V4L/DVB (3309): SAA7134: GPIO IRQ improvements

[linux-2.6-omap-h63xx.git] / fs / compat.c

diff --git a/fs/compat.c b/fs/compat.c
index 55ac0324aaf1649f1326994f31267ad90e542063..271b75d1597f507bacbd78b7be31227d5492dd2e 100644 (file)
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -494,9 +494,21 @@ asmlinkage long compat_sys_fcntl64(unsigned int fd, unsigned int cmd,
                ret = sys_fcntl(fd, cmd, (unsigned long)&f);
                set_fs(old_fs);
                if (cmd == F_GETLK && ret == 0) {
-                       if ((f.l_start >= COMPAT_OFF_T_MAX) ||
-                           ((f.l_start + f.l_len) > COMPAT_OFF_T_MAX))
+                       /* GETLK was successfule and we need to return the data...
+                        * but it needs to fit in the compat structure.
+                        * l_start shouldn't be too big, unless the original
+                        * start + end is greater than COMPAT_OFF_T_MAX, in which
+                        * case the app was asking for trouble, so we return
+                        * -EOVERFLOW in that case.
+                        * l_len could be too big, in which case we just truncate it,
+                        * and only allow the app to see that part of the conflicting
+                        * lock that might make sense to it anyway
+                        */
+
+                       if (f.l_start > COMPAT_OFF_T_MAX)
                                ret = -EOVERFLOW;
+                       if (f.l_len > COMPAT_OFF_T_MAX)
+                               f.l_len = COMPAT_OFF_T_MAX;
                        if (ret == 0)
                                ret = put_compat_flock(&f, compat_ptr(arg));
                }
@@ -515,9 +527,11 @@ asmlinkage long compat_sys_fcntl64(unsigned int fd, unsigned int cmd,
                                (unsigned long)&f);
                set_fs(old_fs);
                if (cmd == F_GETLK64 && ret == 0) {
-                       if ((f.l_start >= COMPAT_LOFF_T_MAX) ||
-                           ((f.l_start + f.l_len) > COMPAT_LOFF_T_MAX))
+                       /* need to return lock information - see above for commentary */
+                       if (f.l_start > COMPAT_LOFF_T_MAX)
                                ret = -EOVERFLOW;
+                       if (f.l_len > COMPAT_LOFF_T_MAX)
+                               f.l_len = COMPAT_LOFF_T_MAX;
                        if (ret == 0)
                                ret = put_compat_flock64(&f, compat_ptr(arg));
                }