From 7bda4b40c5624c3f1c69227f8ebfd46a4b83f2ef Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Sun, 2 Jul 2017 02:13:29 +0200 Subject: [PATCH] bpf: extend bpf_trace_printk to support %i Currently, bpf_trace_printk does not support common formatting symbol '%i' however vsprintf does and is what eventually gets called by bpf helper. If users are used to '%i' and currently make use of it, then bpf_trace_printk will just return with error without dumping anything to the trace pipe, so just add support for '%i' to the helper. Signed-off-by: John Fastabend Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- kernel/trace/bpf_trace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 5c6d538..3738519 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -122,8 +122,8 @@ static const struct bpf_func_proto *bpf_get_probe_write_proto(void) } /* - * limited trace_printk() - * only %d %u %x %ld %lu %lx %lld %llu %llx %p %s conversion specifiers allowed + * Only limited trace_printk() conversion specifiers allowed: + * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s */ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, u64, arg2, u64, arg3) @@ -198,7 +198,8 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, i++; } - if (fmt[i] != 'd' && fmt[i] != 'u' && fmt[i] != 'x') + if (fmt[i] != 'i' && fmt[i] != 'd' && + fmt[i] != 'u' && fmt[i] != 'x') return -EINVAL; fmt_cnt++; } -- 2.7.4