[PATCH v2 12/14] powerpc/64s: machine check do not trace real-mode handler

[Nicholas Piggin]

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 <naveen.n....@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
 arch/powerpc/kernel/mce.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index c1684be0d8b7..36e99adb8710 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -557,10 +557,13 @@ 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 = local_paca->ftrace_enabled;
+
+       local_paca->ftrace_enabled = 0;
        if (!nested)
                nmi_enter();
 
@@ -574,6 +577,7 @@ long machine_check_early(struct pt_regs *regs)
 
        if (!nested)
                nmi_exit();
+       local_paca->ftrace_enabled = ftrace_enabled;
 
        return handled;
 }
-- 
2.23.0