Commit a4719f5b authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32: Statically initialise first emergency context 



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: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4a67ba422be75713286dca0c86ee0d3df2eb6dfa.1615552867.git.christophe.leroy@csgroup.eu
parent 9b6150fb

arch/powerpc/kernel/head_32.h

+1 −5
Original line number Diff line number Diff line
@@ -205,11 +205,7 @@ 
	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

arch/powerpc/kernel/setup_32.c

+1 −1
Original line number Diff line number Diff line
@@ -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)

{