From abd106fb437ad1cd8c8df8ccabd0fa941ef6342a Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 8 May 2020 14:34:05 +1000 Subject: powerpc/64s: machine check do not trace real-mode handler Rather than notrace annotations throughout a significant part of the machine check code across kernel/ pseries/ and powernv/ which can easily be broken and is infrequently tested, use paca->ftrace_enabled to blanket-disable tracing of the real-mode non-maskable handler. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Reviewed-by: Christophe Leroy Acked-by: Naveen N. Rao Link: https://lore.kernel.org/r/20200508043408.886394-14-npiggin@gmail.com --- arch/powerpc/kernel/mce.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c index be7e3f92a7b5..fd90c0eda229 100644 --- a/arch/powerpc/kernel/mce.c +++ b/arch/powerpc/kernel/mce.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -571,10 +572,14 @@ EXPORT_SYMBOL_GPL(machine_check_print_event_info); * * regs->nip and regs->msr contains srr0 and ssr1. */ -long machine_check_early(struct pt_regs *regs) +long notrace machine_check_early(struct pt_regs *regs) { long handled = 0; bool nested = in_nmi(); + u8 ftrace_enabled = this_cpu_get_ftrace_enabled(); + + this_cpu_set_ftrace_enabled(0); + if (!nested) nmi_enter(); @@ -589,6 +594,8 @@ long machine_check_early(struct pt_regs *regs) if (!nested) nmi_exit(); + this_cpu_set_ftrace_enabled(ftrace_enabled); + return handled; } -- cgit v1.2.3