Re: [PATCH] selftest/timerns: fix clang build failures for abs() calls

On Fri, May 3, 2024 at 4:30 AM John Hubbard jhubbard@nvidia.com wrote:

First of all, in order to build with clang at all, one must first apply Valentin Obst's build fix for LLVM [1]. Once that is done, then when building with clang, via:

make LLVM=1 -C tools/testing/selftests

...then clang warns about mismatches between the expected and required integer length being supplied to abs(3).

Fix this by using the correct variant of abs(3): labs(3) or llabs(3), in these cases.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c...

Signed-off-by: John Hubbard jhubbard@nvidia.com

LGTM, even potentially fixes the testing post-2038.

Reviewed-by: Dmitry Safonov dima@arista.com

---

tools/testing/selftests/timens/exec.c | 6 +++--- tools/testing/selftests/timens/timer.c | 2 +- tools/testing/selftests/timens/timerfd.c | 2 +- tools/testing/selftests/timens/vfork_exec.c | 4 ++-- 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/timens/exec.c b/tools/testing/selftests/timens/exec.c index e40dc5be2f66..d12ff955de0d 100644 --- a/tools/testing/selftests/timens/exec.c +++ b/tools/testing/selftests/timens/exec.c @@ -30,7 +30,7 @@ int main(int argc, char *argv[])

            for (i = 0; i < 2; i++) {
                    _gettime(CLOCK_MONOTONIC, &tst, i);

•                   if (abs(tst.tv_sec - now.tv_sec) > 5)
  

•                   if (labs(tst.tv_sec - now.tv_sec) > 5)
                            return pr_fail("%ld %ld\n", now.tv_sec, tst.tv_sec);
            }
            return 0;
  

@@ -50,7 +50,7 @@ int main(int argc, char *argv[])

    for (i = 0; i < 2; i++) {
            _gettime(CLOCK_MONOTONIC, &tst, i);

•           if (abs(tst.tv_sec - now.tv_sec) > 5)
  

•           if (labs(tst.tv_sec - now.tv_sec) > 5)
                    return pr_fail("%ld %ld\n",
                                    now.tv_sec, tst.tv_sec);
    }
  

@@ -70,7 +70,7 @@ int main(int argc, char *argv[]) /* Check that a child process is in the new timens. */ for (i = 0; i < 2; i++) { _gettime(CLOCK_MONOTONIC, &tst, i);

•                   if (abs(tst.tv_sec - now.tv_sec - OFFSET) > 5)
  

•                   if (labs(tst.tv_sec - now.tv_sec - OFFSET) > 5)
                            return pr_fail("%ld %ld\n",
                                            now.tv_sec + OFFSET, tst.tv_sec);
            }
  

diff --git a/tools/testing/selftests/timens/timer.c b/tools/testing/selftests/timens/timer.c index 5e7f0051bd7b..5b939f59dfa4 100644 --- a/tools/testing/selftests/timens/timer.c +++ b/tools/testing/selftests/timens/timer.c @@ -56,7 +56,7 @@ int run_test(int clockid, struct timespec now) return pr_perror("timerfd_gettime");

            elapsed = new_value.it_value.tv_sec;

•           if (abs(elapsed - 3600) > 60) {
  

•           if (llabs(elapsed - 3600) > 60) {
                    ksft_test_result_fail("clockid: %d elapsed: %lld\n",
                                          clockid, elapsed);
                    return 1;
  

diff --git a/tools/testing/selftests/timens/timerfd.c b/tools/testing/selftests/timens/timerfd.c index 9edd43d6b2c1..a4196bbd6e33 100644 --- a/tools/testing/selftests/timens/timerfd.c +++ b/tools/testing/selftests/timens/timerfd.c @@ -61,7 +61,7 @@ int run_test(int clockid, struct timespec now) return pr_perror("timerfd_gettime(%d)", clockid);

            elapsed = new_value.it_value.tv_sec;

•           if (abs(elapsed - 3600) > 60) {
  

•           if (llabs(elapsed - 3600) > 60) {
                    ksft_test_result_fail("clockid: %d elapsed: %lld\n",
                                          clockid, elapsed);
                    return 1;
  

diff --git a/tools/testing/selftests/timens/vfork_exec.c b/tools/testing/selftests/timens/vfork_exec.c index beb7614941fb..5b8907bf451d 100644 --- a/tools/testing/selftests/timens/vfork_exec.c +++ b/tools/testing/selftests/timens/vfork_exec.c @@ -32,7 +32,7 @@ static void *tcheck(void *_args)

    for (i = 0; i < 2; i++) {
            _gettime(CLOCK_MONOTONIC, &tst, i);

•           if (abs(tst.tv_sec - now->tv_sec) > 5) {
  

•           if (labs(tst.tv_sec - now->tv_sec) > 5) {
                    pr_fail("%s: in-thread: unexpected value: %ld (%ld)\n",
                            args->tst_name, tst.tv_sec, now->tv_sec);
                    return (void *)1UL;
  

@@ -64,7 +64,7 @@ static int check(char *tst_name, struct timespec *now)

    for (i = 0; i < 2; i++) {
            _gettime(CLOCK_MONOTONIC, &tst, i);

•           if (abs(tst.tv_sec - now->tv_sec) > 5)
  

•           if (labs(tst.tv_sec - now->tv_sec) > 5)
                    return pr_fail("%s: unexpected value: %ld (%ld)\n",
                                    tst_name, tst.tv_sec, now->tv_sec);
    }
  
  

base-commit: f03359bca01bf4372cf2c118cd9a987a5951b1c8 prerequisite-patch-id: b901ece2a5b78503e2fb5480f20e304d36a0ea27 -- 2.45.0