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| author | Heiko Carstens <hca@linux.ibm.com> | 2023-12-08 15:03:15 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-08 11:25:02 +0100 |
| commit | 65def53e047b63deb755d0e24cda4ada145dd5b8 (patch) | |
| tree | e9124480b4949b5bb3a24c91671e540b0898312e | |
| parent | 27db23931d575ca7f3b017250b96ce9ee1c4959e (diff) | |
| download | linux-stable-65def53e047b63deb755d0e24cda4ada145dd5b8.tar.gz linux-stable-65def53e047b63deb755d0e24cda4ada145dd5b8.tar.bz2 linux-stable-65def53e047b63deb755d0e24cda4ada145dd5b8.zip | |
s390/vx: fix save/restore of fpu kernel context
[ Upstream commit e6b2dab41888332bf83f592131e7ea07756770a4 ]
The KERNEL_FPR mask only contains a flag for the first eight vector
registers. However floating point registers overlay parts of the first
sixteen vector registers.
This could lead to vector register corruption if a kernel fpu context uses
any of the vector registers 8 to 15 and is interrupted or calls a
KERNEL_FPR context. If that context uses also vector registers 8 to 15,
their contents will be corrupted on return.
Luckily this is currently not a real bug, since the kernel has only one
KERNEL_FPR user with s390_adjust_jiffies() and it is only using floating
point registers 0 to 2.
Fix this by using the correct bits for KERNEL_FPR.
Fixes: 7f79695cc1b6 ("s390/fpu: improve kernel_fpu_[begin|end]")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/s390/include/asm/fpu/api.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/include/asm/fpu/api.h b/arch/s390/include/asm/fpu/api.h index 34a7ae68485c..be16a6c0f127 100644 --- a/arch/s390/include/asm/fpu/api.h +++ b/arch/s390/include/asm/fpu/api.h @@ -76,7 +76,7 @@ static inline int test_fp_ctl(u32 fpc) #define KERNEL_VXR_HIGH (KERNEL_VXR_V16V23|KERNEL_VXR_V24V31) #define KERNEL_VXR (KERNEL_VXR_LOW|KERNEL_VXR_HIGH) -#define KERNEL_FPR (KERNEL_FPC|KERNEL_VXR_V0V7) +#define KERNEL_FPR (KERNEL_FPC|KERNEL_VXR_LOW) struct kernel_fpu; |