Commit d6a6a555 authored by Florent Revest's avatar Florent Revest Committed by Andrii Nakryiko
Browse files

libbpf: Move BPF_SEQ_PRINTF and BPF_SNPRINTF to bpf_helpers.h 



These macros are convenient wrappers around the bpf_seq_printf and
bpf_snprintf helpers. They are currently provided by bpf_tracing.h which
targets low level tracing primitives. bpf_helpers.h is a better fit.

The __bpf_narg and __bpf_apply are needed in both files and provided
twice. __bpf_empty isn't used anywhere and is removed from bpf_tracing.h

Reported-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarFlorent Revest <revest@chromium.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210526164643.2881368-1-revest@chromium.org
parent aa7f1f03

kernel/bpf/preload/iterators/iterators.bpf.c

+0 −1
Original line number Diff line number Diff line
@@ -2,7 +2,6 @@ 
/* Copyright (c) 2020 Facebook */

#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include <bpf/bpf_core_read.h>



#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)

tools/lib/bpf/bpf_helpers.h

+66 −0
Original line number Diff line number Diff line
@@ -158,4 +158,70 @@ enum libbpf_tristate { 
#define __kconfig __attribute__((section(".kconfig")))

#define __ksym __attribute__((section(".ksyms")))



#ifndef ___bpf_concat

#define ___bpf_concat(a, b) a ## b

#endif

#ifndef ___bpf_apply

#define ___bpf_apply(fn, n) ___bpf_concat(fn, n)

#endif

#ifndef ___bpf_nth

#define ___bpf_nth(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, N, ...) N

#endif

#ifndef ___bpf_narg

#define ___bpf_narg(...) \

	___bpf_nth(_, ##__VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)

#endif



#define ___bpf_fill0(arr, p, x) do {} while (0)

#define ___bpf_fill1(arr, p, x) arr[p] = x

#define ___bpf_fill2(arr, p, x, args...) arr[p] = x; ___bpf_fill1(arr, p + 1, args)

#define ___bpf_fill3(arr, p, x, args...) arr[p] = x; ___bpf_fill2(arr, p + 1, args)

#define ___bpf_fill4(arr, p, x, args...) arr[p] = x; ___bpf_fill3(arr, p + 1, args)

#define ___bpf_fill5(arr, p, x, args...) arr[p] = x; ___bpf_fill4(arr, p + 1, args)

#define ___bpf_fill6(arr, p, x, args...) arr[p] = x; ___bpf_fill5(arr, p + 1, args)

#define ___bpf_fill7(arr, p, x, args...) arr[p] = x; ___bpf_fill6(arr, p + 1, args)

#define ___bpf_fill8(arr, p, x, args...) arr[p] = x; ___bpf_fill7(arr, p + 1, args)

#define ___bpf_fill9(arr, p, x, args...) arr[p] = x; ___bpf_fill8(arr, p + 1, args)

#define ___bpf_fill10(arr, p, x, args...) arr[p] = x; ___bpf_fill9(arr, p + 1, args)

#define ___bpf_fill11(arr, p, x, args...) arr[p] = x; ___bpf_fill10(arr, p + 1, args)

#define ___bpf_fill12(arr, p, x, args...) arr[p] = x; ___bpf_fill11(arr, p + 1, args)

#define ___bpf_fill(arr, args...) \

	___bpf_apply(___bpf_fill, ___bpf_narg(args))(arr, 0, args)



/*

 * BPF_SEQ_PRINTF to wrap bpf_seq_printf to-be-printed values

 * in a structure.

 */

#define BPF_SEQ_PRINTF(seq, fmt, args...)			\

({								\

	static const char ___fmt[] = fmt;			\

	unsigned long long ___param[___bpf_narg(args)];		\

								\

	_Pragma("GCC diagnostic push")				\

	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	\

	___bpf_fill(___param, args);				\

	_Pragma("GCC diagnostic pop")				\

								\

	bpf_seq_printf(seq, ___fmt, sizeof(___fmt),		\

		       ___param, sizeof(___param));		\

})



/*

 * BPF_SNPRINTF wraps the bpf_snprintf helper with variadic arguments instead of

 * an array of u64.

