linux-kernel - Re: [PATCH v4 37/39] x86: Add PTRACE interface for shadow stack

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Message-ID: <a34d766dc3bf09e445320e0f94fb8d8e6301c7b5.camel@intel.com>
Date:   Fri, 9 Dec 2022 17:08:20 +0000
From:   "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
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Subject: Re: [PATCH v4 37/39] x86: Add PTRACE interface for shadow stack

On Fri, 2022-12-09 at 19:04 +0200, Mike Rapoport wrote:
> >   /*
> >    * xstateregs_active == regset_fpregs_active. Please refer to the
> > comment
> > diff --git a/arch/x86/kernel/fpu/regset.c
> > b/arch/x86/kernel/fpu/regset.c
> > index 6d056b68f4ed..00f3d5c9b682 100644
> > --- a/arch/x86/kernel/fpu/regset.c
> > +++ b/arch/x86/kernel/fpu/regset.c
> > @@ -8,6 +8,7 @@
> >   #include <asm/fpu/api.h>
> >   #include <asm/fpu/signal.h>
> >   #include <asm/fpu/regset.h>
> > +#include <asm/prctl.h>
> >   
> >   #include "context.h"
> >   #include "internal.h"
> > @@ -174,6 +175,92 @@ int xstateregs_set(struct task_struct *target,
> > const struct user_regset *regset,
> >        return ret;
> >   }
> >   
> > +
> > +#ifdef CONFIG_X86_USER_SHADOW_STACK
> > +int ssp_active(struct task_struct *target, const struct
> > user_regset *regset)
> > +{
> > +     if (shstk_enabled())
> 
> This is not going to work with ptrace as shstk_enabled() checks
> current
> rather than target.

Oh right, thanks. I can change shstk_enabled() to take a task_struct.