Relax /proc fix a bit

Clearign all of i_mode was a bit draconian. We only really care about
S_ISUID/ISGID, after all.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/proc/base.c

@@ -1338,8 +1338,8 @@ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
 		} else {
 			inode->i_uid = 0;
 			inode->i_gid = 0;
-			inode->i_mode = 0;
 		}
+		inode->i_mode &= ~(S_ISUID | S_ISGID);
 		security_task_to_inode(task, inode);
 		put_task_struct(task);
 		return 1;
@@ -1390,6 +1390,7 @@ 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);
 				security_task_to_inode(task, inode);
 				put_task_struct(task);
 				return 1;