Re: [PATCH] memfd: drop warning for missing exec-related flags

From: Andrew Morton
Date: Sun Sep 10 2023 - 17:35:10 EST


On Wed, 06 Sep 2023 17:02:06 +1000 Aleksa Sarai <cyphar@xxxxxxxxxx> wrote:

> Commit 434ed3350f57 ("memfd: improve userspace warnings for missing
> exec-related flags") attempted to make these warnings more useful (so
> they would work as an incentive to get users to switch to specifying
> these flags -- as intended by the original MFD_NOEXEC_SEAL patchset).
> Unfortunately, it turns out that even INFO-level logging is too extreme
> to enable by default and alternative solutions to the spam issue (such
> as doing more extreme rate-limiting per-task) are either too ugly or
> overkill for something as simple as emitting a log as a developer aid.
>
> Given that the flags are new and there is no harm to not specifying them
> (after all, we maintain backwards compatibility) we can just drop the
> warnings for now until some time in the future when most programs have
> migrated and distributions start using vm.memfd_noexec=1 (where failing
> to pass the flag would result in unexpected errors for programs that use
> executable memfds).
>
> Fixes: 434ed3350f57 ("memfd: improve userspace warnings for missing exec-related flags")

This was reverted, so please propose a new patch against 6.6-rc1.