backported vs2.1.x fix to irq handling, which caused incorrect scheduler behavior
[linux-2.6.git] / fs / proc / base.c
index 65f144a..0e73286 100644 (file)
  *  go into icache. We cache the reference to task_struct upon lookup too.
  *  Eventually it should become a filesystem in its own. We don't use the
  *  rest of procfs anymore.
+ *
+ *
+ *  Changelog:
+ *  17-Jan-2005
+ *  Allan Bezerra
+ *  Bruna Moreira <bruna.moreira@indt.org.br>
+ *  Edjard Mota <edjard.mota@indt.org.br>
+ *  Ilias Biris <ilias.biris@indt.org.br>
+ *  Mauricio Lin <mauricio.lin@indt.org.br>
+ *
+ *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
+ *
+ *  A new process specific entry (smaps) included in /proc. It shows the
+ *  size of rss for each memory area. The maps entry lacks information
+ *  about physical memory size (rss) for each mapped file, i.e.,
+ *  rss information for executables and library files.
+ *  This additional information is useful for any tools that need to know
+ *  about physical memory consumption for a process specific library.
+ *
+ *  Changelog:
+ *  21-Feb-2005
+ *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
+ *  Pud inclusion in the page table walking.
+ *
+ *  ChangeLog:
+ *  10-Mar-2005
+ *  10LE Instituto Nokia de Tecnologia - INdT:
+ *  A better way to walks through the page table as suggested by Hugh Dickins.
+ *
+ *  Simo Piiroinen <simo.piiroinen@nokia.com>:
+ *  Smaps information related to shared, private, clean and dirty pages.
+ *
+ *  Paul Mundt <paul.mundt@nokia.com>:
+ *  Overall revision about smaps.
  */
 
 #include <asm/uaccess.h>
 
-#include <linux/config.h>
 #include <linux/errno.h>
 #include <linux/time.h>
 #include <linux/proc_fs.h>
 #include <linux/stat.h>
 #include <linux/init.h>
+#include <linux/capability.h>
 #include <linux/file.h>
 #include <linux/string.h>
 #include <linux/seq_file.h>
 #include <linux/namespace.h>
 #include <linux/mm.h>
 #include <linux/smp_lock.h>
+#include <linux/rcupdate.h>
 #include <linux/kallsyms.h>
 #include <linux/mount.h>
 #include <linux/security.h>
 #include <linux/ptrace.h>
-#include <linux/vs_network.h>
+#include <linux/tracehook.h>
+#include <linux/seccomp.h>
+#include <linux/cpuset.h>
+#include <linux/audit.h>
+#include <linux/poll.h>
+
+#include "internal.h"
+
+/* NOTE:
+ *     Implementing inode permission operations in /proc is almost
+ *     certainly an error.  Permission checks need to happen during
+ *     each system call not at open time.  The reason is that most of
+ *     what we wish to check for permissions in /proc varies at runtime.
+ *
+ *     The classic example of a problem is opening file descriptors
+ *     in /proc for a task before it execs a suid executable.
+ */
 
 /*
  * For hysterical raisins we keep the same inumbers as in the old procfs.
@@ -49,6 +100,9 @@ enum pid_directory_inos {
        PROC_TGID_TASK,
        PROC_TGID_STATUS,
        PROC_TGID_MEM,
+#ifdef CONFIG_SECCOMP
+       PROC_TGID_SECCOMP,
+#endif
        PROC_TGID_CWD,
        PROC_TGID_ROOT,
        PROC_TGID_EXE,
@@ -59,24 +113,41 @@ enum pid_directory_inos {
        PROC_TGID_STAT,
        PROC_TGID_STATM,
        PROC_TGID_MAPS,
+       PROC_TGID_NUMA_MAPS,
        PROC_TGID_MOUNTS,
+       PROC_TGID_MOUNTSTATS,
        PROC_TGID_WCHAN,
+#ifdef CONFIG_MMU
+       PROC_TGID_SMAPS,
+#endif
 #ifdef CONFIG_SCHEDSTATS
        PROC_TGID_SCHEDSTAT,
 #endif
+#ifdef CONFIG_CPUSETS
+       PROC_TGID_CPUSET,
+#endif
 #ifdef CONFIG_SECURITY
        PROC_TGID_ATTR,
        PROC_TGID_ATTR_CURRENT,
        PROC_TGID_ATTR_PREV,
        PROC_TGID_ATTR_EXEC,
        PROC_TGID_ATTR_FSCREATE,
+       PROC_TGID_ATTR_KEYCREATE,
+       PROC_TGID_ATTR_SOCKCREATE,
 #endif
        PROC_TGID_VX_INFO,
        PROC_TGID_IP_INFO,
-       PROC_TGID_FD_DIR,
+#ifdef CONFIG_AUDITSYSCALL
+       PROC_TGID_LOGINUID,
+#endif
+       PROC_TGID_OOM_SCORE,
+       PROC_TGID_OOM_ADJUST,
        PROC_TID_INO,
        PROC_TID_STATUS,
        PROC_TID_MEM,
+#ifdef CONFIG_SECCOMP
+       PROC_TID_SECCOMP,
+#endif
        PROC_TID_CWD,
        PROC_TID_ROOT,
        PROC_TID_EXE,
@@ -87,23 +158,43 @@ enum pid_directory_inos {
        PROC_TID_STAT,
        PROC_TID_STATM,
        PROC_TID_MAPS,
+       PROC_TID_NUMA_MAPS,
        PROC_TID_MOUNTS,
+       PROC_TID_MOUNTSTATS,
        PROC_TID_WCHAN,
+#ifdef CONFIG_MMU
+       PROC_TID_SMAPS,
+#endif
 #ifdef CONFIG_SCHEDSTATS
        PROC_TID_SCHEDSTAT,
 #endif
+#ifdef CONFIG_CPUSETS
+       PROC_TID_CPUSET,
+#endif
 #ifdef CONFIG_SECURITY
        PROC_TID_ATTR,
        PROC_TID_ATTR_CURRENT,
        PROC_TID_ATTR_PREV,
        PROC_TID_ATTR_EXEC,
        PROC_TID_ATTR_FSCREATE,
+       PROC_TID_ATTR_KEYCREATE,
+       PROC_TID_ATTR_SOCKCREATE,
 #endif
        PROC_TID_VX_INFO,
        PROC_TID_IP_INFO,
+#ifdef CONFIG_AUDITSYSCALL
+       PROC_TID_LOGINUID,
+#endif
+       PROC_TID_OOM_SCORE,
+       PROC_TID_OOM_ADJUST,
+
+       /* Add new entries before this */
        PROC_TID_FD_DIR = 0x8000,       /* 0x8000-0xffff */
 };
 
+/* Worst case buffer size needed for holding an integer. */
+#define PROC_NUMBUF 10
+
 struct pid_entry {
        int type;
        int len;
@@ -123,11 +214,21 @@ static struct pid_entry tgid_base_stuff[] = {
        E(PROC_TGID_STAT,      "stat",    S_IFREG|S_IRUGO),
        E(PROC_TGID_STATM,     "statm",   S_IFREG|S_IRUGO),
        E(PROC_TGID_MAPS,      "maps",    S_IFREG|S_IRUSR),
+#ifdef CONFIG_NUMA
+       E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
+#endif
        E(PROC_TGID_MEM,       "mem",     S_IFREG|S_IRUSR|S_IWUSR),
+#ifdef CONFIG_SECCOMP
+       E(PROC_TGID_SECCOMP,   "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
+#endif
        E(PROC_TGID_CWD,       "cwd",     S_IFLNK|S_IRWXUGO),
        E(PROC_TGID_ROOT,      "root",    S_IFLNK|S_IRWXUGO),
        E(PROC_TGID_EXE,       "exe",     S_IFLNK|S_IRWXUGO),
        E(PROC_TGID_MOUNTS,    "mounts",  S_IFREG|S_IRUGO),
+       E(PROC_TGID_MOUNTSTATS, "mountstats", S_IFREG|S_IRUSR),
+#ifdef CONFIG_MMU
+       E(PROC_TGID_SMAPS,     "smaps",   S_IFREG|S_IRUSR),
+#endif
 #ifdef CONFIG_SECURITY
        E(PROC_TGID_ATTR,      "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
 #endif
@@ -136,9 +237,17 @@ static struct pid_entry tgid_base_stuff[] = {
 #endif
 #ifdef CONFIG_SCHEDSTATS
        E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
+#endif
+#ifdef CONFIG_CPUSETS
+       E(PROC_TGID_CPUSET,    "cpuset",  S_IFREG|S_IRUGO),
 #endif
        E(PROC_TGID_VX_INFO,   "vinfo",   S_IFREG|S_IRUGO),
        E(PROC_TGID_IP_INFO,   "ninfo",   S_IFREG|S_IRUGO),
+       E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
+       E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
+#ifdef CONFIG_AUDITSYSCALL
+       E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
+#endif
        {0,0,NULL,0}
 };
 static struct pid_entry tid_base_stuff[] = {
@@ -150,11 +259,20 @@ static struct pid_entry tid_base_stuff[] = {
        E(PROC_TID_STAT,       "stat",    S_IFREG|S_IRUGO),
        E(PROC_TID_STATM,      "statm",   S_IFREG|S_IRUGO),
        E(PROC_TID_MAPS,       "maps",    S_IFREG|S_IRUSR),
+#ifdef CONFIG_NUMA
+       E(PROC_TID_NUMA_MAPS,  "numa_maps",    S_IFREG|S_IRUGO),
+#endif
        E(PROC_TID_MEM,        "mem",     S_IFREG|S_IRUSR|S_IWUSR),
+#ifdef CONFIG_SECCOMP
+       E(PROC_TID_SECCOMP,    "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
+#endif
        E(PROC_TID_CWD,        "cwd",     S_IFLNK|S_IRWXUGO),
        E(PROC_TID_ROOT,       "root",    S_IFLNK|S_IRWXUGO),
        E(PROC_TID_EXE,        "exe",     S_IFLNK|S_IRWXUGO),
        E(PROC_TID_MOUNTS,     "mounts",  S_IFREG|S_IRUGO),
+#ifdef CONFIG_MMU
+       E(PROC_TID_SMAPS,      "smaps",   S_IFREG|S_IRUSR),
+#endif
 #ifdef CONFIG_SECURITY
        E(PROC_TID_ATTR,       "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
 #endif
@@ -163,9 +281,17 @@ static struct pid_entry tid_base_stuff[] = {
 #endif
 #ifdef CONFIG_SCHEDSTATS
        E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
+#endif
+#ifdef CONFIG_CPUSETS
+       E(PROC_TID_CPUSET,     "cpuset",  S_IFREG|S_IRUGO),
 #endif
        E(PROC_TID_VX_INFO,    "vinfo",   S_IFREG|S_IRUGO),
        E(PROC_TID_IP_INFO,    "ninfo",   S_IFREG|S_IRUGO),
+       E(PROC_TID_OOM_SCORE,  "oom_score",S_IFREG|S_IRUGO),
+       E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
+#ifdef CONFIG_AUDITSYSCALL
+       E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
+#endif
        {0,0,NULL,0}
 };
 
