From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "yury.khrustalev@arm.com" <yury.khrustalev@arm.com>
Cc: "adhemerval.zanella@linaro.org" <adhemerval.zanella@linaro.org>,
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Subject: Re: [PATCH RFC 0/3] arm64/gcs: Allow reuse of user managed shadow stacks
Date: Fri, 26 Sep 2025 15:39:46 +0000 [thread overview]
Message-ID: <04dc6271e11b453204255779fcd3c29573c9c296.camel@intel.com> (raw)
In-Reply-To: <aNasTpkYm8n1AHZ7@arm.com>
On Fri, 2025-09-26 at 16:07 +0100, Yury Khrustalev wrote:
> > I think we should see a fuller solution from the glibc side before
> > adding new
> > kernel features like this. (apologies if I missed it).
>
> What do you mean by "a fuller solution from the glibc side"? A
> solution
> for re-using shadow stacks?
I mean some code or a fuller explained solution that uses this new
kernel functionality. I think the scheme that Florian suggested in the
thread linked above (longjmp() to the start of the stack) will have
trouble if the thread pivots to a new shadow stack before exiting (e.g.
ucontext).
> Right now Glibc cannot do anything about
> shadow stacks for new threads because clone3 interface doesn't allow
> it.
If you enable WRSS (or the arm equivalent) you can re-use shadow stacks
today by writing a token.
next prev parent reply other threads:[~2025-09-26 15:39 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-21 13:21 [PATCH RFC 0/3] arm64/gcs: Allow reuse of user managed shadow stacks Mark Brown
2025-09-21 13:21 ` [PATCH RFC 1/3] arm64/gcs: Support reuse of GCS for exited threads Mark Brown
2025-09-25 16:46 ` Catalin Marinas
2025-09-25 17:01 ` Mark Brown
2025-09-25 18:36 ` Catalin Marinas
2025-09-25 19:00 ` Mark Brown
2025-09-26 11:14 ` Catalin Marinas
2025-09-26 11:37 ` Mark Brown
2025-09-21 13:21 ` [PATCH RFC 2/3] kselftest/arm64: Validate PR_SHADOW_STACK_EXIT_TOKEN in basic-gcs Mark Brown
2025-09-21 13:21 ` [PATCH RFC 3/3] kselftest/arm64: Add PR_SHADOW_STACK_EXIT_TOKEN to gcs-locking Mark Brown
2025-09-25 20:40 ` [PATCH RFC 0/3] arm64/gcs: Allow reuse of user managed shadow stacks Edgecombe, Rick P
2025-09-25 23:22 ` Mark Brown
2025-09-25 23:58 ` Edgecombe, Rick P
2025-09-26 0:44 ` Mark Brown
2025-09-26 15:46 ` Edgecombe, Rick P
2025-09-26 16:09 ` Mark Brown
2025-09-29 18:37 ` Deepak Gupta
2025-09-26 15:07 ` Yury Khrustalev
2025-09-26 15:39 ` Edgecombe, Rick P [this message]
2025-09-26 16:03 ` Mark Brown
2025-09-26 19:17 ` Edgecombe, Rick P
2025-09-29 15:47 ` Mark Brown
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