That line is used to generate the bpf-helpers(7) manual page. It is a no-fill line, since it represents a command, which means that the formatter can't break the line, and instead just runs across the right margin (in most set-ups this means that the pager will break the line). Using <fmt> makes it end exactly at the 80-col right margin, both in the header file, and also in the manual page, and also seems to be a sensible name. Cc: bpf <bpf@xxxxxxxxxxxxxxx> Cc: linux-man <linux-man@xxxxxxxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Cc: Andrii Nakryiko <andrii@xxxxxxxxxx> Cc: Martin KaFai Lau <kafai@xxxxxx> Cc: Song Liu <songliubraving@xxxxxx> Cc: Yonghong Song <yhs@xxxxxx> Cc: John Fastabend <john.fastabend@xxxxxxxxx> Cc: KP Singh <kpsingh@xxxxxxxxxx> Cc: Stanislav Fomichev <sdf@xxxxxxxxxx> Cc: Hao Luo <haoluo@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Cc: Quentin Monnet <quentin@xxxxxxxxxxxxx> Signed-off-by: Alejandro Colomar <alx.manpages@xxxxxxxxx> --- Hi, We are adding another linter to the manual pages, which lints about output going past the right margin of the terminal. The following results triggered in the bpf-helpers(7) page: $ make lint-man-groff LINT (groff) tmp/lint/man7/bpf-helpers.7.lint-man.groff.touch an.tmac:man7/bpf-helpers.7:3: style: .TH missing third argument; suggest document modification date in ISO 8601 format (YYYY-MM-DD) an.tmac:man7/bpf-helpers.7:3: style: .TH missing fourth argument; suggest package/project name and version (e.g., "groff 1.23.0") an.tmac:man7/bpf-helpers.7:3: style: .TH missing fifth argument and second argument '7' not a recognized manual section; specify volume title 114: telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg> 2642: int res = bpf_probe_read_user_str(buf, sizeof(buf), found style problems; aborting make: *** [lib/lint-man.mk:50: tmp/lint/man7/bpf-helpers.7.lint-man.groff.touch] Error 1 This patch addresses the issue in line 114 (that line count is in the output rendered page, not in the man(7) source file). I'm not sure which of those files are used to produce the manual page, but for consistency I thought it was best to fix both in the same way. Cheers, Alex include/uapi/linux/bpf.h | 5 ++--- tools/include/uapi/linux/bpf.h | 5 ++--- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index ef78e0e1a754..c03ae39c03b2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1619,7 +1619,7 @@ union bpf_attr { * * :: * - * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg> + * telnet-470 [001] .N.. 419421.045894: 0x00000001: <fmt> * * In the above: * @@ -1636,8 +1636,7 @@ union bpf_attr { * * ``419421.045894`` is a timestamp. * * ``0x00000001`` is a fake value used by BPF for the * instruction pointer register. - * * ``<formatted msg>`` is the message formatted with - * *fmt*. + * * ``<fmt>`` is the message formatted with *fmt*. * * The conversion specifiers supported by *fmt* are similar, but * more limited than for printk(). They are **%d**, **%i**, diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index ef78e0e1a754..c03ae39c03b2 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1619,7 +1619,7 @@ union bpf_attr { * * :: * - * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg> + * telnet-470 [001] .N.. 419421.045894: 0x00000001: <fmt> * * In the above: * @@ -1636,8 +1636,7 @@ union bpf_attr { * * ``419421.045894`` is a timestamp. * * ``0x00000001`` is a fake value used by BPF for the * instruction pointer register. - * * ``<formatted msg>`` is the message formatted with - * *fmt*. + * * ``<fmt>`` is the message formatted with *fmt*. * * The conversion specifiers supported by *fmt* are similar, but * more limited than for printk(). They are **%d**, **%i**, -- 2.37.2