Commit 002d3afc authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

selftests/bpf: add CO-RE relocs struct flavors tests 



Add tests verifying that BPF program can use various struct/union
"flavors" to extract data from the same target struct/union.

Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent df36e621

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

+34 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <test_progs.h>

#include "progs/core_reloc_types.h"



#define STRUCT_TO_CHAR_PTR(struct_name) (const char *)&(struct struct_name)



#define FLAVORS_DATA(struct_name) STRUCT_TO_CHAR_PTR(struct_name) {	\

	.a = 42,							\

	.b = 0xc001,							\

	.c = 0xbeef,							\

}



#define FLAVORS_CASE_COMMON(name)					\

	.case_name = #name,						\

	.bpf_obj_file = "test_core_reloc_flavors.o",			\

	.btf_src_file = "btf__core_reloc_" #name ".o"			\



#define FLAVORS_CASE(name) {						\

	FLAVORS_CASE_COMMON(name),					\

	.input = FLAVORS_DATA(core_reloc_##name),			\

	.input_len = sizeof(struct core_reloc_##name),			\

	.output = FLAVORS_DATA(core_reloc_flavors),			\

	.output_len = sizeof(struct core_reloc_flavors),		\

}



#define FLAVORS_ERR_CASE(name) {					\

	FLAVORS_CASE_COMMON(name),					\

	.fails = true,							\

}



struct core_reloc_test_case {

	const char *case_name;
@@ -23,6 +50,13 @@ static struct core_reloc_test_case test_cases[] = { 
		.output = "\1", /* true */

		.output_len = 1,

	},



	/* validate BPF program can use multiple flavors to match against

	 * single target BTF type

	 */

	FLAVORS_CASE(flavors),



	FLAVORS_ERR_CASE(flavors__err_wrong_name),

};



struct data {

tools/testing/selftests/bpf/progs/btf__core_reloc_flavors.c

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+3 −0
Original line number Diff line number Diff line 
#include "core_reloc_types.h"



void f(struct core_reloc_flavors x) {}

tools/testing/selftests/bpf/progs/btf__core_reloc_flavors__err_wrong_name.c

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Original line number Diff line number Diff line 
#include "core_reloc_types.h"



void f(struct core_reloc_flavors__err_wrong_name x) {}

tools/testing/selftests/bpf/progs/core_reloc_types.h

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Original line number Diff line number Diff line 
/*

 * FLAVORS

 */

struct core_reloc_flavors {

	int a;

	int b;

	int c;

};



/* this is not a flavor, as it doesn't have triple underscore */

struct core_reloc_flavors__err_wrong_name {

	int a;

	int b;

	int c;

};

tools/testing/selftests/bpf/progs/test_core_reloc_flavors.c

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+62 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook



#include <linux/bpf.h>

#include <stdint.h>

#include "bpf_helpers.h"



char _license[] SEC("license") = "GPL";



static volatile struct data {

	char in[256];

	char out[256];

} data;



struct core_reloc_flavors {

	int a;

	int b;

	int c;

};



/* local flavor with reversed layout */

struct core_reloc_flavors___reversed {

	int c;

	int b;

	int a;

};



/* local flavor with nested/overlapping layout */

struct core_reloc_flavors___weird {

	struct {

		int b;

	};

	/* a and c overlap in local flavor, but this should still work

	 * correctly with target original flavor

	 */

	union {

		int a;

		int c;

	};

};



SEC("raw_tracepoint/sys_enter")

int test_core_flavors(void *ctx)

{

	struct core_reloc_flavors *in_orig = (void *)&data.in;

	struct core_reloc_flavors___reversed *in_rev = (void *)&data.in;

	struct core_reloc_flavors___weird *in_weird = (void *)&data.in;

	struct core_reloc_flavors *out = (void *)&data.out;



	/* read a using weird layout */

	if (BPF_CORE_READ(&out->a, &in_weird->a))

		return 1;

	/* read b using reversed layout */

	if (BPF_CORE_READ(&out->b, &in_rev->b))

		return 1;

	/* read c using original layout */

	if (BPF_CORE_READ(&out->c, &in_orig->c))

		return 1;



	return 0;

}