On Tue, Jul 5, 2022 at 9:41 AM David Vernet <void@xxxxxxxxxxxxx> wrote:
>
> On Mon, Jul 04, 2022 at 07:33:51PM +0200, Adam Sindelar wrote:
>
> Thanks for fixing this, Adam.
>
> > mrelease_test should return KSFT_SKIP when process_mrelease is not
> > defined, but due to a perror call consuming the errno, it returns
> > KSFT_FAIL.
> >
> > This patch decides the exit code before calling perror.
> >
>
> We should probably also include a "Fixes" line here (see [0]):
>
> Fixes: 33776141b812 ("selftests: vm: add process_mrelease tests")
>
> [0]: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
>
> > Signed-off-by: Adam Sindelar <adam@xxxxxxxxxxxx>
> > ---
> > v1->v2: Fixed second instance in the same file
> >
> > tools/testing/selftests/vm/mrelease_test.c | 7 +++++--
> > 1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/testing/selftests/vm/mrelease_test.c b/tools/testing/selftests/vm/mrelease_test.c
> > index 96671c2f7d48..e8b17258579b 100644
> > --- a/tools/testing/selftests/vm/mrelease_test.c
> > +++ b/tools/testing/selftests/vm/mrelease_test.c
> > @@ -100,8 +100,10 @@ int main(void)
> >
> > /* Test a wrong pidfd */
> > if (!syscall(__NR_process_mrelease, -1, 0) || errno != EBADF) {
> > + /* perror overwrites errno, so this line must be first */
> > + res = (errno == ENOSYS ? KSFT_SKIP : KSFT_FAIL);
> > perror("process_mrelease with wrong pidfd");
> > - exit(errno == ENOSYS ? KSFT_SKIP : KSFT_FAIL);
> > + exit(res);
> > }
> >
> > /* Start the test with 1MB child memory allocation */
> > @@ -156,8 +158,9 @@ int main(void)
> > run_negative_tests(pidfd);
> >
> > if (kill(pid, SIGKILL)) {
> > + res = (errno == ENOSYS ? KSFT_SKIP : KSFT_FAIL);
> > perror("kill");
> > - exit(errno == ENOSYS ? KSFT_SKIP : KSFT_FAIL);
> > + exit(res);
> > }
> >
> > success = (syscall(__NR_process_mrelease, pidfd, 0) == 0);
> > --
> > 2.35.1
> >
>
> This looks good to me, but it looks like there are a couple of other places
> where we're doing the wrong thing, i.e. in run_negative_tests() and after
> calling waitpid(). Could you please fix those as well?
>
> Also adding Suren to cc.
Thanks for adding me, David!
The fixes look good but there are 5 places in all this fix is needed:
https://elixir.bootlin.com/linux/v5.19-rc5/source/tools/testing/selftests/vm/mrelease_test.c#L68
https://elixir.bootlin.com/linux/v5.19-rc5/source/tools/testing/selftests/vm/mrelease_test.c#L76
https://elixir.bootlin.com/linux/v5.19-rc5/source/tools/testing/selftests/vm/mrelease_test.c#L103
https://elixir.bootlin.com/linux/v5.19-rc5/source/tools/testing/selftests/vm/mrelease_test.c#L159
https://elixir.bootlin.com/linux/v5.19-rc5/source/tools/testing/selftests/vm/mrelease_test.c#L175
Thanks for catching this, Adam!
Suren.
>
> - David
