Re: [PATCH 0/2] x86/fpu: Allow restoring signal frames with larger xstate_size

[Borislav Petkov]

On Tue, Sep 29, 2026 at 11:26:19PM +0000, Andrei Vagin wrote:
> When a process is checkpointed on one machine and restored on another
> (e.g., via CRIU during container/process migration), any signal frame on
> its stack carries the xstate layout of the source CPU.
> 
> Commit fd14edd82077 ("x86/fpu: Pre-fault only required size of xstate
> buffer") enabled restoring signal frames created on CPUs with a smaller
> xstate_size than the destination host's default. However,
> check_xstate_in_sigframe() still enforces that a signal frame's
> xstate_size must not exceed the current task's fpstate->user_size.

Hmm, what happened? Change of heart after the fact?

So I guess I am zapping fd14edd82077 from tip:x86/fpu now and then we test
some more before we try this again?

-- 
Regards/Gruss,
    Boris.

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