Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull fpu state cleanups from Ingo Molnar:
 "This tree streamlines further aspects of FPU handling by eliminating
  the prepare_to_copy() complication and moving that logic to
  arch_dup_task_struct().

  It also fixes the FPU dumps in threaded core dumps, removes and old
  (and now invalid) assumption plus micro-optimizes the exit path by
  avoiding an FPU save for dead tasks."

Fixed up trivial add-add conflict in arch/sh/kernel/process.c that came
in because we now do the FPU handling in arch_dup_task_struct() rather
than the legacy (and now gone) prepare_to_copy().

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, fpu: drop the fpu state during thread exit
  x86, xsave: remove thread_has_fpu() bug check in __sanitize_i387_state()
  coredump: ensure the fpu state is flushed for proper multi-threaded core dump
  fork: move the real prepare_to_copy() users to arch_dup_task_struct()

1 files changed, 14 insertions, 1 deletions

diff --git a/fs/exec.c b/fs/exec.c
index d038968b54b4..1e8efdc80412 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1938,8 +1938,21 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
                 core_waiters = zap_threads(tsk, mm, core_state, exit_code);
         up_write(&mm->mmap_sem);
 
-        if (core_waiters > 0)
+        if (core_waiters > 0) {
+                struct core_thread *ptr;
+
                 wait_for_completion(&core_state->startup);
+                /*
+                 * Wait for all the threads to become inactive, so that
+                 * all the thread context (extended register state, like
+                 * fpu etc) gets copied to the memory.
+                 */
+                ptr = core_state->dumper.next;
+                while (ptr != NULL) {
+                        wait_task_inactive(ptr->task, 0);
+                        ptr = ptr->next;
+                }
+        }
 
         return core_waiters;
 }