The __bpf_printk convenience macro was using a 'char' fmt string holder
as it predates support for globals in libbpf. Move to more efficient
'static const char', but provide a fallback to the old way via
BPF_NO_GLOBAL_DATA so users on old kernels can still use the macro.
Signed-off-by: Dave Marchevsky <davemarchevsky@xxxxxx>
---
tools/lib/bpf/bpf_helpers.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 5f087306cdfe..a1d5ec6f285c 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -216,10 +216,16 @@ enum libbpf_tristate {
___param, sizeof(___param)); \
})
+#ifdef BPF_NO_GLOBAL_DATA
+#define BPF_PRINTK_FMT_TYPE char
+#else
+#define BPF_PRINTK_FMT_TYPE static const char
+#endif
+
/* Helper macro to print out debug messages */
#define __bpf_printk(fmt, ...) \
({ \
- char ____fmt[] = fmt; \
+ BPF_PRINTK_FMT_TYPE ____fmt[] = fmt; \
bpf_trace_printk(____fmt, sizeof(____fmt), \
##__VA_ARGS__); \
})
--
2.30.2
