Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.0-rc5

Cross-merge BPF and other fixes after downstream PR.

Minor conflicts in:
  tools/testing/selftests/bpf/progs/exceptions_fail.c
  tools/testing/selftests/bpf/progs/verifier_bounds.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

19 files changed, 361 insertions, 192 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 09fcbb125155..c5876c91face 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -1787,7 +1787,16 @@ static void btf_free_id(struct btf *btf)
 	 * of the _bh() version.
 	 */
 	spin_lock_irqsave(&btf_idr_lock, flags);
-	idr_remove(&btf_idr, btf->id);
+	if (btf->id) {
+		idr_remove(&btf_idr, btf->id);
+		/*
+		 * Clear the id here to make this function idempotent, since it will get
+		 * called a couple of times for module BTFs: on module unload, and then
+		 * the final btf_put(). btf_alloc_id() starts IDs with 1, so we can use
+		 * 0 as sentinel value.
+		 */
+		WRITE_ONCE(btf->id, 0);
+	}
 	spin_unlock_irqrestore(&btf_idr_lock, flags);
 }
 
@@ -8116,7 +8125,7 @@ static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
 {
 	const struct btf *btf = filp->private_data;
 
-	seq_printf(m, "btf_id:\t%u\n", btf->id);
+	seq_printf(m, "btf_id:\t%u\n", READ_ONCE(btf->id));
 }
 #endif
 
@@ -8198,7 +8207,7 @@ int btf_get_info_by_fd(const struct btf *btf,
 	if (copy_from_user(&info, uinfo, info_copy))
 		return -EFAULT;
 
-	info.id = btf->id;
+	info.id = READ_ONCE(btf->id);
 	ubtf = u64_to_user_ptr(info.btf);
 	btf_copy = min_t(u32, btf->data_size, info.btf_size);
 	if (copy_to_user(ubtf, btf->data, btf_copy))
@@ -8261,7 +8270,7 @@ int btf_get_fd_by_id(u32 id)
 
 u32 btf_obj_id(const struct btf *btf)
 {
-	return btf->id;
+	return READ_ONCE(btf->id);
 }
 
 bool btf_is_kernel(const struct btf *btf)
@@ -8383,6 +8392,13 @@ static int btf_module_notify(struct notifier_block *nb, unsigned long op,
 			if (btf_mod->module != module)
 				continue;
 
+			/*
+			 * For modules, we do the freeing of BTF IDR as soon as
+			 * module goes away to disable BTF discovery, since the
+			 * btf_try_get_module() on such BTFs will fail. This may
+			 * be called again on btf_put(), but it's ok to do so.
+			 */
+			btf_free_id(btf_mod->btf);
 			list_del(&btf_mod->list);
 			if (btf_mod->sysfs_attr)
 				sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 229c74f3d6ae..67eb12b637a5 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1422,6 +1422,27 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from,
 		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
 		break;
+
+	case BPF_ST | BPF_PROBE_MEM32 | BPF_DW:
+	case BPF_ST | BPF_PROBE_MEM32 | BPF_W:
+	case BPF_ST | BPF_PROBE_MEM32 | BPF_H:
+	case BPF_ST | BPF_PROBE_MEM32 | BPF_B:
+		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^
+				      from->imm);
+		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		/*
+		 * Cannot use BPF_STX_MEM() macro here as it
+		 * hardcodes BPF_MEM mode, losing PROBE_MEM32
+		 * and breaking arena addressing in the JIT.
+		 */
+		*to++ = (struct bpf_insn) {
+			.code  = BPF_STX | BPF_PROBE_MEM32 |
+				 BPF_SIZE(from->code),
+			.dst_reg = from->dst_reg,
+			.src_reg = BPF_REG_AX,
+			.off   = from->off,
+		};
+		break;
 	}
 out:
 	return to - to_buff;
@@ -1736,6 +1757,12 @@ bool bpf_opcode_in_insntable(u8 code)
 }
 
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
+/* Absolute value of s32 without undefined behavior for S32_MIN */
+static u32 abs_s32(s32 x)
+{
+	return x >= 0 ? (u32)x : -(u32)x;
+}
+
 /**
  *	___bpf_prog_run - run eBPF program on a given context
  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
@@ -1900,8 +1927,8 @@ select_insn:
 			DST = do_div(AX, (u32) SRC);
 			break;
 		case 1:
-			AX = abs((s32)DST);
-			AX = do_div(AX, abs((s32)SRC));
+			AX = abs_s32((s32)DST);
+			AX = do_div(AX, abs_s32((s32)SRC));
 			if ((s32)DST < 0)
 				DST = (u32)-AX;
 			else
@@ -1928,8 +1955,8 @@ select_insn:
 			DST = do_div(AX, (u32) IMM);
 			break;
 		case 1:
-			AX = abs((s32)DST);
-			AX = do_div(AX, abs((s32)IMM));
+			AX = abs_s32((s32)DST);
+			AX = do_div(AX, abs_s32((s32)IMM));
 			if ((s32)DST < 0)
 				DST = (u32)-AX;
 			else
@@ -1955,8 +1982,8 @@ select_insn:
 			DST = (u32) AX;
 			break;
 		case 1:
-			AX = abs((s32)DST);
-			do_div(AX, abs((s32)SRC));
+			AX = abs_s32((s32)DST);
+			do_div(AX, abs_s32((s32)SRC));
 			if (((s32)DST < 0) == ((s32)SRC < 0))
 				DST = (u32)AX;
 			else
@@ -1982,8 +2009,8 @@ select_insn:
 			DST = (u32) AX;
 			break;
 		case 1:
-			AX = abs((s32)DST);
-			do_div(AX, abs((s32)IMM));
+			AX = abs_s32((s32)DST);
+			do_div(AX, abs_s32((s32)IMM));
 			if (((s32)DST < 0) == ((s32)IMM < 0))
 				DST = (u32)AX;
 			else
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 80a9eab79cac..cd008b146ee5 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -15932,6 +15932,13 @@ static void scalar_byte_swap(struct bpf_reg_state *dst_reg, struct bpf_insn *ins
 	/* Apply bswap if alu64 or switch between big-endian and little-endian machines */
 	bool need_bswap = alu64 || (to_le == is_big_endian);
 
+	/*
+	 * If the register is mutated, manually reset its scalar ID to break
+	 * any existing ties and avoid incorrect bounds propagation.
+	 */
+	if (need_bswap || insn->imm == 16 || insn->imm == 32)
+		dst_reg->id = 0;
+
 	if (need_bswap) {
 		if (insn->imm == 16)
 			dst_reg->var_off = tnum_bswap16(dst_reg->var_off);
@@ -16014,7 +16021,7 @@ static int maybe_fork_scalars(struct bpf_verifier_env *env, struct bpf_insn *ins
 	else
 		return 0;
 
