From: Andrew Morton <akpm@osdl.org>

Display the most-recently-opened sysfs file's name when oopsing.

From: Adrian Bunk <bunk@stusta.de>

  Build fix

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 arch/i386/kernel/traps.c |    5 +++++
 fs/sysfs/file.c          |    8 ++++++++
 2 files changed, 13 insertions(+)

diff -puN fs/sysfs/file.c~sysfs-crash-debugging fs/sysfs/file.c
--- devel/fs/sysfs/file.c~sysfs-crash-debugging	2005-11-22 22:31:16.000000000 -0800
+++ devel-akpm/fs/sysfs/file.c	2005-11-22 22:31:16.000000000 -0800
@@ -7,6 +7,7 @@
 #include <linux/kobject.h>
 #include <linux/namei.h>
 #include <linux/poll.h>
+#include <linux/limits.h>
 #include <asm/uaccess.h>
 #include <asm/semaphore.h>
 
@@ -324,8 +326,14 @@ static int check_perm(struct inode * ino
 	return error;
 }
 
+char last_sysfs_file[PATH_MAX];
+
 static int sysfs_open_file(struct inode * inode, struct file * filp)
 {
+	char *p = d_path(filp->f_dentry, sysfs_mount, last_sysfs_file,
+			sizeof(last_sysfs_file));
+	if (p)
+		memmove(last_sysfs_file, p, strlen(p) + 1);
 	return check_perm(inode,filp);
 }
 
diff -puN arch/i386/kernel/traps.c~sysfs-crash-debugging arch/i386/kernel/traps.c
--- devel/arch/i386/kernel/traps.c~sysfs-crash-debugging	2005-11-22 22:31:16.000000000 -0800
+++ devel-akpm/arch/i386/kernel/traps.c	2005-11-22 22:31:16.000000000 -0800
@@ -95,6 +95,8 @@ static int kstack_depth_to_print = 24;
 struct notifier_block *i386die_chain;
 static DEFINE_SPINLOCK(die_notifier_lock);
 
+extern char last_sysfs_file[];
+
 int register_die_notifier(struct notifier_block *nb)
 {
 	int err = 0;
@@ -388,6 +388,9 @@ void die(const char * str, struct pt_reg
 #endif
 		if (nl)
 			printk("\n");
+#ifdef CONFIG_SYSFS
+		printk(KERN_ALERT "last sysfs file: %s\n", last_sysfs_file);
+#endif
 		if (notify_die(DIE_OOPS, str, regs, err,
 					current->thread.trap_no, SIGSEGV) !=
 				NOTIFY_STOP)
--- linux-2.6.14/arch/x86_64/kernel/traps.c~	2005-12-02 18:38:28.000000000 -0500
+++ linux-2.6.14/arch/x86_64/kernel/traps.c	2005-12-02 18:38:57.000000000 -0500
@@ -75,6 +75,8 @@ asmlinkage void call_debug(void);
 struct notifier_block *die_chain;
 static DEFINE_SPINLOCK(die_notifier_lock);
 
+extern char last_sysfs_file[];
+
 int register_die_notifier(struct notifier_block *nb)
 {
 	int err = 0;
@@ -416,6 +416,9 @@ void __die(const char * str, struct pt_r
 	printk("DEBUG_PAGEALLOC");
 #endif
 	printk("\n");
+#ifdef CONFIG_SYSFS
+	printk(KERN_ALERT "last sysfs file: %s\n", last_sysfs_file);
+#endif
 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
 	show_registers(regs);
 	/* Executive summary in case the oops scrolled away */