4 files changed, 135 insertions, 66 deletions

diff --git a/kernel/bpf/cgroup_iter.c b/kernel/bpf/cgroup_iter.c
index 0d200a993489..9fcf09f2ef00 100644
--- a/kernel/bpf/cgroup_iter.c
+++ b/kernel/bpf/cgroup_iter.c
@@ -196,7 +196,7 @@ static int bpf_iter_attach_cgroup(struct bpf_prog *prog,
 		return -EINVAL;
 
 	if (fd)
-		cgrp = cgroup_get_from_fd(fd);
+		cgrp = cgroup_v1v2_get_from_fd(fd);
 	else if (id)
 		cgrp = cgroup_get_from_id(id);
 	else /* walk the entire hierarchy by default. */
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 7f486677ab1f..2319946715e0 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1392,6 +1392,9 @@ static void cgroup_destroy_root(struct cgroup_root *root)
 	cgroup_free_root(root);
 }
 
+/*
+ * Returned cgroup is without refcount but it's valid as long as cset pins it.
+ */
 static inline struct cgroup *__cset_cgroup_from_root(struct css_set *cset,
 					    struct cgroup_root *root)
 {
@@ -1403,6 +1406,7 @@ static inline struct cgroup *__cset_cgroup_from_root(struct css_set *cset,
 		res_cgroup = cset->dfl_cgrp;
 	} else {
 		struct cgrp_cset_link *link;
+		lockdep_assert_held(&css_set_lock);
 
 		list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
 			struct cgroup *c = link->cgrp;
@@ -1414,6 +1418,7 @@ static inline struct cgroup *__cset_cgroup_from_root(struct css_set *cset,
 		}
 	}
 
+	BUG_ON(!res_cgroup);
 	return res_cgroup;
 }
 
@@ -1436,23 +1441,36 @@ current_cgns_cgroup_from_root(struct cgroup_root *root)
 
 	rcu_read_unlock();
 
-	BUG_ON(!res);
 	return res;
 }
 
+/*
+ * Look up cgroup associated with current task's cgroup namespace on the default
+ * hierarchy.
+ *
+ * Unlike current_cgns_cgroup_from_root(), this doesn't need locks:
+ * - Internal rcu_read_lock is unnecessary because we don't dereference any rcu
+ *   pointers.
+ * - css_set_lock is not needed because we just read cset->dfl_cgrp.
+ * - As a bonus returned cgrp is pinned with the current because it cannot
+ *   switch cgroup_ns asynchronously.
+ */
+static struct cgroup *current_cgns_cgroup_dfl(void)
+{
+	struct css_set *cset;
+
+	cset = current->nsproxy->cgroup_ns->root_cset;
+	return __cset_cgroup_from_root(cset, &cgrp_dfl_root);
+}
+
 /* look up cgroup associated with given css_set on the specified hierarchy */
 static struct cgroup *cset_cgroup_from_root(struct css_set *cset,
 					    struct cgroup_root *root)
 {
-	struct cgroup *res = NULL;
-
 	lockdep_assert_held(&cgroup_mutex);
 	lockdep_assert_held(&css_set_lock);
 
-	res = __cset_cgroup_from_root(cset, root);
-
-	BUG_ON(!res);
-	return res;
+	return __cset_cgroup_from_root(cset, root);
 }
 
 /*
@@ -6191,9 +6209,7 @@ struct cgroup *cgroup_get_from_id(u64 id)
 	if (!cgrp)
 		return ERR_PTR(-ENOENT);
 
-	spin_lock_irq(&css_set_lock);
-	root_cgrp = current_cgns_cgroup_from_root(&cgrp_dfl_root);
-	spin_unlock_irq(&css_set_lock);
+	root_cgrp = current_cgns_cgroup_dfl();
 	if (!cgroup_is_descendant(cgrp, root_cgrp)) {
 		cgroup_put(cgrp);
 		return ERR_PTR(-ENOENT);
@@ -6294,16 +6310,42 @@ void cgroup_fork(struct task_struct *child)
 	INIT_LIST_HEAD(&child->cg_list);
 }
 
-static struct cgroup *cgroup_get_from_file(struct file *f)
+/**
+ * cgroup_v1v2_get_from_file - get a cgroup pointer from a file pointer
+ * @f: file corresponding to cgroup_dir
+ *
+ * Find the cgroup from a file pointer associated with a cgroup directory.
+ * Returns a pointer to the cgroup on success. ERR_PTR is returned if the
+ * cgroup cannot be found.
+ */
+static struct cgroup *cgroup_v1v2_get_from_file(struct file *f)
 {
 	struct cgroup_subsys_state *css;
-	struct cgroup *cgrp;
 
 	css = css_tryget_online_from_dir(f->f_path.dentry, NULL);
 	if (IS_ERR(css))
 		return ERR_CAST(css);
 