@@ -175,6 +301,8 @@ static struct pid_entry tgid_attr_stuff[] = {
        E(PROC_TGID_ATTR_PREV,     "prev",     S_IFREG|S_IRUGO),
        E(PROC_TGID_ATTR_EXEC,     "exec",     S_IFREG|S_IRUGO|S_IWUGO),
        E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
+       E(PROC_TGID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
+       E(PROC_TGID_ATTR_SOCKCREATE, "sockcreate", S_IFREG|S_IRUGO|S_IWUGO),
        {0,0,NULL,0}
 };
 static struct pid_entry tid_attr_stuff[] = {
@@ -182,36 +310,30 @@ static struct pid_entry tid_attr_stuff[] = {
        E(PROC_TID_ATTR_PREV,      "prev",     S_IFREG|S_IRUGO),
        E(PROC_TID_ATTR_EXEC,      "exec",     S_IFREG|S_IRUGO|S_IWUGO),
        E(PROC_TID_ATTR_FSCREATE,  "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
+       E(PROC_TID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
+       E(PROC_TID_ATTR_SOCKCREATE, "sockcreate", S_IFREG|S_IRUGO|S_IWUGO),
        {0,0,NULL,0}
 };
 #endif
 
 #undef E
 
-static inline struct task_struct *proc_task(struct inode *inode)
-{
-       return PROC_I(inode)->task;
-}
-
-static inline int proc_type(struct inode *inode)
-{
-       return PROC_I(inode)->type;
-}
-
-int proc_tid_stat(struct task_struct*,char*);
-int proc_tgid_stat(struct task_struct*,char*);
-int proc_pid_status(struct task_struct*,char*);
-int proc_pid_statm(struct task_struct*,char*);
-
 static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
 {
-       struct task_struct *task = proc_task(inode);
-       struct files_struct *files;
+       struct task_struct *task = get_proc_task(inode);
+       struct files_struct *files = NULL;
        struct file *file;
-       int fd = proc_type(inode) - PROC_TID_FD_DIR;
+       int fd = proc_fd(inode);
 
-       files = get_files_struct(task);
+       if (task) {
+               files = get_files_struct(task);
+               put_task_struct(task);
+       }
        if (files) {
+               /*
+                * We are not taking a ref to the file structure, so we must
+                * hold ->file_lock.
+                */
                spin_lock(&files->file_lock);
                file = fcheck_files(files, fd);
                if (file) {
@@ -227,42 +349,40 @@ static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsm
        return -ENOENT;
 }
 
-static int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
+static struct fs_struct *get_fs_struct(struct task_struct *task)
 {
-       struct vm_area_struct * vma;
-       int result = -ENOENT;
-       struct task_struct *task = proc_task(inode);
-       struct mm_struct * mm = get_task_mm(task);
+       struct fs_struct *fs;
+       task_lock(task);
+       fs = task->fs;
+       if(fs)
+               atomic_inc(&fs->count);
+       task_unlock(task);
+       return fs;
+}
 
-       if (!mm)
-               goto out;
-       down_read(&mm->mmap_sem);
-       vma = mm->mmap;
-       while (vma) {
-               if ((vma->vm_flags & VM_EXECUTABLE) && 
-                   vma->vm_file) {
-                       *mnt = mntget(vma->vm_file->f_vfsmnt);
-                       *dentry = dget(vma->vm_file->f_dentry);
-                       result = 0;
-                       break;
-               }
-               vma = vma->vm_next;
+static int get_nr_threads(struct task_struct *tsk)
+{
+       /* Must be called with the rcu_read_lock held */
+       unsigned long flags;
+       int count = 0;
+
+       if (lock_task_sighand(tsk, &flags)) {
+               count = atomic_read(&tsk->signal->count);
+               unlock_task_sighand(tsk, &flags);
        }
-       up_read(&mm->mmap_sem);
-       mmput(mm);
-out:
-       return result;
+       return count;
 }
 
 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
 {
-       struct fs_struct *fs;
+       struct task_struct *task = get_proc_task(inode);
+       struct fs_struct *fs = NULL;
        int result = -ENOENT;
-       task_lock(proc_task(inode));
-       fs = proc_task(inode)->fs;
-       if(fs)
-               atomic_inc(&fs->count);
-       task_unlock(proc_task(inode));
+
+       if (task) {
+               fs = get_fs_struct(task);
+               put_task_struct(task);
+       }
        if (fs) {
                read_lock(&fs->lock);
                *mnt = mntget(fs->pwdmnt);
@@ -276,13 +396,14 @@ static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfs
 
 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
 {
-       struct fs_struct *fs;
+       struct task_struct *task = get_proc_task(inode);
+       struct fs_struct *fs = NULL;
        int result = -ENOENT;
-       task_lock(proc_task(inode));
-       fs = proc_task(inode)->fs;
-       if(fs)
-               atomic_inc(&fs->count);
-       task_unlock(proc_task(inode));
+
+       if (task) {
+               fs = get_fs_struct(task);
+               put_task_struct(task);
+       }
        if (fs) {
                read_lock(&fs->lock);
                *mnt = mntget(fs->rootmnt);
@@ -294,38 +415,24 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
        return result;
 }
 
-#define MAY_PTRACE(task) \
-       (task == current || \
-       (task->parent == current && \
-       (task->ptrace & PT_PTRACED) && \
-        (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
-        security_ptrace(current,task) == 0))
-
-static int may_ptrace_attach(struct task_struct *task)
+struct mm_struct *mm_for_maps(struct task_struct *task)
 {
-       int retval = 0;
-
+       struct mm_struct *mm = get_task_mm(task);
+       if (!mm)
+               return NULL;
+       down_read(&mm->mmap_sem);
        task_lock(task);
-
-       if (!task->mm)
-               goto out;
-       if (((current->uid != task->euid) ||
-            (current->uid != task->suid) ||
-            (current->uid != task->uid) ||
-            (current->gid != task->egid) ||
-            (current->gid != task->sgid) ||
-            (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE))
-               goto out;
-       rmb();
-       if (task->mm->dumpable != 1 && !capable(CAP_SYS_PTRACE))
+       if (task->mm != mm)
                goto out;
-       if (security_ptrace(current, task))
+       if (task->mm != current->mm && __ptrace_may_attach(task) < 0)
                goto out;
-
-       retval = 1;
+       task_unlock(task);
+       return mm;
 out:
        task_unlock(task);
-       return retval;
+       up_read(&mm->mmap_sem);
+       mmput(mm);
+       return NULL;
 }
 
 static int proc_pid_environ(struct task_struct *task, char * buffer)
@@ -337,7 +444,7 @@ static int proc_pid_environ(struct task_struct *task, char * buffer)
                if (len > PAGE_SIZE)
                        len = PAGE_SIZE;
                res = access_process_vm(task, mm->env_start, buffer, len, 0);
-               if (!may_ptrace_attach(task))
+               if (!ptrace_may_attach(task))
                        res = -ESRCH;
                mmput(mm);
        }
@@ -410,7 +517,7 @@ static int proc_pid_wchan(struct task_struct *task, char *buffer)
        char *modname;
        const char *sym_name;
        unsigned long wchan, size, offset;
-       char namebuf[128];
+       char namebuf[KSYM_NAME_LEN+1];
 
        wchan = get_wchan(task);
 
@@ -434,99 +541,96 @@ static int proc_pid_schedstat(struct task_struct *task, char *buffer)
 }
 #endif
 
+/* The badness from the OOM killer */
+unsigned long badness(struct task_struct *p, unsigned long uptime);
+static int proc_oom_score(struct task_struct *task, char *buffer)
+{
+       unsigned long points;
+       struct timespec uptime;
+
+       do_posix_clock_monotonic_gettime(&uptime);
+       points = badness(task, uptime.tv_sec);
+       return sprintf(buffer, "%lu\n", points);
+}
+
 /************************************************************************/
 /*                       Here the fs part begins                        */
 /************************************************************************/
 
