Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "A CONFIG_STACK_GROWSUP=y fix, and a hotplug llc CPU mask fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix unreleased llc_shared_mask bit during CPU hotplug
  sched: Fix end_of_stack() and location of stack canary for architectures using CONFIG_STACK_GROWSUP

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5c2c885ee52b..1f07040d28e3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2608,9 +2608,22 @@ static inline void setup_thread_stack(struct task_struct *p, struct task_struct
         task_thread_info(p)->task = p;
 }
 
+/*
+ * Return the address of the last usable long on the stack.
+ *
+ * When the stack grows down, this is just above the thread
+ * info struct. Going any lower will corrupt the threadinfo.
+ *
+ * When the stack grows up, this is the highest address.
+ * Beyond that position, we corrupt data on the next page.
+ */
 static inline unsigned long *end_of_stack(struct task_struct *p)
 {
+#ifdef CONFIG_STACK_GROWSUP
+        return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
+#else
         return (unsigned long *)(task_thread_info(p) + 1);
+#endif
 }
 
 #endif