Re: shell: enable OOM protection by default

Petr Vorel <[email protected]>
Newsgroups gmane.linux.ltp
Message-ID <20260810171429.GC1049677@pevik>
Hi Andrea,

> Hi Andrea,

> On Aug 10, 2026, Andrea Cervesato wrote:
> > shell: enable OOM protection by default

> > +	if ! echo "$value" > "$path"; then
> > +		tst_res TWARN "Can't adjust score"
> > +	fi

> Could this avoid reporting TWARN when CAP_SYS_RESOURCE is absent, as
> tst_memutils.c does? Lowering oom_score_adj requires that capability, so
> every unprivileged shell test now gets a warning result. The new self-test
> itself reports TCONF but exits 36 because this TWARN remains counted.

Ah, this really needs to be guarded behind  if [ "$(id -ru)" != 0 ]; then 

If you're in a mood for it, you could factor out [ "$(id -ru)" != 0 ] check into
it's own function tst_check_root or tst_is_root which would be then used in
tst_require_root and in this function.

I repeat my suggestion from last revision: add a helper into testcases/lib which
will just call C function. That way the behavior will be the same (use
capabilities). That would be more clearer solution.

Kind regards,
Petr

> > +	(
> > +		TST_CHILD=1
> > +		_tst_disable_oom_protection
> > +		trap '_tst_cleanup_timer; _tst_write_results' EXIT
> > +
> > +		if [ "$TST_ALL_FILESYSTEMS" = 1 ]; then
> > +			_tst_run_tcases_per_fs
> > +		else
> > +			_tst_run_iterations
> > +		fi
> > +	) &
> > +
> > +	wait $!
> > +	ret=$?

> How can the protected parent perform cleanup if this child is OOM-killed
> or times out? TST_DO_CLEANUP and TST_MOUNT_FLAG are set only in the
> subshell. On an abnormal child exit, the parent therefore reports TBROK
> without calling TST_CLEANUP or unmounting a device mounted by
> _prepare_device(), leaving external test state behind.

Sounds serious :). I'll comment on the patch itself.

Kind regards,
Petr

> Verdict - Needs revision

> ---
> Note:

> The agent can sometimes produce false positives although often its
> findings are genuine. If you find issues with the review, please
> comment this email or ignore the suggestions.

> Regards,
> LTP AI Reviewer

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