-	branch = push_stack(env, env->insn_idx + 1, env->insn_idx, false);
+	branch = push_stack(env, env->insn_idx, env->insn_idx, false);
 	if (IS_ERR(branch))
 		return PTR_ERR(branch);
 
@@ -17423,6 +17430,12 @@ static void sync_linked_regs(struct bpf_verifier_env *env, struct bpf_verifier_s
 			continue;
 		if ((reg->id & ~BPF_ADD_CONST) != (known_reg->id & ~BPF_ADD_CONST))
 			continue;
+		/*
+		 * Skip mixed 32/64-bit links: the delta relationship doesn't
+		 * hold across different ALU widths.
+		 */
+		if (((reg->id ^ known_reg->id) & BPF_ADD_CONST) == BPF_ADD_CONST)
+			continue;
 		if ((!(reg->id & BPF_ADD_CONST) && !(known_reg->id & BPF_ADD_CONST)) ||
 		    reg->delta == known_reg->delta) {
 			s32 saved_subreg_def = reg->subreg_def;
@@ -17450,7 +17463,7 @@ static void sync_linked_regs(struct bpf_verifier_env *env, struct bpf_verifier_s
 			scalar32_min_max_add(reg, &fake_reg);
 			scalar_min_max_add(reg, &fake_reg);
 			reg->var_off = tnum_add(reg->var_off, fake_reg.var_off);
-			if (known_reg->id & BPF_ADD_CONST32)
+			if ((reg->id | known_reg->id) & BPF_ADD_CONST32)
 				zext_32_to_64(reg);
 			reg_bounds_sync(reg);
 		}
@@ -19936,11 +19949,14 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold,
 		 * Also verify that new value satisfies old value range knowledge.
 		 */
 
-		/* ADD_CONST mismatch: different linking semantics */
-		if ((rold->id & BPF_ADD_CONST) && !(rcur->id & BPF_ADD_CONST))
-			return false;
-
-		if (rold->id && !(rold->id & BPF_ADD_CONST) && (rcur->id & BPF_ADD_CONST))
+		/*
+		 * ADD_CONST flags must match exactly: BPF_ADD_CONST32 and
+		 * BPF_ADD_CONST64 have different linking semantics in
+		 * sync_linked_regs() (alu32 zero-extends, alu64 does not),
+		 * so pruning across different flag types is unsafe.
+		 */
+		if (rold->id &&
+		    (rold->id & BPF_ADD_CONST) != (rcur->id & BPF_ADD_CONST))
 			return false;
 
 		/* Both have offset linkage: offsets must match */
@@ -20973,7 +20989,8 @@ static int process_bpf_exit_full(struct bpf_verifier_env *env,
 	 * state when it exits.
 	 */
 	int err = check_resource_leak(env, exception_exit,
-				      !env->cur_state->curframe,
+				      exception_exit || !env->cur_state->curframe,
+				      exception_exit ? "bpf_throw" :
 				      "BPF_EXIT instruction in main prog");
 	if (err)
 		return err;
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index be1d71dda317..01fc2a93f3ef 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -5109,6 +5109,12 @@ repeat:
 		return;
 
 	task = list_entry(it->task_pos, struct task_struct, cg_list);
+	/*
+	 * Hide tasks that are exiting but not yet removed. Keep zombie
+	 * leaders with live threads visible.
+	 */
+	if ((task->flags & PF_EXITING) && !atomic_read(&task->signal->live))
+		goto repeat;
 
 	if (it->flags & CSS_TASK_ITER_PROCS) {
 		/* if PROCS, skip over tasks which aren't group leaders */
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index e200de7c60b6..d21868455341 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -879,7 +879,7 @@ generate_doms:
 	/*
 	 * Cgroup v2 doesn't support domain attributes, just set all of them
 	 * to SD_ATTR_INIT. Also non-isolating partition root CPUs are a
-	 * subset of HK_TYPE_DOMAIN housekeeping CPUs.
+	 * subset of HK_TYPE_DOMAIN_BOOT housekeeping CPUs.
 	 */
 	for (i = 0; i < ndoms; i++) {
 		/*
@@ -888,7 +888,7 @@ generate_doms:
 		 */
 		if (!csa || csa[i] == &top_cpuset)
 			cpumask_and(doms[i], top_cpuset.effective_cpus,
-				    housekeeping_cpumask(HK_TYPE_DOMAIN));
+				    housekeeping_cpumask(HK_TYPE_DOMAIN_BOOT));
 		else
 			cpumask_copy(doms[i], csa[i]->effective_cpus);
 		if (dattr)
@@ -1329,17 +1329,22 @@ static bool prstate_housekeeping_conflict(int prstate, struct cpumask *new_cpus)
 }
 
 /*
- * update_hk_sched_domains - Update HK cpumasks & rebuild sched domains
+ * cpuset_update_sd_hk_unlock - Rebuild sched domains, update HK & unlock
  *
- * Update housekeeping cpumasks and rebuild sched domains if necessary.
- * This should be called at the end of cpuset or hotplug actions.
+ * Update housekeeping cpumasks and rebuild sched domains if necessary and
+ * then do a cpuset_full_unlock().
+ * This should be called at the end of cpuset operation.
  */
-static void update_hk_sched_domains(void)
+static void cpuset_update_sd_hk_unlock(void)
+	__releases(&cpuset_mutex)
+	__releases(&cpuset_top_mutex)
 {
+	/* force_sd_rebuild will be cleared in rebuild_sched_domains_locked() */
+	if (force_sd_rebuild)
+		rebuild_sched_domains_locked();
+
 	if (update_housekeeping) {
-		/* Updating HK cpumasks implies rebuild sched domains */
 		update_housekeeping = false;
-		force_sd_rebuild = true;
 		cpumask_copy(isolated_hk_cpus, isolated_cpus);
 
 		/*
@@ -1350,22 +1355,19 @@ static void update_hk_sched_domains(void)
 		mutex_unlock(&cpuset_mutex);
 		cpus_read_unlock();
 		WARN_ON_ONCE(housekeeping_update(isolated_hk_cpus));
-		cpus_read_lock();
-		mutex_lock(&cpuset_mutex);
+		mutex_unlock(&cpuset_top_mutex);
+	} else {
+		cpuset_full_unlock();
 	}
-	/* force_sd_rebuild will be cleared in rebuild_sched_domains_locked() */
-	if (force_sd_rebuild)
-		rebuild_sched_domains_locked();
 }
 
 /*
- * Work function to invoke update_hk_sched_domains()
+ * Work function to invoke cpuset_update_sd_hk_unlock()
  */
 static void hk_sd_workfn(struct work_struct *work)
 {
 	cpuset_full_lock();
-	update_hk_sched_domains();
-	cpuset_full_unlock();
+	cpuset_update_sd_hk_unlock();
 }
 
 /**
@@ -3230,8 +3232,7 @@ ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 
 	free_cpuset(trialcs);
 out_unlock:
-	update_hk_sched_domains();
-	cpuset_full_unlock();
+	cpuset_update_sd_hk_unlock();
 	if (of_cft(of)->private == FILE_MEMLIST)
 		schedule_flush_migrate_mm();
 	return retval ?: nbytes;
@@ -3338,8 +3339,7 @@ static ssize_t cpuset_partition_write(struct kernfs_open_file *of, char *buf,
 	cpuset_full_lock();
 	if (is_cpuset_online(cs))
 		retval = update_prstate(cs, val);
-	update_hk_sched_domains();
-	cpuset_full_unlock();
+	cpuset_update_sd_hk_unlock();
 	return retval ?: nbytes;
 }
 
@@ -3513,8 +3513,7 @@ static void cpuset_css_killed(struct cgroup_subsys_state *css)
 	/* Reset valid partition back to member */
 	if (is_partition_valid(cs))
 		update_prstate(cs, PRS_MEMBER);
-	update_hk_sched_domains();
-	cpuset_full_unlock();
+	cpuset_update_sd_hk_unlock();
 }
 
 static void cpuset_css_free(struct cgroup_subsys_state *css)
@@ -3923,11 +3922,13 @@ static void cpuset_handle_hotplug(void)
 		rcu_read_unlock();
 	}
 
-
 	/*
-	 * Queue a work to call housekeeping_update() & rebuild_sched_domains()
-	 * There will be a slight delay before the HK_TYPE_DOMAIN housekeeping
-	 * cpumask can correctly reflect what is in isolated_cpus.
+	 * rebuild_sched_domains() will always be called directly if needed
+	 * to make sure that newly added or removed CPU will be reflected in
+	 * the sched domains. However, if isolated partition invalidation
+	 * or recreation is being done (update_housekeeping set), a work item
+	 * will be queued to call housekeeping_update() to update the
+	 * corresponding housekeeping cpumasks after some slight delay.
 	 *
 	 * We rely on WORK_STRUCT_PENDING_BIT to not requeue a work item that
 	 * is still pending. Before the pending bit is cleared, the work data
@@ -3936,8 +3937,10 @@ static void cpuset_handle_hotplug(void)
 	 * previously queued work. Since hk_sd_workfn() doesn't use the work
 	 * item at all, this is not a problem.
 	 */
-	if (update_housekeeping || force_sd_rebuild)
-		queue_work(system_unbound_wq, &hk_sd_work);
+	if (force_sd_rebuild)
+		rebuild_sched_domains_cpuslocked();
+	if (update_housekeeping)
+		queue_work(system_dfl_wq, &hk_sd_work);
 
 	free_tmpmasks(ptmp);
 }
diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c
index 1f4067fbdb94..a20d4097744a 100644
--- a/kernel/crash_dump_dm_crypt.c
+++ b/kernel/crash_dump_dm_crypt.c
@@ -168,8 +168,8 @@ static int read_key_from_user_keying(struct dm_crypt_key *dm_key)
 
 	memcpy(dm_key->data, ukp->data, ukp->datalen);
 	dm_key->key_size = ukp->datalen;
-	kexec_dprintk("Get dm crypt key (size=%u) %s: %8ph\n", dm_key->key_size,
-		      dm_key->key_desc, dm_key->data);
+	kexec_dprintk("Get dm crypt key (size=%u) %s\n", dm_key->key_size,
+		      dm_key->key_desc);
 
 out:
 	up_read(&key->sem);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1f5699b339ec..89b40e439717 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4813,7 +4813,7 @@ static void __perf_event_read(void *info)
 	struct perf_event *sub, *event = data->event;
 	struct perf_event_context *ctx = event->ctx;
 	struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
-	struct pmu *pmu = event->pmu;
+	struct pmu *pmu;
 
 	/*
 	 * If this is a task context, we need to check whether it is
@@ -4825,7 +4825,7 @@ static void __perf_event_read(void *info)
 	if (ctx->task && cpuctx->task_ctx != ctx)
 		return;
 
-	raw_spin_lock(&ctx->lock);
+	guard(raw_spinlock)(&ctx->lock);
 	ctx_time_update_event(ctx, event);
 
 	perf_event_update_time(event);
@@ -4833,25 +4833,22 @@ static void __perf_event_read(void *info)
 		perf_event_update_sibling_time(event);
 
 	if (event->state != PERF_EVENT_STATE_ACTIVE)
-		goto unlock;
+		return;
 
 	if (!data->group) {
-		pmu->read(event);
+		perf_pmu_read(event);
 		data->ret = 0;
-		goto unlock;
+		return;
 	}
 
+	pmu = event->pmu_ctx->pmu;
 	pmu->start_txn(pmu, PERF_PMU_TXN_READ);
 
-	pmu->read(event);
-
+	perf_pmu_read(event);
 	for_each_sibling_event(sub, event)
 		perf_pmu_read(sub);
 
 	data->ret = pmu->commit_txn(pmu);
-
-unlock:
-	raw_spin_unlock(&ctx->lock);
 }
 
 static inline u64 perf_event_count(struct perf_event *event, bool self)
@@ -14744,7 +14741,7 @@ inherit_event(struct perf_event *parent_event,
 	get_ctx(child_ctx);
 	child_event->ctx = child_ctx;
 
-	pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event);
+	pmu_ctx = find_get_pmu_context(parent_event->pmu_ctx->pmu, child_ctx, child_event);
 	if (IS_ERR(pmu_ctx)) {
 		free_event(child_event);
 		return ERR_CAST(pmu_ctx);
diff --git a/kernel/fork.c b/kernel/fork.c
index 65113a304518..bc2bf58b93b6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1000,6 +1000,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 #ifdef CONFIG_SCHED_MM_CID
 	tsk->mm_cid.cid = MM_CID_UNSET;
 	tsk->mm_cid.active = 0;
+	INIT_HLIST_NODE(&tsk->mm_cid.node);
 #endif
 	return tsk;
 
@@ -1586,7 +1587,6 @@ static int copy_mm(u64 clone_flags, struct task_struct *tsk)
 
 	tsk->mm = mm;
 	tsk->active_mm = mm;
-	sched_mm_cid_fork(tsk);
 	return 0;
 }
 
@@ -2498,7 +2498,6 @@ bad_fork_cleanup_namespaces:
 	exit_nsproxy_namespaces(p);
 bad_fork_cleanup_mm:
 	if (p->mm) {
-		sched_mm_cid_exit(p);
 		mm_clear_owner(p->mm, p);
 		mmput(p->mm);
 	}
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ab25b4aa9095..bfc89083daa9 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1144,12 +1144,12 @@ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
 	lockdep_assert_held(&kprobe_mutex);
 
 	ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0);
-	if (WARN_ONCE(ret < 0, "Failed to arm kprobe-ftrace at %pS (error %d)\n", p->addr, ret))
+	if (ret < 0)
 		return ret;
 
 	if (*cnt == 0) {
 		ret = register_ftrace_function(ops);
-		if (WARN(ret < 0, "Failed to register kprobe-ftrace (error %d)\n", ret)) {
+		if (ret < 0) {
 			/*
 			 * At this point, sinec ops is not registered, we should be sefe from
 			 * registering empty filter.
@@ -1178,6 +1178,10 @@ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
 	int ret;
 
 	lockdep_assert_held(&kprobe_mutex);
+	if (unlikely(kprobe_ftrace_disabled)) {
+		/* Now ftrace is disabled forever, disarm is already done. */
+		return 0;
+	}
 
 	if (*cnt == 1) {
 		ret = unregister_ftrace_function(ops);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b7f77c165a6e..496dff740dca 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4729,8 +4729,11 @@ void sched_cancel_fork(struct task_struct *p)
 	scx_cancel_fork(p);
 }
 
+static void sched_mm_cid_fork(struct task_struct *t);
+
 void sched_post_fork(struct task_struct *p)
 {
+	sched_mm_cid_fork(p);
 	uclamp_post_fork(p);
 	scx_post_fork(p);
 }
@@ -10617,13 +10620,10 @@ static inline void mm_cid_transit_to_cpu(struct task_struct *t, struct mm_cid_pc
 	}
 }
 
-static bool mm_cid_fixup_task_to_cpu(struct task_struct *t, struct mm_struct *mm)
+static void mm_cid_fixup_task_to_cpu(struct task_struct *t, struct mm_struct *mm)
 {
 	/* Remote access to mm::mm_cid::pcpu requires rq_lock */
 	guard(task_rq_lock)(t);
-	/* If the task is not active it is not in the users count */
-	if (!t->mm_cid.active)
-		return false;
 	if (cid_on_task(t->mm_cid.cid)) {
 		/* If running on the CPU, put the CID in transit mode, otherwise drop it */
 		if (task_rq(t)->curr == t)
@@ -10631,69 +10631,43 @@ static bool mm_cid_fixup_task_to_cpu(struct task_struct *t, struct mm_struct *mm
 		else
 			mm_unset_cid_on_task(t);
 	}
-	return true;
 }
 
-static void mm_cid_do_fixup_tasks_to_cpus(struct mm_struct *mm)
+static void mm_cid_fixup_tasks_to_cpus(void)
 {
-	struct task_struct *p, *t;
-	unsigned int users;
+	struct mm_struct *mm = current->mm;
+	struct task_struct *t;
 
-	/*
-	 * This can obviously race with a concurrent affinity change, which
-	 * increases the number of allowed CPUs for this mm, but that does
-	 * not affect the mode and only changes the CID constraints. A
-	 * possible switch back to per task mode happens either in the
-	 * deferred handler function or in the next fork()/exit().
-	 *
-	 * The caller has already transferred. The newly incoming task is
-	 * already accounted for, but not yet visible.
-	 */
-	users = mm->mm_cid.users - 2;
-	if (!users)
-		return;
+	lockdep_assert_held(&mm->mm_cid.mutex);
 
-	guard(rcu)();
-	for_other_threads(current, t) {
-		if (mm_cid_fixup_task_to_cpu(t, mm))
-			users--;
+	hlist_for_each_entry(t, &mm->mm_cid.user_list, mm_cid.node) {
+		/* Current has already transferred before invoking the fixup. */
+		if (t != current)
+			mm_cid_fixup_task_to_cpu(t, mm);
 	}
 
-	if (!users)
-		return;
-
-	/* Happens only for VM_CLONE processes. */
-	for_each_process_thread(p, t) {
-		if (t == current || t->mm != mm)
-			continue;
-		if (mm_cid_fixup_task_to_cpu(t, mm)) {
-			if (--users == 0)
-				return;
-		}
-	}
-}
-
-static void mm_cid_fixup_tasks_to_cpus(void)
-{
-	struct mm_struct *mm = current->mm;
-
-	mm_cid_do_fixup_tasks_to_cpus(mm);
 	mm_cid_complete_transit(mm, MM_CID_ONCPU);
 }
 
 static bool sched_mm_cid_add_user(struct task_struct *t, struct mm_struct *mm)
 {
+	lockdep_assert_held(&mm->mm_cid.lock);
+
 	t->mm_cid.active = 1;
+	hlist_add_head(&t->mm_cid.node, &mm->mm_cid.user_list);
 	mm->mm_cid.users++;
 	return mm_update_max_cids(mm);
 }
 
-void sched_mm_cid_fork(struct task_struct *t)
+static void sched_mm_cid_fork(struct task_struct *t)
 {
 	struct mm_struct *mm = t->mm;
 	bool percpu;
 
-	WARN_ON_ONCE(!mm || t->mm_cid.cid != MM_CID_UNSET);
+	if (!mm)
+		return;
+
+	WARN_ON_ONCE(t->mm_cid.cid != MM_CID_UNSET);
 
 	guard(mutex)(&mm->mm_cid.mutex);
 	scoped_guard(raw_spinlock_irq, &mm->mm_cid.lock) {
@@ -10732,12 +10706,13 @@ void sched_mm_cid_fork(struct task_struct *t)
 
 static bool sched_mm_cid_remove_user(struct task_struct *t)
 {
+	lockdep_assert_held(&t->mm->mm_cid.lock);
+
 	t->mm_cid.active = 0;
-	scoped_guard(preempt) {
-		/* Clear the transition bit */
-		t->mm_cid.cid = cid_from_transit_cid(t->mm_cid.cid);
-		mm_unset_cid_on_task(t);
-	}
+	/* Clear the transition bit */
+	t->mm_cid.cid = cid_from_transit_cid(t->mm_cid.cid);
+	mm_unset_cid_on_task(t);
+	hlist_del_init(&t->mm_cid.node);
 	t->mm->mm_cid.users--;
 	return mm_update_max_cids(t->mm);
 }
@@ -10880,11 +10855,13 @@ void mm_init_cid(struct mm_struct *mm, struct task_struct *p)
 	mutex_init(&mm->mm_cid.mutex);
 	mm->mm_cid.irq_work = IRQ_WORK_INIT_HARD(mm_cid_irq_work);
 	INIT_WORK(&mm->mm_cid.work, mm_cid_work_fn);
+	INIT_HLIST_HEAD(&mm->mm_cid.user_list);
 	cpumask_copy(mm_cpus_allowed(mm), &p->cpus_mask);
 	bitmap_zero(mm_cidmask(mm), num_possible_cpus());
 }
 #else /* CONFIG_SCHED_MM_CID */
 static inline void mm_update_cpus_allowed(struct mm_struct *mm, const struct cpumask *affmsk) { }
+static inline void sched_mm_cid_fork(struct task_struct *t) { }
 #endif /* !CONFIG_SCHED_MM_CID */
 
 static DEFINE_PER_CPU(struct sched_change_ctx, sched_change_ctx);
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 1594987d637b..26a6ac2f8826 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -1103,7 +1103,7 @@ static void dispatch_enqueue(struct scx_sched *sch, struct scx_dispatch_q *dsq,
 	}
 
 	/* seq records the order tasks are queued, used by BPF DSQ iterator */
-	dsq->seq++;
+	WRITE_ONCE(dsq->seq, dsq->seq + 1);
 	p->scx.dsq_seq = dsq->seq;
 
 	dsq_mod_nr(dsq, 1);
@@ -1470,16 +1470,15 @@ static void clr_task_runnable(struct task_struct *p, bool reset_runnable_at)
 		p->scx.flags |= SCX_TASK_RESET_RUNNABLE_AT;
 }
 
-static void enqueue_task_scx(struct rq *rq, struct task_struct *p, int enq_flags)
+static void enqueue_task_scx(struct rq *rq, struct task_struct *p, int core_enq_flags)
 {
 	struct scx_sched *sch = scx_root;
 	int sticky_cpu = p->scx.sticky_cpu;
+	u64 enq_flags = core_enq_flags | rq->scx.extra_enq_flags;
 
 	if (enq_flags & ENQUEUE_WAKEUP)
 		rq->scx.flags |= SCX_RQ_IN_WAKEUP;
 
-	enq_flags |= rq->scx.extra_enq_flags;
-
 	if (sticky_cpu >= 0)
 		p->scx.sticky_cpu = -1;
 
@@ -3908,8 +3907,8 @@ static u32 bypass_lb_cpu(struct scx_sched *sch, struct rq *rq,
 	 * consider offloading iff the total queued duration is over the
 	 * threshold.
 	 */
-	min_delta_us = scx_bypass_lb_intv_us / SCX_BYPASS_LB_MIN_DELTA_DIV;
-	if (delta < DIV_ROUND_UP(min_delta_us, scx_slice_bypass_us))
+	min_delta_us = READ_ONCE(scx_bypass_lb_intv_us) / SCX_BYPASS_LB_MIN_DELTA_DIV;
+	if (delta < DIV_ROUND_UP(min_delta_us, READ_ONCE(scx_slice_bypass_us)))
 		return 0;
 
 	raw_spin_rq_lock_irq(rq);
@@ -4137,7 +4136,7 @@ static void scx_bypass(bool bypass)
 		WARN_ON_ONCE(scx_bypass_depth <= 0);
 		if (scx_bypass_depth != 1)
 			goto unlock;
-		WRITE_ONCE(scx_slice_dfl, scx_slice_bypass_us * NSEC_PER_USEC);
+		WRITE_ONCE(scx_slice_dfl, READ_ONCE(scx_slice_bypass_us) * NSEC_PER_USEC);
 		bypass_timestamp = ktime_get_ns();
 		if (sch)
 			scx_add_event(sch, SCX_EV_BYPASS_ACTIVATE, 1);
@@ -5259,13 +5258,14 @@ static int scx_enable(struct sched_ext_ops *ops, struct bpf_link *link)
 	if (!READ_ONCE(helper)) {
 		mutex_lock(&helper_mutex);
 		if (!helper) {
-			helper = kthread_run_worker(0, "scx_enable_helper");
-			if (IS_ERR_OR_NULL(helper)) {
-				helper = NULL;
+			struct kthread_worker *w =
+				kthread_run_worker(0, "scx_enable_helper");
+			if (IS_ERR_OR_NULL(w)) {
 				mutex_unlock(&helper_mutex);
 				return -ENOMEM;
 			}
-			sched_set_fifo(helper->task);
+			sched_set_fifo(w->task);
+			WRITE_ONCE(helper, w);
 		}
 		mutex_unlock(&helper_mutex);
 	}
diff --git a/kernel/sched/ext_internal.h b/kernel/sched/ext_internal.h
index 11ebb744d893..00b450597f3e 100644
--- a/kernel/sched/ext_internal.h
+++ b/kernel/sched/ext_internal.h
@@ -1035,26 +1035,108 @@ static const char *scx_enable_state_str[] = {
 };
 
