powerpc/32: Statically initialise first emergency context

[ Upstream commit a4719f5bb6d7dc220bffdc1b9f5ce5eaa5543581 ]

The check of the emergency context initialisation in
vmap_stack_overflow is buggy for the SMP case, as it
compares r1 with 0 while in the SMP case r1 is offseted
by the CPU id.

Instead of fixing it, just perform static initialisation
of the first emergency context.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4a67ba422be75713286dca0c86ee0d3df2eb6dfa.1615552867.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Christophe Leroy 2021-03-12 12:50:25 +00:00 committed by Greg Kroah-Hartman
parent b9f9313c75
commit 286b3ff9fd
2 changed files with 2 additions and 6 deletions

View File

@ -338,11 +338,7 @@
lis r1, emergency_ctx@ha
#endif
lwz r1, emergency_ctx@l(r1)
cmpwi cr1, r1, 0
bne cr1, 1f
lis r1, init_thread_union@ha
addi r1, r1, init_thread_union@l
1: addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
EXCEPTION_PROLOG_2
SAVE_NVGPRS(r11)
addi r3, r1, STACK_FRAME_OVERHEAD

View File

@ -164,7 +164,7 @@ void __init irqstack_early_init(void)
}
#ifdef CONFIG_VMAP_STACK
void *emergency_ctx[NR_CPUS] __ro_after_init;
void *emergency_ctx[NR_CPUS] __ro_after_init = {[0] = &init_stack};
void __init emergency_stack_init(void)
{