diff options
| author | Andy Lutomirski <luto@kernel.org> | 2021-01-20 21:09:49 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-27 11:47:49 +0100 |
| commit | c5885886c72c4fcb283bd8f5066ddf2e44afc094 (patch) | |
| tree | d34583d65ec41725b116f7518cc6122ef34c278c /arch/csky | |
| parent | d1a9cd1dc53c6ff3126e627b80ebf324ef4b8ee9 (diff) | |
x86/mmx: Use KFPU_387 for MMX string operations
commit 67de8dca50c027ca0fa3b62a488ee5035036a0da upstream.
The default kernel_fpu_begin() doesn't work on systems that support XMM but
haven't yet enabled CR4.OSFXSR. This causes crashes when _mmx_memcpy() is
called too early because LDMXCSR generates #UD when the aforementioned bit
is clear.
Fix it by using kernel_fpu_begin_mask(KFPU_387) explicitly.
Fixes: 7ad816762f9b ("x86/fpu: Reset MXCSR to default in kernel_fpu_begin()")
Reported-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Krzysztof Piotr Olędzki <ole@ans.pl>
Tested-by: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/e7bf21855fe99e5f3baa27446e32623358f69e8d.1611205691.git.luto@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/csky')
0 files changed, 0 insertions, 0 deletions