1 files changed, 16 insertions, 29 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 8a5a8b06461..2ea176b2280 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1166,10 +1166,8 @@ ssize_t redirected_tty_write(struct file *file, const char __user *buf,
         struct file *p = NULL;
 
         spin_lock(&redirect_lock);
-        if (redirect) {
-                get_file(redirect);
-                p = redirect;
-        }
+        if (redirect)
+                p = get_file(redirect);
         spin_unlock(&redirect_lock);
 
         if (p) {
@@ -2264,8 +2262,7 @@ static int tioccons(struct file *file)
                 spin_unlock(&redirect_lock);
                 return -EBUSY;
         }
-        get_file(file);
-        redirect = file;
+        redirect = get_file(file);
         spin_unlock(&redirect_lock);
         return 0;
 }
@@ -2809,6 +2806,13 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd,
 }
 #endif
 
+static int this_tty(const void *t, struct file *file, unsigned fd)
+{
+        if (likely(file->f_op->read != tty_read))
+                return 0;
+        return file_tty(file) != t ? 0 : fd + 1;
+}
+        
 /*
  * This implements the "Secure Attention Key" ---  the idea is to
  * prevent trojan horses by killing all processes associated with this
@@ -2836,8 +2840,6 @@ void __do_SAK(struct tty_struct *tty)
         struct task_struct *g, *p;
         struct pid *session;
         int             i;
-        struct file     *filp;
-        struct fdtable *fdt;
 
         if (!tty)
                 return;
@@ -2867,27 +2869,12 @@ void __do_SAK(struct tty_struct *tty)
                         continue;
                 }
                 task_lock(p);
-                if (p->files) {
-                        /*
-                         * We don't take a ref to the file, so we must
-                         * hold ->file_lock instead.
-                         */
-                        spin_lock(&p->files->file_lock);
-                        fdt = files_fdtable(p->files);
-                        for (i = 0; i < fdt->max_fds; i++) {
-                                filp = fcheck_files(p->files, i);
-                                if (!filp)
-                                        continue;
-                                if (filp->f_op->read == tty_read &&
-                                    file_tty(filp) == tty) {
-                                        printk(KERN_NOTICE "SAK: killed process %d"
-                                            " (%s): fd#%d opened to the tty\n",
-                                            task_pid_nr(p), p->comm, i);
-                                        force_sig(SIGKILL, p);
-                                        break;
-                                }
-                        }
-                        spin_unlock(&p->files->file_lock);
+                i = iterate_fd(p->files, 0, this_tty, tty);
+                if (i != 0) {
+                        printk(KERN_NOTICE "SAK: killed process %d"
+                            " (%s): fd#%d opened to the tty\n",
+                                    task_pid_nr(p), p->comm, i - 1);
+                        force_sig(SIGKILL, p);
                 }
                 task_unlock(p);
         } while_each_thread(g, p);