gianfar: Fix possible overrun and simplify interrupt name field creation

[linux-2.6-block.git] / kernel / printk.c

diff --git a/kernel/printk.c b/kernel/printk.c
index 0b3ea2cbd5fb68850021af4b2af106b80a1825cb..b663c2c95d3922e4c080e8974c09c6ce99b4355f 100644 (file)
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1216,13 +1216,27 @@ int is_console_locked(void)
        return console_locked;
 }
 
+/*
+ * Delayed printk facility, for scheduler-internal messages:
+ */
+#define PRINTK_BUF_SIZE                512
+
+#define PRINTK_PENDING_WAKEUP  0x01
+#define PRINTK_PENDING_SCHED   0x02
+
 static DEFINE_PER_CPU(int, printk_pending);
+static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
 
 void printk_tick(void)
 {
        if (__this_cpu_read(printk_pending)) {
-               __this_cpu_write(printk_pending, 0);
-               wake_up_interruptible(&log_wait);
+               int pending = __this_cpu_xchg(printk_pending, 0);
+               if (pending & PRINTK_PENDING_SCHED) {
+                       char *buf = __get_cpu_var(printk_sched_buf);
+                       printk(KERN_WARNING "[sched_delayed] %s", buf);
+               }
+               if (pending & PRINTK_PENDING_WAKEUP)
+                       wake_up_interruptible(&log_wait);
        }
 }
 
@@ -1236,7 +1250,7 @@ int printk_needs_cpu(int cpu)
 void wake_up_klogd(void)
 {
        if (waitqueue_active(&log_wait))
-               this_cpu_write(printk_pending, 1);
+               this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
 }
 
 /**
@@ -1629,6 +1643,26 @@ late_initcall(printk_late_init);
 
 #if defined CONFIG_PRINTK
 
+int printk_sched(const char *fmt, ...)
+{
+       unsigned long flags;
+       va_list args;
+       char *buf;
+       int r;
+
+       local_irq_save(flags);
+       buf = __get_cpu_var(printk_sched_buf);
+
+       va_start(args, fmt);
+       r = vsnprintf(buf, PRINTK_BUF_SIZE, fmt, args);
+       va_end(args);
+
+       __this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+       local_irq_restore(flags);
+
+       return r;
+}
+
 /*
  * printk rate limiting, lifted from the networking subsystem.
  *