Merge branch 'akpm' (patches from Andrew Morton) into next

Merge more updates from Andrew Morton:

 - Most of the rest of MM.

   This includes "mark remap_file_pages syscall as deprecated" but the
   actual "replace remap_file_pages syscall with emulation" is held
   back.  I guess we'll need to work out when to pull the trigger on
   that one.

 - various minor cleanups to obscure filesystems

 - the drivers/rtc queue

 - hfsplus updates

 - ufs, hpfs, fatfs, affs, reiserfs

 - Documentation/

 - signals

 - procfs

 - cpu hotplug

 - lib/idr.c

 - rapidio

 - sysctl

 - ipc updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (171 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 32 insertions, 0 deletions

diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 07d0df6bf768..077904c8b70d 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -5,6 +5,7 @@
 #include <linux/sched.h>                /* For struct task_struct.  */
 #include <linux/err.h>                  /* for IS_ERR_VALUE */
 #include <linux/bug.h>                  /* For BUG_ON.  */
+#include <linux/pid_namespace.h>        /* For task_active_pid_ns.  */
 #include <uapi/linux/ptrace.h>
 
 /*
@@ -129,6 +130,37 @@ static inline void ptrace_event(int event, unsigned long message)
 }
 
 /**
+ * ptrace_event_pid - possibly stop for a ptrace event notification
+ * @event:      %PTRACE_EVENT_* value to report
+ * @pid:        process identifier for %PTRACE_GETEVENTMSG to return
+ *
+ * Check whether @event is enabled and, if so, report @event and @pid
+ * to the ptrace parent.  @pid is reported as the pid_t seen from the
+ * the ptrace parent's pid namespace.
+ *
+ * Called without locks.
+ */
+static inline void ptrace_event_pid(int event, struct pid *pid)
+{
+        /*
+         * FIXME: There's a potential race if a ptracer in a different pid
+         * namespace than parent attaches between computing message below and
+         * when we acquire tasklist_lock in ptrace_stop().  If this happens,
+         * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG.
+         */
+        unsigned long message = 0;
+        struct pid_namespace *ns;
+
+        rcu_read_lock();
+        ns = task_active_pid_ns(rcu_dereference(current->parent));
+        if (ns)
+                message = pid_nr_ns(pid, ns);
+        rcu_read_unlock();
+
+        ptrace_event(event, message);
+}
+
+/**
  * ptrace_init_task - initialize ptrace state for a new child
  * @child:              new child task
  * @ptrace:             true if child should be ptrace'd by parent's tracer