On Thu, 2017-04-27 at 14:46 +0200, Borislav Petkov wrote:
> On Fri, Apr 21, 2017 at 11:22:31PM +0200, Rafael J. Wysocki wrote:
> > > #ifdef CONFIG_ACPI_APEI_PCIEAER
> > > - else if (!uuid_le_cmp(*(uuid_le *)gdata-
> > > >section_type,
> > > - CPER_SEC_PCIE)) {
> > > + else if (!uuid_le_cmp_p(sec_type, CPER_SEC_PCIE))
> > > {
> > > struct cper_sec_pcie *pcie_err;
> > > pcie_err = (struct cper_sec_pcie
> > > *)(gdata+1);
> > > if (sev == GHES_SEV_RECOVERABLE &&
> > >
> >
> > But this one is for Boris.
>
> I don't see anything wrong with it upon a brief inspection.
Lukas pointed to this:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68725
>
> What could be improved here, though, is if the whole uuid_* types
> handling be changed so that gcc doesn't generate yucky code. Because
> here's what it does now, regardless of this patch:
>
> .file 16 "./include/linux/uuid.h"
> .loc 16 63 0
> leaq 16(%rsp), %rsi #,
> movl $16, %edx #,
> movq %r15, %rdi # gdata,
> movb $84, 16(%rsp) #, MEM[(struct *)&u2]
> movb $-23, 17(%rsp) #, MEM[(struct *)&u2 + 1B]
> movb $-107, 18(%rsp) #, MEM[(struct *)&u2 + 2B]
> movb $-39, 19(%rsp) #, MEM[(struct *)&u2 + 3B]
> movb $-63, 20(%rsp) #, MEM[(struct *)&u2 + 4B]
> movb $-69, 21(%rsp) #, MEM[(struct *)&u2 + 5B]
> movb $15, 22(%rsp) #, MEM[(struct *)&u2 + 6B]
> movb $67, 23(%rsp) #, MEM[(struct *)&u2 + 7B]
> movb $-83, 24(%rsp) #, MEM[(struct *)&u2 + 8B]
> movb $-111, 25(%rsp) #, MEM[(struct *)&u2 + 9B]
> movb $-76, 26(%rsp) #, MEM[(struct *)&u2 + 10B]
> movb $77, 27(%rsp) #, MEM[(struct *)&u2 + 11B]
> movb $-53, 28(%rsp) #, MEM[(struct *)&u2 + 12B]
> movb $60, 29(%rsp) #, MEM[(struct *)&u2 + 13B]
> movb $111, 30(%rsp) #, MEM[(struct *)&u2 + 14B]
> movb $53, 31(%rsp) #, MEM[(struct *)&u2 + 15B]
> call memcmp #
>
> So it is basically building that UUID byte by byte before calling
> memcmp.
>
> And I'm wondering if those 16-byte arrays could be replaced with
>
> typedef struct {
> u64 a, b;
> } u128;
>
> from the crypto code.
>
> And whether the code generated by gcc would look much saner. Because
> the
> CPU can handle two qwords much better/faster than 16 u8s.
>
> Anyway, in case someone feels bored...
>
> --
> Regards/Gruss,
> Boris.
>
> SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton,
> HRB 21284 (AG Nürnberg)
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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