 /*
- * sched_ext_entity->ops_state
+ * Task Ownership State Machine (sched_ext_entity->ops_state)
  *
- * Used to track the task ownership between the SCX core and the BPF scheduler.
- * State transitions look as follows:
+ * The sched_ext core uses this state machine to track task ownership
+ * between the SCX core and the BPF scheduler. This allows the BPF
+ * scheduler to dispatch tasks without strict ordering requirements, while
+ * the SCX core safely rejects invalid dispatches.
  *
- * NONE -> QUEUEING -> QUEUED -> DISPATCHING
- *   ^              |                 |
- *   |              v                 v
- *   \-------------------------------/
+ * State Transitions
  *
- * QUEUEING and DISPATCHING states can be waited upon. See wait_ops_state() call
- * sites for explanations on the conditions being waited upon and why they are
- * safe. Transitions out of them into NONE or QUEUED must store_release and the
- * waiters should load_acquire.
+ *       .------------> NONE (owned by SCX core)
+ *       |               |           ^
+ *       |       enqueue |           | direct dispatch
+ *       |               v           |
+ *       |           QUEUEING -------'
+ *       |               |
+ *       |       enqueue |
+ *       |     completes |
+ *       |               v
+ *       |            QUEUED (owned by BPF scheduler)
+ *       |               |
+ *       |      dispatch |
+ *       |               |
+ *       |               v
+ *       |          DISPATCHING
+ *       |               |
+ *       |      dispatch |
+ *       |     completes |
+ *       `---------------'
  *
- * Tracking scx_ops_state enables sched_ext core to reliably determine whether
- * any given task can be dispatched by the BPF scheduler at all times and thus
- * relaxes the requirements on the BPF scheduler. This allows the BPF scheduler
- * to try to dispatch any task anytime regardless of its state as the SCX core
- * can safely reject invalid dispatches.
+ * State Descriptions
+ *
+ * - %SCX_OPSS_NONE:
+ *     Task is owned by the SCX core. It's either on a run queue, running,
+ *     or being manipulated by the core scheduler. The BPF scheduler has no
+ *     claim on this task.
+ *
+ * - %SCX_OPSS_QUEUEING:
+ *     Transitional state while transferring a task from the SCX core to
+ *     the BPF scheduler. The task's rq lock is held during this state.
+ *     Since QUEUEING is both entered and exited under the rq lock, dequeue
+ *     can never observe this state (it would be a BUG). When finishing a
+ *     dispatch, if the task is still in %SCX_OPSS_QUEUEING the completion
+ *     path busy-waits for it to leave this state (via wait_ops_state())
+ *     before retrying.
+ *
+ * - %SCX_OPSS_QUEUED:
+ *     Task is owned by the BPF scheduler. It's on a DSQ (dispatch queue)
+ *     and the BPF scheduler is responsible for dispatching it. A QSEQ
+ *     (queue sequence number) is embedded in this state to detect
+ *     dispatch/dequeue races: if a task is dequeued and re-enqueued, the
+ *     QSEQ changes and any in-flight dispatch operations targeting the old
+ *     QSEQ are safely ignored.
+ *
+ * - %SCX_OPSS_DISPATCHING:
+ *     Transitional state while transferring a task from the BPF scheduler
+ *     back to the SCX core. This state indicates the BPF scheduler has
+ *     selected the task for execution. When dequeue needs to take the task
+ *     off a DSQ and it is still in %SCX_OPSS_DISPATCHING, the dequeue path
+ *     busy-waits for it to leave this state (via wait_ops_state()) before
+ *     proceeding. Exits to %SCX_OPSS_NONE when dispatch completes.
+ *
+ * Memory Ordering
+ *
+ * Transitions out of %SCX_OPSS_QUEUEING and %SCX_OPSS_DISPATCHING into
+ * %SCX_OPSS_NONE or %SCX_OPSS_QUEUED must use atomic_long_set_release()
+ * and waiters must use atomic_long_read_acquire(). This ensures proper
+ * synchronization between concurrent operations.
+ *
+ * Cross-CPU Task Migration
+ *
+ * When moving a task in the %SCX_OPSS_DISPATCHING state, we can't simply
+ * grab the target CPU's rq lock because a concurrent dequeue might be
+ * waiting on %SCX_OPSS_DISPATCHING while holding the source rq lock
+ * (deadlock).
+ *
+ * The sched_ext core uses a "lock dancing" protocol coordinated by
+ * p->scx.holding_cpu. When moving a task to a different rq:
+ *
+ *   1. Verify task can be moved (CPU affinity, migration_disabled, etc.)
+ *   2. Set p->scx.holding_cpu to the current CPU
+ *   3. Set task state to %SCX_OPSS_NONE; dequeue waits while DISPATCHING
+ *      is set, so clearing DISPATCHING first prevents the circular wait
+ *      (safe to lock the rq we need)
+ *   4. Unlock the current CPU's rq
+ *   5. Lock src_rq (where the task currently lives)
+ *   6. Verify p->scx.holding_cpu == current CPU, if not, dequeue won the
+ *      race (dequeue clears holding_cpu to -1 when it takes the task), in
+ *      this case migration is aborted
+ *   7. If src_rq == dst_rq: clear holding_cpu and enqueue directly
+ *      into dst_rq's local DSQ (no lock swap needed)
+ *   8. Otherwise: call move_remote_task_to_local_dsq(), which releases
+ *      src_rq, locks dst_rq, and performs the deactivate/activate
+ *      migration cycle (dst_rq is held on return)
+ *   9. Unlock dst_rq and re-lock the current CPU's rq to restore
+ *      the lock state expected by the caller
+ *
+ * If any verification fails, abort the migration.
+ *
+ * This state tracking allows the BPF scheduler to try to dispatch any task
+ * at any time regardless of its state. The SCX core can safely
+ * reject/ignore invalid dispatches, simplifying the BPF scheduler
+ * implementation.
  */
 enum scx_ops_state {
 	SCX_OPSS_NONE,		/* owned by the SCX core */
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 3681b6ad9276..a83be0c834dd 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -161,6 +161,14 @@ static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	return cpuidle_enter(drv, dev, next_state);
 }
 
+static void idle_call_stop_or_retain_tick(bool stop_tick)
+{
+	if (stop_tick || tick_nohz_tick_stopped())
+		tick_nohz_idle_stop_tick();
+	else
+		tick_nohz_idle_retain_tick();
+}
+
 /**
  * cpuidle_idle_call - the main idle function
  *
@@ -170,7 +178,7 @@ static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
  * set, and it returns with polling set.  If it ever stops polling, it
  * must clear the polling bit.
  */
-static void cpuidle_idle_call(void)
+static void cpuidle_idle_call(bool stop_tick)
 {
 	struct cpuidle_device *dev = cpuidle_get_device();
 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
@@ -186,7 +194,7 @@ static void cpuidle_idle_call(void)
 	}
 
 	if (cpuidle_not_available(drv, dev)) {
-		tick_nohz_idle_stop_tick();
+		idle_call_stop_or_retain_tick(stop_tick);
 
 		default_idle_call();
 		goto exit_idle;
@@ -221,24 +229,35 @@ static void cpuidle_idle_call(void)
 
 		next_state = cpuidle_find_deepest_state(drv, dev, max_latency_ns);
 		call_cpuidle(drv, dev, next_state);
-	} else {
-		bool stop_tick = true;
+	} else if (drv->state_count > 1) {
+		/*
+		 * stop_tick is expected to be true by default by cpuidle
+		 * governors, which allows them to select idle states with
+		 * target residency above the tick period length.
+		 */
+		stop_tick = true;
 
 		/*
 		 * Ask the cpuidle framework to choose a convenient idle state.
 		 */
 		next_state = cpuidle_select(drv, dev, &stop_tick);
 
