exec: avoid propagating PF_NO_SETAFFINITY into userspace child

Userspace process doesn't want the PF_NO_SETAFFINITY, but its parent may be
a kernel worker thread which has PF_NO_SETAFFINITY set, and this worker thread
can do kernel_thread() to create the child.
Clearing this flag in usersapce child to enable its migrating capability.

Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/exec.c b/fs/exec.c
index 493b102..44218a7 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1087,8 +1087,8 @@ int flush_old_exec(struct linux_binprm * bprm)
        bprm->mm = NULL;                /* We're using it now */
 
        set_fs(USER_DS);
-       current->flags &=
-               ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | PF_NOFREEZE);
+       current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
+                                       PF_NOFREEZE | PF_NO_SETAFFINITY);
        flush_thread();
        current->personality &= ~bprm->per_clear;