 /* permission checks */
-
-static int proc_check_root(struct inode *inode)
+static int proc_fd_access_allowed(struct inode *inode)
 {
-       struct dentry *de, *base, *root;
-       struct vfsmount *our_vfsmnt, *vfsmnt, *mnt;
-       int res = 0;
-
-       if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
-               return -ENOENT;
-       read_lock(&current->fs->lock);
-       our_vfsmnt = mntget(current->fs->rootmnt);
-       base = dget(current->fs->root);
-       read_unlock(&current->fs->lock);
-
-       spin_lock(&vfsmount_lock);
-       de = root;
-       mnt = vfsmnt;
-
-       while (vfsmnt != our_vfsmnt) {
-               if (vfsmnt == vfsmnt->mnt_parent)
-                       goto out;
-               de = vfsmnt->mnt_mountpoint;
-               vfsmnt = vfsmnt->mnt_parent;
+       struct task_struct *task;
+       int allowed = 0;
+       /* Allow access to a task's file descriptors if it is us or we
+        * may use ptrace attach to the process and find out that
+        * information.
+        */
+       task = get_proc_task(inode);
+       if (task) {
+               allowed = ptrace_may_attach(task);
+               put_task_struct(task);
        }
-
-       if (!is_subdir(de, base))
-               goto out;
-       spin_unlock(&vfsmount_lock);
-
-exit:
-       dput(base);
-       mntput(our_vfsmnt);
-       dput(root);
-       mntput(mnt);
-       return res;
-out:
-       spin_unlock(&vfsmount_lock);
-       res = -EACCES;
-       goto exit;
+       return allowed;
 }
 
-static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
+static int proc_setattr(struct dentry *dentry, struct iattr *attr)
 {
-       if (generic_permission(inode, mask, NULL) != 0)
-               return -EACCES;
-       return proc_check_root(inode);
-}
+       int error;
+       struct inode *inode = dentry->d_inode;
 
-extern struct seq_operations proc_pid_maps_op;
-static int maps_open(struct inode *inode, struct file *file)
-{
-       struct task_struct *task = proc_task(inode);
-       int ret = seq_open(file, &proc_pid_maps_op);
-       if (!ret) {
-               struct seq_file *m = file->private_data;
-               m->private = task;
+       if (attr->ia_valid & ATTR_MODE)
+               return -EPERM;
+
+       error = inode_change_ok(inode, attr);
+       if (!error) {
+               error = security_inode_setattr(dentry, attr);
+               if (!error)
+                       error = inode_setattr(inode, attr);
        }
-       return ret;
+       return error;
 }
 
-static struct file_operations proc_maps_operations = {
-       .open           = maps_open,
-       .read           = seq_read,
-       .llseek         = seq_lseek,
-       .release        = seq_release,
+static struct inode_operations proc_def_inode_operations = {
+       .setattr        = proc_setattr,
 };
 
 extern struct seq_operations mounts_op;
+struct proc_mounts {
+       struct seq_file m;
+       int event;
+};
+
 static int mounts_open(struct inode *inode, struct file *file)
 {
-       struct task_struct *task = proc_task(inode);
-       int ret = seq_open(file, &mounts_op);
+       struct task_struct *task = get_proc_task(inode);
+       struct namespace *namespace = NULL;
+       struct proc_mounts *p;
+       int ret = -EINVAL;
 
-       if (!ret) {
-               struct seq_file *m = file->private_data;
-               struct namespace *namespace;
+       if (task) {
                task_lock(task);
                namespace = task->namespace;
                if (namespace)
                        get_namespace(namespace);
                task_unlock(task);
+               put_task_struct(task);
+       }
 
-               if (namespace)
-                       m->private = namespace;
-               else {
-                       seq_release(inode, file);
-                       ret = -EINVAL;
+       if (namespace) {
+               ret = -ENOMEM;
+               p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
+               if (p) {
+                       file->private_data = &p->m;
+                       ret = seq_open(file, &mounts_op);
+                       if (!ret) {
+                               p->m.private = namespace;
+                               p->event = namespace->event;
+                               return 0;
+                       }
+                       kfree(p);
                }
+               put_namespace(namespace);
        }
        return ret;
 }
@@ -539,11 +643,66 @@ static int mounts_release(struct inode *inode, struct file *file)
        return seq_release(inode, file);
 }
 
+static unsigned mounts_poll(struct file *file, poll_table *wait)
+{
+       struct proc_mounts *p = file->private_data;
+       struct namespace *ns = p->m.private;
+       unsigned res = 0;
+
+       poll_wait(file, &ns->poll, wait);
+
+       spin_lock(&vfsmount_lock);
+       if (p->event != ns->event) {
+               p->event = ns->event;
+               res = POLLERR;
+       }
+       spin_unlock(&vfsmount_lock);
+
+       return res;
+}
+
 static struct file_operations proc_mounts_operations = {
        .open           = mounts_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = mounts_release,
+       .poll           = mounts_poll,
+};
+
+extern struct seq_operations mountstats_op;
+static int mountstats_open(struct inode *inode, struct file *file)
+{
+       int ret = seq_open(file, &mountstats_op);
+
+       if (!ret) {
+               struct seq_file *m = file->private_data;
+               struct namespace *namespace = NULL;
+               struct task_struct *task = get_proc_task(inode);
+
+               if (task) {
+                       task_lock(task);
+                       namespace = task->namespace;
+                       if (namespace)
+                               get_namespace(namespace);
+                       task_unlock(task);
+                       put_task_struct(task);
+               }
+
+               if (namespace)
+                       m->private = namespace;
+               else {
+                       seq_release(inode, file);
+                       ret = -EINVAL;
+               }
+       }
+       return ret;
+}
+
+static struct file_operations proc_mountstats_operations = {
+       .open           = mountstats_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = mounts_release,
 };
 
 #define PROC_BLOCK_SIZE        (3*1024)                /* 4K page size but our output routines use some slack for overruns */
@@ -554,18 +713,27 @@ static ssize_t proc_info_read(struct file * file, char __user * buf,
        struct inode * inode = file->f_dentry->d_inode;
        unsigned long page;
        ssize_t length;
-       struct task_struct *task = proc_task(inode);
+       struct task_struct *task = get_proc_task(inode);
+
+       length = -ESRCH;
+       if (!task)
+               goto out_no_task;
 
        if (count > PROC_BLOCK_SIZE)
                count = PROC_BLOCK_SIZE;
+
+       length = -ENOMEM;
        if (!(page = __get_free_page(GFP_KERNEL)))
-               return -ENOMEM;
+               goto out;
 
        length = PROC_I(inode)->op.proc_read(task, (char*)page);
 
        if (length >= 0)
                length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
        free_page(page);
+out:
+       put_task_struct(task);
+out_no_task:
        return length;
 }
 
@@ -582,13 +750,17 @@ static int mem_open(struct inode* inode, struct file* file)
 static ssize_t mem_read(struct file * file, char __user * buf,
                        size_t count, loff_t *ppos)
 {
-       struct task_struct *task = proc_task(file->f_dentry->d_inode);
+       struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
        char *page;
        unsigned long src = *ppos;
        int ret = -ESRCH;
        struct mm_struct *mm;
 
-       if (!MAY_PTRACE(task) || !may_ptrace_attach(task))
+       if (!task)
+               goto out_no_task;
+
+       if (!tracehook_allow_access_process_vm(task)
+           || !ptrace_may_attach(task))
                goto out;
 
        ret = -ENOMEM;
@@ -614,7 +786,8 @@ static ssize_t mem_read(struct file * file, char __user * buf,
 
                this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
                retval = access_process_vm(task, src, page, this_len, 0);
-               if (!retval || !MAY_PTRACE(task) || !may_ptrace_attach(task)) {
+               if (!retval || !tracehook_allow_access_process_vm(task)
+                   || !ptrace_may_attach(task)) {
                        if (!ret)
                                ret = -EIO;
                        break;
@@ -637,6 +810,8 @@ out_put:
 out_free:
        free_page((unsigned long) page);
 out:
+       put_task_struct(task);
+out_no_task:
        return ret;
 }
 
@@ -649,15 +824,21 @@ static ssize_t mem_write(struct file * file, const char * buf,
 {
        int copied = 0;
        char *page;
-       struct task_struct *task = proc_task(file->f_dentry->d_inode);
+       struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
        unsigned long dst = *ppos;
 
-       if (!MAY_PTRACE(task) || !may_ptrace_attach(task))
-               return -ESRCH;
+       copied = -ESRCH;
+       if (!task)
+               goto out_no_task;
 
+       if (!tracehook_allow_access_process_vm(task)
+           || !ptrace_may_attach(task))
+               goto out;
+
+       copied = -ENOMEM;
        page = (char *)__get_free_page(GFP_USER);
        if (!page)
-               return -ENOMEM;
+               goto out;
 
        while (count > 0) {
                int this_len, retval;
@@ -680,6 +861,9 @@ static ssize_t mem_write(struct file * file, const char * buf,
        }
        *ppos = dst;
        free_page((unsigned long) page);
+out:
+       put_task_struct(task);
+out_no_task:
        return copied;
 }
 #endif
@@ -707,11 +891,206 @@ static struct file_operations proc_mem_operations = {
        .open           = mem_open,
 };
 
