On 2015/7/14 3:54, Arnaldo Carvalho de Melo wrote:
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.
Yes, it should be better.
Thank you,
- 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
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