| Message ID | 20230906-memfd-reduce-spam-v1-1-1f0d35facd95@cyphar.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | memfd: drop warning for missing exec-related flags | expand |
On Wed, Sep 06, 2023 at 05:02:06PM +1000, Aleksa Sarai 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") > Reported-by: Damian Tometzki <dtometzki@fedoraproject.org> > Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> > --- Looks good to me, Reviewed-by: Christian Brauner <brauner@kernel.org>
On Wed, 06 Sep 2023 17:02:06 +1000 Aleksa Sarai <cyphar@cyphar.com> 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.
diff --git a/mm/memfd.c b/mm/memfd.c index 1cad1904fc26..d3a1ba4208c9 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -315,12 +315,6 @@ SYSCALL_DEFINE2(memfd_create, if ((flags & MFD_EXEC) && (flags & MFD_NOEXEC_SEAL)) return -EINVAL; - if (!(flags & (MFD_EXEC | MFD_NOEXEC_SEAL))) { - pr_info_ratelimited( - "%s[%d]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set\n", - current->comm, task_pid_nr(current)); - } - error = check_sysctl_memfd_noexec(&flags); if (error < 0) return error;
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") Reported-by: Damian Tometzki <dtometzki@fedoraproject.org> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> --- mm/memfd.c | 6 ------ 1 file changed, 6 deletions(-) --- base-commit: 2374b401b0e0b9ab6d91eead30f9a049f8d620cf change-id: 20230906-memfd-reduce-spam-8788fc0b951e Best regards,