[PATCH v3 3/3] Add mremap tests

[Adhemerval Zanella Netto]

On 22/07/24 18:13, H.J. Lu wrote:
> On Tue, Jul 23, 2024, 2:50 AM Adhemerval Zanella Netto <adhemerval.zanella@linaro.org <mailto:adhemerval.zanella@linaro.org>> wrote:
> 
> 
> 
>     On 17/07/24 04:59, H.J. Lu wrote:

>     > +static int
>     > +mremap_failure_exit (int err, int flags)
>     > +{
>     > +  if (err != EINVAL)
>     > +    return EXIT_FAILURE;
>     > +
>     > +  unsigned int kernel = get_linux_kernel_version ();
>     > +  TEST_VERIFY_EXIT (kernel != 0);
>     > +
>     > +  /* Since MREMAP_FIXED was added to Linux kernel 2.3.31, return
>     > +     EXIT_FAILURE if the kernel is 2.3.31 or newer.  */
>     > +  if (flags == MREMAP_FIXED
>     > +      && kernel >= make_linux_kernel_version (2, 3, 31))
>     > +    return EXIT_FAILURE;
>     > +
>     > +  /* Since MREMAP_DONTUNMAP was added to Linux kernel 5.7, return
>     > +     EXIT_FAILURE if the kernel is 5.7 or newer.  */
>     > +  if (flags == MREMAP_DONTUNMAP
>     > +      && kernel >= make_linux_kernel_version (5, 7, 0))
>     > +    return EXIT_FAILURE;
>     > +
>     > +  return EXIT_UNSUPPORTED;
>     > +}
> 
>     I still think we should test for functionality and not tie the tests
>     for an specific Linux version.  So just set unsupported if mremap
>     MREMAP_DONTUNMAP fails with EINVAL.
> 
> 
> Do you have suggestions to make the test
> to fail on supported kernel without the
> mremap fix?

I don't think we should for this specific case, we are testing that the libc
is passing the correct arguments to the kernel; so either EINVAL (meaning
invalid/unsupported flags) or a successful call is expected (assuming that
the mremap usage is valid).