kgdb: 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@windriver.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 2f7f454605c2..11f3515ca83f 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -1365,6 +1365,7 @@ 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
@@ -1399,6 +1400,8 @@ 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();
@@ -1474,6 +1477,9 @@ 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);
@@ -1505,6 +1511,8 @@ kgdb_restore:
                 else
                         kgdb_sstep_pid = 0;
         }
+        if (trace_on)
+                tracing_on();
         /* Free kgdb_active */
         atomic_set(&kgdb_active, -1);
         touch_softlockup_watchdog_sync();