From 250af0997c71a4e45e07a35321fcd0db1c7a61c0 Mon Sep 17 00:00:00 2001
From: Neil Horman <nhorman@tuxdriver.com>
Date: Thu, 2 Apr 2009 16:58:57 -0700
Subject: [PATCH] --- yaml --- r: 139727 b: refs/heads/master c:
 04d491ab2a53008a1aa98ac09561768c7f3adda3 h: refs/heads/master i:   139725:
 db02602779c8b121edf370628d518e22772b7aba   139723:
 21438b203f2e7a6c23846f8f421564b97dc65082   139719:
 60ad9d9691113a036594d735fea8479391bbc776   139711:
 bfbdd06ae4d97601d57b5e483d1fb3e04207b0c0 v: v3

---
 [refs]                       |  2 +-
 trunk/include/linux/kernel.h |  4 ++++
 trunk/kernel/kexec.c         |  1 +
 trunk/kernel/printk.c        | 19 +++++++++++++++++++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index e56d9c0d8481..97ed9579c600 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 23c36c1aec895fd52d7dd8cd3ce4bbce43c969fd
+refs/heads/master: 04d491ab2a53008a1aa98ac09561768c7f3adda3
diff --git a/trunk/include/linux/kernel.h b/trunk/include/linux/kernel.h
index e720b0da7751..556d781e69fe 100644
--- a/trunk/include/linux/kernel.h
+++ b/trunk/include/linux/kernel.h
@@ -242,6 +242,7 @@ extern struct ratelimit_state printk_ratelimit_state;
 extern int printk_ratelimit(void);
 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 				   unsigned int interval_msec);
+void log_buf_kexec_setup(void);
 #else
 static inline int vprintk(const char *s, va_list args)
 	__attribute__ ((format (printf, 1, 0)));
@@ -253,6 +254,9 @@ static inline int printk_ratelimit(void) { return 0; }
 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 					  unsigned int interval_msec)	\
 		{ return false; }
+static inline void log_buf_kexec_setup(void)
+{
+}
 #endif
 
 extern int printk_needs_cpu(int cpu);
diff --git a/trunk/kernel/kexec.c b/trunk/kernel/kexec.c
index 93eed85fe017..589832aac41f 100644
--- a/trunk/kernel/kexec.c
+++ b/trunk/kernel/kexec.c
@@ -1409,6 +1409,7 @@ static int __init crash_save_vmcoreinfo_init(void)
 	VMCOREINFO_OFFSET(list_head, prev);
 	VMCOREINFO_OFFSET(vm_struct, addr);
 	VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
+	log_buf_kexec_setup();
 	VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
 	VMCOREINFO_NUMBER(NR_FREE_PAGES);
 	VMCOREINFO_NUMBER(PG_lru);
diff --git a/trunk/kernel/printk.c b/trunk/kernel/printk.c
index e3602d0755b0..a5f61a9acedb 100644
--- a/trunk/kernel/printk.c
+++ b/trunk/kernel/printk.c
@@ -32,6 +32,7 @@
 #include <linux/security.h>
 #include <linux/bootmem.h>
 #include <linux/syscalls.h>
+#include <linux/kexec.h>
 
 #include <asm/uaccess.h>
 
@@ -135,6 +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);