[LTP] [PATCH] syscalls/fanotify19: Add test cases for elevated reader privileges

[Petr Vorel <pvorel@suse.cz>]

Hi Amir,

> Even when event reader has elevated privileges, the information provided
> in events is determined by the privileges of the user that created the
> fanotify group.

> Add test cases for unprivileged listener and privileged event reader.

> This is a regression test for kernel commit
> a8b98c808eab ("fanotify: fix permission model of unprivileged group")

> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---

> Hi Petr,

> Added test for a fix in v5.13-rc5.

Thanks for your patch, pushed!

Things I've found, not related to this patch:

TBROK when running with higher number of iterations:
./fanotify19 -i 30
...
fanotify19.c:224: TPASS: Received event: mask=2b, pid=11351 fd=-1
fanotify19.c:224: TPASS: Received event: mask=b, pid=11351 fd=-1
fanotify19.c:224: TPASS: Received event: mask=a, pid=11351 fd=-1
fanotify19.c:224: TPASS: Received event: mask=8, pid=11351 fd=-1
fanotify19.c:147: TINFO: Test #3 unprivileged lisneter, privileged reader - events by child
fanotify19.c:151: TINFO: Running as privileged user, revoking.
fanotify19.c:136: TBROK: Child process terminated incorrectly. Aborting

Summary:
passed   316
failed   0
broken   1
skipped  0
warnings 0

Could you have look into it?

very minor nit: checkpatch complains about minor issues. Although all but quoted
string split across lines are easily fixable we don't need to bother with it.
But could you please use checkpatch for new tests?
Also I'd personally join also strings which are below 100 chars, because it
helps to grep.

> @@ -248,6 +285,10 @@ static struct tst_test test = {
>  	.needs_root = 1,
>  	.mount_device = 1,
>  	.mntpoint = MOUNT_PATH,
> +	.tags = (const struct tst_tag[]) {
> +		{"linux-git", "a8b98c808eab"},
FYI we also support "linux-stable-git", but we mainly use it for stable branch
specific patches (something required just for stable), not for regular backports
of fixes.

Kind regards,
Petr