-static struct inode_operations proc_mem_inode_operations = {
-       .permission     = proc_permission,
+static ssize_t oom_adjust_read(struct file *file, char __user *buf,
+                               size_t count, loff_t *ppos)
+{
+       struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
+       char buffer[PROC_NUMBUF];
+       size_t len;
+       int oom_adjust;
+       loff_t __ppos = *ppos;
+
+       if (!task)
+               return -ESRCH;
+       oom_adjust = task->oomkilladj;
+       put_task_struct(task);
+
+       len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
+       if (__ppos >= len)
+               return 0;
+       if (count > len-__ppos)
+               count = len-__ppos;
+       if (copy_to_user(buf, buffer + __ppos, count))
+               return -EFAULT;
+       *ppos = __ppos + count;
+       return count;
+}
+
+static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
+                               size_t count, loff_t *ppos)
+{
+       struct task_struct *task;
+       char buffer[PROC_NUMBUF], *end;
+       int oom_adjust;
+
+       if (!capable(CAP_SYS_RESOURCE))
+               return -EPERM;
+       memset(buffer, 0, sizeof(buffer));
+       if (count > sizeof(buffer) - 1)
+               count = sizeof(buffer) - 1;
+       if (copy_from_user(buffer, buf, count))
+               return -EFAULT;
+       oom_adjust = simple_strtol(buffer, &end, 0);
+       if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
+               return -EINVAL;
+       if (*end == '\n')
+               end++;
+       task = get_proc_task(file->f_dentry->d_inode);
+       if (!task)
+               return -ESRCH;
+       task->oomkilladj = oom_adjust;
+       put_task_struct(task);
+       if (end - buffer == 0)
+               return -EIO;
+       return end - buffer;
+}
+
+static struct file_operations proc_oom_adjust_operations = {
+       .read           = oom_adjust_read,
+       .write          = oom_adjust_write,
+};
+
+#ifdef CONFIG_AUDITSYSCALL
+#define TMPBUFLEN 21
+static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
+                                 size_t count, loff_t *ppos)
+{
+       struct inode * inode = file->f_dentry->d_inode;
+       struct task_struct *task = get_proc_task(inode);
+       ssize_t length;
+       char tmpbuf[TMPBUFLEN];
+
+       if (!task)
+               return -ESRCH;
+       length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
+                               audit_get_loginuid(task->audit_context));
+       put_task_struct(task);
+       return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
+}
+
+static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
+                                  size_t count, loff_t *ppos)
+{
+       struct inode * inode = file->f_dentry->d_inode;
+       char *page, *tmp;
+       ssize_t length;
+       uid_t loginuid;
+
+       if (!capable(CAP_AUDIT_CONTROL))
+               return -EPERM;
+
+       if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
+               return -EPERM;
+
+       if (count >= PAGE_SIZE)
+               count = PAGE_SIZE - 1;
+
+       if (*ppos != 0) {
+               /* No partial writes. */
+               return -EINVAL;
+       }
+       page = (char*)__get_free_page(GFP_USER);
+       if (!page)
+               return -ENOMEM;
+       length = -EFAULT;
+       if (copy_from_user(page, buf, count))
+               goto out_free_page;
+
+       page[count] = '\0';
+       loginuid = simple_strtoul(page, &tmp, 10);
+       if (tmp == page) {
+               length = -EINVAL;
+               goto out_free_page;
+
+       }
+       length = audit_set_loginuid(current, loginuid);
+       if (likely(length == 0))
+               length = count;
+
+out_free_page:
+       free_page((unsigned long) page);
+       return length;
+}
+
+static struct file_operations proc_loginuid_operations = {
+       .read           = proc_loginuid_read,
+       .write          = proc_loginuid_write,
+};
+#endif
+
+#ifdef CONFIG_SECCOMP
+static ssize_t seccomp_read(struct file *file, char __user *buf,
+                           size_t count, loff_t *ppos)
+{
+       struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
+       char __buf[20];
+       loff_t __ppos = *ppos;
+       size_t len;
+
+       if (!tsk)
+               return -ESRCH;
+       /* no need to print the trailing zero, so use only len */
+       len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
+       put_task_struct(tsk);
+       if (__ppos >= len)
+               return 0;
+       if (count > len - __ppos)
+               count = len - __ppos;
+       if (copy_to_user(buf, __buf + __ppos, count))
+               return -EFAULT;
+       *ppos = __ppos + count;
+       return count;
+}
+
+static ssize_t seccomp_write(struct file *file, const char __user *buf,
+                            size_t count, loff_t *ppos)
+{
+       struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
+       char __buf[20], *end;
+       unsigned int seccomp_mode;
+       ssize_t result;
+
+       result = -ESRCH;
+       if (!tsk)
+               goto out_no_task;
+
+       /* can set it only once to be even more secure */
+       result = -EPERM;
+       if (unlikely(tsk->seccomp.mode))
+               goto out;
+
+       result = -EFAULT;
+       memset(__buf, 0, sizeof(__buf));
+       count = min(count, sizeof(__buf) - 1);
+       if (copy_from_user(__buf, buf, count))
+               goto out;
+
+       seccomp_mode = simple_strtoul(__buf, &end, 0);
+       if (*end == '\n')
+               end++;
+       result = -EINVAL;
+       if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
+               tsk->seccomp.mode = seccomp_mode;
+               set_tsk_thread_flag(tsk, TIF_SECCOMP);
+       } else
+               goto out;
+       result = -EIO;
+       if (unlikely(!(end - __buf)))
+               goto out;
+       result = end - __buf;
+out:
+       put_task_struct(tsk);
+out_no_task:
+       return result;
+}
+
+static struct file_operations proc_seccomp_operations = {
+       .read           = seccomp_read,
+       .write          = seccomp_write,
 };
+#endif /* CONFIG_SECCOMP */
 
-static int proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
        struct inode *inode = dentry->d_inode;
        int error = -EACCES;
@@ -719,16 +1098,14 @@ static int proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
        /* We don't need a base pointer in the /proc filesystem */
        path_release(nd);
 
-       if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
-               goto out;
-       error = proc_check_root(inode);
-       if (error)
+       /* Are we allowed to snoop on the tasks file descriptors? */
+       if (!proc_fd_access_allowed(inode))
                goto out;
 
        error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
        nd->last_type = LAST_BIND;
 out:
-       return error;
+       return ERR_PTR(error);
 }
 
 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
@@ -764,12 +1141,8 @@ static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int b
        struct dentry *de;
        struct vfsmount *mnt = NULL;
 
-       lock_kernel();
-
-       if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
-               goto out;
-       error = proc_check_root(inode);
-       if (error)
+       /* Are we allowed to snoop on the tasks file descriptors? */
+       if (!proc_fd_access_allowed(inode))
                goto out;
 
        error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
@@ -780,29 +1153,29 @@ static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int b
        dput(de);
        mntput(mnt);
 out:
-       unlock_kernel();
        return error;
 }
 
 static struct inode_operations proc_pid_link_inode_operations = {
        .readlink       = proc_pid_readlink,
-       .follow_link    = proc_pid_follow_link
+       .follow_link    = proc_pid_follow_link,
+       .setattr        = proc_setattr,
 };
 
-#define NUMBUF 10
-
 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
 {
-       struct inode *inode = filp->f_dentry->d_inode;
-       struct task_struct *p = proc_task(inode);
+       struct dentry *dentry = filp->f_dentry;
+       struct inode *inode = dentry->d_inode;
+       struct task_struct *p = get_proc_task(inode);
        unsigned int fd, tid, ino;
        int retval;
-       char buf[NUMBUF];
+       char buf[PROC_NUMBUF];
        struct files_struct * files;
+       struct fdtable *fdt;
 
        retval = -ENOENT;
-       if (!pid_alive(p))
-               goto out;
+       if (!p)
+               goto out_no_task;
        retval = 0;
        tid = p->pid;
 
@@ -813,7 +1186,7 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
                                goto out;
                        filp->f_pos++;
                case 1:
-                       ino = fake_ino(tid, PROC_TID_INO);
+                       ino = parent_ino(dentry);
                        if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
                                goto out;
                        filp->f_pos++;
@@ -821,17 +1194,18 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
                        files = get_files_struct(p);
                        if (!files)
                                goto out;
-                       spin_lock(&files->file_lock);
+                       rcu_read_lock();
+                       fdt = files_fdtable(files);
                        for (fd = filp->f_pos-2;
-                            fd < files->max_fds;
+                            fd < fdt->max_fds;
                             fd++, filp->f_pos++) {
                                unsigned int i,j;
 
                                if (!fcheck_files(files, fd))
                                        continue;
-                               spin_unlock(&files->file_lock);
+                               rcu_read_unlock();
 
-                               j = NUMBUF;
+                               j = PROC_NUMBUF;
                                i = fd;
                                do {
                                        j--;
@@ -840,16 +1214,18 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
                                } while (i);
 
                                ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
-                               if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
-                                       spin_lock(&files->file_lock);
+                               if (filldir(dirent, buf+j, PROC_NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
+                                       rcu_read_lock();
                                        break;
                                }
-                               spin_lock(&files->file_lock);
+                               rcu_read_lock();
                        }
-                       spin_unlock(&files->file_lock);
+                       rcu_read_unlock();
                        put_files_struct(files);
        }
 out:
+       put_task_struct(p);
+out_no_task:
        return retval;
 }
 
@@ -861,16 +1237,18 @@ static int proc_pident_readdir(struct file *filp,
        int pid;
        struct dentry *dentry = filp->f_dentry;
        struct inode *inode = dentry->d_inode;
+       struct task_struct *task = get_proc_task(inode);
        struct pid_entry *p;
        ino_t ino;
-       int ret;
+       int ret, hide;
 
        ret = -ENOENT;
-       if (!pid_alive(proc_task(inode)))
+       if (!task)
                goto out;
 
        ret = 0;
-       pid = proc_task(inode)->pid;
+       pid = task->pid;
+       put_task_struct(task);
        i = filp->f_pos;
        switch (i) {
        case 0:
@@ -894,11 +1272,20 @@ static int proc_pident_readdir(struct file *filp,
                        goto out;
                }
                p = ents + i;
+               hide = vx_flags(VXF_INFO_HIDE, 0);
                while (p->name) {
+                       if (hide) {
+                               switch (p->type) {
+                               case PROC_TGID_VX_INFO:
+                               case PROC_TGID_IP_INFO:
+                                       goto skip;
+                               }
+                       }
                        if (filldir(dirent, p->name, p->len, filp->f_pos,
                                    fake_ino(pid, p->type), p->mode >> 12) < 0)
                                goto out;
                        filp->f_pos++;
+               skip:
                        p++;
                }
        }
@@ -953,22 +1340,20 @@ static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_st
 
