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authorDave Marchevsky <davemarchevsky@fb.com>2021-09-17 21:29:07 +0300
committerAlexei Starovoitov <ast@kernel.org>2021-09-18 00:02:05 +0300
commit6c66b0e7c91a1320c1b85ad8150bdd534eb4ddae (patch)
treefe11dc67b044b33bb16b5603bfe14652594fcc7e /tools/lib/bpf/bpf_helpers.h
parentc2758baa9798bf75d79a9aad8792edb8b694373e (diff)
downloadlinux-6c66b0e7c91a1320c1b85ad8150bdd534eb4ddae.tar.xz
libbpf: Use static const fmt string in __bpf_printk
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@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210917182911.2426606-6-davemarchevsky@fb.com
Diffstat (limited to 'tools/lib/bpf/bpf_helpers.h')
-rw-r--r--tools/lib/bpf/bpf_helpers.h8
1 files changed, 7 insertions, 1 deletions
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 55a308796625..963b1060d944 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -216,9 +216,15 @@ enum libbpf_tristate {
___param, sizeof(___param)); \
})
+#ifdef BPF_NO_GLOBAL_DATA
+#define BPF_PRINTK_FMT_MOD
+#else
+#define BPF_PRINTK_FMT_MOD static const
+#endif
+
#define __bpf_printk(fmt, ...) \
({ \
- char ____fmt[] = fmt; \
+ BPF_PRINTK_FMT_MOD char ____fmt[] = fmt; \
bpf_trace_printk(____fmt, sizeof(____fmt), \
##__VA_ARGS__); \
})