Thread (9 messages) flat view 9 messages, 4 authors, 2017-02-20

Re: [PATCH] powerpc/xmon: Fix an unexpected xmon onoff state change

From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2017-02-16 05:09:25
Also in: lkml

Pan Xinhui [off-list ref] writes:
quoted hunk ↗ jump to hunk
Once xmon is triggered by sysrq-x, it is enabled always afterwards even
if it is disabled during boot. This will cause a system reset interrut
fail to dump. So keep xmon in its original state after exit.

Signed-off-by: Pan Xinhui <redacted>
---
 arch/powerpc/xmon/xmon.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 9c0e17c..721212f 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -76,6 +76,7 @@ static int xmon_gate;
 #endif /* CONFIG_SMP */
 
 static unsigned long in_xmon __read_mostly = 0;
+static int xmon_off = 0;
 
 static unsigned long adrs;
 static int size = 1;
@@ -3250,6 +3251,8 @@ static void sysrq_handle_xmon(int key)
 	/* ensure xmon is enabled */
 	xmon_init(1);
 	debugger(get_irq_regs());
+	if (xmon_off)
+		xmon_init(0);
 }
I don't think this is right.

xmon_off is only true if you boot with xmon=off on the command line.

So if you boot with CONFIG_XMON_DEFAULT=n, and nothing on the command
line, then enter xmon via sysrq, then exit, xmon will still be enabled.

cheers
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help