Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan...

* 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc:
  proc: remove write-only variable in proc_pident_lookup()
  proc: fix sparse warning
  proc: add /proc/*/stack
  proc: remove '##' usage
  proc: remove useless WARN_ONs
  proc: stop using BKL

diff --combined Documentation/filesystems/proc.txt
index 32e94635484f968c40291264d6e5b7df14d813ae,334ef2f983fa5e9ecfbf4118b9f4380463d81645..d105eb45282ae5f6a1f978872fdb6a101f089b12
--- 1/Documentation/filesystems/proc.txt
--- 2/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@@ -140,6 -140,7 +140,7 @@@ Table 1-1: Process specific entries in 
   statm                Process memory status information
   status               Process status in human readable form
   wchan                If CONFIG_KALLSYMS is set, a pre-decoded wchan
+  stack                Report full stack trace, enable via CONFIG_STACKTRACE
   smaps                Extension based on maps, the rss size for each mapped file
  ..............................................................................
  
@@@ -1385,15 -1386,6 +1386,15 @@@ swapcache reclaim.  Decreasing vfs_cach
  to retain dentry and inode caches.  Increasing vfs_cache_pressure beyond 100
  causes the kernel to prefer to reclaim dentries and inodes.
  
 +dirty_background_bytes
 +----------------------
 +
 +Contains the amount of dirty memory at which the pdflush background writeback
 +daemon will start writeback.
 +
 +If dirty_background_bytes is written, dirty_background_ratio becomes a function
 +of its value (dirty_background_bytes / the amount of dirtyable system memory).
 +
  dirty_background_ratio
  ----------------------
  
@@@ -1402,29 -1394,14 +1403,29 @@@ pages + file cache, not including locke
  pages at which the pdflush background writeback daemon will start writing out
  dirty data.
  
 +If dirty_background_ratio is written, dirty_background_bytes becomes a function
 +of its value (dirty_background_ratio * the amount of dirtyable system memory).
 +
 +dirty_bytes
 +-----------
 +
 +Contains the amount of dirty memory at which a process generating disk writes
 +will itself start writeback.
 +
 +If dirty_bytes is written, dirty_ratio becomes a function of its value
 +(dirty_bytes / the amount of dirtyable system memory).
 +
  dirty_ratio
 ------------------
 +-----------
  
  Contains, as a percentage of the dirtyable system memory (free pages + mapped
  pages + file cache, not including locked pages and HugePages), the number of
  pages at which a process which is generating disk writes will itself start
  writing out dirty data.
  
 +If dirty_ratio is written, dirty_bytes becomes a function of its value
 +(dirty_ratio * the amount of dirtyable system memory).
 +
  dirty_writeback_centisecs
  -------------------------
  

diff --combined fs/proc/base.c
index 10fd5223d600aec609a2adb1ea8e1693dd923562,0bc9ca03b91e60ce38ecea56e964a957882c9027..0c9de19a1633820856dae04bf71c21c3bed14da8
--- 1/fs/proc/base.c
--- 2/fs/proc/base.c
+++ b/fs/proc/base.c
@@@ -65,6 -65,7 +65,7 @@@
  #include <linux/mm.h>
  #include <linux/rcupdate.h>
  #include <linux/kallsyms.h>
+ #include <linux/stacktrace.h>
  #include <linux/resource.h>
  #include <linux/module.h>
  #include <linux/mount.h>
@@@ -109,25 -110,22 +110,22 @@@ struct pid_entry 
        .op   = OP,                                     \
  }
  
