1 files changed, 22 insertions, 41 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1c8b280146d7..57b8159f26f3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1799,10 +1799,15 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
         if (task) {
                 files = get_files_struct(task);
                 if (files) {
+                        struct file *file;
                         rcu_read_lock();
-                        if (fcheck_files(files, fd)) {
+                        file = fcheck_files(files, fd);
+                        if (file) {
+                                unsigned i_mode, f_mode = file->f_mode;
+
                                 rcu_read_unlock();
                                 put_files_struct(files);
+
                                 if (task_dumpable(task)) {
                                         rcu_read_lock();
                                         cred = __task_cred(task);
@@ -1813,7 +1818,14 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
                                         inode->i_uid = 0;
                                         inode->i_gid = 0;
                                 }
-                                inode->i_mode &= ~(S_ISUID | S_ISGID);
+
+                                i_mode = S_IFLNK;
+                                if (f_mode & FMODE_READ)
+                                        i_mode |= S_IRUSR | S_IXUSR;
+                                if (f_mode & FMODE_WRITE)
+                                        i_mode |= S_IWUSR | S_IXUSR;
+                                inode->i_mode = i_mode;
+
                                 security_task_to_inode(task, inode);
                                 put_task_struct(task);
                                 return 1;
@@ -1837,8 +1849,6 @@ static struct dentry *proc_fd_instantiate(struct inode *dir,
         struct dentry *dentry, struct task_struct *task, const void *ptr)
 {
         unsigned fd = *(const unsigned *)ptr;
-        struct file *file;
-        struct files_struct *files;
         struct inode *inode;
         struct proc_inode *ei;
         struct dentry *error = ERR_PTR(-ENOENT);
@@ -1848,25 +1858,6 @@ static struct dentry *proc_fd_instantiate(struct inode *dir,
                 goto out;
         ei = PROC_I(inode);
         ei->fd = fd;
-        files = get_files_struct(task);
-        if (!files)
-                goto out_iput;
-        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)
-                goto out_unlock;
-        if (file->f_mode & FMODE_READ)
-                inode->i_mode |= S_IRUSR | S_IXUSR;
-        if (file->f_mode & FMODE_WRITE)
-                inode->i_mode |= S_IWUSR | S_IXUSR;
-        spin_unlock(&files->file_lock);
-        put_files_struct(files);
 
         inode->i_op = &proc_pid_link_inode_operations;
         inode->i_size = 64;
@@ -1879,12 +1870,6 @@ static struct dentry *proc_fd_instantiate(struct inode *dir,
 
  out:
         return error;
-out_unlock:
-        spin_unlock(&files->file_lock);
-        put_files_struct(files);
-out_iput:
-        iput(inode);
-        goto out;
 }
 
 static struct dentry *proc_lookupfd_common(struct inode *dir,
@@ -2177,16 +2162,16 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
                 goto out;
 
         result = ERR_PTR(-EACCES);
-        if (lock_trace(task))
+        if (!ptrace_may_access(task, PTRACE_MODE_READ))
                 goto out_put_task;
 
         result = ERR_PTR(-ENOENT);
         if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
-                goto out_unlock;
+                goto out_put_task;
 
         mm = get_task_mm(task);
         if (!mm)
-                goto out_unlock;
+                goto out_put_task;
 
         down_read(&mm->mmap_sem);
         vma = find_exact_vma(mm, vm_start, vm_end);
@@ -2198,8 +2183,6 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
 out_no_vma:
         up_read(&mm->mmap_sem);
         mmput(mm);
-out_unlock:
-        unlock_trace(task);
 out_put_task:
         put_task_struct(task);
 out:
@@ -2233,7 +2216,7 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
                 goto out;
 
         ret = -EACCES;
-        if (lock_trace(task))
+        if (!ptrace_may_access(task, PTRACE_MODE_READ))
                 goto out_put_task;
 
         ret = 0;
@@ -2241,12 +2224,12 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
         case 0:
                 ino = inode->i_ino;
                 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
-                        goto out_unlock;
+                        goto out_put_task;
                 filp->f_pos++;
         case 1:
                 ino = parent_ino(dentry);
                 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
-                        goto out_unlock;
+                        goto out_put_task;
                 filp->f_pos++;
         default:
         {
@@ -2257,7 +2240,7 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
                 mm = get_task_mm(task);
                 if (!mm)
-                        goto out_unlock;
+                        goto out_put_task;
                 down_read(&mm->mmap_sem);
 
                 nr_files = 0;
@@ -2287,7 +2270,7 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
                                         flex_array_free(fa);
                                 up_read(&mm->mmap_sem);
                                 mmput(mm);
-                                goto out_unlock;
+                                goto out_put_task;
                         }
                         for (i = 0, vma = mm->mmap, pos = 2; vma;
                                         vma = vma->vm_next) {
@@ -2332,8 +2315,6 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
         }
         }
 
-out_unlock:
-        unlock_trace(task);
 out_put_task:
         put_task_struct(task);
 out: