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| author | Alexander Gordeev <agordeev@linux.ibm.com> | 2021-12-10 16:32:11 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2021-12-16 19:58:07 +0100 |
| commit | c7ed509b21b6566990ff39a6744cd5e214b5dca9 (patch) | |
| tree | acd60b4b292b8e02a2fc4338653b9ce4d09ab763 /arch/s390/kernel/smp.c | |
| parent | cff2d3abc8da078a0447d785736204d8a0ad49b0 (diff) | |
| download | linux-stable-c7ed509b21b6566990ff39a6744cd5e214b5dca9.tar.gz linux-stable-c7ed509b21b6566990ff39a6744cd5e214b5dca9.tar.bz2 linux-stable-c7ed509b21b6566990ff39a6744cd5e214b5dca9.zip | |
s390/nmi: disable interrupts on extended save area update
Updating of the pointer to machine check extended save area
on the IPL CPU needs the lowcore protection to be disabled.
Disable interrupts while the protection is off to avoid
unnoticed writes to the lowcore.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/smp.c')
| -rw-r--r-- | arch/s390/kernel/smp.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 2590c31a8fc3..1172aaf0b7e2 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -212,7 +212,7 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW); lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW); lc->preempt_count = PREEMPT_DISABLED; - if (nmi_alloc_per_cpu(lc)) + if (nmi_alloc_mcesa(&lc->mcesad)) goto out; lowcore_ptr[cpu] = lc; pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); @@ -239,7 +239,7 @@ static void pcpu_free_lowcore(struct pcpu *pcpu) mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET; pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); lowcore_ptr[cpu] = NULL; - nmi_free_per_cpu(lc); + nmi_free_mcesa(&lc->mcesad); stack_free(async_stack); stack_free(mcck_stack); free_pages(nodat_stack, THREAD_SIZE_ORDER); @@ -1271,14 +1271,15 @@ static int __init smp_reinit_ipl_cpu(void) { unsigned long async_stack, nodat_stack, mcck_stack; struct lowcore *lc, *lc_ipl; - unsigned long flags; + unsigned long flags, cr0; + u64 mcesad; lc_ipl = lowcore_ptr[0]; lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER); async_stack = stack_alloc(); mcck_stack = stack_alloc(); - if (!lc || !nodat_stack || !async_stack || !mcck_stack) + if (!lc || !nodat_stack || !async_stack || !mcck_stack || nmi_alloc_mcesa(&mcesad)) panic("Couldn't allocate memory"); local_irq_save(flags); @@ -1287,6 +1288,10 @@ static int __init smp_reinit_ipl_cpu(void) S390_lowcore.nodat_stack = nodat_stack + STACK_INIT_OFFSET; S390_lowcore.async_stack = async_stack + STACK_INIT_OFFSET; S390_lowcore.mcck_stack = mcck_stack + STACK_INIT_OFFSET; + __ctl_store(cr0, 0, 0); + __ctl_clear_bit(0, 28); /* disable lowcore protection */ + S390_lowcore.mcesad = mcesad; + __ctl_load(cr0, 0, 0); lowcore_ptr[0] = lc; local_mcck_enable(); local_irq_restore(flags); |