Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 215 insertions, 0 deletions

diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c
new file mode 100644
index 000000000..24a68eef7
--- /dev/null
+++ b/net/mac80211/mesh_sync.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2011-2012, Pavel Zubarev <pavel.zubarev@gmail.com>
+ * Copyright 2011-2012, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
+ * Copyright 2011-2012, cozybit Inc.
+ * Copyright (C) 2021,2023 Intel Corporation
+ */
+
+#include "ieee80211_i.h"
+#include "mesh.h"
+#include "driver-ops.h"
+
+/* This is not in the standard.  It represents a tolerable tsf drift below
+ * which we do no TSF adjustment.
+ */
+#define TOFFSET_MINIMUM_ADJUSTMENT 10
+
+/* This is not in the standard. It is a margin added to the
+ * Toffset setpoint to mitigate TSF overcorrection
+ * introduced by TSF adjustment latency.
+ */
+#define TOFFSET_SET_MARGIN 20
+
+/* This is not in the standard.  It represents the maximum Toffset jump above
+ * which we'll invalidate the Toffset setpoint and choose a new setpoint.  This
+ * could be, for instance, in case a neighbor is restarted and its TSF counter
+ * reset.
+ */
+#define TOFFSET_MAXIMUM_ADJUSTMENT 800		/* 0.8 ms */
+
+struct sync_method {
+	u8 method;
+	struct ieee80211_mesh_sync_ops ops;
+};
+
+/**
+ * mesh_peer_tbtt_adjusting - check if an mp is currently adjusting its TBTT
+ *
+ * @cfg: mesh config element from the mesh peer (or %NULL)
+ *
+ * Returns: If the mesh peer is currently adjusting its TBTT
+ */
+static bool mesh_peer_tbtt_adjusting(const struct ieee80211_meshconf_ie *cfg)
+{
+	return cfg &&
+	       (cfg->meshconf_cap & IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING);
+}
+
+void mesh_sync_adjust_tsf(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+	/* sdata->vif.bss_conf.beacon_int in 1024us units, 0.04% */
+	u64 beacon_int_fraction = sdata->vif.bss_conf.beacon_int * 1024 / 2500;
+	u64 tsf;
+	u64 tsfdelta;
+
+	spin_lock_bh(&ifmsh->sync_offset_lock);
+	if (ifmsh->sync_offset_clockdrift_max < beacon_int_fraction) {
+		msync_dbg(sdata, "TSF : max clockdrift=%lld; adjusting\n",
+			  (long long) ifmsh->sync_offset_clockdrift_max);
+		tsfdelta = -ifmsh->sync_offset_clockdrift_max;
+		ifmsh->sync_offset_clockdrift_max = 0;
+	} else {
+		msync_dbg(sdata, "TSF : max clockdrift=%lld; adjusting by %llu\n",
+			  (long long) ifmsh->sync_offset_clockdrift_max,
+			  (unsigned long long) beacon_int_fraction);
+		tsfdelta = -beacon_int_fraction;
+		ifmsh->sync_offset_clockdrift_max -= beacon_int_fraction;
+	}
+	spin_unlock_bh(&ifmsh->sync_offset_lock);
+
+	if (local->ops->offset_tsf) {
+		drv_offset_tsf(local, sdata, tsfdelta);
+	} else {
+		tsf = drv_get_tsf(local, sdata);
+		if (tsf != -1ULL)
+			drv_set_tsf(local, sdata, tsf + tsfdelta);
+	}
+}
+
+static void
+mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata, u16 stype,
+			      struct ieee80211_mgmt *mgmt, unsigned int len,
+			      const struct ieee80211_meshconf_ie *mesh_cfg,
+			      struct ieee80211_rx_status *rx_status)
+{
+	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+	struct ieee80211_local *local = sdata->local;
+	struct sta_info *sta;
+	u64 t_t, t_r;
+
+	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
+
+	/* standard mentions only beacons */
+	if (stype != IEEE80211_STYPE_BEACON)
+		return;
+
+	/*
+	 * Get time when timestamp field was received.  If we don't
+	 * have rx timestamps, then use current tsf as an approximation.
+	 * drv_get_tsf() must be called before entering the rcu-read
+	 * section.
