Em Thu, Jul 09, 2015 at 12:35:09PM +0000, Wang Nan escreveu:
<SNIP>
> +static int
> +bpf_object__create_maps(struct bpf_object *obj)
> +{
> + unsigned int i;
> + size_t nr_maps;
> + int *pfd;
> +
> + nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
> + if (!obj->maps_buf || !nr_maps) {
> + pr_debug("don't need create maps for %s\n",
> + obj->path);
> + return 0;
> + }
> +
> + obj->map_fds = malloc(sizeof(int) * nr_maps);
> + if (!obj->map_fds) {
> + pr_warning("realloc perf_bpf_map_fds failed\n");
> + return -ENOMEM;
> + }
> + obj->nr_map_fds = nr_maps;
> +
> + /* fill all fd with -1 */
> + memset(obj->map_fds, 0xff, sizeof(int) * nr_maps);
Huh? Each entry is an int... If you want to set it all to -1, why don't
you do it as:
memset(obj->map_fds, -1, sizeof(int) * nr_maps);
That way we can even remove that comment :) Doing it, please let me know
if this has some magic twist that makes it be right as-is, if so, please
provide a better comment.
- Arnaldo
> +
> + pfd = obj->map_fds;
> + for (i = 0; i < nr_maps; i++) {
> + struct bpf_map_def def;
> +
> + def = *(struct bpf_map_def *)(obj->maps_buf +
> + i * sizeof(struct bpf_map_def));
> +
> + *pfd = bpf_create_map(def.type,
> + def.key_size,
> + def.value_size,
> + def.max_entries);
> + if (*pfd < 0) {
> + size_t j;
> + int err = *pfd;
> +
> + pr_warning("failed to create map: %s\n",
> + strerror(errno));
> + for (j = 0; j < i; j++)
> + zclose(obj->map_fds[j]);
> + obj->nr_map_fds = 0;
> + zfree(&obj->map_fds);
> + return err;
> + }
> + pr_debug("create map: fd=%d\n", *pfd);
> + pfd++;
> + }
> +
> + zfree(&obj->maps_buf);
> + obj->maps_buf_sz = 0;
> + return 0;
> +}
> +
> static int bpf_object__collect_reloc(struct bpf_object *obj)
> {
> int i, err;
> @@ -671,6 +736,42 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
> return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz);
> }
>
> +int bpf_object__unload(struct bpf_object *obj)
> +{
> + size_t i;
> +
> + if (!obj)
> + return -EINVAL;
> +
> + for (i = 0; i < obj->nr_map_fds; i++)
> + zclose(obj->map_fds[i]);
> + zfree(&obj->map_fds);
> + obj->nr_map_fds = 0;
> +
> + return 0;
> +}
> +
> +int bpf_object__load(struct bpf_object *obj)
> +{
> + if (!obj)
> + return -EINVAL;
> +
> + if (obj->loaded) {
> + pr_warning("object should not be loaded twice\n");
> + return -EINVAL;
> + }
> +
> + obj->loaded = true;
> + if (bpf_object__create_maps(obj))
> + goto out;
> +
> + return 0;
> +out:
> + bpf_object__unload(obj);
> + pr_warning("failed to load object '%s'\n", obj->path);
> + return -EINVAL;
> +}
> +
> void bpf_object__close(struct bpf_object *obj)
> {
> size_t i;
> @@ -679,6 +780,7 @@ void bpf_object__close(struct bpf_object *obj)
> return;
>
> bpf_object__elf_finish(obj);
> + bpf_object__unload(obj);
>
> zfree(&obj->maps_buf);
>
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index 6e75acd..3e69600 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -30,6 +30,10 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
> size_t obj_buf_sz);
> void bpf_object__close(struct bpf_object *object);
>
> +/* Load/unload object into/from kernel */
> +int bpf_object__load(struct bpf_object *obj);
> +int bpf_object__unload(struct bpf_object *obj);
> +
> /*
> * We don't need __attribute__((packed)) now since it is
> * unnecessary for 'bpf_map_def' because they are all aligned.
> --
> 1.8.3.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
