Messages in this thread | | | Date | Wed, 7 Aug 2013 08:51:19 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2] x86, AMD: Make cpu_has_amd_erratum() use the correct struct cpuinfo_x86 |
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On Tue, Jul 23, 2013 at 07:40:49PM +0200, Torsten Kaiser wrote: > cpu_has_amd_erratum() is buggy, because it uses the per-cpu cpu_info > before it is filled by smp_store_boot_cpu_info() / smp_store_cpu_info(). > > If early microcode loading is enabled its collect_cpu_info_amd_early() will > fill ->x86 and so the fallback to boot_cpu_data is not used. > But ->x86_vendor was not filled and is still 0 == X86_VENDOR_INTEL resulting in > no errata fixes getting applied and my system hangs on boot. > > Using cpu_info in cpu_has_amd_erratum() is wrong anyway: Its only caller > init_amd() will have a struct cpuinfo_x86 as parameter and the set_cpu_bug() > that is controlled by cpu_has_amd_erratum() also only uses that struct. > > So pass the struct cpuinfo_x86 from init_amd() to cpu_has_amd_erratum() and > the broken fallback can be dropped. > > I also added an WARN_ON() into the vendor check because init_amd() can only > be used by AMD CPUs and if the current failure hadn't been silent this bug > would have been much more obvious. > > V2: At request of Borislav Petkov: BUG_ON -> WARN_ON and subject change > > Signed-off-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Acked-by: Borislav Petkov <bp@suse.de>
-- Regards/Gruss, Boris.
Sent from a fat crate under my desk. Formatting is fine. --
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