+	 */
+	if (ieee80211_have_rx_timestamp(rx_status))
+		t_r = ieee80211_calculate_rx_timestamp(&local->hw, rx_status,
+						       len + FCS_LEN, 24);
+	else
+		t_r = drv_get_tsf(local, sdata);
+
+	rcu_read_lock();
+	sta = sta_info_get(sdata, mgmt->sa);
+	if (!sta)
+		goto no_sync;
+
+	/* check offset sync conditions (13.13.2.2.1)
+	 *
+	 * TODO also sync to
+	 * dot11MeshNbrOffsetMaxNeighbor non-peer non-MBSS neighbors
+	 */
+
+	if (mesh_peer_tbtt_adjusting(mesh_cfg)) {
+		msync_dbg(sdata, "STA %pM : is adjusting TBTT\n",
+			  sta->sta.addr);
+		goto no_sync;
+	}
+
+	/* Timing offset calculation (see 13.13.2.2.2) */
+	t_t = le64_to_cpu(mgmt->u.beacon.timestamp);
+	sta->mesh->t_offset = t_t - t_r;
+
+	if (test_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN)) {
+		s64 t_clockdrift = sta->mesh->t_offset_setpoint - sta->mesh->t_offset;
+		msync_dbg(sdata,
+			  "STA %pM : t_offset=%lld, t_offset_setpoint=%lld, t_clockdrift=%lld\n",
+			  sta->sta.addr, (long long) sta->mesh->t_offset,
+			  (long long) sta->mesh->t_offset_setpoint,
+			  (long long) t_clockdrift);
+
+		if (t_clockdrift > TOFFSET_MAXIMUM_ADJUSTMENT ||
+		    t_clockdrift < -TOFFSET_MAXIMUM_ADJUSTMENT) {
+			msync_dbg(sdata,
+				  "STA %pM : t_clockdrift=%lld too large, setpoint reset\n",
+				  sta->sta.addr,
+				  (long long) t_clockdrift);
+			clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
+			goto no_sync;
+		}
+
+		spin_lock_bh(&ifmsh->sync_offset_lock);
+		if (t_clockdrift > ifmsh->sync_offset_clockdrift_max)
+			ifmsh->sync_offset_clockdrift_max = t_clockdrift;
+		spin_unlock_bh(&ifmsh->sync_offset_lock);
+	} else {
+		sta->mesh->t_offset_setpoint = sta->mesh->t_offset - TOFFSET_SET_MARGIN;
+		set_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
+		msync_dbg(sdata,
+			  "STA %pM : offset was invalid, t_offset=%lld\n",
+			  sta->sta.addr,
+			  (long long) sta->mesh->t_offset);
+	}
+
+no_sync:
+	rcu_read_unlock();
+}
+
+static void mesh_sync_offset_adjust_tsf(struct ieee80211_sub_if_data *sdata,
+					 struct beacon_data *beacon)
+{
+	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+
+	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
+	WARN_ON(!rcu_read_lock_held());
+
+	spin_lock_bh(&ifmsh->sync_offset_lock);
+
+	if (ifmsh->sync_offset_clockdrift_max > TOFFSET_MINIMUM_ADJUSTMENT) {
+		/* Since adjusting the tsf here would
+		 * require a possibly blocking call
+		 * to the driver tsf setter, we punt
+		 * the tsf adjustment to the mesh tasklet
+		 */
+		msync_dbg(sdata,
+			  "TSF : kicking off TSF adjustment with clockdrift_max=%lld\n",
+			  ifmsh->sync_offset_clockdrift_max);
+		set_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags);
+	} else {
+		msync_dbg(sdata,
+			  "TSF : max clockdrift=%lld; too small to adjust\n",
+			  (long long)ifmsh->sync_offset_clockdrift_max);
+		ifmsh->sync_offset_clockdrift_max = 0;
+	}
+	spin_unlock_bh(&ifmsh->sync_offset_lock);
+}
+
+static const struct sync_method sync_methods[] = {
+	{
+		.method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
+		.ops = {
+			.rx_bcn_presp = &mesh_sync_offset_rx_bcn_presp,
+			.adjust_tsf = &mesh_sync_offset_adjust_tsf,
+		}
+	},
+};
+
+const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method)
+{
+	int i;
+
+	for (i = 0 ; i < ARRAY_SIZE(sync_methods); ++i) {
+		if (sync_methods[i].method == method)
+			return &sync_methods[i].ops;
+	}
+	return NULL;
+}