linux-kernel - [PATCH 7/8] debug_core: Turn off tracing while in the debugger

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Date:	Mon, 22 Mar 2010 14:17:28 -0500
From:	Jason Wessel <jason.wessel@...driver.com>
To:	torvalds@...ux-foundation.org
Cc:	linux-kernel@...r.kernel.org, kgdb-bugreport@...ts.sourceforge.net,
	Jason Wessel <jason.wessel@...driver.com>
Subject: [PATCH 7/8] debug_core: Turn off tracing while in the debugger

The kernel debugger should turn off kernel tracing any time the
debugger is active and restore it on resume.

Signed-off-by: Jason Wessel <jason.wessel@...driver.com>
Reviewed-by: Steven Rostedt <rostedt@...dmis.org>
---
 kernel/debug/debug_core.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index f471268..ab2a43f 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -449,6 +449,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
 	int sstep_tries = 100;
 	int error = 0;
 	int i, cpu;
+	int trace_on = 0;
 acquirelock:
 	/*
 	 * Interrupts will be restored by the 'trap return' code, except when
@@ -483,6 +484,8 @@ return_normal:
 			 */
 			if (arch_kgdb_ops.correct_hw_break)
 				arch_kgdb_ops.correct_hw_break();
+			if (trace_on)
+				tracing_on();
 			atomic_dec(&cpu_in_kgdb[cpu]);
 			touch_softlockup_watchdog_sync();
 			clocksource_touch_watchdog();
@@ -558,6 +561,9 @@ return_normal:
 	kgdb_single_step = 0;
 	kgdb_contthread = current;
 	exception_level = 0;
+	trace_on = tracing_is_on();
+	if (trace_on)
+		tracing_off();
 
 	/* Talk to debugger with gdbserial protocol */
 	error = gdb_serial_stub(ks);
@@ -589,6 +595,8 @@ kgdb_restore:
 		else
 			kgdb_sstep_pid = 0;
 	}
+	if (trace_on)
+		tracing_on();
 	/* Free kgdb_active */
 	atomic_set(&kgdb_active, -1);
 	touch_softlockup_watchdog_sync();
-- 
1.6.4.rc1

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