- #define DIR(NAME, MODE, OTYPE)                                                        \
-       NOD(NAME, (S_IFDIR|(MODE)),                                             \
-               &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations,   \
-               {} )
- #define LNK(NAME, OTYPE)                                      \
+ #define DIR(NAME, MODE, iops, fops)   \
+       NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
+ #define LNK(NAME, get_link)                                   \
        NOD(NAME, (S_IFLNK|S_IRWXUGO),                          \
                &proc_pid_link_inode_operations, NULL,          \
-               { .proc_get_link = &proc_##OTYPE##_link } )
- #define REG(NAME, MODE, OTYPE)                                \
-       NOD(NAME, (S_IFREG|(MODE)), NULL,               \
-               &proc_##OTYPE##_operations, {})
- #define INF(NAME, MODE, OTYPE)                                \
+               { .proc_get_link = get_link } )
+ #define REG(NAME, MODE, fops)                         \
+       NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
+ #define INF(NAME, MODE, read)                         \
        NOD(NAME, (S_IFREG|(MODE)),                     \
                NULL, &proc_info_file_operations,       \
-               { .proc_read = &proc_##OTYPE } )
- #define ONE(NAME, MODE, OTYPE)                                \
+               { .proc_read = read } )
+ #define ONE(NAME, MODE, show)                         \
        NOD(NAME, (S_IFREG|(MODE)),                     \
                NULL, &proc_single_file_operations,     \
-               { .proc_show = &proc_##OTYPE } )
+               { .proc_show = show } )
  
  /*
   * Count the number of hardlinks for the pid_entry table, excluding the .
@@@ -308,9 -306,9 +306,9 @@@ static int proc_pid_auxv(struct task_st
        struct mm_struct *mm = get_task_mm(task);
        if (mm) {
                unsigned int nwords = 0;
-               do
+               do {
                        nwords += 2;
-               while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
+               } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
                res = nwords * sizeof(mm->saved_auxv[0]);
                if (res > PAGE_SIZE)
                        res = PAGE_SIZE;
@@@ -340,6 -338,37 +338,37 @@@ static int proc_pid_wchan(struct task_s
  }
  #endif /* CONFIG_KALLSYMS */
  
+ #ifdef CONFIG_STACKTRACE
+ 
+ #define MAX_STACK_TRACE_DEPTH 64
+ 
+ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
+                         struct pid *pid, struct task_struct *task)
+ {
+       struct stack_trace trace;
+       unsigned long *entries;
+       int i;
+ 
+       entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
+       if (!entries)
+               return -ENOMEM;
+ 
+       trace.nr_entries        = 0;
+       trace.max_entries       = MAX_STACK_TRACE_DEPTH;
+       trace.entries           = entries;
+       trace.skip              = 0;
+       save_stack_trace_tsk(task, &trace);
+ 
+       for (i = 0; i < trace.nr_entries; i++) {
+               seq_printf(m, "[<%p>] %pS\n",
+                          (void *)entries[i], (void *)entries[i]);
+       }
+       kfree(entries);
+ 
+       return 0;
+ }
+ #endif
+ 
  #ifdef CONFIG_SCHEDSTATS
  /*
   * Provides /proc/PID/schedstat
@@@ -1186,8 -1215,6 +1215,6 @@@ static int sched_show(struct seq_file *
        struct inode *inode = m->private;
        struct task_struct *p;
  
-       WARN_ON(!inode);
- 
        p = get_proc_task(inode);
        if (!p)
                return -ESRCH;
@@@ -1205,8 -1232,6 +1232,6 @@@ sched_write(struct file *file, const ch
        struct inode *inode = file->f_path.dentry->d_inode;
        struct task_struct *p;
  
-       WARN_ON(!inode);
- 
        p = get_proc_task(inode);
        if (!p)
                return -ESRCH;
@@@ -1426,6 -1451,8 +1451,6 @@@ static struct inode *proc_pid_make_inod
        if (!ei->pid)
                goto out_unlock;
  
 -      inode->i_uid = 0;
 -      inode->i_gid = 0;
        if (task_dumpable(task)) {
                rcu_read_lock();
                cred = __task_cred(task);
@@@ -1974,13 -2001,11 +1999,11 @@@ static struct dentry *proc_pident_looku
                                         const struct pid_entry *ents,
                                         unsigned int nents)
  {
-       struct inode *inode;
        struct dentry *error;
        struct task_struct *task = get_proc_task(dir);
        const struct pid_entry *p, *last;
  
        error = ERR_PTR(-ENOENT);
-       inode = NULL;
  
        if (!task)
                goto out_no_task;
@@@ -2136,12 -2161,12 +2159,12 @@@ static const struct file_operations pro
  };
  