 */

#define BPF_SNPRINTF(out, out_size, fmt, args...)		\

({								\

	static const char ___fmt[] = fmt;			\

	unsigned long long ___param[___bpf_narg(args)];		\

								\

	_Pragma("GCC diagnostic push")				\

	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	\

	___bpf_fill(___param, args);				\

	_Pragma("GCC diagnostic pop")				\

								\

	bpf_snprintf(out, out_size, ___fmt,			\

		     ___param, sizeof(___param));		\

})



#endif

tools/lib/bpf/bpf_tracing.h

+8 −54
Original line number Diff line number Diff line
@@ -295,13 +295,19 @@ struct pt_regs; 
			  (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })

#endif



#ifndef ___bpf_concat

#define ___bpf_concat(a, b) a ## b

#endif

#ifndef ___bpf_apply

#define ___bpf_apply(fn, n) ___bpf_concat(fn, n)

#endif

#ifndef ___bpf_nth

#define ___bpf_nth(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, N, ...) N

#endif

#ifndef ___bpf_narg

#define ___bpf_narg(...) \

	___bpf_nth(_, ##__VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)

#define ___bpf_empty(...) \

	___bpf_nth(_, ##__VA_ARGS__, N, N, N, N, N, N, N, N, N, N, 0)

#endif



#define ___bpf_ctx_cast0() ctx

#define ___bpf_ctx_cast1(x) ___bpf_ctx_cast0(), (void *)ctx[0]
@@ -413,56 +419,4 @@ typeof(name(0)) name(struct pt_regs *ctx) \ 
}									    \

static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)



#define ___bpf_fill0(arr, p, x) do {} while (0)

#define ___bpf_fill1(arr, p, x) arr[p] = x

#define ___bpf_fill2(arr, p, x, args...) arr[p] = x; ___bpf_fill1(arr, p + 1, args)

#define ___bpf_fill3(arr, p, x, args...) arr[p] = x; ___bpf_fill2(arr, p + 1, args)

#define ___bpf_fill4(arr, p, x, args...) arr[p] = x; ___bpf_fill3(arr, p + 1, args)

#define ___bpf_fill5(arr, p, x, args...) arr[p] = x; ___bpf_fill4(arr, p + 1, args)

#define ___bpf_fill6(arr, p, x, args...) arr[p] = x; ___bpf_fill5(arr, p + 1, args)

#define ___bpf_fill7(arr, p, x, args...) arr[p] = x; ___bpf_fill6(arr, p + 1, args)

#define ___bpf_fill8(arr, p, x, args...) arr[p] = x; ___bpf_fill7(arr, p + 1, args)

#define ___bpf_fill9(arr, p, x, args...) arr[p] = x; ___bpf_fill8(arr, p + 1, args)

#define ___bpf_fill10(arr, p, x, args...) arr[p] = x; ___bpf_fill9(arr, p + 1, args)

#define ___bpf_fill11(arr, p, x, args...) arr[p] = x; ___bpf_fill10(arr, p + 1, args)

#define ___bpf_fill12(arr, p, x, args...) arr[p] = x; ___bpf_fill11(arr, p + 1, args)

#define ___bpf_fill(arr, args...) \

	___bpf_apply(___bpf_fill, ___bpf_narg(args))(arr, 0, args)



/*

 * BPF_SEQ_PRINTF to wrap bpf_seq_printf to-be-printed values

 * in a structure.

 */

#define BPF_SEQ_PRINTF(seq, fmt, args...)			\

({								\

	static const char ___fmt[] = fmt;			\

	unsigned long long ___param[___bpf_narg(args)];		\

								\

	_Pragma("GCC diagnostic push")				\

	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	\

	___bpf_fill(___param, args);				\

	_Pragma("GCC diagnostic pop")				\

								\

	bpf_seq_printf(seq, ___fmt, sizeof(___fmt),		\

		       ___param, sizeof(___param));		\

})



/*

 * BPF_SNPRINTF wraps the bpf_snprintf helper with variadic arguments instead of

 * an array of u64.

 */

#define BPF_SNPRINTF(out, out_size, fmt, args...)		\

({								\

	static const char ___fmt[] = fmt;			\

	unsigned long long ___param[___bpf_narg(args)];		\

								\

	_Pragma("GCC diagnostic push")				\

	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	\

	___bpf_fill(___param, args);				\

	_Pragma("GCC diagnostic pop")				\

								\

	bpf_snprintf(out, out_size, ___fmt,			\

		     ___param, sizeof(___param));		\

})



#endif

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

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Original line number Diff line number Diff line
@@ -2,7 +2,6 @@ 
/* Copyright (c) 2020 Facebook */

#include "bpf_iter.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>



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

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

+0 −1
Original line number Diff line number Diff line
@@ -2,7 +2,6 @@ 
/* Copyright (c) 2020 Facebook */

#include "bpf_iter.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>



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