**** GENERATING kernel ABI metadata ****
**** kABI checking is enabled in kernel SPEC file. ****
*** ERROR - ABI BREAKAGE WAS DETECTED ***

The following symbols have been changed (this will cause an ABI breakage):

dev_get_stats
consume_skb
skb_tstamp_tx
skb_queue_purge
kthread_bind
dev_get_by_name
skb_copy_expand
__dev_get_by_name
alloc_netdev_mqs
kill_block_super
netdev_rx_handler_unregister
__netdev_alloc_skb
register_netdevice
xt_unregister_targets
free_netdev
napi_get_frags
netif_napi_add
skb_pad
kthread_stop
napi_gro_frags
netif_device_attach
skb_push
__napi_complete
dev_kfree_skb_irq
skb_dequeue
netlink_broadcast
skb_copy
kfree_skb
dev_set_mac_address
dev_open
napi_gro_receive
kthread_create_on_node
skb_copy_bits
netlink_unicast
debugfs_create_file
skb_queue_head
skb_unlink
netdev_master_upper_dev_get
netif_rx
skb_trim
dev_get_by_index
debugfs_remove
current_task
skb_checksum
netif_device_detach
lock_sock_nested
pskb_expand_head
netdev_rx_handler_register
__skb_gso_segment
__nlmsg_put
unregister_netdev
netif_napi_del
sock_alloc_send_skb
__alloc_skb
unregister_netdevice_queue
__pskb_pull_tail
dev_set_allmulti
___pskb_trim
xt_register_targets
skb_realloc_headroom
netif_set_real_num_tx_queues
netdev_change_features
sk_alloc
dev_set_mtu
release_sock
napi_complete
register_netdev
__napi_schedule
dev_kfree_skb_any
netdev_master_upper_dev_link
debugfs_create_dir
skb_queue_tail
__netif_schedule
skb_partial_csum_set
skb_checksum_help
netdev_update_features
dev_close
netif_receive_skb
skb_clone
netif_rx_ni
sk_free
ip6_route_output
dev_set_promiscuity
__dev_get_by_index
skb_put
skb_pull
dev_queue_xmit
netdev_features_change
skb_dequeue_tail

From: "T.kabe" <kabe@>
Subject: ptrace: fix fork event messages across pid namespaces

[upstream commit 4e52365f279564cef0ddd41db5237f0471381093]
Author: Matthew Dempsky <mdempsky@chromium.org>
Date:   Fri Jun 6 14:36:42 2014 -0700

    ptrace: fix fork event messages across pid namespaces
    
    When tracing a process in another pid namespace, it's important for fork
    event messages to contain the child's pid as seen from the tracer's pid
    namespace, not the parent's.  Otherwise, the tracer won't be able to
    correlate the fork event with later SIGTRAP signals it receives from the
    child.
    
    We still risk a race condition if a ptracer from a different pid
    namespace attaches after we compute the pid_t value.  However, sending a
    bogus fork event message in this unlikely scenario is still a vast
    improvement over the status quo where we always send bogus fork event
    messages to debuggers in a different pid namespace than the forking
    process.
    
    Signed-off-by: Matthew Dempsky <mdempsky@chromium.org>
    Acked-by: Oleg Nesterov <oleg@redhat.com>
    Cc: Kees Cook <keescook@chromium.org>
    Cc: Julien Tinnes <jln@chromium.org>
    Cc: Roland McGrath <mcgrathr@chromium.org>
    Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff -up ./include/linux/ptrace.h.dist ./include/linux/ptrace.h
--- ./include/linux/ptrace.h.dist	2017-04-22 15:17:16.000000000 +0900
+++ ./include/linux/ptrace.h	2017-06-12 09:33:22.753256752 +0900
@@ -129,6 +129,45 @@ static inline void ptrace_event(int even
 }
 
 /**
+ * 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)
+{
+	/*#include <linux/pid_namespace.h>	 * For task_active_pid_ns.  */
+	/*
+	 * DANGEROUS kABI USAGE WARNING:
+	 * Including whole <linux/pid_namespace.h> breaks kABI making 
+	 * opaque pointer visible, so revert to just declaring the 
+	 * required function here.
+	 */ 
+	extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
+	/*
+	 * 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
diff -up ./kernel/fork.c.dist ./kernel/fork.c
--- ./kernel/fork.c.dist	2017-04-22 15:17:16.000000000 +0900
+++ ./kernel/fork.c	2017-06-12 09:44:02.072915995 +0900
@@ -1718,10 +1718,12 @@ long do_fork(unsigned long clone_flags,
 	 */
 	if (!IS_ERR(p)) {
 		struct completion vfork;
+		struct pid *pid;
 
 		trace_sched_process_fork(current, p);
 
-		nr = task_pid_vnr(p);
+		pid = get_task_pid(p, PIDTYPE_PID);
+		nr = pid_vnr(pid);
 
 		if (clone_flags & CLONE_PARENT_SETTID)
 			put_user(nr, parent_tidptr);
@@ -1736,12 +1738,14 @@ long do_fork(unsigned long clone_flags,
 
 		/* forking complete and child started to run, tell ptracer */
 		if (unlikely(trace))
-			ptrace_event(trace, nr);
+			ptrace_event_pid(trace, pid);
 
 		if (clone_flags & CLONE_VFORK) {
 			if (!wait_for_vfork_done(p, &vfork))
-				ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
+				ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
 		}
+
+		put_pid(pid);
 	} else {
 		nr = PTR_ERR(p);
 	}