Patch "bpftool: Fix pretty print dump for maps without BTF loaded" has been added to the 5.17-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    bpftool: Fix pretty print dump for maps without BTF loaded

to the 5.17-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     bpftool-fix-pretty-print-dump-for-maps-without-btf-l.patch
and it can be found in the queue-5.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 103a4cfba70ad57bdcb646208bcb5514d37e44e1
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
Date:   Wed Feb 16 10:21:02 2022 +0100

    bpftool: Fix pretty print dump for maps without BTF loaded
    
    [ Upstream commit f76d8507d23834f7e56b0fe95c82605e7d7e0efe ]
    
    The commit e5043894b21f ("bpftool: Use libbpf_get_error() to check error")
    fails to dump map without BTF loaded in pretty mode (-p option).
    
    Fixing this by making sure get_map_kv_btf won't fail in case there's
    no BTF available for the map.
    
    Fixes: e5043894b21f ("bpftool: Use libbpf_get_error() to check error")
    Suggested-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
    Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
    Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
    Link: https://lore.kernel.org/bpf/20220216092102.125448-1-jolsa@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 7a341a472ea4..e746642de292 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -805,29 +805,30 @@ static int maps_have_btf(int *fds, int nb_fds)
 
 static struct btf *btf_vmlinux;
 
-static struct btf *get_map_kv_btf(const struct bpf_map_info *info)
+static int get_map_kv_btf(const struct bpf_map_info *info, struct btf **btf)
 {
-	struct btf *btf = NULL;
+	int err = 0;
 
 	if (info->btf_vmlinux_value_type_id) {
 		if (!btf_vmlinux) {
 			btf_vmlinux = libbpf_find_kernel_btf();
-			if (libbpf_get_error(btf_vmlinux))
+			err = libbpf_get_error(btf_vmlinux);
+			if (err) {
 				p_err("failed to get kernel btf");
+				return err;
+			}
 		}
-		return btf_vmlinux;
+		*btf = btf_vmlinux;
 	} else if (info->btf_value_type_id) {
-		int err;
-
-		btf = btf__load_from_kernel_by_id(info->btf_id);
-		err = libbpf_get_error(btf);
-		if (err) {
+		*btf = btf__load_from_kernel_by_id(info->btf_id);
+		err = libbpf_get_error(*btf);
+		if (err)
 			p_err("failed to get btf");
-			btf = ERR_PTR(err);
-		}
+	} else {
+		*btf = NULL;
 	}
 
-	return btf;
+	return err;
 }
 
 static void free_map_kv_btf(struct btf *btf)
@@ -862,8 +863,7 @@ map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr,
 	prev_key = NULL;
 
 	if (wtr) {
-		btf = get_map_kv_btf(info);
-		err = libbpf_get_error(btf);
+		err = get_map_kv_btf(info, &btf);
 		if (err) {
 			goto exit_free;
 		}
@@ -1054,8 +1054,7 @@ static void print_key_value(struct bpf_map_info *info, void *key,
 	json_writer_t *btf_wtr;
 	struct btf *btf;
 
-	btf = get_map_kv_btf(info);
-	if (libbpf_get_error(btf))
+	if (get_map_kv_btf(info, &btf))
 		return;
 
 	if (json_output) {