PM: check sysdev_suspend(PMSG_FREEZE) return value

[safe/jmp/linux-2.6] / kernel / printk.c

diff --git a/kernel/printk.c b/kernel/printk.c
index aee891a..5052b54 100644 (file)
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -13,7 +13,7 @@
  * Fixed SMP synchronization, 08/08/99, Manfred Spraul
  *     manfred@colorfullife.com
  * Rewrote bits to get rid of console_lock
- *     01Mar01 Andrew Morton <andrewm@uow.edu.au>
+ *     01Mar01 Andrew Morton
  */
 
 #include <linux/kernel.h>
@@ -32,6 +32,7 @@
 #include <linux/security.h>
 #include <linux/bootmem.h>
 #include <linux/syscalls.h>
+#include <linux/kexec.h>
 
 #include <asm/uaccess.h>
 
@@ -73,7 +74,6 @@ EXPORT_SYMBOL(oops_in_progress);
  * driver system.
  */
 static DECLARE_MUTEX(console_sem);
-static DECLARE_MUTEX(secondary_console_sem);
 struct console *console_drivers;
 EXPORT_SYMBOL_GPL(console_drivers);
 
@@ -136,6 +136,24 @@ static char *log_buf = __log_buf;
 static int log_buf_len = __LOG_BUF_LEN;
 static unsigned logged_chars; /* Number of chars produced since last read+clear operation */
 
+#ifdef CONFIG_KEXEC
+/*
+ * This appends the listed symbols to /proc/vmcoreinfo
+ *
+ * /proc/vmcoreinfo is used by various utiilties, like crash and makedumpfile to
+ * obtain access to symbols that are otherwise very difficult to locate.  These
+ * symbols are specifically used so that utilities can access and extract the
+ * dmesg log from a vmcore file after a crash.
+ */
+void log_buf_kexec_setup(void)
+{
+       VMCOREINFO_SYMBOL(log_buf);
+       VMCOREINFO_SYMBOL(log_end);
+       VMCOREINFO_SYMBOL(log_buf_len);
+       VMCOREINFO_SYMBOL(logged_chars);
+}
+#endif
+
 static int __init log_buf_len_setup(char *str)
 {
        unsigned size = memparse(str, &str);
@@ -233,45 +251,6 @@ static inline void boot_delay_msec(void)
 #endif
 
 /*
- * Return the number of unread characters in the log buffer.
- */
-static int log_buf_get_len(void)
-{
-       return logged_chars;
-}
-
-/*
- * Copy a range of characters from the log buffer.
- */
-int log_buf_copy(char *dest, int idx, int len)
-{
-       int ret, max;
-       bool took_lock = false;
-
-       if (!oops_in_progress) {
-               spin_lock_irq(&logbuf_lock);
-               took_lock = true;
-       }
-
-       max = log_buf_get_len();
-       if (idx < 0 || idx >= max) {
-               ret = -1;
-       } else {
-               if (len > max)
-                       len = max;
-               ret = len;
-               idx += (log_end - max);
-               while (len-- > 0)
-                       dest[len] = LOG_BUF(idx + len);
-       }
-
-       if (took_lock)
-               spin_unlock_irq(&logbuf_lock);
-
-       return ret;
-}
-
-/*
  * Commands to do_syslog:
  *
  *     0 -- Close the log.  Currently a NOP.
@@ -421,7 +400,7 @@ out:
        return error;
 }
 
-asmlinkage long sys_syslog(int type, char __user *buf, int len)
+SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
 {
        return do_syslog(type, buf, len);
 }
@@ -590,6 +569,8 @@ static int have_callable_console(void)
  *
  * See also:
  * printf(3)
+ *
+ * See the vsnprintf() documentation for format string extensions over C99.
  */
 
 asmlinkage int printk(const char *fmt, ...)
@@ -656,7 +637,7 @@ static int acquire_console_semaphore_for_printk(unsigned int cpu)
 static const char recursion_bug_msg [] =
                KERN_CRIT "BUG: recent printk recursion!\n";
 static int recursion_bug;
-       static int new_text_line = 1;
+static int new_text_line = 1;
 static char printk_buf[1024];
 
 asmlinkage int vprintk(const char *fmt, va_list args)
@@ -699,7 +680,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
        if (recursion_bug) {
                recursion_bug = 0;
                strcpy(printk_buf, recursion_bug_msg);
-               printed_len = sizeof(recursion_bug_msg);
+               printed_len = strlen(recursion_bug_msg);
        }
        /* Emit the output into the temporary buffer */
        printed_len += vscnprintf(printk_buf + printed_len,
@@ -779,11 +760,6 @@ EXPORT_SYMBOL(vprintk);
 
 #else
 
-asmlinkage long sys_syslog(int type, char __user *buf, int len)
-{
-       return -ENOSYS;
-}
-
 static void call_console_drivers(unsigned start, unsigned end)
 {
 }
@@ -933,12 +909,14 @@ void suspend_console(void)
        printk("Suspending console(s) (use no_console_suspend to debug)\n");
        acquire_console_sem();
        console_suspended = 1;
+       up(&console_sem);
 }
 
 void resume_console(void)
 {
        if (!console_suspend_enabled)
                return;
+       down(&console_sem);
        console_suspended = 0;
        release_console_sem();
 }
@@ -954,11 +932,9 @@ void resume_console(void)
 void acquire_console_sem(void)
 {
        BUG_ON(in_interrupt());
-       if (console_suspended) {
-               down(&secondary_console_sem);
-               return;
-       }
        down(&console_sem);
+       if (console_suspended)
+               return;
        console_locked = 1;
        console_may_schedule = 1;
 }
@@ -968,6 +944,10 @@ int try_acquire_console_sem(void)
 {
        if (down_trylock(&console_sem))
                return -1;
+       if (console_suspended) {
+               up(&console_sem);
+               return -1;
+       }
        console_locked = 1;
        console_may_schedule = 0;
        return 0;
@@ -1021,7 +1001,7 @@ void release_console_sem(void)
        unsigned wake_klogd = 0;
 
        if (console_suspended) {
-               up(&secondary_console_sem);
+               up(&console_sem);
                return;
        }
 
@@ -1331,8 +1311,11 @@ EXPORT_SYMBOL(printk_ratelimit);
 bool printk_timed_ratelimit(unsigned long *caller_jiffies,
                        unsigned int interval_msecs)
 {
-       if (*caller_jiffies == 0 || time_after(jiffies, *caller_jiffies)) {
-               *caller_jiffies = jiffies + msecs_to_jiffies(interval_msecs);
+       if (*caller_jiffies == 0
+                       || !time_in_range(jiffies, *caller_jiffies,
+                                       *caller_jiffies
+                                       + msecs_to_jiffies(interval_msecs))) {
+               *caller_jiffies = jiffies;
                return true;
        }
        return false;