[LTP] [PATCH v2] syscalls/munmap04: Check errno while trying to exhaust VMA count

[Ricardo B. Marlière]

On Mon Jul 28, 2025 at 11:23 AM -03, Ricardo B. Marlière wrote:
> From: Ricardo B. Marlière <rbm@suse.com>
>
> In the loop that exhausts the amount of VMAs we must check not only for
> MAP_FAILED return from mmap() but also if the error was EEXIST. In that
> case, keep retrying with increasing addresses. While at it, add a sanity
> check if no regions were mapped.
>
> Suggested-by: Cyril Hrubis <chrubis@suse.cz>
> Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
> ---
> Changes in v2:
> - EDITME: describe what is new in this series revision.
> - EDITME: use bulletpoints and terse descriptions.
> - Link to v1: https://lore.kernel.org/r/20250728-fixes-munmap04-v1-1-e32ef11d594a@suse.com

Oops, forgot to edit this:

Changes in v2:
- Check for errno == EEXIST instead of removing MAP_FIXED_NOREPLACE flag

> ---
>  testcases/kernel/syscalls/munmap/munmap04.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/testcases/kernel/syscalls/munmap/munmap04.c b/testcases/kernel/syscalls/munmap/munmap04.c
> index e046d17a75f8f75c5b11d569c33da41d7adc7d09..aeb905286e9d4214ac6423ef26e9570674b60530 100644
> --- a/testcases/kernel/syscalls/munmap/munmap04.c
> +++ b/testcases/kernel/syscalls/munmap/munmap04.c
> @@ -40,14 +40,17 @@ static void setup(void)
>  			     vma_size, PROT_NONE,
>  			     MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE,
>  			     -1, 0);
> +		if (p == MAP_FAILED && errno == EEXIST)
> +			continue;
>  		if (p == MAP_FAILED)
>  			break;
>  		maps[map_count++] = p;
>  	}
>  
>  	if (map_count == MAP_MAX_COUNT)
> -		tst_brk(TBROK, "Mapped all %d regions, expected less",
> -			map_count);
> +		tst_brk(TBROK, "Mapped all %d regions, expected less", map_count);
> +	if (map_count == 0)
> +		tst_brk(TBROK, "Mapped 0 regions");
>  
>  	tst_res(TINFO, "Mapped %d regions", map_count);
>  }
>
> ---
> base-commit: 6af619552ce7676171e47b88964ffb5b08499b36
> change-id: 20250728-fixes-munmap04-02083c550c6b
>
> Best regards,