strace/bpf-add-support-for-btf_-fields-in-BPF_MAP_CREATE.patch

From 14a9b6ca66109fc1231eb16e98a9ce4262fb610c Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Tue, 12 Mar 2019 11:17:20 +0000
Subject: [PATCH 269/293] bpf: add support for btf_* fields in BPF_MAP_CREATE

* bpf_attr.h (struct BPF_MAP_CREATE_struct): Add btf_fd,
btf_key_type_id, and btf_value_type_id fields.
* bpf.c (BEGIN_BPF_CMD_DECODER(BPF_MAP_CREATE)): Decode btf_fd,
btf_key_type_id, and btf_value_type_id fields introduced by Linux
commits v4.18-rc1~114^2~417^2~1^2~3 and v4.18-rc1~114^2~148^2~7^2~2.
* tests/bpf.c (BPF_MAP_CREATE_checks): Check it.
* tests/bpf-obj_get_info_by_fd.c (print_map_create): Update expected
output.
---
 bpf.c                          | 10 ++++++++++
 bpf_attr.h                     |  5 ++++-
 tests/bpf-obj_get_info_by_fd.c |  4 ++++
 tests/bpf.c                    | 20 ++++++++++++++++++++
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/bpf.c b/bpf.c
index 6fb4c2c..bf7cd6c 100644
--- a/bpf.c
+++ b/bpf.c
@@ -232,6 +232,16 @@ BEGIN_BPF_CMD_DECODER(BPF_MAP_CREATE)
 	if (len <= offsetof(struct BPF_MAP_CREATE_struct, map_ifindex))
 		break;
 	PRINT_FIELD_IFINDEX(", ", attr, map_ifindex);
+
+	/*
+	 * The following three fields were introduced by Linux commits
+	 * v4.18-rc1~114^2~417^2~1^2~3 and v4.18-rc1~114^2~148^2~7^2~2.
+	 */
+	if (len <= offsetof(struct BPF_MAP_CREATE_struct, btf_fd))
+		break;
+	PRINT_FIELD_FD(", ", attr, btf_fd, tcp);
+	PRINT_FIELD_U(", ", attr, btf_key_type_id);
+	PRINT_FIELD_U(", ", attr, btf_value_type_id);
 }
 END_BPF_CMD_DECODER(RVAL_DECODED | RVAL_FD)
 
diff --git a/bpf_attr.h b/bpf_attr.h
index cb49896..a789d10 100644
--- a/bpf_attr.h
+++ b/bpf_attr.h
@@ -65,11 +65,14 @@ struct BPF_MAP_CREATE_struct {
 	uint32_t numa_node;
 	char     map_name[BPF_OBJ_NAME_LEN];
 	uint32_t map_ifindex;
+	uint32_t btf_fd;
+	uint32_t btf_key_type_id;
+	uint32_t btf_value_type_id;
 };
 
 #define BPF_MAP_CREATE_struct_size \
 	sizeof(struct BPF_MAP_CREATE_struct)
-#define expected_BPF_MAP_CREATE_struct_size 48
+#define expected_BPF_MAP_CREATE_struct_size 60
 
 struct BPF_MAP_LOOKUP_ELEM_struct {
 	uint32_t map_fd;
diff --git a/tests/bpf-obj_get_info_by_fd.c b/tests/bpf-obj_get_info_by_fd.c
index ff06e27..02d14e5 100644
--- a/tests/bpf-obj_get_info_by_fd.c
+++ b/tests/bpf-obj_get_info_by_fd.c
@@ -103,6 +103,10 @@ print_map_create(void *attr_void, size_t size, long rc)
 		printf(", map_name=\"test_map\"");
 	if (size > offsetof(struct BPF_MAP_CREATE_struct, map_ifindex))
 		printf(", map_ifindex=0");
+	if (size > offsetof(struct BPF_MAP_CREATE_struct, btf_fd)) {
+		printf(", btf_fd=0</dev/null>"
+		       ", btf_key_type_id=0, btf_value_type_id=0");
+	}
 	printf("}, %zu) = ", size);
 	if (rc >= 0)
 		printf("%ld<anon_inode:bpf-map>\n", rc);
diff --git a/tests/bpf.c b/tests/bpf.c
index cfed319..b18a056 100644
--- a/tests/bpf.c
+++ b/tests/bpf.c
@@ -420,6 +420,26 @@ static struct bpf_attr_check BPF_MAP_CREATE_checks[] = {
 		       ", map_ifindex=" IFINDEX_LO_STR,
 		.init_fn = init_BPF_MAP_CREATE_attr7,
 	},
+	{ /* 8 */
+		.data = { .BPF_MAP_CREATE_data = {
+			.btf_fd = 0xbadc0ded,
+			.btf_key_type_id = 0xfacefeed,
+			.btf_value_type_id = 0xcafef00d
+		} },
+		.size = offsetofend(struct BPF_MAP_CREATE_struct,
+				    btf_value_type_id),
+		.str = "map_type=BPF_MAP_TYPE_UNSPEC"
+		       ", key_size=0"
+		       ", value_size=0"
+		       ", max_entries=0"
+		       ", map_flags=0"
+		       ", inner_map_fd=0"
+		       ", map_name=\"\""
+		       ", map_ifindex=0"
+		       ", btf_fd=-1159983635"
+		       ", btf_key_type_id=4207869677"
+		       ", btf_value_type_id=3405705229"
+	},
 };
 
 static const struct bpf_attr_check BPF_MAP_LOOKUP_ELEM_checks[] = {
-- 
1.7.12.4