        /* Common stuff */
        ei = PROC_I(inode);
-       ei->task = NULL;
        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
        inode->i_ino = fake_ino(task->pid, ino);
-
-       if (!pid_alive(task))
-               goto out_unlock;
+       inode->i_op = &proc_def_inode_operations;
 
        /*
         * grab the reference to task.
         */
-       get_task_struct(task);
-       ei->task = task;
-       ei->type = ino;
+       ei->pid = get_pid(task->pids[PIDTYPE_PID].pid);
+       if (!ei->pid)
+               goto out_unlock;
+
        inode->i_uid = 0;
        inode->i_gid = 0;
-       if (ino == PROC_TGID_INO || ino == PROC_TID_INO || task_dumpable(task)) {
+       if (task_dumpable(task)) {
                inode->i_uid = task->euid;
                inode->i_gid = task->egid;
        }
@@ -979,7 +1364,6 @@ out:
        return inode;
 
 out_unlock:
-       ei->pde = NULL;
        iput(inode);
        return NULL;
 }
@@ -993,79 +1377,110 @@ out_unlock:
  *
  * Rewrite the inode's ownerships here because the owning task may have
  * performed a setuid(), etc.
+ *
+ * Before the /proc/pid/status file was created the only way to read
+ * the effective uid of a /process was to stat /proc/pid.  Reading
+ * /proc/pid/status is slow enough that procps and other packages
+ * kept stating /proc/pid.  To keep the rules in /proc simple I have
+ * made this apply to all per process world readable and executable
+ * directories.
  */
 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
        struct inode *inode = dentry->d_inode;
-       struct task_struct *task = proc_task(inode);
+       struct task_struct *task = get_proc_task(inode);
+       int ret = 0;
+
+       if (task) {
+               int pid = (inode->i_ino >> 16) & 0xFFFF;
 
-       if (!vx_check(vx_task_xid(task), VX_WATCH|VX_IDENT))
-               goto out_drop;
-       /* discard wrong fakeinit */
+               if (!vx_proc_pid_visible(task, pid))
+                       goto out_drop;
 
-       if (pid_alive(task)) {
-               if (proc_type(inode) == PROC_TGID_INO || proc_type(inode) == PROC_TID_INO || task_dumpable(task)) {
+               ret = 1;
+               if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
+                   task_dumpable(task)) {
                        inode->i_uid = task->euid;
                        inode->i_gid = task->egid;
                } else {
                        inode->i_uid = 0;
                        inode->i_gid = 0;
                }
+               inode->i_mode &= ~(S_ISUID | S_ISGID);
                security_task_to_inode(task, inode);
-               return 1;
+               goto out_put;
        }
 out_drop:
        d_drop(dentry);
+out_put:
+       if (task)
+               put_task_struct(task);
+       return ret;
+}
+
+static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+{
+       struct inode *inode = dentry->d_inode;
+       struct task_struct *task;
+       generic_fillattr(inode, stat);
+
+       rcu_read_lock();
+       stat->uid = 0;
+       stat->gid = 0;
+       task = pid_task(proc_pid(inode), PIDTYPE_PID);
+       if (task) {
+               if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
+                   task_dumpable(task)) {
+                       stat->uid = task->euid;
+                       stat->gid = task->egid;
+               }
+       }
+       rcu_read_unlock();
        return 0;
 }
 
 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
        struct inode *inode = dentry->d_inode;
-       struct task_struct *task = proc_task(inode);
-       int fd = proc_type(inode) - PROC_TID_FD_DIR;
+       struct task_struct *task = get_proc_task(inode);
+       int fd = proc_fd(inode);
        struct files_struct *files;
 
-       files = get_files_struct(task);
-       if (files) {
-               spin_lock(&files->file_lock);
-               if (fcheck_files(files, fd)) {
-                       spin_unlock(&files->file_lock);
-                       put_files_struct(files);
-                       if (task_dumpable(task)) {
-                               inode->i_uid = task->euid;
-                               inode->i_gid = task->egid;
-                       } else {
-                               inode->i_uid = 0;
-                               inode->i_gid = 0;
+       if (task) {
+               files = get_files_struct(task);
+               if (files) {
+                       rcu_read_lock();
+                       if (fcheck_files(files, fd)) {
+                               rcu_read_unlock();
+                               put_files_struct(files);
+                               if (task_dumpable(task)) {
+                                       inode->i_uid = task->euid;
+                                       inode->i_gid = task->egid;
+                               } else {
+                                       inode->i_uid = 0;
+                                       inode->i_gid = 0;
+                               }
+                               inode->i_mode &= ~(S_ISUID | S_ISGID);
+                               security_task_to_inode(task, inode);
+                               put_task_struct(task);
+                               return 1;
                        }
-                       security_task_to_inode(task, inode);
-                       return 1;
+                       rcu_read_unlock();
+                       put_files_struct(files);
                }
-               spin_unlock(&files->file_lock);
-               put_files_struct(files);
+               put_task_struct(task);
        }
        d_drop(dentry);
        return 0;
 }
 
-static void pid_base_iput(struct dentry *dentry, struct inode *inode)
-{
-       struct task_struct *task = proc_task(inode);
-       spin_lock(&task->proc_lock);
-       if (task->proc_dentry == dentry)
-               task->proc_dentry = NULL;
-       spin_unlock(&task->proc_lock);
-       iput(inode);
-}
-
 static int pid_delete_dentry(struct dentry * dentry)
 {
        /* Is the task we represent dead?
         * If so, then don't put the dentry on the lru list,
         * kill it immediately.
         */
-       return !pid_alive(proc_task(dentry->d_inode));
+       return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
 }
 
 static struct dentry_operations tid_fd_dentry_operations =
@@ -1080,13 +1495,6 @@ static struct dentry_operations pid_dentry_operations =
        .d_delete       = pid_delete_dentry,
 };
 
-static struct dentry_operations pid_base_dentry_operations =
-{
-       .d_revalidate   = pid_revalidate,
-       .d_iput         = pid_base_iput,
-       .d_delete       = pid_delete_dentry,
-};
-
 /* Lookups */
 
 static unsigned name_to_int(struct dentry *dentry)
@@ -1114,26 +1522,33 @@ out:
 /* SMP-safe */
 static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
 {
-       struct task_struct *task = proc_task(dir);
+       struct task_struct *task = get_proc_task(dir);
        unsigned fd = name_to_int(dentry);
+       struct dentry *result = ERR_PTR(-ENOENT);
        struct file * file;
        struct files_struct * files;
        struct inode *inode;
        struct proc_inode *ei;
 
+       if (!task)
+               goto out_no_task;
        if (fd == ~0U)
                goto out;
-       if (!pid_alive(task))
-               goto out;
 
        inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
        if (!inode)
                goto out;
        ei = PROC_I(inode);
+       ei->fd = fd;
        files = get_files_struct(task);
        if (!files)
                goto out_unlock;
        inode->i_mode = S_IFLNK;
+
+       /*
+        * We are not taking a ref to the file structure, so we must
+        * hold ->file_lock.
+        */
        spin_lock(&files->file_lock);
        file = fcheck_files(files, fd);
        if (!file)
@@ -1149,19 +1564,25 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
        ei->op.proc_get_link = proc_fd_link;
        dentry->d_op = &tid_fd_dentry_operations;
        d_add(dentry, inode);
-       return NULL;
+       /* Close the race of the process dying before we return the dentry */
+       if (tid_fd_revalidate(dentry, NULL))
+               result = NULL;
+out:
+       put_task_struct(task);
+out_no_task:
+       return result;
 
 out_unlock2:
        spin_unlock(&files->file_lock);
        put_files_struct(files);
 out_unlock:
        iput(inode);
-out:
-       return ERR_PTR(-ENOENT);
+       goto out;
 }
 
 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir);
 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd);
+static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
 
 static struct file_operations proc_fd_operations = {
        .read           = generic_read_dir,
@@ -1178,12 +1599,13 @@ static struct file_operations proc_task_operations = {
  */
 static struct inode_operations proc_fd_inode_operations = {
        .lookup         = proc_lookupfd,
-       .permission     = proc_permission,
+       .setattr        = proc_setattr,
 };
 
 static struct inode_operations proc_task_inode_operations = {
        .lookup         = proc_task_lookup,
-       .permission     = proc_permission,
+       .getattr        = proc_task_getattr,
+       .setattr        = proc_setattr,
 };
 
 #ifdef CONFIG_SECURITY
@@ -1193,12 +1615,17 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
        struct inode * inode = file->f_dentry->d_inode;
        unsigned long page;
        ssize_t length;
-       struct task_struct *task = proc_task(inode);
+       struct task_struct *task = get_proc_task(inode);
+
+       length = -ESRCH;
+       if (!task)
+               goto out_no_task;
 
        if (count > PAGE_SIZE)
                count = PAGE_SIZE;
+       length = -ENOMEM;
        if (!(page = __get_free_page(GFP_KERNEL)))
-               return -ENOMEM;
+               goto out;
 
        length = security_getprocattr(task, 
                                      (char*)file->f_dentry->d_name.name, 
@@ -1206,6 +1633,9 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
        if (length >= 0)
                length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
        free_page(page);
+out:
+       put_task_struct(task);
+out_no_task:
        return length;
 }
 
@@ -1215,26 +1645,36 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
        struct inode * inode = file->f_dentry->d_inode;
        char *page; 
        ssize_t length; 
-       struct task_struct *task = proc_task(inode); 
+       struct task_struct *task = get_proc_task(inode);
 
+       length = -ESRCH;
+       if (!task)
+               goto out_no_task;
        if (count > PAGE_SIZE) 
                count = PAGE_SIZE; 
-       if (*ppos != 0) {
-               /* No partial writes. */
-               return -EINVAL;
-       }
+
+       /* No partial writes. */
+       length = -EINVAL;
+       if (*ppos != 0)
+               goto out;
+
+       length = -ENOMEM;
        page = (char*)__get_free_page(GFP_USER); 
        if (!page) 
-               return -ENOMEM;
+               goto out;
+
        length = -EFAULT; 
        if (copy_from_user(page, buf, count)) 
-               goto out;
+               goto out_free;
 
        length = security_setprocattr(task, 
                                      (char*)file->f_dentry->d_name.name, 
                                      (void*)page, count);
-out:
+out_free:
        free_page((unsigned long) page);
+out:
+       put_task_struct(task);
+out_no_task:
        return length;
 } 
 
@@ -1252,22 +1692,25 @@ static struct inode_operations proc_tgid_attr_inode_operations;
 extern int proc_pid_vx_info(struct task_struct *, char *);
 extern int proc_pid_nx_info(struct task_struct *, char *);
 
+extern int proc_pid_vx_info(struct task_struct *, char *);
+extern int proc_pid_nx_info(struct task_struct *, char *);
+
 /* SMP-safe */
 static struct dentry *proc_pident_lookup(struct inode *dir, 
                                         struct dentry *dentry,
                                         struct pid_entry *ents)
 {
        struct inode *inode;
-       int error;
-       struct task_struct *task = proc_task(dir);
+       struct dentry *error;
+       struct task_struct *task = get_proc_task(dir);
        struct pid_entry *p;
        struct proc_inode *ei;
 
-       error = -ENOENT;
+       error = ERR_PTR(-ENOENT);
        inode = NULL;
 
-       if (!pid_alive(task))
-               goto out;
+       if (!task)
+               goto out_no_task;
 
        for (p = ents; p->name; p++) {
                if (p->len != dentry->d_name.len)
@@ -1278,7 +1721,18 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
        if (!p->name)
                goto out;
 
-       error = -EINVAL;
+       switch(p->type) {
+               case PROC_TID_VX_INFO:
+               case PROC_TGID_VX_INFO:
+               case PROC_TID_IP_INFO:
+               case PROC_TGID_IP_INFO:
+                       if (task_vx_flags(task, VXF_INFO_HIDE, 0))
+                               goto out;
+               default:
+                       break;
+       }
+
+       error = ERR_PTR(-EINVAL);
        inode = proc_pid_make_inode(dir->i_sb, task, p->type);
        if (!inode)
                goto out;
@@ -1291,7 +1745,7 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
         */
        switch(p->type) {
                case PROC_TGID_TASK:
-                       inode->i_nlink = 3;
+                       inode->i_nlink = 2;
                        inode->i_op = &proc_task_inode_operations;
                        inode->i_fop = &proc_task_operations;
                        break;
@@ -1353,15 +1807,36 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
                case PROC_TGID_MAPS:
                        inode->i_fop = &proc_maps_operations;
                        break;
+#ifdef CONFIG_NUMA
+               case PROC_TID_NUMA_MAPS:
+               case PROC_TGID_NUMA_MAPS:
+                       inode->i_fop = &proc_numa_maps_operations;
+                       break;
+#endif
                case PROC_TID_MEM:
                case PROC_TGID_MEM:
-                       inode->i_op = &proc_mem_inode_operations;
                        inode->i_fop = &proc_mem_operations;
                        break;
+#ifdef CONFIG_SECCOMP
+               case PROC_TID_SECCOMP:
+               case PROC_TGID_SECCOMP:
+                       inode->i_fop = &proc_seccomp_operations;
+                       break;
+#endif /* CONFIG_SECCOMP */
                case PROC_TID_MOUNTS:
                case PROC_TGID_MOUNTS:
                        inode->i_fop = &proc_mounts_operations;
                        break;
+#ifdef CONFIG_MMU
+               case PROC_TID_SMAPS:
+               case PROC_TGID_SMAPS:
+                       inode->i_fop = &proc_smaps_operations;
+                       break;
+#endif
+               case PROC_TID_MOUNTSTATS:
+               case PROC_TGID_MOUNTSTATS:
+                       inode->i_fop = &proc_mountstats_operations;
+                       break;
 #ifdef CONFIG_SECURITY
                case PROC_TID_ATTR:
                        inode->i_nlink = 2;
@@ -1381,6 +1856,10 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
                case PROC_TGID_ATTR_EXEC:
                case PROC_TID_ATTR_FSCREATE:
                case PROC_TGID_ATTR_FSCREATE:
+               case PROC_TID_ATTR_KEYCREATE:
+               case PROC_TGID_ATTR_KEYCREATE:
+               case PROC_TID_ATTR_SOCKCREATE:
+               case PROC_TGID_ATTR_SOCKCREATE:
                        inode->i_fop = &proc_pid_attr_operations;
                        break;
 #endif
@@ -1397,6 +1876,27 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
                        inode->i_fop = &proc_info_file_operations;
                        ei->op.proc_read = proc_pid_schedstat;
                        break;
+#endif
+#ifdef CONFIG_CPUSETS
+               case PROC_TID_CPUSET:
+               case PROC_TGID_CPUSET:
+                       inode->i_fop = &proc_cpuset_operations;
+                       break;
+#endif
+               case PROC_TID_OOM_SCORE:
+               case PROC_TGID_OOM_SCORE:
+                       inode->i_fop = &proc_info_file_operations;
+                       ei->op.proc_read = proc_oom_score;
+                       break;
+               case PROC_TID_OOM_ADJUST:
+               case PROC_TGID_OOM_ADJUST:
+                       inode->i_fop = &proc_oom_adjust_operations;
+                       break;
+#ifdef CONFIG_AUDITSYSCALL
+               case PROC_TID_LOGINUID:
+               case PROC_TGID_LOGINUID:
+                       inode->i_fop = &proc_loginuid_operations;
+                       break;
 #endif
                case PROC_TID_VX_INFO:
                case PROC_TGID_VX_INFO:
@@ -1408,31 +1908,21 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
                        inode->i_fop = &proc_info_file_operations;
                        ei->op.proc_read = proc_pid_nx_info;
                        break;
-#ifdef CONFIG_DELAY_ACCT
-               case PROC_TID_DELAY_ACCT:
-               case PROC_TGID_DELAY_ACCT:
-                       inode->i_fop = &proc_info_file_operations;
-                       ei->op.proc_read = proc_pid_schedstat;
-                       break;
-#endif
-#ifdef CONFIG_SCHEDSTATS
-               case PROC_TID_SCHEDSTAT:
-               case PROC_TGID_SCHEDSTAT:
-                       inode->i_fop = &proc_info_file_operations;
-                       ei->op.proc_read = proc_pid_schedstat;
-                       break;
-#endif
                default:
                        printk("procfs: impossible type (%d)",p->type);
                        iput(inode);
-                       return ERR_PTR(-EINVAL);
+                       error = ERR_PTR(-EINVAL);
+                       goto out;
        }
        dentry->d_op = &pid_dentry_operations;
        d_add(dentry, inode);
-       return NULL;
-
+       /* Close the race of the process dying before we return the dentry */
+       if (pid_revalidate(dentry, NULL))
+               error = NULL;
 out:
-       return ERR_PTR(error);
+       put_task_struct(task);
+out_no_task:
+       return error;
 }
 
 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
@@ -1455,10 +1945,14 @@ static struct file_operations proc_tid_base_operations = {
 
 static struct inode_operations proc_tgid_base_inode_operations = {
        .lookup         = proc_tgid_base_lookup,
+       .getattr        = pid_getattr,
+       .setattr        = proc_setattr,
 };
 
 static struct inode_operations proc_tid_base_inode_operations = {
        .lookup         = proc_tid_base_lookup,
+       .getattr        = pid_getattr,
+       .setattr        = proc_setattr,
 };
 
 #ifdef CONFIG_SECURITY
@@ -1500,10 +1994,14 @@ static struct dentry *proc_tid_attr_lookup(struct inode *dir,
 
 static struct inode_operations proc_tgid_attr_inode_operations = {
        .lookup         = proc_tgid_attr_lookup,
+       .getattr        = pid_getattr,
+       .setattr        = proc_setattr,
 };
 
 static struct inode_operations proc_tid_attr_inode_operations = {
        .lookup         = proc_tid_attr_lookup,
+       .getattr        = pid_getattr,
+       .setattr        = proc_setattr,
 };
 #endif
 
@@ -1513,16 +2011,16 @@ static struct inode_operations proc_tid_attr_inode_operations = {
 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
                              int buflen)
 {
-       char tmp[30];
+       char tmp[PROC_NUMBUF];
        sprintf(tmp, "%d", vx_map_tgid(current->tgid));
        return vfs_readlink(dentry,buffer,buflen,tmp);
 }
 
-static int proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
-       char tmp[30];
+       char tmp[PROC_NUMBUF];
        sprintf(tmp, "%d", vx_map_tgid(current->tgid));
-       return vfs_follow_link(nd,tmp);
+       return ERR_PTR(vfs_follow_link(nd,tmp));
 }      
 
 static struct inode_operations proc_self_inode_operations = {
@@ -1531,63 +2029,80 @@ static struct inode_operations proc_self_inode_operations = {
 };
 