  static const struct pid_entry attr_dir_stuff[] = {
-       REG("current",    S_IRUGO|S_IWUGO, pid_attr),
-       REG("prev",       S_IRUGO,         pid_attr),
-       REG("exec",       S_IRUGO|S_IWUGO, pid_attr),
-       REG("fscreate",   S_IRUGO|S_IWUGO, pid_attr),
-       REG("keycreate",  S_IRUGO|S_IWUGO, pid_attr),
-       REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
+       REG("current",    S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+       REG("prev",       S_IRUGO,         proc_pid_attr_operations),
+       REG("exec",       S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+       REG("fscreate",   S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+       REG("keycreate",  S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+       REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
  };
  
  static int proc_attr_dir_readdir(struct file * filp,
@@@ -2347,6 -2372,8 +2370,6 @@@ static struct dentry *proc_base_instant
        if (!ei->pid)
                goto out_iput;
  
 -      inode->i_uid = 0;
 -      inode->i_gid = 0;
        inode->i_mode = p->mode;
        if (S_ISDIR(inode->i_mode))
                inode->i_nlink = 2;
@@@ -2461,74 -2488,77 +2484,77 @@@ static const struct file_operations pro
  static const struct inode_operations proc_task_inode_operations;
  
  static const struct pid_entry tgid_base_stuff[] = {
-       DIR("task",       S_IRUGO|S_IXUGO, task),
-       DIR("fd",         S_IRUSR|S_IXUSR, fd),
-       DIR("fdinfo",     S_IRUSR|S_IXUSR, fdinfo),
+       DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
+       DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
+       DIR("fdinfo",     S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
  #ifdef CONFIG_NET
-       DIR("net",        S_IRUGO|S_IXUGO, net),
+       DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
  #endif
-       REG("environ",    S_IRUSR, environ),
-       INF("auxv",       S_IRUSR, pid_auxv),
-       ONE("status",     S_IRUGO, pid_status),
-       ONE("personality", S_IRUSR, pid_personality),
-       INF("limits",     S_IRUSR, pid_limits),
+       REG("environ",    S_IRUSR, proc_environ_operations),
+       INF("auxv",       S_IRUSR, proc_pid_auxv),
+       ONE("status",     S_IRUGO, proc_pid_status),
+       ONE("personality", S_IRUSR, proc_pid_personality),
+       INF("limits",     S_IRUSR, proc_pid_limits),
  #ifdef CONFIG_SCHED_DEBUG
-       REG("sched",      S_IRUGO|S_IWUSR, pid_sched),
+       REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
  #endif
  #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
-       INF("syscall",    S_IRUSR, pid_syscall),
+       INF("syscall",    S_IRUSR, proc_pid_syscall),
  #endif
-       INF("cmdline",    S_IRUGO, pid_cmdline),
-       ONE("stat",       S_IRUGO, tgid_stat),
-       ONE("statm",      S_IRUGO, pid_statm),
-       REG("maps",       S_IRUGO, maps),
+       INF("cmdline",    S_IRUGO, proc_pid_cmdline),
+       ONE("stat",       S_IRUGO, proc_tgid_stat),
+       ONE("statm",      S_IRUGO, proc_pid_statm),
+       REG("maps",       S_IRUGO, proc_maps_operations),
