Commit 99e18fad authored by Eduard Zingerman's avatar Eduard Zingerman Committed by Andrii Nakryiko
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selftests/bpf: Tests for btf_dedup_resolve_fwds 



Tests to verify the following behavior of `btf_dedup_resolve_fwds`:
- remapping for struct forward declarations;
- remapping for union forward declarations;
- no remapping if forward declaration kind does not match similarly
  named struct or union declaration;
- no remapping if forward declaration name is ambiguous;
- base ids are considered for fwd resolution in split btf scenario.

Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Reviewed-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20221109142611.879983-4-eddyz87@gmail.com
parent 082108fd

tools/testing/selftests/bpf/prog_tests/btf.c

+176 −0
Original line number Diff line number Diff line
@@ -7690,6 +7690,182 @@ static struct btf_dedup_test dedup_tests[] = { 
		BTF_STR_SEC("\0e1\0e1_val\0td"),

	},

},

{

	.descr = "dedup: standalone fwd declaration struct",

	/*

	 * Verify that CU1:foo and CU2:foo would be unified and that

	 * typedef/ptr would be updated to point to CU1:foo.

	 *

	 * // CU 1:

	 * struct foo { int x; };

	 *

	 * // CU 2:

	 * struct foo;

	 * typedef struct foo *foo_ptr;

	 */

	.input = {

		.raw_types = {

			/* CU 1 */

			BTF_STRUCT_ENC(NAME_NTH(1), 1, 4),             /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			/* CU 2 */

			BTF_FWD_ENC(NAME_NTH(1), 0),                   /* [3] */

			BTF_PTR_ENC(3),                                /* [4] */

			BTF_TYPEDEF_ENC(NAME_NTH(3), 4),               /* [5] */

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0foo_ptr"),

	},

	.expect = {

		.raw_types = {

			BTF_STRUCT_ENC(NAME_NTH(1), 1, 4),             /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			BTF_PTR_ENC(1),                                /* [3] */

			BTF_TYPEDEF_ENC(NAME_NTH(3), 3),               /* [4] */

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0foo_ptr"),

	},

},

{

	.descr = "dedup: standalone fwd declaration union",

	/*

	 * Verify that CU1:foo and CU2:foo would be unified and that

	 * typedef/ptr would be updated to point to CU1:foo.

	 * Same as "dedup: standalone fwd declaration struct" but for unions.

	 *

	 * // CU 1:

	 * union foo { int x; };

	 *

	 * // CU 2:

	 * union foo;

	 * typedef union foo *foo_ptr;

	 */

	.input = {

		.raw_types = {

			/* CU 1 */

			BTF_UNION_ENC(NAME_NTH(1), 1, 4),              /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			/* CU 2 */

			BTF_FWD_ENC(NAME_TBD, 1),                      /* [3] */

			BTF_PTR_ENC(3),                                /* [4] */

			BTF_TYPEDEF_ENC(NAME_NTH(3), 4),               /* [5] */

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0foo_ptr"),

	},

	.expect = {

		.raw_types = {

			BTF_UNION_ENC(NAME_NTH(1), 1, 4),              /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			BTF_PTR_ENC(1),                                /* [3] */

			BTF_TYPEDEF_ENC(NAME_NTH(3), 3),               /* [4] */

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0foo_ptr"),

	},

},

{

	.descr = "dedup: standalone fwd declaration wrong kind",

	/*

	 * Negative test for btf_dedup_resolve_fwds:

	 * - CU1:foo is a struct, C2:foo is a union, thus CU2:foo is not deduped;

	 * - typedef/ptr should remain unchanged as well.

	 *

	 * // CU 1:

	 * struct foo { int x; };

	 *

	 * // CU 2:

	 * union foo;

	 * typedef union foo *foo_ptr;

	 */

	.input = {

		.raw_types = {

			/* CU 1 */

			BTF_STRUCT_ENC(NAME_NTH(1), 1, 4),             /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			/* CU 2 */

			BTF_FWD_ENC(NAME_NTH(3), 1),                   /* [3] */

			BTF_PTR_ENC(3),                                /* [4] */

			BTF_TYPEDEF_ENC(NAME_NTH(3), 4),               /* [5] */

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0foo_ptr"),

	},

	.expect = {

		.raw_types = {

			/* CU 1 */

			BTF_STRUCT_ENC(NAME_NTH(1), 1, 4),             /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			/* CU 2 */

			BTF_FWD_ENC(NAME_NTH(3), 1),                   /* [3] */

			BTF_PTR_ENC(3),                                /* [4] */

			BTF_TYPEDEF_ENC(NAME_NTH(3), 4),               /* [5] */

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0foo_ptr"),

	},

},

{

	.descr = "dedup: standalone fwd declaration name conflict",

	/*

	 * Negative test for btf_dedup_resolve_fwds:

	 * - two candidates for CU2:foo dedup, thus it is unchanged;

	 * - typedef/ptr should remain unchanged as well.

