From: wangyufen <wangyufen@huawei.com>
To: <sdf@google.com>
Cc: <andrii@kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>,
<martin.lau@linux.dev>, <song@kernel.org>, <yhs@fb.com>,
<john.fastabend@gmail.com>, <kpsingh@kernel.org>,
<haoluo@google.com>, <jolsa@kernel.org>,
<paul.walmsley@sifive.com>, <palmer@dabbelt.com>,
<aou@eecs.berkeley.edu>, <davem@davemloft.net>, <kuba@kernel.org>,
<hawk@kernel.org>, <nathan@kernel.org>, <ndesaulniers@google.com>,
<trix@redhat.com>, <bpf@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
<llvm@lists.linux.dev>
Subject: Re: [bpf-next 2/2] libbpf: Add pathname_concat() helper
Date: Tue, 13 Sep 2022 10:55:42 +0800 [thread overview]
Message-ID: <6e010796-5f5b-0930-44dc-df1792f98eb9@huawei.com> (raw)
In-Reply-To: <Yxt07BE7TOX6dGh2@google.com>
在 2022/9/10 1:16, sdf@google.com 写道:
> On 09/09, Wang Yufen wrote:
>> Move snprintf and len check to common helper pathname_concat() to
>> make the
>> code simpler.
>
>> Signed-off-by: Wang Yufen <wangyufen@huawei.com>
>> ---
>> tools/lib/bpf/libbpf.c | 74
>> ++++++++++++++++++--------------------------------
>> 1 file changed, 27 insertions(+), 47 deletions(-)
>
>> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
>> index 5854b92..238a03e 100644
>> --- a/tools/lib/bpf/libbpf.c
>> +++ b/tools/lib/bpf/libbpf.c
>> @@ -2096,20 +2096,31 @@ static bool get_map_field_int(const char
>> *map_name, const struct btf *btf,
>> return true;
>> }
>
>> -static int build_map_pin_path(struct bpf_map *map, const char *path)
>> +static int pathname_concat(const char *path, const char *name, char
>> *buf)
>> {
>> - char buf[PATH_MAX];
>> int len;
>
>> - if (!path)
>> - path = "/sys/fs/bpf";
>> -
>> - len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
>> + len = snprintf(buf, PATH_MAX, "%s/%s", path, name);
>> if (len < 0)
>> return -EINVAL;
>> else if (len >= PATH_MAX)
>> return -ENAMETOOLONG;
>
>> + return 0;
>> +}
>> +
>> +static int build_map_pin_path(struct bpf_map *map, const char *path)
>> +{
>> + char buf[PATH_MAX];
>> + int err;
>> +
>> + if (!path)
>> + path = "/sys/fs/bpf";
>> +
>> + err = pathname_concat(path, bpf_map__name(map), buf);
>> + if (err)
>> + return err;
>> +
>> return bpf_map__set_pin_path(map, buf);
>> }
>
>> @@ -7959,17 +7970,8 @@ int bpf_object__pin_maps(struct bpf_object
>> *obj, const char *path)
>> continue;
>
>> if (path) {
>> - int len;
>> -
>> - len = snprintf(buf, PATH_MAX, "%s/%s", path,
>> - bpf_map__name(map));
>> - if (len < 0) {
>> - err = -EINVAL;
>> - goto err_unpin_maps;
>> - } else if (len >= PATH_MAX) {
>> - err = -ENAMETOOLONG;
>
> [..]
>
>> + if (pathname_concat(path, bpf_map__name(map), buf))
>> goto err_unpin_maps;
>> - }
>
> You're breaking error reporting here and in a bunch of other places.
> Should be:
>
> err = pathname_concat();
> if (err)
> goto err_unpin_maps;
>
Thanks for your comments.
Sure, my bad.
> I have the same attitude towards this patch as the first one in the
> series: not worth it. Nothing is currently broken, the code as is
> relatively
> readable, this version is not much simpler, it just looks slightly
> different
> taste-wise..