-		if (stop_tick || tick_nohz_tick_stopped())
-			tick_nohz_idle_stop_tick();
-		else
-			tick_nohz_idle_retain_tick();
+		idle_call_stop_or_retain_tick(stop_tick);
 
 		entered_state = call_cpuidle(drv, dev, next_state);
 		/*
 		 * Give the governor an opportunity to reflect on the outcome
 		 */
 		cpuidle_reflect(dev, entered_state);
+	} else {
+		idle_call_stop_or_retain_tick(stop_tick);
+
+		/*
+		 * If there is only a single idle state (or none), there is
+		 * nothing meaningful for the governor to choose.  Skip the
+		 * governor and always use state 0.
+		 */
+		call_cpuidle(drv, dev, 0);
 	}
 
 exit_idle:
@@ -259,6 +278,7 @@ exit_idle:
 static void do_idle(void)
 {
 	int cpu = smp_processor_id();
+	bool got_tick = false;
 
 	/*
 	 * Check if we need to update blocked load
@@ -329,8 +349,9 @@ static void do_idle(void)
 			tick_nohz_idle_restart_tick();
 			cpu_idle_poll();
 		} else {
-			cpuidle_idle_call();
+			cpuidle_idle_call(got_tick);
 		}
+		got_tick = tick_nohz_idle_got_tick();
 		arch_cpu_idle_exit();
 	}
 
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 36fd2313ae7e..0d832317d576 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -697,7 +697,7 @@ EXPORT_SYMBOL(clock_t_to_jiffies);
  *
  * Return: jiffies_64 value converted to 64-bit "clock_t" (CLOCKS_PER_SEC)
  */
-u64 jiffies_64_to_clock_t(u64 x)
+notrace u64 jiffies_64_to_clock_t(u64 x)
 {
 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
 # if HZ < USER_HZ
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8df69e702706..413310912609 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6606,9 +6606,9 @@ int update_ftrace_direct_mod(struct ftrace_ops *ops, struct ftrace_hash *hash, b
 	if (!orig_hash)
 		goto unlock;
 
-	/* Enable the tmp_ops to have the same functions as the direct ops */
+	/* Enable the tmp_ops to have the same functions as the hash object. */
 	ftrace_ops_init(&tmp_ops);
-	tmp_ops.func_hash = ops->func_hash;
+	tmp_ops.func_hash->filter_hash = hash;
 
 	err = register_ftrace_function_nolock(&tmp_ops);
 	if (err)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 17d0ea0cc3e6..170170bd83bd 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2053,7 +2053,7 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer)
 
 		entries += ret;
 		entry_bytes += local_read(&head_page->page->commit);
-		local_set(&cpu_buffer->head_page->entries, ret);
+		local_set(&head_page->entries, ret);
 
 		if (head_page == cpu_buffer->commit_page)
 			break;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ebd996f8710e..a626211ceb9a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -555,7 +555,7 @@ static bool update_marker_trace(struct trace_array *tr, int enabled)
 	lockdep_assert_held(&event_mutex);
 
 	if (enabled) {
-		if (!list_empty(&tr->marker_list))
+		if (tr->trace_flags & TRACE_ITER(COPY_MARKER))
 			return false;
 
 		list_add_rcu(&tr->marker_list, &marker_copies);
@@ -563,10 +563,10 @@ static bool update_marker_trace(struct trace_array *tr, int enabled)
 		return true;
 	}
 
-	if (list_empty(&tr->marker_list))
+	if (!(tr->trace_flags & TRACE_ITER(COPY_MARKER)))
 		return false;
 
-	list_del_init(&tr->marker_list);
+	list_del_rcu(&tr->marker_list);
 	tr->trace_flags &= ~TRACE_ITER(COPY_MARKER);
 	return true;
 }
@@ -6784,6 +6784,23 @@ char *trace_user_fault_read(struct trace_user_buf_info *tinfo,
 
 	do {
 		/*
+		 * It is possible that something is trying to migrate this
+		 * task. What happens then, is when preemption is enabled,
+		 * the migration thread will preempt this task, try to
+		 * migrate it, fail, then let it run again. That will
+		 * cause this to loop again and never succeed.
+		 * On failures, enabled and disable preemption with
+		 * migration enabled, to allow the migration thread to
+		 * migrate this task.
+		 */
+		if (trys) {
+			preempt_enable_notrace();
+			preempt_disable_notrace();
+			cpu = smp_processor_id();
+			buffer = per_cpu_ptr(tinfo->tbuf, cpu)->buf;
+		}
+
+		/*
 		 * If for some reason, copy_from_user() always causes a context
 		 * switch, this would then cause an infinite loop.
 		 * If this task is preempted by another user space task, it
@@ -9744,18 +9761,19 @@ static int __remove_instance(struct trace_array *tr)
 
 	list_del(&tr->list);
 
-	/* Disable all the flags that were enabled coming in */
-	for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) {
-		if ((1ULL << i) & ZEROED_TRACE_FLAGS)
-			set_tracer_flag(tr, 1ULL << i, 0);
-	}
-
 	if (printk_trace == tr)
 		update_printk_trace(&global_trace);
 
+	/* Must be done before disabling all the flags */
 	if (update_marker_trace(tr, 0))
 		synchronize_rcu();
 
+	/* Disable all the flags that were enabled coming in */
+	for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) {
+		if ((1ULL << i) & ZEROED_TRACE_FLAGS)
+			set_tracer_flag(tr, 1ULL << i, 0);
+	}
+
 	tracing_set_nop(tr);
 	clear_ftrace_function_probes(tr);
 	event_trace_del_tracer(tr);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index aeaec79bc09c..b77119d71641 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -190,7 +190,7 @@ struct worker_pool {
 	int			id;		/* I: pool ID */
 	unsigned int		flags;		/* L: flags */
 
-	unsigned long		watchdog_ts;	/* L: watchdog timestamp */
+	unsigned long		last_progress_ts;	/* L: last forward progress timestamp */
 	bool			cpu_stall;	/* WD: stalled cpu bound pool */
 
 	/*
@@ -1697,7 +1697,7 @@ static void __pwq_activate_work(struct pool_workqueue *pwq,
 	WARN_ON_ONCE(!(*wdb & WORK_STRUCT_INACTIVE));
 	trace_workqueue_activate_work(work);
 	if (list_empty(&pwq->pool->worklist))
-		pwq->pool->watchdog_ts = jiffies;
+		pwq->pool->last_progress_ts = jiffies;
 	move_linked_works(work, &pwq->pool->worklist, NULL);
 	__clear_bit(WORK_STRUCT_INACTIVE_BIT, wdb);
 }
@@ -2348,7 +2348,7 @@ retry:
 	 */
 	if (list_empty(&pwq->inactive_works) && pwq_tryinc_nr_active(pwq, false)) {
 		if (list_empty(&pool->worklist))
-			pool->watchdog_ts = jiffies;
+			pool->last_progress_ts = jiffies;
 
 		trace_workqueue_activate_work(work);
 		insert_work(pwq, work, &pool->worklist, work_flags);
@@ -3204,6 +3204,7 @@ __acquires(&pool->lock)
 	worker->current_pwq = pwq;
 	if (worker->task)
 		worker->current_at = worker->task->se.sum_exec_runtime;
+	worker->current_start = jiffies;
 	work_data = *work_data_bits(work);
 	worker->current_color = get_work_color(work_data);
 
