From: Daniel Borkmann <daniel@iogearbox.net>
Date: Fri, 22 Nov 2019 21:07:55 +0100
Subject: bpf: Move bpf_free_used_maps into sleepable section
Patch-mainline: v5.5-rc1
Git-commit: 6332be04c039a72fca32ed0a4265bac58d606bb6
References: bsc#1154353

We later on are going to need a sleepable context as opposed to plain
RCU callback in order to untrack programs we need to poke at runtime
and tracking as well as image update is performed under mutex.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/09823b1d5262876e9b83a8e75df04cf0467357a4.1574452833.git.daniel@iogearbox.net
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/linux/bpf.h  |    4 ++++
 kernel/bpf/core.c    |   23 +++++++++++++++++++++++
 kernel/bpf/syscall.c |   20 --------------------
 3 files changed, 27 insertions(+), 20 deletions(-)

--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1031,6 +1031,10 @@ static inline int bpf_prog_test_run_flow
 {
 	return -ENOTSUPP;
 }
+
+static inline void bpf_map_put(struct bpf_map *map)
+{
+}
 #endif /* CONFIG_BPF_SYSCALL */
 
 static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2003,12 +2003,35 @@ int bpf_prog_array_copy_info(struct bpf_
 								     : 0;
 }
 
+static void bpf_free_cgroup_storage(struct bpf_prog_aux *aux)
+{
+	enum bpf_cgroup_storage_type stype;
+
+	for_each_cgroup_storage_type(stype) {
+		if (!aux->cgroup_storage[stype])
+			continue;
+		bpf_cgroup_storage_release(aux->prog,
+					   aux->cgroup_storage[stype]);
+	}
+}
+
+static void bpf_free_used_maps(struct bpf_prog_aux *aux)
+{
+	int i;
+
+	bpf_free_cgroup_storage(aux);
+	for (i = 0; i < aux->used_map_cnt; i++)
+		bpf_map_put(aux->used_maps[i]);
+	kfree(aux->used_maps);
+}
+
 static void bpf_prog_free_deferred(struct work_struct *work)
 {
 	struct bpf_prog_aux *aux;
 	int i;
 
 	aux = container_of(work, struct bpf_prog_aux, work);
+	bpf_free_used_maps(aux);
 	if (bpf_prog_is_dev_bound(aux))
 		bpf_prog_offload_destroy(aux->prog);
 #ifdef CONFIG_PERF_EVENTS
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1302,25 +1302,6 @@ static int find_prog_type(enum bpf_prog_
 	return 0;
 }
 
-/* drop refcnt on maps used by eBPF program and free auxilary data */
-static void free_used_maps(struct bpf_prog_aux *aux)
-{
-	enum bpf_cgroup_storage_type stype;
-	int i;
-
-	for_each_cgroup_storage_type(stype) {
-		if (!aux->cgroup_storage[stype])
-			continue;
-		bpf_cgroup_storage_release(aux->prog,
-					   aux->cgroup_storage[stype]);
-	}
-
-	for (i = 0; i < aux->used_map_cnt; i++)
-		bpf_map_put(aux->used_maps[i]);
-
-	kfree(aux->used_maps);
-}
-
 int __bpf_prog_charge(struct user_struct *user, u32 pages)
 {
 	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
@@ -1415,7 +1396,6 @@ static void __bpf_prog_put_rcu(struct rc
 
 	kvfree(aux->func_info);
 	kfree(aux->func_info_aux);
-	free_used_maps(aux);
 	bpf_prog_uncharge_memlock(aux->prog);
 	security_bpf_prog_free(aux);
 	bpf_prog_free(aux->prog);