1 files changed, 101 insertions, 20 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index af643b5aefe8..8418fcc0a6ab 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -81,6 +81,7 @@
 #include <linux/elf.h>
 #include <linux/pid_namespace.h>
 #include <linux/fs_struct.h>
+#include <linux/slab.h>
 #include "internal.h"
 
 /* NOTE:
@@ -442,12 +443,13 @@ static const struct file_operations proc_lstats_operations = {
 unsigned long badness(struct task_struct *p, unsigned long uptime);
 static int proc_oom_score(struct task_struct *task, char *buffer)
 {
-        unsigned long points;
+        unsigned long points = 0;
         struct timespec uptime;
 
         do_posix_clock_monotonic_gettime(&uptime);
         read_lock(&tasklist_lock);
-        points = badness(task->group_leader, uptime.tv_sec);
+        if (pid_alive(task))
+                points = badness(task, uptime.tv_sec);
         read_unlock(&tasklist_lock);
         return sprintf(buffer, "%lu\n", points);
 }
@@ -647,17 +649,11 @@ static int mounts_release(struct inode *inode, struct file *file)
 static unsigned mounts_poll(struct file *file, poll_table *wait)
 {
         struct proc_mounts *p = file->private_data;
-        struct mnt_namespace *ns = p->ns;
         unsigned res = POLLIN | POLLRDNORM;
 
-        poll_wait(file, &ns->poll, wait);
-
-        spin_lock(&vfsmount_lock);
-        if (p->event != ns->event) {
-                p->event = ns->event;
+        poll_wait(file, &p->ns->poll, wait);
+        if (mnt_had_events(p))
                 res |= POLLERR | POLLPRI;
-        }
-        spin_unlock(&vfsmount_lock);
 
         return res;
 }
@@ -1095,8 +1091,12 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
         if (!capable(CAP_AUDIT_CONTROL))
                 return -EPERM;
 
-        if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
+        rcu_read_lock();
+        if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
+                rcu_read_unlock();
                 return -EPERM;
+        }
+        rcu_read_unlock();
 
         if (count >= PAGE_SIZE)
                 count = PAGE_SIZE - 1;
@@ -1265,6 +1265,72 @@ static const struct file_operations proc_pid_sched_operations = {
 
 #endif
 
+static ssize_t comm_write(struct file *file, const char __user *buf,
+                                size_t count, loff_t *offset)
+{
+        struct inode *inode = file->f_path.dentry->d_inode;
+        struct task_struct *p;
+        char buffer[TASK_COMM_LEN];
+
+        memset(buffer, 0, sizeof(buffer));
+        if (count > sizeof(buffer) - 1)
+                count = sizeof(buffer) - 1;
+        if (copy_from_user(buffer, buf, count))
+                return -EFAULT;
+
+        p = get_proc_task(inode);
+        if (!p)
+                return -ESRCH;
+
+        if (same_thread_group(current, p))
+                set_task_comm(p, buffer);
+        else
+                count = -EINVAL;
+
+        put_task_struct(p);
+
+        return count;
+}
+
+static int comm_show(struct seq_file *m, void *v)
+{
+        struct inode *inode = m->private;
+        struct task_struct *p;
+
+        p = get_proc_task(inode);
+        if (!p)
+                return -ESRCH;
+
+        task_lock(p);
+        seq_printf(m, "%s\n", p->comm);
+        task_unlock(p);
+
+        put_task_struct(p);
+
+        return 0;
+}
+
+static int comm_open(struct inode *inode, struct file *filp)
+{
+        int ret;
+
+        ret = single_open(filp, comm_show, NULL);
+        if (!ret) {
+                struct seq_file *m = filp->private_data;
+
+                m->private = inode;
+        }
+        return ret;
+}
+
+static const struct file_operations proc_pid_set_comm_operations = {
+        .open           = comm_open,
+        .read           = seq_read,
+        .write          = comm_write,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
 /*
  * We added or removed a vma mapping the executable. The vmas are only mapped
  * during exec and are not mapped with the mmap system call.
@@ -1353,7 +1419,6 @@ static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
                 goto out;
 
         error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
-        nd->last_type = LAST_BIND;
 out:
         return ERR_PTR(error);
 }
@@ -2200,7 +2265,7 @@ static const struct inode_operations proc_attr_dir_inode_operations = {
 
 #endif
 
-#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
+#ifdef CONFIG_ELF_CORE
 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
                                          size_t count, loff_t *ppos)
 {
@@ -2304,16 +2369,30 @@ static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
         struct pid_namespace *ns = dentry->d_sb->s_fs_info;
         pid_t tgid = task_tgid_nr_ns(current, ns);
-        char tmp[PROC_NUMBUF];
-        if (!tgid)
-                return ERR_PTR(-ENOENT);
-        sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
-        return ERR_PTR(vfs_follow_link(nd,tmp));
+        char *name = ERR_PTR(-ENOENT);
+        if (tgid) {
+                name = __getname();
+                if (!name)
+                        name = ERR_PTR(-ENOMEM);
+                else
+                        sprintf(name, "%d", tgid);
+        }
+        nd_set_link(nd, name);
+        return NULL;
+}
+
+static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
+                                void *cookie)
+{
+        char *s = nd_get_link(nd);
+        if (!IS_ERR(s))
+                __putname(s);
 }
 
 static const struct inode_operations proc_self_inode_operations = {
         .readlink       = proc_self_readlink,
         .follow_link    = proc_self_follow_link,
+        .put_link       = proc_self_put_link,
 };
 
 /*
@@ -2504,6 +2583,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #ifdef CONFIG_SCHED_DEBUG
         REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
 #endif
+        REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
         INF("syscall",    S_IRUSR, proc_pid_syscall),
 #endif
@@ -2556,7 +2636,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #ifdef CONFIG_FAULT_INJECTION
         REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
 #endif
-#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
+#ifdef CONFIG_ELF_CORE
         REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
 #endif
 #ifdef CONFIG_TASK_IO_ACCOUNTING
@@ -2829,7 +2909,7 @@ out_no_task:
  */
 static const struct pid_entry tid_base_stuff[] = {
         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),
+        DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
         REG("environ",   S_IRUSR, proc_environ_operations),
         INF("auxv",      S_IRUSR, proc_pid_auxv),
         ONE("status",    S_IRUGO, proc_pid_status),
@@ -2838,6 +2918,7 @@ static const struct pid_entry tid_base_stuff[] = {
 #ifdef CONFIG_SCHED_DEBUG
         REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
 #endif
+        REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
         INF("syscall",   S_IRUSR, proc_pid_syscall),
 #endif