xfs: fix reading of wrapped log data

[karo-tx-linux.git] / kernel / sys.c

diff --git a/kernel/sys.c b/kernel/sys.c
index 241507f23eca097871bec58f5976476f352f3d75..909148a08ec5bbe140f193bab9ec17590c528b1c 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -368,6 +368,7 @@ EXPORT_SYMBOL(unregister_reboot_notifier);
 void kernel_restart(char *cmd)
 {
        kernel_restart_prepare(cmd);
+       disable_nonboot_cpus();
        if (!cmd)
                printk(KERN_EMERG "Restarting system.\n");
        else
@@ -1264,15 +1265,16 @@ DECLARE_RWSEM(uts_sem);
  * Work around broken programs that cannot handle "Linux 3.0".
  * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
  */
-static int override_release(char __user *release, int len)
+static int override_release(char __user *release, size_t len)
 {
        int ret = 0;
-       char buf[65];
 
        if (current->personality & UNAME26) {
-               char *rest = UTS_RELEASE;
+               const char *rest = UTS_RELEASE;
+               char buf[65] = { 0 };
                int ndots = 0;
                unsigned v;
+               size_t copy;
 
                while (*rest) {
                        if (*rest == '.' && ++ndots >= 3)
@@ -1282,8 +1284,9 @@ static int override_release(char __user *release, int len)
                        rest++;
                }
                v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
-               snprintf(buf, len, "2.6.%u%s", v, rest);
-               ret = copy_to_user(release, buf, len);
+               copy = clamp_t(size_t, len, 1, sizeof(buf));
+               copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
+               ret = copy_to_user(release, buf, copy + 1);
        }
        return ret;
 }