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| author | Sven Schnelle <[email protected]> | 2020-11-20 13:17:52 +0000 |
|---|---|---|
| committer | Heiko Carstens <[email protected]> | 2020-11-23 10:52:13 +0000 |
| commit | 1179f170b6f0af7bb0b3b7628136eaac450ddf31 (patch) | |
| tree | 19e8acb64e0968b41de4899cc1315c41b002839e /fs/btrfs/dev-replace.c | |
| parent | s390/cpum_sf.c: fix file permission for cpum_sfb_size (diff) | |
| download | kernel-1179f170b6f0af7bb0b3b7628136eaac450ddf31.tar.gz kernel-1179f170b6f0af7bb0b3b7628136eaac450ddf31.zip | |
s390: fix fpu restore in entry.S
We need to disable interrupts in load_fpu_regs(). Otherwise an
interrupt might come in after the registers are loaded, but before
CIF_FPU is cleared in load_fpu_regs(). When the interrupt returns,
CIF_FPU will be cleared and the registers will never be restored.
The entry.S code usually saves the interrupt state in __SF_EMPTY on the
stack when disabling/restoring interrupts. sie64a however saves the pointer
to the sie control block in __SF_SIE_CONTROL, which references the same
location. This is non-obvious to the reader. To avoid thrashing the sie
control block pointer in load_fpu_regs(), move the __SIE_* offsets eight
bytes after __SF_EMPTY on the stack.
Cc: <[email protected]> # 5.8
Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S")
Reported-by: Pierre Morel <[email protected]>
Signed-off-by: Sven Schnelle <[email protected]>
Acked-by: Christian Borntraeger <[email protected]>
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Diffstat (limited to 'fs/btrfs/dev-replace.c')
0 files changed, 0 insertions, 0 deletions