Messages in this thread | | | Date | Mon, 26 Nov 2018 18:49:45 +0100 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH] x86/fpu: XRSTOR is expected to raise #GP |
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On 2018-11-26 18:27:06 [+0100], Jann Horn wrote: > commit 75045f77f7a7 ("x86/extable: Introduce _ASM_EXTABLE_UA for uaccess > fixups") incorrectly replaced the fixup entry for XSTATE_OP with a > user-#PF-only fixup. However, XRSTOR can also raise #GP when the supplied > address points to userspace memory. Change it back.
The #GP is raised if the xstate content is invalid. But I guess the details don't matter.
> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > Fixes: 75045f77f7a7 ("x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups") > Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> --- > arch/x86/include/asm/fpu/internal.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h > index 5f7290e6e954..69dcdf195b61 100644 > --- a/arch/x86/include/asm/fpu/internal.h > +++ b/arch/x86/include/asm/fpu/internal.h > @@ -226,7 +226,7 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu) > "3: movl $-2,%[err]\n\t" \ > "jmp 2b\n\t" \ > ".popsection\n\t" \ > - _ASM_EXTABLE_UA(1b, 3b) \ > + _ASM_EXTABLE(1b, 3b) \
So you revert to what we had before. That works, tested.
> : [err] "=r" (err) \ > : "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \ > : "memory") > -- > 2.20.0.rc0.387.gc7a69e6b6c-goog
Sebastian
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