Re: [PATCH v3 14/15] powerpc/64s: system reset do not trace

2020-04-06 Thread Christophe Leroy




Le 07/04/2020 à 07:16, Nicholas Piggin a écrit :

Similarly to the previous patch, do not trace system reset. This code
is used when there is a crash or hang, and tracing disturbs the system
more and has been known to crash in the crash handling path.

Acked-by: Naveen N. Rao 
Signed-off-by: Nicholas Piggin 


Reviewed-by: Christophe Leroy 


---
  arch/powerpc/kernel/traps.c | 5 +
  1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 9f221772eb73..1beae89bb871 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -443,6 +443,9 @@ void system_reset_exception(struct pt_regs *regs)
unsigned long hsrr0, hsrr1;
bool nested = in_nmi();
bool saved_hsrrs = false;
+   u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
+
+   this_cpu_set_ftrace_enabled(0);
  
  	/*

 * Avoid crashes in case of nested NMI exceptions. Recoverability
@@ -524,6 +527,8 @@ void system_reset_exception(struct pt_regs *regs)
if (!nested)
nmi_exit();
  
+	this_cpu_set_ftrace_enabled(ftrace_enabled);

+
/* What should we do here? We could issue a shutdown or hard reset. */
  }
  



[PATCH v3 14/15] powerpc/64s: system reset do not trace

2020-04-06 Thread Nicholas Piggin
Similarly to the previous patch, do not trace system reset. This code
is used when there is a crash or hang, and tracing disturbs the system
more and has been known to crash in the crash handling path.

Acked-by: Naveen N. Rao 
Signed-off-by: Nicholas Piggin 
---
 arch/powerpc/kernel/traps.c | 5 +
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 9f221772eb73..1beae89bb871 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -443,6 +443,9 @@ void system_reset_exception(struct pt_regs *regs)
unsigned long hsrr0, hsrr1;
bool nested = in_nmi();
bool saved_hsrrs = false;
+   u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
+
+   this_cpu_set_ftrace_enabled(0);
 
/*
 * Avoid crashes in case of nested NMI exceptions. Recoverability
@@ -524,6 +527,8 @@ void system_reset_exception(struct pt_regs *regs)
if (!nested)
nmi_exit();
 
+   this_cpu_set_ftrace_enabled(ftrace_enabled);
+
/* What should we do here? We could issue a shutdown or hard reset. */
 }
 
-- 
2.23.0