diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index a8c1f99e9607..4640f6d64f8b 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -616,6 +616,24 @@ void __init exc_lvl_early_init(void) #endif /* + * Emergency stacks are used for a range of things, from asynchronous + * NMIs (system reset, machine check) to synchronous, process context. + * We set preempt_count to zero, even though that isn't necessarily correct. To + * get the right value we'd need to copy it from the previous thread_info, but + * doing that might fault causing more problems. + * TODO: what to do with accounting? + */ +static void emerg_stack_init_thread_info(struct thread_info *ti, int cpu) +{ + ti->task = NULL; + ti->cpu = cpu; + ti->preempt_count = 0; + ti->local_flags = 0; + ti->flags = 0; + klp_init_thread_info(ti); +} + +/* * Stack space used when we detect a bad kernel stack pointer, and * early in SMP boots before relocation is enabled. Exclusive emergency * stack for machine checks. @@ -633,24 +651,31 @@ void __init emergency_stack_init(void) * Since we use these as temporary stacks during secondary CPU * bringup, we need to get at them in real mode. This means they * must also be within the RMO region. + * + * The IRQ stacks allocated elsewhere in this file are zeroed and + * initialized in kernel/irq.c. These are initialized here in order + * to have emergency stacks available as early as possible. */ limit = min(safe_stack_limit(), ppc64_rma_size); for_each_possible_cpu(i) { struct thread_info *ti; ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit)); - klp_init_thread_info(ti); + memset(ti, 0, THREAD_SIZE); + emerg_stack_init_thread_info(ti, i); paca[i].emergency_sp = (void *)ti + THREAD_SIZE; #ifdef CONFIG_PPC_BOOK3S_64 /* emergency stack for NMI exception handling. */ ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit)); - klp_init_thread_info(ti); + memset(ti, 0, THREAD_SIZE); + emerg_stack_init_thread_info(ti, i); paca[i].nmi_emergency_sp = (void *)ti + THREAD_SIZE; /* emergency stack for machine check exception handling. */ ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit)); - klp_init_thread_info(ti); + memset(ti, 0, THREAD_SIZE); + emerg_stack_init_thread_info(ti, i); paca[i].mc_emergency_sp = (void *)ti + THREAD_SIZE; #endif } |