-	cgrp = css->cgroup;
+	return css->cgroup;
+}
+
+/**
+ * cgroup_get_from_file - same as cgroup_v1v2_get_from_file, but only supports
+ * cgroup2.
+ * @f: file corresponding to cgroup2_dir
+ */
+static struct cgroup *cgroup_get_from_file(struct file *f)
+{
+	struct cgroup *cgrp = cgroup_v1v2_get_from_file(f);
+
+	if (IS_ERR(cgrp))
+		return ERR_CAST(cgrp);
+
+	if (!cgroup_on_dfl(cgrp)) {
+		cgroup_put(cgrp);
+		return ERR_PTR(-EBADF);
+	}
+
 	return cgrp;
 }
 
@@ -6772,10 +6814,8 @@ struct cgroup *cgroup_get_from_path(const char *path)
 	struct cgroup *cgrp = ERR_PTR(-ENOENT);
 	struct cgroup *root_cgrp;
 
-	spin_lock_irq(&css_set_lock);
-	root_cgrp = current_cgns_cgroup_from_root(&cgrp_dfl_root);
+	root_cgrp = current_cgns_cgroup_dfl();
 	kn = kernfs_walk_and_get(root_cgrp->kn, path);
-	spin_unlock_irq(&css_set_lock);
 	if (!kn)
 		goto out;
 
@@ -6800,15 +6840,15 @@ out:
 EXPORT_SYMBOL_GPL(cgroup_get_from_path);
 
 /**
- * cgroup_get_from_fd - get a cgroup pointer from a fd
- * @fd: fd obtained by open(cgroup2_dir)
+ * cgroup_v1v2_get_from_fd - get a cgroup pointer from a fd
+ * @fd: fd obtained by open(cgroup_dir)
  *
  * Find the cgroup from a fd which should be obtained
  * by opening a cgroup directory.  Returns a pointer to the
  * cgroup on success. ERR_PTR is returned if the cgroup
  * cannot be found.
  */
-struct cgroup *cgroup_get_from_fd(int fd)
+struct cgroup *cgroup_v1v2_get_from_fd(int fd)
 {
 	struct cgroup *cgrp;
 	struct file *f;
@@ -6817,10 +6857,29 @@ struct cgroup *cgroup_get_from_fd(int fd)
 	if (!f)
 		return ERR_PTR(-EBADF);
 
-	cgrp = cgroup_get_from_file(f);
+	cgrp = cgroup_v1v2_get_from_file(f);
 	fput(f);
 	return cgrp;
 }
+
+/**
+ * cgroup_get_from_fd - same as cgroup_v1v2_get_from_fd, but only supports
+ * cgroup2.
+ * @fd: fd obtained by open(cgroup2_dir)
+ */
+struct cgroup *cgroup_get_from_fd(int fd)
+{
+	struct cgroup *cgrp = cgroup_v1v2_get_from_fd(fd);
+
+	if (IS_ERR(cgrp))
+		return ERR_CAST(cgrp);
+
+	if (!cgroup_on_dfl(cgrp)) {
+		cgroup_put(cgrp);
+		return ERR_PTR(-EBADF);
+	}
+	return cgrp;
+}
 EXPORT_SYMBOL_GPL(cgroup_get_from_fd);
 
 static u64 power_of_ten(int power)
diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c
index 460c12b7dfea..7971e989e425 100644
--- a/kernel/gcov/gcc_4_7.c
+++ b/kernel/gcov/gcc_4_7.c
@@ -30,6 +30,13 @@
 
 #define GCOV_TAG_FUNCTION_LENGTH	3
 
+/* Since GCC 12.1 sizes are in BYTES and not in WORDS (4B). */
+#if (__GNUC__ >= 12)
+#define GCOV_UNIT_SIZE				4
+#else
+#define GCOV_UNIT_SIZE				1
+#endif
+
 static struct gcov_info *gcov_info_head;
 
 /**
@@ -383,12 +390,18 @@ size_t convert_to_gcda(char *buffer, struct gcov_info *info)
 	pos += store_gcov_u32(buffer, pos, info->version);
 	pos += store_gcov_u32(buffer, pos, info->stamp);
 
+#if (__GNUC__ >= 12)
+	/* Use zero as checksum of the compilation unit. */
+	pos += store_gcov_u32(buffer, pos, 0);
+#endif
+
 	for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
 		fi_ptr = info->functions[fi_idx];
 
