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(parent: b0dc553) | patch
x86/fpu/64: Don't FNINIT in kernel_fpu_begin()
authorAndy Lutomirski <luto@kernel.org>
Thu, 21 Jan 2021 05:09:51 +0000 (21:09 -0800)
committerBorislav Petkov <bp@suse.de>
Fri, 29 Jan 2021 11:27:47 +0000 (12:27 +0100)
commit49200d17d27d5cc1aede2d1bb2a78dbfc1563e65
tree8f126191de040ce89b2800b4e4204fad8d666a64tree | snapshot
parentb0dc553cfc9d3bc2c7b8672b0b2fcf0edf0c3b6ecommit | diff
x86/fpu/64: Don't FNINIT in kernel_fpu_begin()

The remaining callers of kernel_fpu_begin() in 64-bit kernels don't use 387
instructions, so there's no need to sanitize the FPU state.  Skip it to get
most of the performance we lost back.

Reported-by: Krzysztof Olędzki <ole@ans.pl>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/57f8841ccbf9f3c25a23196c888f5f6ec5887577.1611205691.git.luto@kernel.org
arch/x86/include/asm/fpu/api.h diff | blob | history
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