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| author | Andrei Vagin <avagin@gmail.com> | 2021-03-30 21:40:07 -0700 |
|---|---|---|
| committer | Andrei Vagin <avagin@gmail.com> | 2021-04-01 13:28:15 -0700 |
| commit | eb9b8e53a3ef7bb96dcb59a0121fa9ed22f01bfd (patch) | |
| tree | d01a7b7aae854e5b2a89c156d809e1b6aafc4640 /pkg/ring0/lib_amd64.s | |
| parent | 6c10c772e46ffe8d27cffe77aed24f0d334d611c (diff) | |
platform/kvm/x86: restore mxcsr when switching from guest to sentry
Goruntime sets mxcsr once and never changes it.
Reported-by: syzbot+ec55cea6e57ec083b7a6@syzkaller.appspotmail.com
Fixes: #5754
Diffstat (limited to 'pkg/ring0/lib_amd64.s')
| -rw-r--r-- | pkg/ring0/lib_amd64.s | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/pkg/ring0/lib_amd64.s b/pkg/ring0/lib_amd64.s index 2fe83568a..70a43e79e 100644 --- a/pkg/ring0/lib_amd64.s +++ b/pkg/ring0/lib_amd64.s @@ -198,3 +198,15 @@ TEXT ·rdmsr(SB),NOSPLIT,$0-16 MOVL AX, ret+8(FP) MOVL DX, ret+12(FP) RET + +// stmxcsr reads the MXCSR control and status register. +TEXT ·stmxcsr(SB),NOSPLIT,$0-8 + MOVQ addr+0(FP), SI + STMXCSR (SI) + RET + +// ldmxcsr writes to the MXCSR control and status register. +TEXT ·ldmxcsr(SB),NOSPLIT,$0-8 + MOVQ addr+0(FP), SI + LDMXCSR (SI) + RET |