KTAP compliance issues spotted in review:
>>
>> - get_mmap_min_addr() calls strerror(errno) after fclose(), which may
>> clobber errno; save errno before fclose() instead.
>>
>> - Some ksft_*() messages embed "\n\t", so the text after each embedded
>> newline is printed without the "# " prefix. Split those into separate
>> messages.
>>
>> Acked-by: Mike Rapoport (Microsoft) <[email protected]>
>> Reviewed-by: Sarthak Sharma <[email protected]>
>> Signed-off-by: Song Hu <[email protected]>
>> ---
>> tools/testing/selftests/mm/mremap_test.c | 41 +++++++++++++-----------
>> 1 file changed, 23 insertions(+), 18 deletions(-)
>>
>> diff --git a/tools/testing/selftests/mm/mremap_test.c
>> b/tools/testing/selftests/mm/mremap_test.c
>> index 131d9d6db867..28f151daabe4 100644
>> --- a/tools/testing/selftests/mm/mremap_test.c
>> +++ b/tools/testing/selftests/mm/mremap_test.c
>> @@ -111,18 +111,17 @@ static unsigned long long get_mmap_min_addr(void)
>> return addr;
>>
>> fp = fopen("/proc/sys/vm/mmap_min_addr", "r");
>> - if (fp == NULL) {
>> - ksft_print_msg("Failed to open /proc/sys/vm/mmap_min_addr:
>> %s\n",
>> - strerror(errno));
>> - exit(KSFT_SKIP);
>> - }
>> + if (!fp)
>> + ksft_exit_skip("Failed to open /proc/sys/vm/mmap_min_addr:
>> %s\n",
>> + strerror(errno));
>
> The skip conditions are usually at the start of the test before we set
> the total number planned tests. If skip like this happens later, it
> still counts as failure. I found the following corresponding output
> with this patch:
>
> TAP version 13
> # Test configs:
> # threshold_mb=4
> # pattern_seed=1786980558
> 1..26
> ok 1 # SKIP Failed to read /proc/sys/vm/mmap_min_addr: Success
> # 1 skipped test(s) detected. Consider enabling relevant config options to
> improve coverage.
> # Planned tests != run tests (26 != 1)
> # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
> MREMAP_FORCED_SKIP_RC=4
> ### MREMAP FORCED READ-SKIP END
>
Right, get_mmap_min_addr() is first reached from deep inside
run_mremap_test_case(), long after the plan is set. v3 caches
mmap_min_addr in main(), right after ksft_print_header() and before
ksft_set_plan(), so the skip paths now run before the plan. Reproducing
your scenario by injecting a read failure on the sysctl (LD_PRELOAD
fopen shim handing the test /dev/null for it):
TAP version 13
1..0 # SKIP Failed to read /proc/sys/vm/mmap_min_addr: Success
Thanks,
Song
>>
>> n_matched = fscanf(fp, "%llu", &addr);
>> if (n_matched != 1) {
>> - ksft_print_msg("Failed to read /proc/sys/vm/mmap_min_addr:
>> %s\n",
>> - strerror(errno));
>> + int err = errno;
>> +
>> fclose(fp);
>> - exit(KSFT_SKIP);
>> + ksft_exit_skip("Failed to read /proc/sys/vm/mmap_min_addr:
>> %s\n",
>> + strerror(err));
>> }
>>
>> fclose(fp);
>> @@ -1164,10 +1163,11 @@ static void run_mremap_test_case(struct test
>> test_case, int *failures,
>> rand_addr);
>>
>> if (remap_time < 0) {
>> - if (test_case.expect_failure)
>> - ksft_test_result_xfail("%s\n\tExpected mremap
>> failure\n",
>> - test_case.name);
>> - else {
>> + if (test_case.expect_failure) {
>> + ksft_print_msg("%s: expected mremap failure\n",
>> + test_case.name);
>> + ksft_test_result_xfail("%s\n", test_case.name);
>> + } else {
>> ksft_test_result_fail("%s\n", test_case.name);
>> *failures += 1;
>> }
>> @@ -1177,11 +1177,13 @@ static void run_mremap_test_case(struct test
>> test_case, int *failures,
>> * was faulted in.
>> */
>> if (threshold_mb == VALIDATION_NO_THRESHOLD ||
>> - test_case.config.region_size <= threshold_mb * _1MB)
>> - ksft_test_result_pass("%s\n\tmremap time: %12lldns\n",
>> - test_case.name, remap_time);
>> - else
>> + test_case.config.region_size <= threshold_mb * _1MB) {
>> + ksft_print_msg("%s: mremap time: %12lldns\n",
>> + test_case.name, remap_time);
>> ksft_test_result_pass("%s\n", test_case.name);
>> + } else {
>> + ksft_test_result_pass("%s\n", test_case.name);
>> + }
>> }
>> }
>>
>> @@ -1250,13 +1252,16 @@ int main(int argc, char **argv)
>> time_t t;
>> FILE *maps_fp;
>>
>> + ksft_print_header();
>> +
>> pattern_seed = (unsigned int) time(&t);
>>
>> if (parse_args(argc, argv, &threshold_mb, &pattern_seed) < 0)
>> exit(EXIT_FAILURE);
>>
>> - ksft_print_msg("Test
>> configs:\n\tthreshold_mb=%u\n\tpattern_seed=%u\n\n",
>> - threshold_mb, pattern_seed);
>> + ksft_print_msg("Test configs:\n");
>> + ksft_print_msg("threshold_mb=%u\n", threshold_mb);
>> + ksft_print_msg("pattern_seed=%u\n", pattern_seed);
>>
>> /*
>> * set preallocated random array according to test configs; see the
>
> Thanks,
> Usama
