/proc/net/unix uses "%c" to print a single-byte character to escape '\0' in the name of the abstract UNIX domain socket. The following selftest uses it, so this patch adds support for "%c". Note that it does not support wide character ("%lc" and "%llc") for simplicity. Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx> Acked-by: Yonghong Song <yhs@xxxxxx> --- kernel/bpf/helpers.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 32761be48143..4e8540716187 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -907,6 +907,20 @@ int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args, tmp_buf += err; num_spec++; + continue; + } else if (fmt[i] == 'c') { + if (!tmp_buf) + goto nocopy_fmt; + + if (tmp_buf_end == tmp_buf) { + err = -ENOSPC; + goto out; + } + + *tmp_buf = raw_args[num_spec]; + tmp_buf++; + num_spec++; + continue; } -- 2.30.2