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-rw-r--r--kernel/printk.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index 2d607f4..22e070f 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -87,6 +87,12 @@ static DEFINE_SEMAPHORE(console_sem);
struct console *console_drivers;
EXPORT_SYMBOL_GPL(console_drivers);
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map console_lock_dep_map = {
+ .name = "console_lock"
+};
+#endif
+
/*
* This is used for debugging the mess that is the VT code by
* keeping track if we have the console semaphore held. It's
@@ -1908,12 +1914,14 @@ static int __cpuinit console_cpu_notify(struct notifier_block *self,
*/
void console_lock(void)
{
- BUG_ON(in_interrupt());
+ might_sleep();
+
down(&console_sem);
if (console_suspended)
return;
console_locked = 1;
console_may_schedule = 1;
+ mutex_acquire(&console_lock_dep_map, 0, 0, _RET_IP_);
}
EXPORT_SYMBOL(console_lock);
@@ -1935,6 +1943,7 @@ int console_trylock(void)
}
console_locked = 1;
console_may_schedule = 0;
+ mutex_acquire(&console_lock_dep_map, 0, 1, _RET_IP_);
return 1;
}
EXPORT_SYMBOL(console_trylock);
@@ -2095,6 +2104,7 @@ skip:
local_irq_restore(flags);
}
console_locked = 0;
+ mutex_release(&console_lock_dep_map, 1, _RET_IP_);
/* Release the exclusive_console once it is used */
if (unlikely(exclusive_console))
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