 		/* Function record. */
 		pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION);
-		pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION_LENGTH);
+		pos += store_gcov_u32(buffer, pos,
+			GCOV_TAG_FUNCTION_LENGTH * GCOV_UNIT_SIZE);
 		pos += store_gcov_u32(buffer, pos, fi_ptr->ident);
 		pos += store_gcov_u32(buffer, pos, fi_ptr->lineno_checksum);
 		pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
@@ -402,7 +415,8 @@ size_t convert_to_gcda(char *buffer, struct gcov_info *info)
 			/* Counter record. */
 			pos += store_gcov_u32(buffer, pos,
 					      GCOV_TAG_FOR_COUNTER(ct_idx));
-			pos += store_gcov_u32(buffer, pos, ci_ptr->num * 2);
+			pos += store_gcov_u32(buffer, pos,
+				ci_ptr->num * 2 * GCOV_UNIT_SIZE);
 
 			for (cv_idx = 0; cv_idx < ci_ptr->num; cv_idx++) {
 				pos += store_gcov_u64(buffer, pos,
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 7f5eb295fe19..a995ea1ef849 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -346,8 +346,40 @@ static void put_probe_ref(void)
 	mutex_unlock(&blk_probe_mutex);
 }
 
+static int blk_trace_start(struct blk_trace *bt)
+{
+	if (bt->trace_state != Blktrace_setup &&
+	    bt->trace_state != Blktrace_stopped)
+		return -EINVAL;
+
+	blktrace_seq++;
+	smp_mb();
+	bt->trace_state = Blktrace_running;
+	raw_spin_lock_irq(&running_trace_lock);
+	list_add(&bt->running_list, &running_trace_list);
+	raw_spin_unlock_irq(&running_trace_lock);
+	trace_note_time(bt);
+
+	return 0;
+}
+
+static int blk_trace_stop(struct blk_trace *bt)
+{
+	if (bt->trace_state != Blktrace_running)
+		return -EINVAL;
+
+	bt->trace_state = Blktrace_stopped;
+	raw_spin_lock_irq(&running_trace_lock);
+	list_del_init(&bt->running_list);
+	raw_spin_unlock_irq(&running_trace_lock);
+	relay_flush(bt->rchan);
+
+	return 0;
+}
+
 static void blk_trace_cleanup(struct request_queue *q, struct blk_trace *bt)
 {
+	blk_trace_stop(bt);
 	synchronize_rcu();
 	blk_trace_free(q, bt);
 	put_probe_ref();
@@ -362,8 +394,7 @@ static int __blk_trace_remove(struct request_queue *q)
 	if (!bt)
 		return -EINVAL;
 
-	if (bt->trace_state != Blktrace_running)
-		blk_trace_cleanup(q, bt);
+	blk_trace_cleanup(q, bt);
 
 	return 0;
 }
@@ -658,7 +689,6 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name,
 
 static int __blk_trace_startstop(struct request_queue *q, int start)
 {
-	int ret;
 	struct blk_trace *bt;
 
 	bt = rcu_dereference_protected(q->blk_trace,
@@ -666,36 +696,10 @@ static int __blk_trace_startstop(struct request_queue *q, int start)
 	if (bt == NULL)
 		return -EINVAL;
 
-	/*
-	 * For starting a trace, we can transition from a setup or stopped
-	 * trace. For stopping a trace, the state must be running
-	 */
-	ret = -EINVAL;
-	if (start) {
-		if (bt->trace_state == Blktrace_setup ||
-		    bt->trace_state == Blktrace_stopped) {
-			blktrace_seq++;
-			smp_mb();
-			bt->trace_state = Blktrace_running;
-			raw_spin_lock_irq(&running_trace_lock);
-			list_add(&bt->running_list, &running_trace_list);
-			raw_spin_unlock_irq(&running_trace_lock);
-
-			trace_note_time(bt);
-			ret = 0;
-		}
-	} else {
-		if (bt->trace_state == Blktrace_running) {
-			bt->trace_state = Blktrace_stopped;
-			raw_spin_lock_irq(&running_trace_lock);
-			list_del_init(&bt->running_list);
-			raw_spin_unlock_irq(&running_trace_lock);
-			relay_flush(bt->rchan);
-			ret = 0;
-		}
-	}
-
-	return ret;
+	if (start)
+		return blk_trace_start(bt);
+	else
+		return blk_trace_stop(bt);
 }
 
 int blk_trace_startstop(struct request_queue *q, int start)
@@ -772,10 +776,8 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
 void blk_trace_shutdown(struct request_queue *q)
 {
 	if (rcu_dereference_protected(q->blk_trace,
-				      lockdep_is_held(&q->debugfs_mutex))) {
-		__blk_trace_startstop(q, 0);
+				      lockdep_is_held(&q->debugfs_mutex)))
 		__blk_trace_remove(q);
-	}
 }
 
 #ifdef CONFIG_BLK_CGROUP
@@ -1614,13 +1616,7 @@ static int blk_trace_remove_queue(struct request_queue *q)
 	if (bt == NULL)
 		return -EINVAL;
 
-	if (bt->trace_state == Blktrace_running) {
-		bt->trace_state = Blktrace_stopped;
-		raw_spin_lock_irq(&running_trace_lock);
-		list_del_init(&bt->running_list);
-		raw_spin_unlock_irq(&running_trace_lock);
-		relay_flush(bt->rchan);
-	}
+	blk_trace_stop(bt);
 
 	put_probe_ref();
 	synchronize_rcu();