Commit 58250ae3 authored Jul 11, 2022 by Fedor Tokarev Committed by Andrii Nakryiko Jul 29, 2022

bpf: btf: Fix vsnprintf return value check



vsnprintf returns the number of characters which would have been written if
enough space had been available, excluding the terminating null byte. Thus,
the return value of 'len_left' means that the last character has been
dropped.

Signed-off-by: Fedor Tokarev <ftokarev@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220711211317.GA1143610@laptop

parent 64893e83

kernel/bpf/btf.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -6643,7 +6643,7 @@ static void btf_snprintf_show(struct btf_show show, const char fmt,
		if (len < 0) {
		ssnprintf->len_left = 0;
		ssnprintf->len = len;
		} else if (len > ssnprintf->len_left) {
		} else if (len >= ssnprintf->len_left) {
		/* no space, drive on to get length we would have written */
		ssnprintf->len_left = 0;
		ssnprintf->len += len;