	 *

	 * // CU 1:

	 * struct foo { int x; };

	 *

	 * // CU 2:

	 * struct foo;

	 * typedef struct foo *foo_ptr;

	 *

	 * // CU 3:

	 * struct foo { int x; int y; };

	 */

	.input = {

		.raw_types = {

			/* CU 1 */

			BTF_STRUCT_ENC(NAME_NTH(1), 1, 4),             /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			/* CU 2 */

			BTF_FWD_ENC(NAME_NTH(1), 0),                   /* [3] */

			BTF_PTR_ENC(3),                                /* [4] */

			BTF_TYPEDEF_ENC(NAME_NTH(4), 4),               /* [5] */

			/* CU 3 */

			BTF_STRUCT_ENC(NAME_NTH(1), 2, 8),             /* [6] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_MEMBER_ENC(NAME_NTH(3), 2, 0),

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0y\0foo_ptr"),

	},

	.expect = {

		.raw_types = {

			/* CU 1 */

			BTF_STRUCT_ENC(NAME_NTH(1), 1, 4),             /* [1] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */

			/* CU 2 */

			BTF_FWD_ENC(NAME_NTH(1), 0),                   /* [3] */

			BTF_PTR_ENC(3),                                /* [4] */

			BTF_TYPEDEF_ENC(NAME_NTH(4), 4),               /* [5] */

			/* CU 3 */

			BTF_STRUCT_ENC(NAME_NTH(1), 2, 8),             /* [6] */

			BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),

			BTF_MEMBER_ENC(NAME_NTH(3), 2, 0),

			BTF_END_RAW,

		},

		BTF_STR_SEC("\0foo\0x\0y\0foo_ptr"),

	},

},

};



static int btf_type_size(const struct btf_type *t)

tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c

+30 −15
Original line number Diff line number Diff line
@@ -141,6 +141,10 @@ static void test_split_fwd_resolve() { 
	btf__add_field(btf1, "f2", 3, 64, 0);		/*      struct s2 *f2; */

							/* } */

	btf__add_struct(btf1, "s2", 4);			/* [5] struct s2 { */

	btf__add_field(btf1, "f1", 1, 0, 0);		/*      int f1; */

							/* } */

	/* keep this not a part of type the graph to test btf_dedup_resolve_fwds */

	btf__add_struct(btf1, "s3", 4);                 /* [6] struct s3 { */

	btf__add_field(btf1, "f1", 1, 0, 0);		/*      int f1; */

							/* } */
@@ -153,20 +157,24 @@ static void test_split_fwd_resolve() { 
		"\t'f1' type_id=2 bits_offset=0\n"

		"\t'f2' type_id=3 bits_offset=64",

		"[5] STRUCT 's2' size=4 vlen=1\n"

		"\t'f1' type_id=1 bits_offset=0",

		"[6] STRUCT 's3' size=4 vlen=1\n"

		"\t'f1' type_id=1 bits_offset=0");



	btf2 = btf__new_empty_split(btf1);

	if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))

		goto cleanup;



	btf__add_int(btf2, "int", 4, BTF_INT_SIGNED);	/* [6] int */

	btf__add_ptr(btf2, 10);				/* [7] ptr to struct s1 */

	btf__add_fwd(btf2, "s2", BTF_FWD_STRUCT);	/* [8] fwd for struct s2 */

	btf__add_ptr(btf2, 8);				/* [9] ptr to fwd struct s2 */

	btf__add_struct(btf2, "s1", 16);		/* [10] struct s1 { */

	btf__add_field(btf2, "f1", 7, 0, 0);		/*      struct s1 *f1; */

	btf__add_field(btf2, "f2", 9, 64, 0);		/*      struct s2 *f2; */

	btf__add_int(btf2, "int", 4, BTF_INT_SIGNED);	/* [7] int */

	btf__add_ptr(btf2, 11);				/* [8] ptr to struct s1 */

	btf__add_fwd(btf2, "s2", BTF_FWD_STRUCT);	/* [9] fwd for struct s2 */

	btf__add_ptr(btf2, 9);				/* [10] ptr to fwd struct s2 */

	btf__add_struct(btf2, "s1", 16);		/* [11] struct s1 { */

	btf__add_field(btf2, "f1", 8, 0, 0);		/*      struct s1 *f1; */

	btf__add_field(btf2, "f2", 10, 64, 0);		/*      struct s2 *f2; */

							/* } */

	btf__add_fwd(btf2, "s3", BTF_FWD_STRUCT);	/* [12] fwd for struct s3 */

	btf__add_ptr(btf2, 12);				/* [13] ptr to struct s1 */



	VALIDATE_RAW_BTF(

		btf2,
@@ -178,13 +186,17 @@ static void test_split_fwd_resolve() { 
		"\t'f2' type_id=3 bits_offset=64",

		"[5] STRUCT 's2' size=4 vlen=1\n"

		"\t'f1' type_id=1 bits_offset=0",

		"[6] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",

		"[7] PTR '(anon)' type_id=10",

		"[8] FWD 's2' fwd_kind=struct",

		"[9] PTR '(anon)' type_id=8",

		"[10] STRUCT 's1' size=16 vlen=2\n"

		"\t'f1' type_id=7 bits_offset=0\n"

		"\t'f2' type_id=9 bits_offset=64");

		"[6] STRUCT 's3' size=4 vlen=1\n"

		"\t'f1' type_id=1 bits_offset=0",

		"[7] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",

		"[8] PTR '(anon)' type_id=11",

		"[9] FWD 's2' fwd_kind=struct",

		"[10] PTR '(anon)' type_id=9",

		"[11] STRUCT 's1' size=16 vlen=2\n"

		"\t'f1' type_id=8 bits_offset=0\n"

		"\t'f2' type_id=10 bits_offset=64",

		"[12] FWD 's3' fwd_kind=struct",

		"[13] PTR '(anon)' type_id=12");



	err = btf__dedup(btf2, NULL);

	if (!ASSERT_OK(err, "btf_dedup"))
@@ -199,7 +211,10 @@ static void test_split_fwd_resolve() { 
		"\t'f1' type_id=2 bits_offset=0\n"

		"\t'f2' type_id=3 bits_offset=64",

		"[5] STRUCT 's2' size=4 vlen=1\n"

		"\t'f1' type_id=1 bits_offset=0");

		"\t'f1' type_id=1 bits_offset=0",

		"[6] STRUCT 's3' size=4 vlen=1\n"

		"\t'f1' type_id=1 bits_offset=0",

		"[7] PTR '(anon)' type_id=6");



cleanup:

	btf__free(btf2);