[PATCH bpf-next 4/5] libbpf: Introduce a BPF_SNPRINTF helper macro

From: Florent Revest
Date: Wed Mar 10 2021 - 17:03:47 EST


Similarly to BPF_SEQ_PRINTF, this macro turns variadic arguments into an
array of u64, making it more natural to call the bpf_snprintf helper.

Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
---
tools/lib/bpf/bpf_tracing.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index f6a2deb3cd5b..89e82da9b8a0 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -457,4 +457,19 @@ static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)
___ret; \
})

+/*
+ * BPF_SNPRINTF wraps the bpf_snprintf helper with variadic arguments instead of
+ * an array of u64.
+ */
+#define BPF_SNPRINTF(out, out_size, fmt, args...) \
+ ({ \
+ _Pragma("GCC diagnostic push") \
+ _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
+ ___bpf_build_param(args); \
+ _Pragma("GCC diagnostic pop") \
+ int ___ret = bpf_snprintf(out, out_size, fmt, \
+ ___param, sizeof(___param)); \
+ ___ret; \
+ })
+
#endif
--
2.30.1.766.gb4fecdf3b7-goog