aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/setup_64.c
diff options
context:
space:
mode:
authorNicholas Piggin <npiggin@gmail.com>2016-12-20 04:30:06 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2017-04-28 21:02:25 +1000
commitb1ee8a3de5790777f325416ad97340428d8ae25f (patch)
tree7fb570821268ff0eab738759eb345b85bc7df179 /arch/powerpc/kernel/setup_64.c
parentpowerpc/64s: Disallow system reset vs system reset reentrancy (diff)
downloadlinux-dev-b1ee8a3de5790777f325416ad97340428d8ae25f.tar.xz
linux-dev-b1ee8a3de5790777f325416ad97340428d8ae25f.zip
powerpc/64s: Dedicated system reset interrupt stack
The system reset interrupt is used for crash/debug situations, so it is desirable to have as little impact on the normal state of the system as possible. Currently it uses the current kernel stack to process the exception. This stores into the stack which may be involved with the crash. The stack pointer may be corrupted, or it may have overflowed. Avoid or minimise these problems by creating a dedicated NMI stack for the system reset interrupt to use. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/setup_64.c')
-rw-r--r--arch/powerpc/kernel/setup_64.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 729e990a019d..0f7b15860a06 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -628,6 +628,11 @@ void __init emergency_stack_init(void)
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);
+ 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);