 /**
- * proc_pid_unhash -  Unhash /proc/<pid> entry from the dcache.
- * @p: task that should be flushed.
+ * proc_flush_task -  Remove dcache entries for @task from the /proc dcache.
+ *
+ * @task: task that should be flushed.
+ *
+ * Looks in the dcache for
+ * /proc/@pid
+ * /proc/@tgid/task/@pid
+ * if either directory is present flushes it and all of it'ts children
+ * from the dcache.
  *
- * Drops the /proc/<pid> dcache entry from the hash chains.
+ * It is safe and reasonable to cache /proc entries for a task until
+ * that task exits.  After that they just clog up the dcache with
+ * useless entries, possibly causing useful dcache entries to be
+ * flushed instead.  This routine is proved to flush those useless
+ * dcache entries at process exit time.
  *
- * Dropping /proc/<pid> entries and detach_pid must be synchroneous,
- * otherwise e.g. /proc/<pid>/exe might point to the wrong executable,
- * if the pid value is immediately reused. This is enforced by
- * - caller must acquire spin_lock(p->proc_lock)
- * - must be called before detach_pid()
- * - proc_pid_lookup acquires proc_lock, and checks that
- *   the target is not dead by looking at the attach count
- *   of PIDTYPE_PID.
+ * NOTE: This routine is just an optimization so it does not guarantee
+ *       that no dcache entries will exist at process exit time it
+ *       just makes it very unlikely that any will persist.
  */
-
-struct dentry *proc_pid_unhash(struct task_struct *p)
+void proc_flush_task(struct task_struct *task)
 {
-       struct dentry *proc_dentry;
+       struct dentry *dentry, *leader, *dir;
+       char buf[PROC_NUMBUF];
+       struct qstr name;
+
+       name.name = buf;
+       name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
+       dentry = d_hash_and_lookup(proc_mnt->mnt_root, &name);
+       if (dentry) {
+               shrink_dcache_parent(dentry);
+               d_drop(dentry);
+               dput(dentry);
+       }
 
-       proc_dentry = p->proc_dentry;
-       if (proc_dentry != NULL) {
+       if (thread_group_leader(task))
+               goto out;
 
-               spin_lock(&dcache_lock);
-               if (!d_unhashed(proc_dentry)) {
-                       dget_locked(proc_dentry);
-                       __d_drop(proc_dentry);
-               } else
-                       proc_dentry = NULL;
-               spin_unlock(&dcache_lock);
-       }
-       return proc_dentry;
-}
+       name.name = buf;
+       name.len = snprintf(buf, sizeof(buf), "%d", task->tgid);
+       leader = d_hash_and_lookup(proc_mnt->mnt_root, &name);
+       if (!leader)
+               goto out;
 
-/**
- * proc_pid_flush - recover memory used by stale /proc/<pid>/x entries
- * @proc_entry: directoy to prune.
- *
- * Shrink the /proc directory that was used by the just killed thread.
- */
-       
-void proc_pid_flush(struct dentry *proc_dentry)
-{
-       might_sleep();
-       if(proc_dentry != NULL) {
-               shrink_dcache_parent(proc_dentry);
-               dput(proc_dentry);
+       name.name = "task";
+       name.len = strlen(name.name);
+       dir = d_hash_and_lookup(leader, &name);
+       if (!dir)
+               goto out_put_leader;
+
+       name.name = buf;
+       name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
+       dentry = d_hash_and_lookup(dir, &name);
+       if (dentry) {
+               shrink_dcache_parent(dentry);
+               d_drop(dentry);
+               dput(dentry);
        }
+
+       dput(dir);
+out_put_leader:
+       dput(leader);
+out:
+       return;
 }
 
 /* SMP-safe */
 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
 {
+       struct dentry *result = ERR_PTR(-ENOENT);
        struct task_struct *task;
        struct inode *inode;
        struct proc_inode *ei;
        unsigned tgid;
-       int died;
 
        if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
                inode = new_inode(dir->i_sb);
@@ -1608,187 +2123,173 @@ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct
        if (tgid == ~0U)
                goto out;
 
-       read_lock(&tasklist_lock);
-       task = find_task_by_pid(tgid);
+       rcu_read_lock();
+       task = vx_find_proc_task_by_pid(tgid);
        if (task)
                get_task_struct(task);
-       read_unlock(&tasklist_lock);
+       rcu_read_unlock();
        if (!task)
                goto out;
 
-       if (!vx_check(vx_task_xid(task), VX_WATCH|VX_IDENT))
-               goto out_drop_task;
-
        inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
        if (!inode)
-               goto out_drop_task;
+               goto out_put_task;
 
        inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
        inode->i_op = &proc_tgid_base_inode_operations;
        inode->i_fop = &proc_tgid_base_operations;
-       inode->i_nlink = 3;
        inode->i_flags|=S_IMMUTABLE;
+#ifdef CONFIG_SECURITY
+       inode->i_nlink = 5;
+#else
+       inode->i_nlink = 4;
+#endif
 
-       dentry->d_op = &pid_base_dentry_operations;
+       dentry->d_op = &pid_dentry_operations;
 
-       died = 0;
        d_add(dentry, inode);
-       spin_lock(&task->proc_lock);
-       task->proc_dentry = dentry;
-       if (!pid_alive(task)) {
-               dentry = proc_pid_unhash(task);
-               died = 1;
-       }
-       spin_unlock(&task->proc_lock);
+       /* Close the race of the process dying before we return the dentry */
+       if (pid_revalidate(dentry, NULL))
+               result = NULL;
 
-       put_task_struct(task);
-       if (died) {
-               proc_pid_flush(dentry);
-               goto out;
-       }
-       return NULL;
-out_drop_task:
+out_put_task:
        put_task_struct(task);
 out:
-       return ERR_PTR(-ENOENT);
+       return result;
 }
 
 /* SMP-safe */
 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
 {
+       struct dentry *result = ERR_PTR(-ENOENT);
        struct task_struct *task;
-       struct task_struct *leader = proc_task(dir);
+       struct task_struct *leader = get_proc_task(dir);
        struct inode *inode;
        unsigned tid;
 
+       if (!leader)
+               goto out_no_task;
+
        tid = name_to_int(dentry);
        if (tid == ~0U)
                goto out;
        if (vx_current_initpid(tid))
                goto out;
 
-       read_lock(&tasklist_lock);
-       task = find_task_by_pid(tid);
+       rcu_read_lock();
+       task = vx_find_proc_task_by_pid(tid);
        if (task)
                get_task_struct(task);
-       read_unlock(&tasklist_lock);
+       rcu_read_unlock();
        if (!task)
                goto out;
        if (leader->tgid != task->tgid)
                goto out_drop_task;
 
-       if (!vx_check(vx_task_xid(task), VX_WATCH|VX_IDENT))
-               goto out_drop_task;
-
        inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);
+
+
        if (!inode)
                goto out_drop_task;
-
        inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
        inode->i_op = &proc_tid_base_inode_operations;
        inode->i_fop = &proc_tid_base_operations;
-       inode->i_nlink = 3;
        inode->i_flags|=S_IMMUTABLE;
+#ifdef CONFIG_SECURITY
+       inode->i_nlink = 4;
+#else
+       inode->i_nlink = 3;
+#endif
 
-       dentry->d_op = &pid_base_dentry_operations;
+       dentry->d_op = &pid_dentry_operations;
 
        d_add(dentry, inode);
+       /* Close the race of the process dying before we return the dentry */
+       if (pid_revalidate(dentry, NULL))
+               result = NULL;
 
-       put_task_struct(task);
-       return NULL;
 out_drop_task:
        put_task_struct(task);
 out:
-       return ERR_PTR(-ENOENT);
+       put_task_struct(leader);
+out_no_task:
+       return result;
 }
 
-#define PROC_NUMBUF 10
-#define PROC_MAXPIDS 20
-
 /*
- * Get a few tgid's to return for filldir - we need to hold the
- * tasklist lock while doing this, and we must release it before
- * we actually do the filldir itself, so we use a temp buffer..
+ * Find the first tgid to return to user space.
+ *
+ * Usually this is just whatever follows &init_task, but if the users
+ * buffer was too small to hold the full list or there was a seek into
+ * the middle of the directory we have more work to do.
+ *
+ * In the case of a short read we start with find_task_by_pid.
+ *
+ * In the case of a seek we start with &init_task and walk nr
+ * threads past it.
  */
-static int get_tgid_list(int index, unsigned long version, unsigned int *tgids)
-{
-       struct task_struct *p;
-       int nr_tgids = 0;
-
-       index--;
-       read_lock(&tasklist_lock);
-       p = NULL;
-       if (version) {
-               p = find_task_by_real_pid(version);
-               if (p && !thread_group_leader(p))
-                       p = NULL;
+static struct task_struct *first_tgid(int tgid, unsigned int nr)
+{
+       struct task_struct *pos;
+       rcu_read_lock();
+       if (tgid && nr) {
+               pos = vx_find_proc_task_by_pid(tgid);
+               if (pos && thread_group_leader(pos))
+                       goto found;
        }
+       /* If nr exceeds the number of processes get out quickly */
+       pos = NULL;
+       if (nr && nr >= nr_processes())
+               goto done;
 
