diff options
| author | Heiko Carstens <hca@linux.ibm.com> | 2023-12-08 15:03:15 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-05 15:13:28 +0100 |
| commit | 183ea95f7374e04157b871824680aa93783c46e6 (patch) | |
| tree | 6898d91f84c9d987608c0e91b4035e375921b0e9 /arch | |
| parent | 58f3fc83332181468b924c44f188d8bab2835ec1 (diff) | |
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>
Diffstat (limited to 'arch')
| -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 a959b815a58b..b8c7e8538c85 100644 --- a/arch/s390/include/asm/fpu/api.h +++ b/arch/s390/include/asm/fpu/api.h @@ -78,7 +78,7 @@ 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; |