On 11/3/23 13:53, Sam James wrote:
Sam James <sam@xxxxxxxxxx> writes:
I recently hit an issue with systemd-254 which tries to use the new
prctl(PR_SET_MDWE) for systemd's MemoryDenyWriteExecute functionality.
Is this still a problem?
On HPPA, we still need executable stacks, so this option doesn't work
and leads to a segfault on boot.
For kernel we don't need it any longer.
But there might be dependencies on glibc version and/or combination.
So, I've currently lost overview if we still need executable stacks...
Should this call be succeeeding on HPPA, or should we reject it for
now until we have things wired up?
Reported to systemd at https://github.com/systemd/systemd/issues/29775.
Lennart has made clear (and I don't think I disagree) that he considers
this squarely a kernel bug.
I've read the various bug reports and looked at the kernel commits regarding, e.g.
commit b507808ebce23561d4ff8c2aa1fb949fe402bc61
Author: Joey Gouly <joey.gouly@xxxxxxx>
Date: Thu Jan 19 16:03:43 2023 +0000
mm: implement memory-deny-write-execute as a prctl
but what is prctl(PR_SET_MDWE, PR_MDWE*, 0, 0)... expected to return on parisc?
EINVAL? ENOTSUP?
Helge
