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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2019-11-18 09:38:37 +0100 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2019-11-30 10:52:44 +0100 |
| commit | 5a5525b0488ce31e19065f8527dbf50266b5b712 (patch) | |
| tree | 962f0b570a299c36ea29f9dd2cb14943b488ca68 /arch/s390/kernel/asm-offsets.c | |
| parent | s390/smp,vdso: fix ASCE handling (diff) | |
| download | linux-5a5525b0488ce31e19065f8527dbf50266b5b712.tar.xz linux-5a5525b0488ce31e19065f8527dbf50266b5b712.zip | |
s390/vdso: fix getcpu
getcpu reads the required values for cpu and node with two
instructions. This might lead to an inconsistent result if user space
gets preempted and migrated to a different CPU between the two
instructions.
Fix this by using just a single instruction to read both values at
once.
This is currently rather a theoretical bug, since there is no real
NUMA support available (except for NUMA emulation).
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/asm-offsets.c')
| -rw-r--r-- | arch/s390/kernel/asm-offsets.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index 41ac4ad21311..ce33406cfe83 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -78,8 +78,7 @@ int main(void) OFFSET(__VDSO_TS_END, vdso_data, ts_end); OFFSET(__VDSO_ECTG_BASE, vdso_per_cpu_data, ectg_timer_base); OFFSET(__VDSO_ECTG_USER, vdso_per_cpu_data, ectg_user_time); - OFFSET(__VDSO_CPU_NR, vdso_per_cpu_data, cpu_nr); - OFFSET(__VDSO_NODE_ID, vdso_per_cpu_data, node_id); + OFFSET(__VDSO_GETCPU_VAL, vdso_per_cpu_data, getcpu_val); BLANK(); /* constants used by the vdso */ DEFINE(__CLOCK_REALTIME, CLOCK_REALTIME); |