[RFC PATCH 16/22] perf bpf: create maps needed by object file.

[Wang Nan <wangnan0@huawei.com>]

This patch creates maps based on 'map' section in object file using
bpf_create_map(), and store the fds into an array in 'struct bpf_obj'.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
 tools/perf/util/bpf-loader.c | 53 ++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/bpf-loader.h |  2 ++
 2 files changed, 55 insertions(+)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 6a1c800..34ccc10 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -117,6 +117,15 @@ static void bpf_obj_close(struct bpf_obj *obj)
 		free(obj->maps);
 	if (obj->config_str)
 		free(obj->config_str);
+	if (obj->maps_fds) {
+		size_t i;
+
+		for (i = 0; i < obj->nr_maps; i++) {
+			if (obj->maps_fds[i] >= 0)
+				close(obj->maps_fds[i]);
+		}
+		free(obj->maps_fds);
+	}
 	free(obj);
 }
 
@@ -695,6 +704,48 @@ out:
 	return err;
 }
 
+static int
+bpf_obj_create_maps(struct bpf_obj *obj)
+{
+	unsigned int i;
+	size_t nr_maps = obj->nr_maps;
+	int *pfd;
+
+	if (!nr_maps) {
+		pr_debug("bpf: don't need create maps for %s\n",
+			 obj->path);
+		return 0;
+	}
+
+	obj->maps_fds = malloc(sizeof(int) * nr_maps);
+	if (!obj->maps_fds) {
+		pr_err("bpf: realloc perf_bpf_maps_fds failed\n");
+		return -ENOMEM;
+	}
+
+	/* fill all fd with -1 */
+	memset(obj->maps_fds, 0xff, sizeof(int) * nr_maps);
+	
+	pfd = obj->maps_fds;
+	for (i = 0; i < nr_maps; i++) {
+		*pfd = bpf_create_map(&obj->maps[i]);
+		if (*pfd < 0) {
+			size_t j;
+
+			pr_err("bpf: failed to create map: %s\n",
+				strerror(errno));
+			for (j = 0; j < i; i++) {
+				close(obj->maps_fds[j]);
+				obj->maps_fds[j] = -1;
+			}
+			return *pfd;
+		}
+		pr_debug("bpf: create map: fd=%d\n", *pfd);
+		pfd ++;
+	}
+	return 0;
+}
+
 int bpf__load(const char *path)
 {
 	struct bpf_obj *obj;
@@ -723,6 +774,8 @@ int bpf__load(const char *path)
 		goto out;
 	if ((err = bpf_obj_validate(obj)))
 		goto out;
+	if ((err = bpf_obj_create_maps(obj)))
+		goto out;
 
 	list_add(&obj->list, &bpf_obj_list);
 	return 0;
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index 09f77a5..756ac2e 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -46,6 +46,8 @@ struct bpf_obj {
 	size_t nr_maps;
 	char *config_str;
 
+	int *maps_fds;
+
 	/*
 	 * Information when doing elf related work. Only valid if fd
 	 * is valid.
-- 
1.8.3.4