Merge tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux

Pull RCU updates from Joel Fernandes:

 - Updates and additions to MAINTAINERS files, with Boqun being added to
   the RCU entry and Zqiang being added as an RCU reviewer.

   I have also transitioned from reviewer to maintainer; however, Paul
   will be taking over sending RCU pull-requests for the next merge
   window.

 - Resolution of hotplug warning in nohz code, achieved by fixing
   cpu_is_hotpluggable() through interaction with the nohz subsystem.

   Tick dependency modifications by Zqiang, focusing on fixing usage of
   the TICK_DEP_BIT_RCU_EXP bitmask.

 - Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
   kernels, fixed by Zqiang.

 - Improvements to rcu-tasks stall reporting by Neeraj.

 - Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
   increased robustness, affecting several components like mac802154,
   drbd, vmw_vmci, tracing, and more.

   A report by Eric Dumazet showed that the API could be unknowingly
   used in an atomic context, so we'd rather make sure they know what
   they're asking for by being explicit:

      https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/

 - Documentation updates, including corrections to spelling,
   clarifications in comments, and improvements to the srcu_size_state
   comments.

 - Better srcu_struct cache locality for readers, by adjusting the size
   of srcu_struct in support of SRCU usage by Christoph Hellwig.

 - Teach lockdep to detect deadlocks between srcu_read_lock() vs
   synchronize_srcu() contributed by Boqun.

   Previously lockdep could not detect such deadlocks, now it can.

 - Integration of rcutorture and rcu-related tools, targeted for v6.4
   from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
   module parameter, and more

 - Miscellaneous changes, various code cleanups and comment improvements

* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
  checkpatch: Error out if deprecated RCU API used
  mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
  rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
  ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
  net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
  net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
  rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
  rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
  rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
  rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
  rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
  rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
  rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
  rcu/trace: use strscpy() to instead of strncpy()
  tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
  ...

2 files changed, 4 insertions, 4 deletions

diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 74842b453407..782273bb93c2 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -177,7 +177,7 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
 			if (orig_sock_table) {
 				static_branch_dec(&rps_needed);
 				static_branch_dec(&rfs_needed);
-				kvfree_rcu(orig_sock_table);
+				kvfree_rcu_mightsleep(orig_sock_table);
 			}
 		}
 	}
@@ -215,7 +215,7 @@ static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
 				     lockdep_is_held(&flow_limit_update_mutex));
 			if (cur && !cpumask_test_cpu(i, mask)) {
 				RCU_INIT_POINTER(sd->flow_limit, NULL);
-				kfree_rcu(cur);
+				kfree_rcu_mightsleep(cur);
 			} else if (!cur && cpumask_test_cpu(i, mask)) {
 				cur = kzalloc_node(len, GFP_KERNEL,
 						   cpu_to_node(i));
diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c
index 9b0933a185eb..5c191bedd72c 100644
--- a/net/mac802154/scan.c
+++ b/net/mac802154/scan.c
@@ -52,7 +52,7 @@ static int mac802154_scan_cleanup_locked(struct ieee802154_local *local,
 	request = rcu_replace_pointer(local->scan_req, NULL, 1);
 	if (!request)
 		return 0;
-	kfree_rcu(request);
+	kvfree_rcu_mightsleep(request);
 
 	/* Advertize first, while we know the devices cannot be removed */
 	if (aborted)
@@ -403,7 +403,7 @@ int mac802154_stop_beacons_locked(struct ieee802154_local *local,
 	request = rcu_replace_pointer(local->beacon_req, NULL, 1);
 	if (!request)
 		return 0;
-	kfree_rcu(request);
+	kvfree_rcu_mightsleep(request);
 
 	nl802154_beaconing_done(wpan_dev);