Messages in this thread | | | Date | Fri, 11 Mar 2016 10:32:43 -0800 | Subject | Re: [PATCH] x86/FPU: Fix FPU handling on legacy FPU machines | From | Linus Torvalds <> |
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On Fri, Mar 11, 2016 at 3:32 AM, Borislav Petkov <bp@alien8.de> wrote: > 486 cores like Intel Quark support only the very old, legacy x87 FPU > (FSAVE/FRSTOR, CPUID bit FXSR is not set). And our FPU code wasn't > handling the saving and restoring there properly. First, Andy Shevchenko > reported a splat: > > WARNING: CPU: 0 PID: 823 at arch/x86/include/asm/fpu/internal.h:163 fpu__clear+0x8c/0x160 > > which was us trying to execute FXRSTOR on those machines even though > they don't support it. > > After taking care of that, Bryan O'Donoghue reported that a simple FPU > test still failed because we weren't initializing the FPU state properly > on those machines.
Obvious Ack to the patch, along with a "how did this ever work before?" comment..
Linus
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