[LTP] [PATCH v4 4/4] futex_cmp_requeue03: Add EFAULT error coverage test

[Michael Menasherov]

  Hi,

  Following up again on this patch series originally sent on May 7th.
  The LTP AI Reviewer has already approved all four patches with no issues
found.

  Patch series:
    [LTP] [PATCH v4 1/4] futex_wait06: Add EFAULT error coverage test
    [LTP] [PATCH v4 2/4] futex_wait07: Add EINTR error coverage test
    [LTP] [PATCH v4 3/4] futex_wake05: Add EFAULT error coverage test
    [LTP] [PATCH v4 4/4] futex_cmp_requeue03: Add EFAULT error coverage test

  GitHub PR: https://github.com/linux-test-project/ltp/pull/1301

  Is there anything missing or anything I can improve to help move this
forward?

  Thanks. Regards.

On Thu, May 7, 2026 at 2:18 PM Michael Menasherov <mmenashe@redhat.com>
wrote:

> futex(FUTEX_CMP_REQUEUE) has no existing test for EFAULT. Add coverage
> for the cases where uaddr or uaddr2 points to unmapped or inaccessible
> (PROT_NONE) memory.
>
> Signed-off-by: Michael Menasherov <mmenashe@redhat.com>
> ---
>  runtest/syscalls                              |  1 +
>  testcases/kernel/syscalls/futex/.gitignore    |  1 +
>  .../syscalls/futex/futex_cmp_requeue03.c      | 94 +++++++++++++++++++
>  3 files changed, 96 insertions(+)
>  create mode 100644 testcases/kernel/syscalls/futex/futex_cmp_requeue03.c
>
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 4d85a1d26..65baa44dc 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -1908,3 +1908,4 @@ perf_event_open03 perf_event_open03
>  futex_wait06 futex_wait06
>  futex_wait07 futex_wait07
>  futex_wake05 futex_wake05
> +futex_cmp_requeue03 futex_cmp_requeue03
> diff --git a/testcases/kernel/syscalls/futex/.gitignore
> b/testcases/kernel/syscalls/futex/.gitignore
> index c11546e07..231b6bd25 100644
> --- a/testcases/kernel/syscalls/futex/.gitignore
> +++ b/testcases/kernel/syscalls/futex/.gitignore
> @@ -16,3 +16,4 @@
>  /futex_wait06
>  /futex_wait07
>  /futex_wake05
> +/futex_cmp_requeue03
> diff --git a/testcases/kernel/syscalls/futex/futex_cmp_requeue03.c
> b/testcases/kernel/syscalls/futex/futex_cmp_requeue03.c
> new file mode 100644
> index 000000000..4c3c6e358
> --- /dev/null
> +++ b/testcases/kernel/syscalls/futex/futex_cmp_requeue03.c
> @@ -0,0 +1,94 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2026 Red Hat, Inc.
> + */
> +
> +/*\
> + * Check that futex(FUTEX_CMP_REQUEUE) returns EFAULT when uaddr or
> + * uaddr2 points to unmapped memory, or when uaddr points to memory
> + * without read permission (PROT_NONE).
> + */
> +
> +#include <errno.h>
> +#include <sys/mman.h>
> +
> +#include "futextest.h"
> +
> +static futex_t futex_var = FUTEX_INITIALIZER;
> +static futex_t *prot_none_addr;
> +
> +static struct futex_test_variants variants[] = {
> +#if (__NR_futex != __LTP__NR_INVALID_SYSCALL)
> +       { .fntype = FUTEX_FN_FUTEX, .desc = "syscall with old kernel
> spec"},
> +#endif
> +
> +#if (__NR_futex_time64 != __LTP__NR_INVALID_SYSCALL)
> +       { .fntype = FUTEX_FN_FUTEX64, .desc = "syscall time64 with kernel
> spec"},
> +#endif
> +};
> +
> +static struct testcase {
> +       const char *desc;
> +       futex_t *uaddr;
> +       futex_t *uaddr2;
> +       int exp_errno;
> +} testcases[3];
> +
> +static void run(unsigned int n)
> +{
> +       struct futex_test_variants *tv = &variants[tst_variant];
> +       struct testcase *tc = &testcases[n];
> +
> +       TST_EXP_FAIL(futex_cmp_requeue(tv->fntype, tc->uaddr, futex_var,
> +               tc->uaddr2, 1, 1, 0), tc->exp_errno, "%s", tc->desc);
> +}
> +
> +static void setup(void)
> +{
> +       struct futex_test_variants *tv = &variants[tst_variant];
> +       size_t pagesize = getpagesize();
> +       futex_t *unmapped;
> +
> +       tst_res(TINFO, "Testing variant: %s", tv->desc);
> +       futex_supported_by_kernel(tv->fntype);
> +
> +       unmapped = SAFE_MMAP(NULL, pagesize, PROT_READ | PROT_WRITE,
> +               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> +       SAFE_MUNMAP(unmapped, pagesize);
> +
> +       prot_none_addr = SAFE_MMAP(NULL, pagesize, PROT_NONE,
> +               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> +
> +       testcases[0] = (struct testcase){
> +               .desc = "uaddr unmapped",
> +               .uaddr = unmapped,
> +               .uaddr2 = &futex_var,
> +               .exp_errno = EFAULT,
> +       };
> +       testcases[1] = (struct testcase){
> +               .desc = "uaddr2 unmapped",
> +               .uaddr = &futex_var,
> +               .uaddr2 = unmapped,
> +               .exp_errno = EFAULT,
> +       };
> +       testcases[2] = (struct testcase){
> +               .desc = "uaddr PROT_NONE",
> +               .uaddr = prot_none_addr,
> +               .uaddr2 = &futex_var,
> +               .exp_errno = EFAULT,
> +       };
> +}
> +
> +static void cleanup(void)
> +{
> +       if (prot_none_addr)
> +               SAFE_MUNMAP(prot_none_addr, getpagesize());
> +}
> +
> +static struct tst_test test = {
> +       .setup = setup,
> +       .cleanup = cleanup,
> +       .test = run,
> +       .tcnt = ARRAY_SIZE(testcases),
> +       .test_variants = ARRAY_SIZE(variants),
> +};
> --
> 2.53.0
>
>

-- 

Michael Menasherov

Software Quality Engineer - Automotive Kernel

Red Hat <https://www.redhat.com/>
<https://www.redhat.com/>