[LTP] [PATCH v9 2/2] shmctl03: Fix 32-bit compat mode failure

[Petr Vorel]

Hi all,

[ Cc Dan's actual address, Linaro one no longer works ]

> On 64-bit kernels, the default shmmax and shmall values often exceed
> the range of a 32-bit unsigned long or are clipped differently by
> the kernel's compat syscall layer than they appear in /proc.

> Fix this by utilizing the new TST_ASSERT_ULONG() flags to properly
> clamp and truncate the expected values under compat mode.

> Link: https://lore.kernel.org/ltp/aJm5SBOaRoe1e0PB@yuki.lan/
> Suggested-by: Cyril Hrubis <chrubis@suse.cz>
> Reviewed-by: Andrea Cervesato <andrea.cervesato@suse.com>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Reported-by: Dan Carpenter <error27@gmail.com>

> Signed-off-by: Wei Gao <wegao@suse.com>
> ---
>  testcases/kernel/syscalls/shmctl/shmctl03.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)

> diff --git a/testcases/kernel/syscalls/shmctl/shmctl03.c b/testcases/kernel/syscalls/shmctl/shmctl03.c
> index 9e1c2f099..fcb416a1d 100644
> --- a/testcases/kernel/syscalls/shmctl/shmctl03.c
> +++ b/testcases/kernel/syscalls/shmctl/shmctl03.c
> @@ -30,9 +30,16 @@ static void verify_ipcinfo(void)
>  	else
>  		tst_res(TPASS, "shmmin = 1");

> -	TST_ASSERT_ULONG(PATH_KERN_SHMMAX, info.shmmax);
> -	TST_ASSERT_ULONG(PATH_KERN_SHMMNI, info.shmmni);
> -	TST_ASSERT_ULONG(PATH_KERN_SHMALL, info.shmall);
> +	int c = tst_is_compat_mode();
> +
> +	/*
> +	 * On 64-bit kernel, shmmax is clamped to INT_MAX for 32-bit
> +	 * compat syscall, while shmmni and shmall are truncated
> +	 * to 32-bit.
> +	 */
> +	TST_ASSERT_ULONG(PATH_KERN_SHMMAX, info.shmmax, c ? TST_ASSERT_SATURATED_INT : TST_ASSERT_NONE);
> +	TST_ASSERT_ULONG(PATH_KERN_SHMMNI, info.shmmni, c ? TST_ASSERT_TRUNC_32BIT : TST_ASSERT_NONE);
> +	TST_ASSERT_ULONG(PATH_KERN_SHMALL, info.shmall, c ? TST_ASSERT_TRUNC_32BIT : TST_ASSERT_NONE);
>  }

>  static struct tst_test test = {