| Date | Thu, 24 Sep 2020 00:07:12 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v38 18/24] x86/vdso: Add support for exception fixup in vDSO functions |
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On Tue, Sep 15, 2020 at 02:28:36PM +0300, Jarkko Sakkinen wrote: > From: Sean Christopherson <sean.j.christopherson@intel.com> > > The basic concept and implementation is very similar to the kernel's > exception fixup mechanism. The key differences are that the kernel > handler is hardcoded and the fixup entry addresses are relative to > the overall table as opposed to individual entries.
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This gist of this commit message should be also in Documentation/x86/sgx.rst
And I already said the same thing during v33 review:
"That is a very good explanation and I would prefer if it would be in a sgx-specific README or so instead of it getting lost in git..."
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> diff --git a/arch/x86/entry/vdso/extable.h b/arch/x86/entry/vdso/extable.h > new file mode 100644 > index 000000000000..aafdac396948 > --- /dev/null > +++ b/arch/x86/entry/vdso/extable.h > @@ -0,0 +1,29 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef __VDSO_EXTABLE_H > +#define __VDSO_EXTABLE_H > + > +/* > + * Inject exception fixup for vDSO code. Unlike normal exception fixup, > + * vDSO uses a dedicated handler the addresses are relative to the overall > + * exception table, not each individual entry. > + */ > +#ifdef __ASSEMBLY__ > +#define _ASM_VDSO_EXTABLE_HANDLE(from, to) \ > + ASM_VDSO_EXTABLE_HANDLE from to > + > +.macro ASM_VDSO_EXTABLE_HANDLE from:req to:req > + .pushsection __ex_table, "a" > + .long (\from) - __ex_table > + .long (\to) - __ex_table > + .popsection > +.endm > +#else > +#define _ASM_VDSO_EXTABLE_HANDLE(from, to) \ > + ".pushsection __ex_table, \"a\"\n" \ > + ".long (" #from ") - __ex_table\n" \ > + ".long (" #to ") - __ex_table\n" \ > + ".popsection\n" > +#endif > + > +#endif /* __VDSO_EXTABLE_H */ > +
Also from last time:
.git/rebase-apply/patch:122: new blank line at EOF. +
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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