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: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210526164643.2881368-1-revest@chromium.org

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

@@ -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

@@ -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

@@ -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

@@ -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

@@ -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_ipv6_route.c

@@ -3,7 +3,6 @@
 #include "bpf_iter.h"
 #include "bpf_tracing_net.h"
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 
 char _license[] SEC("license") = "GPL";
 

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

@@ -3,7 +3,6 @@
 #include "bpf_iter.h"
 #include "bpf_tracing_net.h"
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 
 char _license[] SEC("license") = "GPL";
 

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

@@ -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_task_btf.c

@@ -2,7 +2,6 @@
 /* Copyright (c) 2020, Oracle and/or its affiliates. */
 #include "bpf_iter.h"
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 #include <bpf/bpf_core_read.h>
 
 #include <errno.h>

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

@@ -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_task_stack.c

@@ -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_task_vma.c

@@ -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_tcp4.c

@@ -3,7 +3,6 @@
 #include "bpf_iter.h"
 #include "bpf_tracing_net.h"
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 #include <bpf/bpf_endian.h>
 
 char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c

@@ -3,7 +3,6 @@
 #include "bpf_iter.h"
 #include "bpf_tracing_net.h"
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 #include <bpf/bpf_endian.h>
 
 char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/bpf_iter_udp4.c

@@ -3,7 +3,6 @@
 #include "bpf_iter.h"
 #include "bpf_tracing_net.h"
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 #include <bpf/bpf_endian.h>
 
 char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/bpf_iter_udp6.c

@@ -3,7 +3,6 @@
 #include "bpf_iter.h"
 #include "bpf_tracing_net.h"
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 #include <bpf/bpf_endian.h>
 
 char _license[] SEC("license") = "GPL";

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

@@ -3,7 +3,6 @@
 
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
 
 __u32 pid = 0;