[PATCH 2/2] powerpc/xmon: Disable tracing when entering xmon

[Breno Leitao]

If tracing is enabled and you get into xmon, the tracing buffer
continues to be updated, causing possible loss of data and unnecessary
tracing information coming from xmon functions.

This patch simple disables tracing when entering xmon, and reenables it
if the kernel is resumed (with 'x').

Signed-off-by: Breno Leitao <leitao at debian.org>
---
 arch/powerpc/xmon/xmon.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 0cbd910193fa..0b766d7780fa 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -89,6 +89,7 @@ static unsigned long nidump = 16;
 static unsigned long ncsum = 4096;
 static int termch;
 static char tmpstr[128];
+static char tracing_enabled;
 
 static long bus_error_jmp[JMP_BUF_LEN];
 static int catch_memory_errors;
@@ -462,6 +463,9 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
 	local_irq_save(flags);
 	hard_irq_disable();
 
+	tracing_enabled = tracing_is_on();
+	tracing_off();
+
 	bp = in_breakpoint_table(regs->nip, &offset);
 	if (bp != NULL) {
 		regs->nip = bp->address + offset;
@@ -982,6 +986,8 @@ cmds(struct pt_regs *excp)
 			break;
 		case 'x':
 		case 'X':
+			if (tracing_enabled)
+				tracing_on();
 			return cmd;
 		case EOF:
 			printf(" <no input ...>\n");
@@ -2353,7 +2359,6 @@ static void dump_tracing(void)
 	else
 		ftrace_dump(DUMP_ALL);
 
-	tracing_on();
 }
 
 static void dump_all_pacas(void)
-- 
2.13.2