From 995ae92b500bf8dbbd1024209e1914aa81ac2b42 Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Wed, 4 Apr 2018 14:50:07 +0000
Subject: [PATCH] bpf_attr: add more size checks

* bpf_attr.h: Add expected sizes of structures.
* gen_bpf_attr_check.sh: Check them.
---
 bpf_attr.h            | 14 ++++++++++++++
 gen_bpf_attr_check.sh |  6 ++++++
 2 files changed, 20 insertions(+)

diff --git a/bpf_attr.h b/bpf_attr.h
index 8ecd6a3a..f284e6d3 100644
--- a/bpf_attr.h
+++ b/bpf_attr.h
@@ -40,6 +40,7 @@ struct BPF_MAP_CREATE_struct {
 
 #define BPF_MAP_CREATE_struct_size \
 	sizeof(struct BPF_MAP_CREATE_struct)
+#define expected_BPF_MAP_CREATE_struct_size 28
 
 struct BPF_MAP_LOOKUP_ELEM_struct {
 	uint32_t map_fd;
@@ -49,6 +50,7 @@ struct BPF_MAP_LOOKUP_ELEM_struct {
 
 #define BPF_MAP_LOOKUP_ELEM_struct_size \
 	sizeof(struct BPF_MAP_LOOKUP_ELEM_struct)
+#define expected_BPF_MAP_LOOKUP_ELEM_struct_size 24
 
 struct BPF_MAP_UPDATE_ELEM_struct {
 	uint32_t map_fd;
@@ -59,6 +61,7 @@ struct BPF_MAP_UPDATE_ELEM_struct {
 
 #define BPF_MAP_UPDATE_ELEM_struct_size \
 	sizeof(struct BPF_MAP_UPDATE_ELEM_struct)
+#define expected_BPF_MAP_UPDATE_ELEM_struct_size 32
 
 struct BPF_MAP_DELETE_ELEM_struct {
 	uint32_t map_fd;
@@ -67,6 +70,7 @@ struct BPF_MAP_DELETE_ELEM_struct {
 
 #define BPF_MAP_DELETE_ELEM_struct_size \
 	sizeof(struct BPF_MAP_DELETE_ELEM_struct)
+#define expected_BPF_MAP_DELETE_ELEM_struct_size 16
 
 struct BPF_MAP_GET_NEXT_KEY_struct {
 	uint32_t map_fd;
@@ -76,6 +80,7 @@ struct BPF_MAP_GET_NEXT_KEY_struct {
 
 #define BPF_MAP_GET_NEXT_KEY_struct_size \
 	sizeof(struct BPF_MAP_GET_NEXT_KEY_struct)
+#define expected_BPF_MAP_GET_NEXT_KEY_struct_size 24
 
 struct BPF_PROG_LOAD_struct {
 	uint32_t prog_type;
@@ -91,6 +96,7 @@ struct BPF_PROG_LOAD_struct {
 
 #define BPF_PROG_LOAD_struct_size \
 	sizeof(struct BPF_PROG_LOAD_struct)
+#define expected_BPF_PROG_LOAD_struct_size 48
 
 struct BPF_OBJ_PIN_struct {
 	uint64_t ATTRIBUTE_ALIGNED(8) pathname;
@@ -99,6 +105,7 @@ struct BPF_OBJ_PIN_struct {
 
 #define BPF_OBJ_PIN_struct_size \
 	offsetofend(struct BPF_OBJ_PIN_struct, bpf_fd)
+#define expected_BPF_OBJ_PIN_struct_size 12
 
 #define BPF_OBJ_GET_struct BPF_OBJ_PIN_struct
 #define BPF_OBJ_GET_struct_size BPF_OBJ_PIN_struct_size
@@ -112,6 +119,7 @@ struct BPF_PROG_ATTACH_struct {
 
 #define BPF_PROG_ATTACH_struct_size \
 	sizeof(struct BPF_PROG_ATTACH_struct)
+#define expected_BPF_PROG_ATTACH_struct_size 16
 
 struct BPF_PROG_DETACH_struct {
 	uint32_t target_fd;
@@ -121,6 +129,7 @@ struct BPF_PROG_DETACH_struct {
 
 #define BPF_PROG_DETACH_struct_size \
 	sizeof(struct BPF_PROG_DETACH_struct)
+#define expected_BPF_PROG_DETACH_struct_size 12
 
 struct BPF_PROG_TEST_RUN_struct /* test */ {
 	uint32_t prog_fd;
@@ -135,6 +144,7 @@ struct BPF_PROG_TEST_RUN_struct /* test */ {
 
 #define BPF_PROG_TEST_RUN_struct_size \
 	sizeof(struct BPF_PROG_TEST_RUN_struct)
+#define expected_BPF_PROG_TEST_RUN_struct_size 40
 
 struct BPF_PROG_GET_NEXT_ID_struct {
 	uint32_t start_id;
@@ -143,6 +153,7 @@ struct BPF_PROG_GET_NEXT_ID_struct {
 
 #define BPF_PROG_GET_NEXT_ID_struct_size \
 	sizeof(struct BPF_PROG_GET_NEXT_ID_struct)
+#define expected_BPF_PROG_GET_NEXT_ID_struct_size 8
 
 #define BPF_MAP_GET_NEXT_ID_struct BPF_PROG_GET_NEXT_ID_struct
 #define BPF_MAP_GET_NEXT_ID_struct_size BPF_PROG_GET_NEXT_ID_struct_size
@@ -154,6 +165,7 @@ struct BPF_PROG_GET_FD_BY_ID_struct {
 
 #define BPF_PROG_GET_FD_BY_ID_struct_size \
 	sizeof(struct BPF_PROG_GET_FD_BY_ID_struct)
+#define expected_BPF_PROG_GET_FD_BY_ID_struct_size 8
 
 struct BPF_MAP_GET_FD_BY_ID_struct {
 	uint32_t map_id;
@@ -162,6 +174,7 @@ struct BPF_MAP_GET_FD_BY_ID_struct {
 
 #define BPF_MAP_GET_FD_BY_ID_struct_size \
 	sizeof(struct BPF_MAP_GET_FD_BY_ID_struct)
+#define expected_BPF_MAP_GET_FD_BY_ID_struct_size 8
 
 struct BPF_OBJ_GET_INFO_BY_FD_struct /* info */ {
 	uint32_t bpf_fd;
@@ -171,5 +184,6 @@ struct BPF_OBJ_GET_INFO_BY_FD_struct /* info */ {
 
 #define BPF_OBJ_GET_INFO_BY_FD_struct_size \
 	sizeof(struct BPF_OBJ_GET_INFO_BY_FD_struct)
+#define expected_BPF_OBJ_GET_INFO_BY_FD_struct_size 16
 
 #endif /* !STRACE_BPF_ATTR_H */
diff --git a/gen_bpf_attr_check.sh b/gen_bpf_attr_check.sh
index 8c7730e7..9da75ad9 100755
--- a/gen_bpf_attr_check.sh
+++ b/gen_bpf_attr_check.sh
@@ -57,6 +57,12 @@ for struct in $(sed -n 's/^struct \(BPF_[^[:space:]]\+_struct\) .*/\1/p' < "$inp
 # endif /* HAVE_UNION_BPF_ATTR_$ENUM$FIELD */
 EOF
 	done
+		cat <<EOF
+
+static_assert(${struct}_size == expected_${struct}_size,
+	      "${struct}_size mismatch");
+EOF
+
 done
 
 cat <<'EOF'
-- 
2.40.0