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From: Alan Maguire <alan.maguire@oracle.com>
To: Eduard Zingerman <eddyz87@gmail.com>,
	bpf@vger.kernel.org, ast@kernel.org
Cc: andrii@kernel.org, daniel@iogearbox.net, kernel-team@fb.com, yhs@fb.com
Subject: Re: [PATCH bpf-next 4/4] selftests/bpf: Tests for btf_dedup_resolve_fwds
Date: Wed, 2 Nov 2022 16:47:16 +0000	[thread overview]
Message-ID: <5f8a9914-e6c2-1ebc-3f7c-f8d706cdd7ad@oracle.com> (raw)
In-Reply-To: <20221102110905.2433622-5-eddyz87@gmail.com>

On 02/11/2022 11:09, Eduard Zingerman wrote:
> 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: Eduard Zingerman <eddyz87@gmail.com>

Really nice having positive and negative tests here!

Reviewed-by: Alan Maguire <alan.maguire@oracle.com>

> ---
>  tools/testing/selftests/bpf/prog_tests/btf.c  | 152 ++++++++++++++++++
>  .../bpf/prog_tests/btf_dedup_split.c          |  45 ++++--
>  2 files changed, 182 insertions(+), 15 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
> index 127b8caa3dc1..f14020d51ab9 100644
> --- a/tools/testing/selftests/bpf/prog_tests/btf.c
> +++ b/tools/testing/selftests/bpf/prog_tests/btf.c
> @@ -7598,6 +7598,158 @@ static struct btf_dedup_test dedup_tests[] = {
>  		BTF_STR_SEC("\0e1\0e1_val"),
>  	},
>  },
> +{
> +	.descr = "dedup: standalone fwd declaration struct",
> +	/*
> +	 * // CU 1:
> +	 * struct foo { int x; };
> +	 * struct foo *a;
> +	 *
> +	 * // CU 2:
> +	 * struct foo;
> +	 * struct foo *b;
> +	 */
> +	.input = {
> +		.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_FWD_ENC(NAME_TBD, 0),                      /* [4] */
> +			BTF_PTR_ENC(4),                                /* [5] */
> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x"),
> +	},
> +	.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_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x"),
> +	},
> +},
> +{
> +	.descr = "dedup: standalone fwd declaration union",
> +	/*
> +	 * // CU 1:
> +	 * union foo { int x; };
> +	 * union foo *another_global;
> +	 *
> +	 * // CU 2:
> +	 * union foo;
> +	 * union foo *some_global;
> +	 */
> +	.input = {
> +		.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_FWD_ENC(NAME_TBD, 1),                      /* [4] */
> +			BTF_PTR_ENC(4),                                /* [5] */
> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x"),
> +	},
> +	.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_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x"),
> +	},
> +},
> +{
> +	.descr = "dedup: standalone fwd declaration wrong kind",
> +	/*
> +	 * // CU 1:
> +	 * struct foo { int x; };
> +	 * struct foo *b;
> +	 *
> +	 * // CU 2:
> +	 * union foo;
> +	 * union foo *a;
> +	 */
> +	.input = {
> +		.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_FWD_ENC(NAME_TBD, 1),                      /* [4] */
> +			BTF_PTR_ENC(4),                                /* [5] */
> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x"),
> +	},
> +	.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_FWD_ENC(NAME_TBD, 1),                      /* [4] */
> +			BTF_PTR_ENC(4),                                /* [5] */
> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x"),
> +	},
> +},
> +{
> +	.descr = "dedup: standalone fwd declaration name conflict",
> +	/*
> +	 * // CU 1:
> +	 * struct foo { int x; };
> +	 * struct foo *a;
> +	 *
> +	 * // CU 2:
> +	 * struct foo;
> +	 * struct foo *b;
> +	 *
> +	 * // CU 3:
> +	 * struct foo { int x; int y; };
> +	 * struct foo *c;
> +	 */
> +	.input = {
> +		.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_FWD_ENC(NAME_TBD, 0),                      /* [4] */
> +			BTF_PTR_ENC(4),                                /* [5] */
> +			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_PTR_ENC(6),                                /* [7] */
> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x\0y"),
> +	},
> +	.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_FWD_ENC(NAME_TBD, 0),                      /* [4] */
> +			BTF_PTR_ENC(4),                                /* [5] */
> +			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_PTR_ENC(6),                                /* [7] */
> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0foo\0x\0y"),
> +	},
> +},
>  
>  };
>  
> diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> index 90aac437576d..d9024c7a892a 100644
> --- a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> +++ b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> @@ -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);
> 

      reply	other threads:[~2022-11-02 16:49 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-02 11:09 [PATCH bpf-next 0/4] libbpf: Resolve unambigous forward declarations Eduard Zingerman
2022-11-02 11:09 ` [PATCH bpf-next 1/4] libbpf: hashmap interface update to uintptr_t -> uintptr_t Eduard Zingerman
2022-11-02 11:09 ` [PATCH bpf-next 2/4] selftests/bpf: hashmap test cases updated for uintptr_t -> uintptr_t interface Eduard Zingerman
2022-11-02 11:09 ` [PATCH bpf-next 3/4] libbpf: Resolve unambigous forward declarations Eduard Zingerman
2022-11-02 16:36   ` Alan Maguire
2022-11-02 16:46     ` Eduard Zingerman
2022-11-02 11:09 ` [PATCH bpf-next 4/4] selftests/bpf: Tests for btf_dedup_resolve_fwds Eduard Zingerman
2022-11-02 16:47   ` Alan Maguire [this message]

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