-       if (p)
-               index = 0;
-       else
-               p = next_task(&init_task);
-
-       for ( ; p != &init_task; p = next_task(p)) {
-               int tgid = p->pid;
-
-               if (!pid_alive(p))
-                       continue;
-               if (!vx_check(vx_task_xid(p), VX_WATCH|VX_IDENT))
-                       continue;
-               if (--index >= 0)
-                       continue;
-               tgids[nr_tgids] = vx_map_tgid(tgid);
-               nr_tgids++;
-               if (nr_tgids >= PROC_MAXPIDS)
-                       break;
+       /* If we haven't found our starting place yet start with
+        * the init_task and walk nr tasks forward.
+        */
+       for (pos = next_task(&init_task); nr > 0; --nr) {
+               pos = next_task(pos);
+               if (pos == &init_task) {
+                       pos = NULL;
+                       goto done;
+               }
        }
-       read_unlock(&tasklist_lock);
-       return nr_tgids;
+found:
+       get_task_struct(pos);
+done:
+       rcu_read_unlock();
+       return pos;
 }
 
 /*
- * Get a few tid's to return for filldir - we need to hold the
- * tasklist lock while doing this, and we must release it before
- * we actually do the filldir itself, so we use a temp buffer..
+ * Find the next task in the task list.
+ * Return NULL if we loop or there is any error.
+ *
+ * The reference to the input task_struct is released.
  */
-static int get_tid_list(int index, unsigned int *tids, struct inode *dir)
+static struct task_struct *next_tgid(struct task_struct *start)
 {
-       struct task_struct *leader_task = proc_task(dir);
-       struct task_struct *task = leader_task;
-       int nr_tids = 0;
-
-       index -= 2;
-       read_lock(&tasklist_lock);
-       /*
-        * The starting point task (leader_task) might be an already
-        * unlinked task, which cannot be used to access the task-list
-        * via next_thread().
-        */
-       if (pid_alive(task)) do {
-               int tid = task->pid;
-
-               if (!vx_check(vx_task_xid(task), VX_WATCH|VX_IDENT))
-                       continue;
-               if (--index >= 0)
-                       continue;
-               tids[nr_tids] = vx_map_pid(tid);
-               nr_tids++;
-               if (nr_tids >= PROC_MAXPIDS)
-                       break;
-       } while ((task = next_thread(task)) != leader_task);
-       read_unlock(&tasklist_lock);
-       return nr_tids;
+       struct task_struct *pos;
+       rcu_read_lock();
+       pos = start;
+       if (pid_alive(start))
+               pos = next_task(start);
+       if (pid_alive(pos) && (pos != &init_task)) {
+               get_task_struct(pos);
+               goto done;
+       }
+       pos = NULL;
+done:
+       rcu_read_unlock();
+       put_task_struct(start);
+       return pos;
 }
 
 /* for the /proc/ directory itself, after non-process stuff has been done */
 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
 {
-       unsigned int tgid_array[PROC_MAXPIDS];
        char buf[PROC_NUMBUF];
        unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
-       unsigned int nr_tgids, i;
-       int next_tgid;
+       struct task_struct *task;
+       int tgid;
 
        if (!nr) {
                ino_t ino = fake_ino(0,PROC_TGID_INO);
@@ -1797,66 +2298,119 @@ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
                filp->f_pos++;
                nr++;
        }
+       nr -= 1;
 
        /* f_version caches the tgid value that the last readdir call couldn't
         * return. lseek aka telldir automagically resets f_version to 0.
         */
-       next_tgid = filp->f_version;
+       tgid = filp->f_version;
        filp->f_version = 0;
-       for (;;) {
-               nr_tgids = get_tgid_list(nr, next_tgid, tgid_array);
-               if (!nr_tgids) {
-                       /* no more entries ! */
-                       break;
-               }
-               next_tgid = 0;
+       for (task = first_tgid(tgid, nr);
+            task;
+            task = next_tgid(task), filp->f_pos++) {
+               int len;
+               ino_t ino;
+               tgid = vx_map_tgid(task->pid);
+               if (!vx_proc_pid_visible(task, tgid))
+                       continue;
 
-               /* do not use the last found pid, reserve it for next_tgid */
-               if (nr_tgids == PROC_MAXPIDS) {
-                       nr_tgids--;
-                       next_tgid = tgid_array[nr_tgids];
+               len = snprintf(buf, sizeof(buf), "%d", tgid);
+               ino = fake_ino(tgid, PROC_TGID_INO);
+               if (filldir(dirent, buf, len, filp->f_pos, ino, DT_DIR) < 0) {
+                       /* returning this tgid failed, save it as the first
+                        * pid for the next readir call */
+                       filp->f_version = tgid;
+                       put_task_struct(task);
+                       break;
                }
+       }
+       return 0;
+}
 
-               for (i=0;i<nr_tgids;i++) {
-                       int tgid = tgid_array[i];
-                       ino_t ino = fake_ino(tgid,PROC_TGID_INO);
-                       unsigned long j = PROC_NUMBUF;
+/*
+ * Find the first tid of a thread group to return to user space.
+ *
+ * Usually this is just the thread group leader, but if the users
+ * buffer was too small or there was a seek into the middle of the
+ * directory we have more work todo.
+ *
+ * In the case of a short read we start with find_task_by_pid.
+ *
+ * In the case of a seek we start with the leader and walk nr
+ * threads past it.
+ */
+static struct task_struct *first_tid(struct task_struct *leader,
+                                       int tid, int nr)
+{
+       struct task_struct *pos;
+
+       rcu_read_lock();
+       /* Attempt to start with the pid of a thread */
+       if (tid && (nr > 0)) {
+               pos = vx_find_proc_task_by_pid(tid);
+               if (pos && (pos->group_leader == leader))
+                       goto found;
+       }
 
-                       do
-                               buf[--j] = '0' + (tgid % 10);
-                       while ((tgid /= 10) != 0);
+       /* If nr exceeds the number of threads there is nothing todo */
+       pos = NULL;
+       if (nr && nr >= get_nr_threads(leader))
+               goto out;
 
-                       if (filldir(dirent, buf+j, PROC_NUMBUF-j, filp->f_pos, ino, DT_DIR) < 0) {
-                               /* returning this tgid failed, save it as the first
-                                * pid for the next readir call */
-                               filp->f_version = tgid_array[i];
-                               goto out;
-                       }
-                       filp->f_pos++;
-                       nr++;
+       /* If we haven't found our starting place yet start
+        * with the leader and walk nr threads forward.
+        */
+       for (pos = leader; nr > 0; --nr) {
+               pos = next_thread(pos);
+               if (pos == leader) {
+                       pos = NULL;
+                       goto out;
                }
        }
+found:
+       get_task_struct(pos);
 out:
-       return 0;
+       rcu_read_unlock();
+       return pos;
+}
+
+/*
+ * Find the next thread in the thread list.
+ * Return NULL if there is an error or no next thread.
+ *
+ * The reference to the input task_struct is released.
+ */
+static struct task_struct *next_tid(struct task_struct *start)
+{
+       struct task_struct *pos = NULL;
+       rcu_read_lock();
+       if (pid_alive(start)) {
+               pos = next_thread(start);
+               if (thread_group_leader(pos))
+                       pos = NULL;
+               else
+                       get_task_struct(pos);
+       }
+       rcu_read_unlock();
+       put_task_struct(start);
+       return pos;
 }
 
 /* for the /proc/TGID/task/ directories */
 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
 {
-       unsigned int tid_array[PROC_MAXPIDS];
        char buf[PROC_NUMBUF];
-       unsigned int nr_tids, i;
        struct dentry *dentry = filp->f_dentry;
        struct inode *inode = dentry->d_inode;
-       struct task_struct *task = proc_task(inode);
+       struct task_struct *leader = get_proc_task(inode);
+       struct task_struct *task;
        int retval = -ENOENT;
        ino_t ino;
+       int tid;
        unsigned long pos = filp->f_pos;  /* avoiding "long long" filp->f_pos */
 
-       if (!vx_check(vx_task_xid(task), VX_WATCH|VX_IDENT))
-               goto out;
-       if (!pid_alive(task))
-               goto out;
+       if (!leader)
+               goto out_no_task;
        retval = 0;
 
        switch (pos) {
@@ -1874,23 +2428,48 @@ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldi
                /* fall through */
        }
 
-       nr_tids = get_tid_list(pos, tid_array, inode);
-
-       for (i = 0; i < nr_tids; i++) {
-               unsigned long j = PROC_NUMBUF;
-               int tid = tid_array[i];
-
-               ino = fake_ino(tid,PROC_TID_INO);
-
-               do
-                       buf[--j] = '0' + (tid % 10);
-               while ((tid /= 10) != 0);
+       /* f_version caches the tgid value that the last readdir call couldn't
+        * return. lseek aka telldir automagically resets f_version to 0.
+        */
+       tid = filp->f_version;
+       filp->f_version = 0;
+       for (task = first_tid(leader, tid, pos - 2);
+            task;
+            task = next_tid(task), pos++) {
+               int len;
+               tid = vx_map_pid(task->pid);
+               if (!vx_proc_pid_visible(task, tid))
+                       continue;
 
-               if (filldir(dirent, buf+j, PROC_NUMBUF-j, pos, ino, DT_DIR) < 0)
+               len = snprintf(buf, sizeof(buf), "%d", tid);
+               ino = fake_ino(tid, PROC_TID_INO);
+               if (filldir(dirent, buf, len, pos, ino, DT_DIR < 0)) {
+                       /* returning this tgid failed, save it as the first
+                        * pid for the next readir call */
+                       filp->f_version = tid;
+                       put_task_struct(task);
                        break;
-               pos++;
+               }
        }
 out:
        filp->f_pos = pos;
+       put_task_struct(leader);
+out_no_task:
        return retval;
 }
+
+static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+{
+       struct inode *inode = dentry->d_inode;
+       struct task_struct *p = get_proc_task(inode);
+       generic_fillattr(inode, stat);
+
+       if (p) {
+               rcu_read_lock();
+               stat->nlink += get_nr_threads(p);
+               rcu_read_unlock();
+               put_task_struct(p);
+       }
+
+       return 0;
+}