  #ifdef CONFIG_NUMA
-       REG("numa_maps",  S_IRUGO, numa_maps),
+       REG("numa_maps",  S_IRUGO, proc_numa_maps_operations),
  #endif
-       REG("mem",        S_IRUSR|S_IWUSR, mem),
-       LNK("cwd",        cwd),
-       LNK("root",       root),
-       LNK("exe",        exe),
-       REG("mounts",     S_IRUGO, mounts),
-       REG("mountinfo",  S_IRUGO, mountinfo),
-       REG("mountstats", S_IRUSR, mountstats),
+       REG("mem",        S_IRUSR|S_IWUSR, proc_mem_operations),
+       LNK("cwd",        proc_cwd_link),
+       LNK("root",       proc_root_link),
+       LNK("exe",        proc_exe_link),
+       REG("mounts",     S_IRUGO, proc_mounts_operations),
+       REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
+       REG("mountstats", S_IRUSR, proc_mountstats_operations),
  #ifdef CONFIG_PROC_PAGE_MONITOR
-       REG("clear_refs", S_IWUSR, clear_refs),
-       REG("smaps",      S_IRUGO, smaps),
-       REG("pagemap",    S_IRUSR, pagemap),
+       REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
+       REG("smaps",      S_IRUGO, proc_smaps_operations),
+       REG("pagemap",    S_IRUSR, proc_pagemap_operations),
  #endif
  #ifdef CONFIG_SECURITY
-       DIR("attr",       S_IRUGO|S_IXUGO, attr_dir),
+       DIR("attr",       S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
  #endif
  #ifdef CONFIG_KALLSYMS
-       INF("wchan",      S_IRUGO, pid_wchan),
+       INF("wchan",      S_IRUGO, proc_pid_wchan),
+ #endif
+ #ifdef CONFIG_STACKTRACE
+       ONE("stack",      S_IRUSR, proc_pid_stack),
  #endif
  #ifdef CONFIG_SCHEDSTATS
-       INF("schedstat",  S_IRUGO, pid_schedstat),
+       INF("schedstat",  S_IRUGO, proc_pid_schedstat),
  #endif
  #ifdef CONFIG_LATENCYTOP
-       REG("latency",  S_IRUGO, lstats),
+       REG("latency",  S_IRUGO, proc_lstats_operations),
  #endif
  #ifdef CONFIG_PROC_PID_CPUSET
-       REG("cpuset",     S_IRUGO, cpuset),
+       REG("cpuset",     S_IRUGO, proc_cpuset_operations),
  #endif
  #ifdef CONFIG_CGROUPS
-       REG("cgroup",  S_IRUGO, cgroup),
+       REG("cgroup",  S_IRUGO, proc_cgroup_operations),
  #endif
-       INF("oom_score",  S_IRUGO, oom_score),
-       REG("oom_adj",    S_IRUGO|S_IWUSR, oom_adjust),
+       INF("oom_score",  S_IRUGO, proc_oom_score),
+       REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
  #ifdef CONFIG_AUDITSYSCALL
-       REG("loginuid",   S_IWUSR|S_IRUGO, loginuid),
-       REG("sessionid",  S_IRUGO, sessionid),
+       REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
+       REG("sessionid",  S_IRUGO, proc_sessionid_operations),
  #endif
  #ifdef CONFIG_FAULT_INJECTION
-       REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
+       REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
  #endif
  #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
-       REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
+       REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
  #endif
  #ifdef CONFIG_TASK_IO_ACCOUNTING
-       INF("io",       S_IRUGO, tgid_io_accounting),
+       INF("io",       S_IRUGO, proc_tgid_io_accounting),
  #endif
  };
  
