[PATCH v4 13/16] powerpc/64s: machine check do not trace real-mode handler
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2020-05-08 05:03:25
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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. Acked-by: Naveen N. Rao <redacted> Reviewed-by: Christophe Leroy <redacted> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/mce.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
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 <linux/export.h> #include <linux/irq_work.h> #include <linux/extable.h> +#include <linux/ftrace.h> #include <asm/machdep.h> #include <asm/mce.h>
@@ -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; }
--
2.23.0