Merge branch 'btf-check-name'

Yonghong Song says:

====================
This patch set added name checking for PTR, ARRAY, VOLATILE, TYPEDEF,
CONST, RESTRICT, STRUCT, UNION, ENUM and FWD types. Such a strict
name checking makes BTF more sound in the kernel and future
BTF-to-header-file converesion ([1]) less fragile.

Patch #1 implemented btf_name_valid_identifier() for name checking
which will be used in Patch #2.
Patch #2 checked name validity for the above mentioned types.
Patch #3 fixed two existing test_btf unit tests exposed by the strict
name checking.
Patch #4 added additional test cases.

This patch set is against bpf tree.

Patch #1 has been implemented in bpf-next commit
Commit 2667a2626f4d ("bpf: btf: Add BTF_KIND_FUNC
and BTF_KIND_FUNC_PROTO"), so there is no need to apply this
patch to bpf-next. In case this patch is applied to bpf-next,
there will be a minor conflict like
  diff --cc kernel/bpf/btf.c
  index a09b2f94ab25,93c233ab2db6..000000000000
  --- a/kernel/bpf/btf.c
  +++ b/kernel/bpf/btf.c
  @@@ -474,7 -451,7 +474,11 @@@ static bool btf_name_valid_identifier(c
          return !*src;
    }

  ++<<<<<<< HEAD
   +const char *btf_name_by_offset(const struct btf *btf, u32 offset)
  ++=======
  + static const char *btf_name_by_offset(const struct btf *btf, u32 offset)
  ++>>>>>>> fa9566b0847d... bpf: btf: implement btf_name_valid_identifier()
    {
          if (!offset)
                  return "(anon)";
Just resolve the conflict by taking the "const char ..." line.

Patches #2, #3 and #4 can be applied to bpf-next without conflict.

[1]: http://vger.kernel.org/lpc-bpf2018.html#session-2
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 368 insertions, 7 deletions

diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c
index f42b3396d622..38e1cbaaffdb 100644
--- a/tools/testing/selftests/bpf/test_btf.c
+++ b/tools/testing/selftests/bpf/test_btf.c
@@ -432,11 +432,11 @@ static struct btf_raw_test raw_tests[] = {
 		/* const void* */	/* [3] */
 		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2),
 		/* typedef const void * const_void_ptr */
-		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 3),
-		/* struct A { */	/* [4] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 3),	/* [4] */
+		/* struct A { */	/* [5] */
 		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), sizeof(void *)),
 		/* const_void_ptr m; */
-		BTF_MEMBER_ENC(NAME_TBD, 3, 0),
+		BTF_MEMBER_ENC(NAME_TBD, 4, 0),
 		/* } */
 		BTF_END_RAW,
 	},
@@ -494,10 +494,10 @@ static struct btf_raw_test raw_tests[] = {
 		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_CONST, 0, 0), 0),
 		/* const void* */	/* [3] */
 		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2),
-		/* typedef const void * const_void_ptr */	/* [4] */
-		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 3),
-		/* const_void_ptr[4] */	/* [5] */
-		BTF_TYPE_ARRAY_ENC(3, 1, 4),
+		/* typedef const void * const_void_ptr */
+		BTF_TYPEDEF_ENC(NAME_TBD, 3),	/* [4] */
+		/* const_void_ptr[4] */
+		BTF_TYPE_ARRAY_ENC(4, 1, 4),	/* [5] */
 		BTF_END_RAW,
 	},
 	.str_sec = "\0const_void_ptr",
@@ -1293,6 +1293,367 @@ static struct btf_raw_test raw_tests[] = {
 },
 
 {
+	.descr = "typedef (invalid name, name_off = 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_TYPEDEF_ENC(0, 1),				/* [2] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__int",
+	.str_sec_size = sizeof("\0__int"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "typedef_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "typedef (invalid name, invalid identifier)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 1),			/* [2] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__!int",
+	.str_sec_size = sizeof("\0__!int"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "typedef_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "ptr type (invalid name, name_off <> 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 1),	/* [2] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__int",
+	.str_sec_size = sizeof("\0__int"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "ptr_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "volatile type (invalid name, name_off <> 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_VOLATILE, 0, 0), 1),	/* [2] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__int",
+	.str_sec_size = sizeof("\0__int"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "volatile_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "const type (invalid name, name_off <> 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_CONST, 0, 0), 1),	/* [2] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__int",
+	.str_sec_size = sizeof("\0__int"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "const_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "restrict type (invalid name, name_off <> 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 1),	/* [2] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_RESTRICT, 0, 0), 2),	/* [3] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__int",
+	.str_sec_size = sizeof("\0__int"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "restrict_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "fwd type (invalid name, name_off = 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FWD, 0, 0), 0),	/* [2] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__skb",
+	.str_sec_size = sizeof("\0__skb"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "fwd_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "fwd type (invalid name, invalid identifier)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_FWD, 0, 0), 0),	/* [2] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__!skb",
+	.str_sec_size = sizeof("\0__!skb"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "fwd_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "array type (invalid name, name_off <> 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_ARRAY, 0, 0), 0),	/* [2] */
+		BTF_ARRAY_ENC(1, 1, 4),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0__skb",
+	.str_sec_size = sizeof("\0__skb"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "array_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "struct type (name_off = 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(0,
+			     BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), 4),	/* [2] */
+		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A",
+	.str_sec_size = sizeof("\0A"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "struct_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+},
+
+{
+	.descr = "struct type (invalid name, invalid identifier)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), 4),	/* [2] */
+		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A!\0B",
+	.str_sec_size = sizeof("\0A!\0B"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "struct_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "struct member (name_off = 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(0,
+			     BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), 4),	/* [2] */
+		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A",
+	.str_sec_size = sizeof("\0A"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "struct_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+},
+
+{
+	.descr = "struct member (invalid name, invalid identifier)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), 4),	/* [2] */
+		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0B*",
+	.str_sec_size = sizeof("\0A\0B*"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "struct_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "enum type (name_off = 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(0,
+			     BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1),
+			     sizeof(int)),				/* [2] */
+		BTF_ENUM_ENC(NAME_TBD, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A\0B",
+	.str_sec_size = sizeof("\0A\0B"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "enum_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+},
+
+{
+	.descr = "enum type (invalid name, invalid identifier)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(NAME_TBD,
+			     BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1),
+			     sizeof(int)),				/* [2] */
+		BTF_ENUM_ENC(NAME_TBD, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A!\0B",
+	.str_sec_size = sizeof("\0A!\0B"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "enum_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "enum member (invalid name, name_off = 0)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(0,
+			     BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1),
+			     sizeof(int)),				/* [2] */
+		BTF_ENUM_ENC(0, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "",
+	.str_sec_size = sizeof(""),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "enum_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+
+{
+	.descr = "enum member (invalid name, invalid identifier)",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
+		BTF_TYPE_ENC(0,
+			     BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1),
+			     sizeof(int)),				/* [2] */
+		BTF_ENUM_ENC(NAME_TBD, 0),
+		BTF_END_RAW,
+	},
+	.str_sec = "\0A!",
+	.str_sec_size = sizeof("\0A!"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "enum_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 4,
+	.btf_load_err = true,
+	.err_str = "Invalid name",
+},
+{
 	.descr = "arraymap invalid btf key (a bit field)",
 	.raw_types = {
 		/* int */				/* [1] */