>
> How about this: if you really want to push this kind of cleanup, send
> selftests that exercise all these error cases? :-)
Ok. I will try. :-)
>
>
>> sanitize_pin_path(buf);
>> pin_path = buf;
>> } else if (!map->pin_path) {
>> @@ -8007,14 +8009,9 @@ int bpf_object__unpin_maps(struct bpf_object
>> *obj, const char *path)
>> char buf[PATH_MAX];
>
>> if (path) {
>> - int len;
>> -
>> - len = snprintf(buf, PATH_MAX, "%s/%s", path,
>> - bpf_map__name(map));
>> - if (len < 0)
>> - return libbpf_err(-EINVAL);
>> - else if (len >= PATH_MAX)
>> - return libbpf_err(-ENAMETOOLONG);
>> + err = pathname_concat(path, bpf_map__name(map), buf);
>> + if (err)
>> + return err;
>> sanitize_pin_path(buf);
>> pin_path = buf;
>> } else if (!map->pin_path) {
>> @@ -8032,6 +8029,7 @@ int bpf_object__unpin_maps(struct bpf_object
>> *obj, const char *path)
>> int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
>> {
>> struct bpf_program *prog;
>> + char buf[PATH_MAX];
>> int err;
>
>> if (!obj)
>> @@ -8043,17 +8041,8 @@ int bpf_object__pin_programs(struct bpf_object
>> *obj, const char *path)
>> }
>
>> bpf_object__for_each_program(prog, obj) {
>> - char buf[PATH_MAX];
>> - int len;
>> -
>> - len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name);
>> - if (len < 0) {
>> - err = -EINVAL;
>> + if (pathname_concat(path, prog->name, buf))
>> goto err_unpin_programs;
>> - } else if (len >= PATH_MAX) {
>> - err = -ENAMETOOLONG;
>> - goto err_unpin_programs;
>> - }
>
>> err = bpf_program__pin(prog, buf);
>> if (err)
>> @@ -8064,13 +8053,7 @@ int bpf_object__pin_programs(struct bpf_object
>> *obj, const char *path)
>
>> err_unpin_programs:
>> while ((prog = bpf_object__prev_program(obj, prog))) {
>> - char buf[PATH_MAX];
>> - int len;
>> -
>> - len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name);
>> - if (len < 0)
>> - continue;
>> - else if (len >= PATH_MAX)
>> + if (pathname_concat(path, prog->name, buf))
>> continue;
>
>> bpf_program__unpin(prog, buf);
>> @@ -8089,13 +8072,10 @@ int bpf_object__unpin_programs(struct
>> bpf_object *obj, const char *path)
>
>> bpf_object__for_each_program(prog, obj) {
>> char buf[PATH_MAX];
>> - int len;
>
>> - len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name);
>> - if (len < 0)
>> - return libbpf_err(-EINVAL);
>> - else if (len >= PATH_MAX)
>> - return libbpf_err(-ENAMETOOLONG);
>> + err = pathname_concat(path, prog->name, buf);
>> + if (err)
>> + return libbpf_err(err);
>
>> err = bpf_program__unpin(prog, buf);
>> if (err)
>> --
>> 1.8.3.1
>
next prev parent reply other threads:[~2022-09-13 2:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-09 5:45 [bpf-next 1/2] libbpf: Add make_path_and_pin() helper for bpf_xxx__pin() Wang Yufen
2022-09-09 5:45 ` [bpf-next 2/2] libbpf: Add pathname_concat() helper Wang Yufen
2022-09-09 17:16 ` sdf
2022-09-13 2:55 ` wangyufen [this message]
2022-09-22 0:42 ` Andrii Nakryiko
2022-09-09 17:06 ` [bpf-next 1/2] libbpf: Add make_path_and_pin() helper for bpf_xxx__pin() sdf
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