Re: [PATCH v7 02/39] prctl: arch-agnostic prctl for shadow stack

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Dec 12, 2023 at 09:22:59PM +0000, Edgecombe, Rick P wrote:
> On Tue, 2023-12-12 at 20:26 +0000, Mark Brown wrote:

> > In general if things have a need to get at prctl()s via ptrace we
> > should
> > just fix that, at least for arm64 there's things like the vector
> > lengths
> > that are currently controlled via prctl(), but it shouldn't be a
> > blocker
> > for the locking specifically.

> ptrace arch_prctl() is a bit odd. Not all values of 'option' are
> supported because ptrace arch_prctl's have to operate cross task. Some
> have extra code to support doing this, and some only know how to
> operate on the current task, so return an error in the ptrace case.

It feels like x86 is doing some things via arch_prctl() rather than
implementing specific ptrace() interfaces for them, there's a lot of
stuff where ptrace isn't a great fit for due to it's concept that it's
going to work with an array of registers so that's understandable.

> I guess a benefit would be that there could be some arch agnostic
> ptrace userspace code. And I'd also guess (really a guess) that most
> ptracing code has some arch awareness already, but the other way is
> probably non-zero. Same for shadow stack enabling code. Then on the
> kernel side we'd have to add and support a ptrace prctl() solution.

> Is it worth the effort? I don't have a strong opinion.

I don't have a strong enough opinion on it to start working on it
immediately at any rate.

Attachment: signature.asc
Description: PGP signature


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [NTFS 3]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [NTFS 3]     [Samba]     [Device Mapper]     [CEPH Development]

  Powered by Linux