在 2022/9/10 1:16, sdf@xxxxxxxxxx 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@xxxxxxxxxx>
---
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
