Merge tag 'bpf-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Add BPF uprobe session support (Jiri Olsa)

 - Optimize uprobe performance (Andrii Nakryiko)

 - Add bpf_fastcall support to helpers and kfuncs (Eduard Zingerman)

 - Avoid calling free_htab_elem() under hash map bucket lock (Hou Tao)

 - Prevent tailcall infinite loop caused by freplace (Leon Hwang)

 - Mark raw_tracepoint arguments as nullable (Kumar Kartikeya Dwivedi)

 - Introduce uptr support in the task local storage map (Martin KaFai
   Lau)

 - Stringify errno log messages in libbpf (Mykyta Yatsenko)

 - Add kmem_cache BPF iterator for perf's lock profiling (Namhyung Kim)

 - Support BPF objects of either endianness in libbpf (Tony Ambardar)

 - Add ksym to struct_ops trampoline to fix stack trace (Xu Kuohai)

 - Introduce private stack for eligible BPF programs (Yonghong Song)

 - Migrate samples/bpf tests to selftests/bpf test_progs (Daniel T. Lee)

 - Migrate test_sock to selftests/bpf test_progs (Jordan Rife)

* tag 'bpf-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (152 commits)
  libbpf: Change hash_combine parameters from long to unsigned long
  selftests/bpf: Fix build error with llvm 19
  libbpf: Fix memory leak in bpf_program__attach_uprobe_multi
  bpf: use common instruction history across all states
  bpf: Add necessary migrate_disable to range_tree.
  bpf: Do not alloc arena on unsupported arches
  selftests/bpf: Set test path for token/obj_priv_implicit_token_envvar
  selftests/bpf: Add a test for arena range tree algorithm
  bpf: Introduce range_tree data structure and use it in bpf arena
  samples/bpf: Remove unused variable in xdp2skb_meta_kern.c
  samples/bpf: Remove unused variables in tc_l2_redirect_kern.c
  bpftool: Cast variable `var` to long long
  bpf, x86: Propagate tailcall info only for subprogs
  bpf: Add kernel symbol for struct_ops trampoline
  bpf: Use function pointers count as struct_ops links count
  bpf: Remove unused member rcu from bpf_struct_ops_map
  selftests/bpf: Add struct_ops prog private stack tests
  bpf: Support private stack for struct_ops progs
  selftests/bpf: Add tracing prog private stack tests
  bpf, x86: Support private stack in jit
  ...

1 files changed, 39 insertions, 17 deletions

diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index b14b87463ee0..3ec941a0ea41 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -896,9 +896,12 @@ find_first_elem:
 static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
 {
 	check_and_free_fields(htab, l);
+
+	migrate_disable();
 	if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
 		bpf_mem_cache_free(&htab->pcpu_ma, l->ptr_to_pptr);
 	bpf_mem_cache_free(&htab->ma, l);
+	migrate_enable();
 }
 
 static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
@@ -948,7 +951,7 @@ static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
 	if (htab_is_prealloc(htab)) {
 		bpf_map_dec_elem_count(&htab->map);
 		check_and_free_fields(htab, l);
-		__pcpu_freelist_push(&htab->freelist, &l->fnode);
+		pcpu_freelist_push(&htab->freelist, &l->fnode);
 	} else {
 		dec_elem_count(htab);
 		htab_elem_free(htab, l);
@@ -1018,7 +1021,6 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
 			 */
 			pl_new = this_cpu_ptr(htab->extra_elems);
 			l_new = *pl_new;
-			htab_put_fd_value(htab, old_elem);
 			*pl_new = old_elem;
 		} else {
 			struct pcpu_freelist_node *l;
@@ -1105,6 +1107,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
 	struct htab_elem *l_new = NULL, *l_old;
 	struct hlist_nulls_head *head;
 	unsigned long flags;
+	void *old_map_ptr;
 	struct bucket *b;
 	u32 key_size, hash;
 	int ret;
@@ -1183,12 +1186,27 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
 	hlist_nulls_add_head_rcu(&l_new->hash_node, head);
 	if (l_old) {
 		hlist_nulls_del_rcu(&l_old->hash_node);
+
+		/* l_old has already been stashed in htab->extra_elems, free
+		 * its special fields before it is available for reuse. Also
+		 * save the old map pointer in htab of maps before unlock
+		 * and release it after unlock.
+		 */
+		old_map_ptr = NULL;
+		if (htab_is_prealloc(htab)) {
+			if (map->ops->map_fd_put_ptr)
+				old_map_ptr = fd_htab_map_get_ptr(map, l_old);
+			check_and_free_fields(htab, l_old);
+		}
+	}
+	htab_unlock_bucket(htab, b, hash, flags);
+	if (l_old) {
+		if (old_map_ptr)
+			map->ops->map_fd_put_ptr(map, old_map_ptr, true);
 		if (!htab_is_prealloc(htab))
 			free_htab_elem(htab, l_old);
-		else
-			check_and_free_fields(htab, l_old);
 	}
-	ret = 0;
+	return 0;
 err:
 	htab_unlock_bucket(htab, b, hash, flags);
 	return ret;
@@ -1432,15 +1450,15 @@ static long htab_map_delete_elem(struct bpf_map *map, void *key)
 		return ret;
 
 	l = lookup_elem_raw(head, hash, key, key_size);
-
-	if (l) {
+	if (l)
 		hlist_nulls_del_rcu(&l->hash_node);
-		free_htab_elem(htab, l);
-	} else {
+	else
 		ret = -ENOENT;
-	}
 
 	htab_unlock_bucket(htab, b, hash, flags);
+
+	if (l)
+		free_htab_elem(htab, l);
 	return ret;
 }
 
@@ -1853,13 +1871,14 @@ again_nocopy:
 			 * may cause deadlock. See comments in function
 			 * prealloc_lru_pop(). Let us do bpf_lru_push_free()
 			 * after releasing the bucket lock.
+			 *
+			 * For htab of maps, htab_put_fd_value() in
+			 * free_htab_elem() may acquire a spinlock with bucket
+			 * lock being held and it violates the lock rule, so
+			 * invoke free_htab_elem() after unlock as well.
 			 */
-			if (is_lru_map) {
-				l->batch_flink = node_to_free;
-				node_to_free = l;
-			} else {
-				free_htab_elem(htab, l);
-			}
+			l->batch_flink = node_to_free;
+			node_to_free = l;
 		}
 		dst_key += key_size;
 		dst_val += value_size;
@@ -1871,7 +1890,10 @@ again_nocopy:
 	while (node_to_free) {
 		l = node_to_free;
 		node_to_free = node_to_free->batch_flink;
-		htab_lru_push_free(htab, l);
+		if (is_lru_map)
+			htab_lru_push_free(htab, l);
+		else
+			free_htab_elem(htab, l);
 	}
 
 next_batch: