Merge branch 'bpf-btf-size-verification-fix'

Andrii Nakryiko says:

====================
BTF size resolution logic isn't always resolving type size correctly, leading
to erroneous map creation failures due to value size mismatch.

This patch set:
1. fixes the issue (patch #1);
2. adds tests for trickier cases (patch #2);
3. and converts few test cases utilizing BTF-defined maps, that previously
   couldn't use typedef'ed arrays due to kernel bug (patch #3).
====================

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

4 files changed, 92 insertions, 4 deletions

diff --git a/tools/testing/selftests/bpf/progs/test_get_stack_rawtp.c b/tools/testing/selftests/bpf/progs/test_get_stack_rawtp.c
index d06b47a09097..33254b771384 100644
--- a/tools/testing/selftests/bpf/progs/test_get_stack_rawtp.c
+++ b/tools/testing/selftests/bpf/progs/test_get_stack_rawtp.c
@@ -47,11 +47,12 @@ struct {
  * issue and avoid complicated C programming massaging.
  * This is an acceptable workaround since there is one entry here.
  */
+typedef __u64 raw_stack_trace_t[2 * MAX_STACK_RAWTP];
 struct {
 	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
 	__uint(max_entries, 1);
 	__type(key, __u32);
-	__u64 (*value)[2 * MAX_STACK_RAWTP];
+	__type(value, raw_stack_trace_t);
 } rawdata_map SEC(".maps");
 
 SEC("tracepoint/raw_syscalls/sys_enter")
diff --git a/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c
index bbfc8337b6f0..f5638e26865d 100644
--- a/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c
+++ b/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c
@@ -36,8 +36,7 @@ struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, 128);
 	__type(key, __u32);
-	/* there seems to be a bug in kernel not handling typedef properly */
-	struct bpf_stack_build_id (*value)[PERF_MAX_STACK_DEPTH];
+	__type(value, stack_trace_t);
 } stack_amap SEC(".maps");
 
 /* taken from /sys/kernel/debug/tracing/events/random/urandom_read/format */
diff --git a/tools/testing/selftests/bpf/progs/test_stacktrace_map.c b/tools/testing/selftests/bpf/progs/test_stacktrace_map.c
index 803c15dc109d..fa0be3e10a10 100644
--- a/tools/testing/selftests/bpf/progs/test_stacktrace_map.c
+++ b/tools/testing/selftests/bpf/progs/test_stacktrace_map.c
@@ -35,7 +35,7 @@ struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, 16384);
 	__type(key, __u32);
-	__u64 (*value)[PERF_MAX_STACK_DEPTH];
+	__type(value, stack_trace_t);
 } stack_amap SEC(".maps");
 
 /* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c
index 8351cb5f4a20..3d617e806054 100644
--- a/tools/testing/selftests/bpf/test_btf.c
+++ b/tools/testing/selftests/bpf/test_btf.c
@@ -3417,6 +3417,94 @@ static struct btf_raw_test raw_tests[] = {
 	.value_type_id = 1,
 	.max_entries = 4,
 },
+/*
+ * typedef int arr_t[16];
+ * struct s {
+ *	arr_t *a;
+ * };
+ */
+{
+	.descr = "struct->ptr->typedef->array->int size resolution",
+	.raw_types = {
+		BTF_STRUCT_ENC(NAME_TBD, 1, 8),			/* [1] */
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),
+		BTF_PTR_ENC(3),					/* [2] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 4),			/* [3] */
+		BTF_TYPE_ARRAY_ENC(5, 5, 16),			/* [4] */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [5] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0s\0a\0arr_t"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "ptr_mod_chain_size_resolve_map",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int) * 16,
+	.key_type_id = 5 /* int */,
+	.value_type_id = 3 /* arr_t */,
+	.max_entries = 4,
+},
+/*
+ * typedef int arr_t[16][8][4];
+ * struct s {
+ *	arr_t *a;
+ * };
+ */
+{
+	.descr = "struct->ptr->typedef->multi-array->int size resolution",
+	.raw_types = {
+		BTF_STRUCT_ENC(NAME_TBD, 1, 8),			/* [1] */
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),
+		BTF_PTR_ENC(3),					/* [2] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 4),			/* [3] */
+		BTF_TYPE_ARRAY_ENC(5, 7, 16),			/* [4] */
+		BTF_TYPE_ARRAY_ENC(6, 7, 8),			/* [5] */
+		BTF_TYPE_ARRAY_ENC(7, 7, 4),			/* [6] */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [7] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0s\0a\0arr_t"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "multi_arr_size_resolve_map",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int) * 16 * 8 * 4,
+	.key_type_id = 7 /* int */,
+	.value_type_id = 3 /* arr_t */,
+	.max_entries = 4,
+},
+/*
+ * typedef int int_t;
+ * typedef int_t arr3_t[4];
+ * typedef arr3_t arr2_t[8];
+ * typedef arr2_t arr1_t[16];
+ * struct s {
+ *	arr1_t *a;
+ * };
+ */
+{
+	.descr = "typedef/multi-arr mix size resolution",
+	.raw_types = {
+		BTF_STRUCT_ENC(NAME_TBD, 1, 8),			/* [1] */
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),
+		BTF_PTR_ENC(3),					/* [2] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 4),			/* [3] */
+		BTF_TYPE_ARRAY_ENC(5, 10, 16),			/* [4] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 6),			/* [5] */
+		BTF_TYPE_ARRAY_ENC(7, 10, 8),			/* [6] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 8),			/* [7] */
+		BTF_TYPE_ARRAY_ENC(9, 10, 4),			/* [8] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 10),			/* [9] */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [10] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0s\0a\0arr1_t\0arr2_t\0arr3_t\0int_t"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "typedef_arra_mix_size_resolve_map",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int) * 16 * 8 * 4,
+	.key_type_id = 10 /* int */,
+	.value_type_id = 3 /* arr_t */,
+	.max_entries = 4,
+},
 
 }; /* struct btf_raw_test raw_tests[] */