src/patches/suse-2.6.27.25/patches.drivers/sysfs-crash-debugging.patch

   1 Subject: display last accessed sysfs file on kernel panic message
   2 From: Andrew Morton <akpm@osdl.org>
   3 Patch-mainline: never
   4
   5 Display the most-recently-opened sysfs file's name when oopsing.
   6
   7 From: Adrian Bunk <bunk@stusta.de>
   8
   9   Build fix
  10
  11 From: Greg Kroah-Hartman <gregkh@suse.de>
  12
  13   Modified to make the api call cleaner, and available to all arches if
  14   need be.  Also added it to x86-64's crash dump message.
  15
  16
  17 Signed-off-by: Adrian Bunk <bunk@stusta.de>
  18 Signed-off-by: Andrew Morton <akpm@osdl.org>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  20 ---
  21  arch/x86/kernel/traps_32.c |    2 ++
  22  arch/x86/kernel/traps_64.c |    2 ++
  23  fs/sysfs/file.c            |   14 ++++++++++++++
  24  fs/sysfs/mount.c           |    2 +-
  25  include/linux/sysfs.h      |    7 +++++++
  26  5 files changed, 26 insertions(+), 1 deletion(-)
  27
  28 --- a/arch/x86/kernel/traps_32.c
  29 +++ b/arch/x86/kernel/traps_32.c
  30 @@ -428,6 +428,8 @@ int __kprobes __die(const char *str, str
  31         printk("DEBUG_PAGEALLOC");
  32  #endif
  33         printk("\n");
  34 +
  35 +       sysfs_printk_last_file();
  36         if (notify_die(DIE_OOPS, str, regs, err,
  37                         current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
  38                 return 1;
  39 --- a/arch/x86/kernel/traps_64.c
  40 +++ b/arch/x86/kernel/traps_64.c
  41 @@ -537,6 +537,8 @@ int __kprobes __die(const char *str, str
  42         printk("DEBUG_PAGEALLOC");
  43  #endif
  44         printk("\n");
  45 +
  46 +       sysfs_printk_last_file();
  47         if (notify_die(DIE_OOPS, str, regs, err,
  48                         current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
  49                 return 1;
  50 --- a/fs/sysfs/file.c
  51 +++ b/fs/sysfs/file.c
  52 @@ -16,6 +16,7 @@
  53  #include <linux/slab.h>
  54  #include <linux/fsnotify.h>
  55  #include <linux/namei.h>
  56 +#include <linux/limits.h>
  57  #include <linux/poll.h>
  58  #include <linux/list.h>
  59  #include <linux/mutex.h>
  60 @@ -23,6 +24,9 @@
  61
  62  #include "sysfs.h"
  63
  64 +/* used in crash dumps to help with debugging */
  65 +static char last_sysfs_file[PATH_MAX];
  66 +
  67  /*
  68   * There's one sysfs_buffer for each open file and one
  69   * sysfs_open_dirent for each sysfs_dirent with one or more open
  70 @@ -328,6 +332,11 @@ static int sysfs_open_file(struct inode
  71         struct sysfs_buffer *buffer;
  72         struct sysfs_ops *ops;
  73         int error = -EACCES;
  74 +       char *p;
  75 +
  76 +       p = d_path(&file->f_path, last_sysfs_file, sizeof(last_sysfs_file));
  77 +       if (p)
  78 +               memmove(last_sysfs_file, p, strlen(p) + 1);
  79
  80         /* need attr_sd for attr and ops, its parent for kobj */
  81         if (!sysfs_get_active_two(attr_sd))
  82 @@ -389,6 +398,11 @@ static int sysfs_open_file(struct inode
  83         return error;
  84  }
  85
  86 +void sysfs_printk_last_file(void)
  87 +{
  88 +       printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file);
  89 +}
  90 +
  91  static int sysfs_release(struct inode *inode, struct file *filp)
  92  {
  93         struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata;
  94 --- a/fs/sysfs/mount.c
  95 +++ b/fs/sysfs/mount.c
  96 @@ -22,7 +22,7 @@
  97  /* Random magic number */
  98  #define SYSFS_MAGIC 0x62656572
  99
 100 -static struct vfsmount *sysfs_mount;
 101 +struct vfsmount *sysfs_mount;
 102  struct super_block * sysfs_sb = NULL;
 103  struct kmem_cache *sysfs_dir_cachep;
 104
 105 --- a/include/linux/sysfs.h
 106 +++ b/include/linux/sysfs.h
 107 @@ -121,6 +121,8 @@ void sysfs_notify(struct kobject *kobj,
 108
 109  extern int __must_check sysfs_init(void);
 110
 111 +void sysfs_printk_last_file(void);
 112 +
 113  #else /* CONFIG_SYSFS */
 114
 115  static inline int sysfs_schedule_callback(struct kobject *kobj,
 116 @@ -231,6 +233,11 @@ static inline int __must_check sysfs_ini
 117         return 0;
 118  }
 119
 120 +static inline void sysfs_printk_last_file(void)
 121 +{
 122 +       ;
 123 +}
 124 +
 125  #endif /* CONFIG_SYSFS */
 126
 127  #endif /* _SYSFS_H_ */