From 855b6232dda2b6941ecd22979893e8a1d25642db Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sat, 19 May 2018 14:35:54 +1000 Subject: powerpc/64: hard disable irqs on the panic()ing CPU Similar to previous patches, hard disable interrupts when a CPU is in panic. This reduces the chance the watchdog has to interfere with the panic, and avoids any other type of masked interrupt being executed when crashing which minimises the length of the crash path. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/setup-common.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 62b1a40d8957..40b44bb53a4e 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -700,12 +700,19 @@ EXPORT_SYMBOL(check_legacy_ioport); static int ppc_panic_event(struct notifier_block *this, unsigned long event, void *ptr) { + /* + * panic does a local_irq_disable, but we really + * want interrupts to be hard disabled. + */ + hard_irq_disable(); + /* * If firmware-assisted dump has been registered then trigger * firmware-assisted dump and let firmware handle everything else. */ crash_fadump(NULL, ptr); - ppc_md.panic(ptr); /* May not return */ + if (ppc_md.panic) + ppc_md.panic(ptr); /* May not return */ return NOTIFY_DONE; } @@ -716,7 +723,8 @@ static struct notifier_block ppc_panic_block = { void __init setup_panic(void) { - if (!ppc_md.panic) + /* PPC64 always does a hard irq disable in its panic handler */ + if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic) return; atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block); } -- cgit v1.2.3