Messages in this thread Patch in this message | | | Date | Wed, 31 Jan 2024 10:20:28 +0200 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH v3 1/2] x86/sev: enforce RIP-relative accesses in early SEV/SME code |
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On Tue, Jan 30, 2024 at 10:08:44PM +0000, Kevin Loughlin wrote: > diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h > index 359ada486fa9..b65e66ee79c4 100644 > --- a/arch/x86/include/asm/mem_encrypt.h > +++ b/arch/x86/include/asm/mem_encrypt.h > @@ -17,6 +17,20 @@ > > #include <asm/bootparam.h> > > +/* > + * Like the address operator "&", evaluates to the address of a LHS variable > + * "var", but also enforces the use of RIP-relative logic. This macro can be > + * used to safely access global data variables prior to kernel relocation. > + */ > +#define RIP_RELATIVE_ADDR(var) \ > +({ \ > + void *rip_rel_ptr; \ > + asm ("lea "#var"(%%rip), %0" \ > + : "=r" (rip_rel_ptr) \ > + : "p" (&var)); \ > + rip_rel_ptr; \ > +}) > +
I don't think it is the right place for the macro. The next patch uses for things unrelated to memory encryption.
> @@ -239,14 +244,14 @@ unsigned long __head __startup_64(unsigned long physaddr, > */ > > next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr); > - pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr); > - pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr); > + early_dynamic_pgts_ptr = fixup_pointer(early_dynamic_pgts, physaddr); > + pud = (pudval_t *) early_dynamic_pgts_ptr[(*next_pgt_ptr)++]; > + pmd = (pmdval_t *) early_dynamic_pgts_ptr[(*next_pgt_ptr)++]; >
This change doesn't belong to this patch. Maybe move it into the next patch and combine with removing fixup_pointer().
-- Kiryl Shutsemau / Kirill A. Shutemov
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