@@ -3352,7 +3353,7 @@ static void process_scheduled_works(struct worker *worker)
 	while ((work = list_first_entry_or_null(&worker->scheduled,
 						struct work_struct, entry))) {
 		if (first) {
-			worker->pool->watchdog_ts = jiffies;
+			worker->pool->last_progress_ts = jiffies;
 			first = false;
 		}
 		process_one_work(worker, work);
@@ -4850,7 +4851,7 @@ static int init_worker_pool(struct worker_pool *pool)
 	pool->cpu = -1;
 	pool->node = NUMA_NO_NODE;
 	pool->flags |= POOL_DISASSOCIATED;
-	pool->watchdog_ts = jiffies;
+	pool->last_progress_ts = jiffies;
 	INIT_LIST_HEAD(&pool->worklist);
 	INIT_LIST_HEAD(&pool->idle_list);
 	hash_init(pool->busy_hash);
@@ -6274,7 +6275,7 @@ static void pr_cont_worker_id(struct worker *worker)
 {
 	struct worker_pool *pool = worker->pool;
 
-	if (pool->flags & WQ_BH)
+	if (pool->flags & POOL_BH)
 		pr_cont("bh%s",
 			pool->attrs->nice == HIGHPRI_NICE_LEVEL ? "-hi" : "");
 	else
@@ -6359,6 +6360,8 @@ static void show_pwq(struct pool_workqueue *pwq)
 			pr_cont(" %s", comma ? "," : "");
 			pr_cont_worker_id(worker);
 			pr_cont(":%ps", worker->current_func);
+			pr_cont(" for %us",
+				jiffies_to_msecs(jiffies - worker->current_start) / 1000);
 			list_for_each_entry(work, &worker->scheduled, entry)
 				pr_cont_work(false, work, &pcws);
 			pr_cont_work_flush(comma, (work_func_t)-1L, &pcws);
@@ -6462,7 +6465,7 @@ static void show_one_worker_pool(struct worker_pool *pool)
 
 	/* How long the first pending work is waiting for a worker. */
 	if (!list_empty(&pool->worklist))
-		hung = jiffies_to_msecs(jiffies - pool->watchdog_ts) / 1000;
+		hung = jiffies_to_msecs(jiffies - pool->last_progress_ts) / 1000;
 
 	/*
 	 * Defer printing to avoid deadlocks in console drivers that
@@ -7580,11 +7583,11 @@ MODULE_PARM_DESC(panic_on_stall_time, "Panic if stall exceeds this many seconds
 
 /*
  * Show workers that might prevent the processing of pending work items.
- * The only candidates are CPU-bound workers in the running state.
- * Pending work items should be handled by another idle worker
- * in all other situations.
+ * A busy worker that is not running on the CPU (e.g. sleeping in
+ * wait_event_idle() with PF_WQ_WORKER cleared) can stall the pool just as
+ * effectively as a CPU-bound one, so dump every in-flight worker.
  */
-static void show_cpu_pool_hog(struct worker_pool *pool)
+static void show_cpu_pool_busy_workers(struct worker_pool *pool)
 {
 	struct worker *worker;
 	unsigned long irq_flags;
@@ -7593,36 +7596,34 @@ static void show_cpu_pool_hog(struct worker_pool *pool)
 	raw_spin_lock_irqsave(&pool->lock, irq_flags);
 
 	hash_for_each(pool->busy_hash, bkt, worker, hentry) {
-		if (task_is_running(worker->task)) {
-			/*
-			 * Defer printing to avoid deadlocks in console
-			 * drivers that queue work while holding locks
-			 * also taken in their write paths.
-			 */
-			printk_deferred_enter();
+		/*
+		 * Defer printing to avoid deadlocks in console
+		 * drivers that queue work while holding locks
+		 * also taken in their write paths.
+		 */
+		printk_deferred_enter();
 
-			pr_info("pool %d:\n", pool->id);
-			sched_show_task(worker->task);
+		pr_info("pool %d:\n", pool->id);
+		sched_show_task(worker->task);
 
-			printk_deferred_exit();
-		}
+		printk_deferred_exit();
 	}
 
 	raw_spin_unlock_irqrestore(&pool->lock, irq_flags);
 }
 
-static void show_cpu_pools_hogs(void)
+static void show_cpu_pools_busy_workers(void)
 {
 	struct worker_pool *pool;
 	int pi;
 
-	pr_info("Showing backtraces of running workers in stalled CPU-bound worker pools:\n");
+	pr_info("Showing backtraces of busy workers in stalled worker pools:\n");
 
 	rcu_read_lock();
 
 	for_each_pool(pool, pi) {
 		if (pool->cpu_stall)
-			show_cpu_pool_hog(pool);
+			show_cpu_pool_busy_workers(pool);
 
 	}
 
@@ -7691,7 +7692,7 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
 			touched = READ_ONCE(per_cpu(wq_watchdog_touched_cpu, pool->cpu));
 		else
 			touched = READ_ONCE(wq_watchdog_touched);
-		pool_ts = READ_ONCE(pool->watchdog_ts);
+		pool_ts = READ_ONCE(pool->last_progress_ts);
 
 		if (time_after(pool_ts, touched))
 			ts = pool_ts;
@@ -7719,7 +7720,7 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
 		show_all_workqueues();
 
 	if (cpu_pool_stall)
-		show_cpu_pools_hogs();
+		show_cpu_pools_busy_workers();
 
 	if (lockup_detected)
 		panic_on_wq_watchdog(max_stall_time);
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
index f6275944ada7..8def1ddc5a1b 100644
--- a/kernel/workqueue_internal.h
+++ b/kernel/workqueue_internal.h
@@ -32,6 +32,7 @@ struct worker {
 	work_func_t		current_func;	/* K: function */
 	struct pool_workqueue	*current_pwq;	/* K: pwq */
 	u64			current_at;	/* K: runtime at start or last wakeup */
+	unsigned long		current_start;	/* K: start time of current work item */
 	unsigned int		current_color;	/* K: color */
 
 	int			sleeping;	/* S: is worker sleeping? */