@@@ -2801,66 -2831,69 +2827,69 @@@ out_no_task
   * Tasks
   */
  static const struct pid_entry tid_base_stuff[] = {
-       DIR("fd",        S_IRUSR|S_IXUSR, fd),
-       DIR("fdinfo",    S_IRUSR|S_IXUSR, fdinfo),
-       REG("environ",   S_IRUSR, environ),
-       INF("auxv",      S_IRUSR, pid_auxv),
-       ONE("status",    S_IRUGO, pid_status),
-       ONE("personality", S_IRUSR, pid_personality),
-       INF("limits",    S_IRUSR, pid_limits),
+       DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
+       DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fd_operations),
+       REG("environ",   S_IRUSR, proc_environ_operations),
+       INF("auxv",      S_IRUSR, proc_pid_auxv),
+       ONE("status",    S_IRUGO, proc_pid_status),
+       ONE("personality", S_IRUSR, proc_pid_personality),
+       INF("limits",    S_IRUSR, proc_pid_limits),
  #ifdef CONFIG_SCHED_DEBUG
-       REG("sched",     S_IRUGO|S_IWUSR, pid_sched),
+       REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
  #endif
  #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
-       INF("syscall",   S_IRUSR, pid_syscall),
+       INF("syscall",   S_IRUSR, proc_pid_syscall),
  #endif
-       INF("cmdline",   S_IRUGO, pid_cmdline),
-       ONE("stat",      S_IRUGO, tid_stat),
-       ONE("statm",     S_IRUGO, pid_statm),
-       REG("maps",      S_IRUGO, maps),
+       INF("cmdline",   S_IRUGO, proc_pid_cmdline),
+       ONE("stat",      S_IRUGO, proc_tid_stat),
+       ONE("statm",     S_IRUGO, proc_pid_statm),
+       REG("maps",      S_IRUGO, proc_maps_operations),
  #ifdef CONFIG_NUMA
-       REG("numa_maps", S_IRUGO, numa_maps),
+       REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
  #endif
-       REG("mem",       S_IRUSR|S_IWUSR, mem),
-       LNK("cwd",       cwd),
-       LNK("root",      root),
-       LNK("exe",       exe),
-       REG("mounts",    S_IRUGO, mounts),
-       REG("mountinfo",  S_IRUGO, mountinfo),
+       REG("mem",       S_IRUSR|S_IWUSR, proc_mem_operations),
+       LNK("cwd",       proc_cwd_link),
+       LNK("root",      proc_root_link),
+       LNK("exe",       proc_exe_link),
+       REG("mounts",    S_IRUGO, proc_mounts_operations),
+       REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
  #ifdef CONFIG_PROC_PAGE_MONITOR
-       REG("clear_refs", S_IWUSR, clear_refs),
-       REG("smaps",     S_IRUGO, smaps),
-       REG("pagemap",    S_IRUSR, pagemap),
+       REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
+       REG("smaps",     S_IRUGO, proc_smaps_operations),
+       REG("pagemap",    S_IRUSR, proc_pagemap_operations),
  #endif
  #ifdef CONFIG_SECURITY
-       DIR("attr",      S_IRUGO|S_IXUGO, attr_dir),
+       DIR("attr",      S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
  #endif
  #ifdef CONFIG_KALLSYMS
-       INF("wchan",     S_IRUGO, pid_wchan),
+       INF("wchan",     S_IRUGO, proc_pid_wchan),
+ #endif
+ #ifdef CONFIG_STACKTRACE
+       ONE("stack",      S_IRUSR, proc_pid_stack),
  #endif
  #ifdef CONFIG_SCHEDSTATS
-       INF("schedstat", S_IRUGO, pid_schedstat),
+       INF("schedstat", S_IRUGO, proc_pid_schedstat),
  #endif
  #ifdef CONFIG_LATENCYTOP
-       REG("latency",  S_IRUGO, lstats),
+       REG("latency",  S_IRUGO, proc_lstats_operations),
  #endif
  #ifdef CONFIG_PROC_PID_CPUSET
-       REG("cpuset",    S_IRUGO, cpuset),
+       REG("cpuset",    S_IRUGO, proc_cpuset_operations),
  #endif
  #ifdef CONFIG_CGROUPS
-       REG("cgroup",  S_IRUGO, cgroup),
+       REG("cgroup",  S_IRUGO, proc_cgroup_operations),
  #endif
-       INF("oom_score", S_IRUGO, oom_score),
-       REG("oom_adj",   S_IRUGO|S_IWUSR, oom_adjust),
+       INF("oom_score", S_IRUGO, proc_oom_score),
+       REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
  #ifdef CONFIG_AUDITSYSCALL
-       REG("loginuid",  S_IWUSR|S_IRUGO, loginuid),
-       REG("sessionid",  S_IRUSR, sessionid),
+       REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
+       REG("sessionid",  S_IRUSR, proc_sessionid_operations),
  #endif
  #ifdef CONFIG_FAULT_INJECTION
-       REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
+       REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
  #endif
  #ifdef CONFIG_TASK_IO_ACCOUNTING
-       INF("io",       S_IRUGO, tid_io_accounting),
+       INF("io",       S_IRUGO, proc_tid_io_accounting),
  #endif
  };