[RFC PATCH v8 38/49] bpf tools: Load instructions buffer using load_program()

[Wang Nan <wangnan0@huawei.com>]

Extract code for loading a 'struct bpf_insn' array into kernel to
load_program() and makes bpf_program__load() to call it. Now we have
function loads instructions into kernel. It will be used by further
patches, which creates different instances from a program and load them
into kernel.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
 tools/lib/bpf/libbpf.c | 51 ++++++++++++++++++++++++++++++--------------------
 1 file changed, 31 insertions(+), 20 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5147a98..a2f2991 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -745,48 +745,59 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
 }
 
 static int
-bpf_program__load(struct bpf_program *prog,
-		  char *license, u32 kern_version)
+load_program(struct bpf_insn *insns, int insns_cnt,
+	     char *license, u32 kern_version, int *pfd)
 {
-	int fd, err;
+	int ret;
 	char *log_buf;
 
-	if (!prog->insns || !prog->insns_cnt)
+	if (!insns || !insns_cnt)
 		return -EINVAL;
 
 	log_buf = malloc(BPF_LOG_BUF_SIZE);
 	if (!log_buf)
 		pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
 
-	fd = bpf_load_program(BPF_PROG_TYPE_KPROBE, prog->insns,
-			      prog->insns_cnt, license,
-			      kern_version, log_buf,
-			      BPF_LOG_BUF_SIZE);
+	ret = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
+			       insns_cnt, license, kern_version,
+			       log_buf, BPF_LOG_BUF_SIZE);
 
-	if (fd >= 0) {
-		prog->fd = fd;
-		pr_debug("load bpf program '%s': fd = %d\n",
-			 prog->section_name, prog->fd);
-		err = 0;
+	if (ret >= 0) {
+		*pfd = ret;
+		ret = 0;
 		goto out;
 	}
 
-	err = -EINVAL;
-	pr_warning("load bpf program '%s' failed: %s\n",
-		   prog->section_name, strerror(errno));
+	ret = -EINVAL;
+	pr_warning("load bpf program failed: %s\n", strerror(errno));
 
 	if (log_buf) {
-		pr_warning("bpf: load: failed to load program '%s':\n",
-			   prog->section_name);
 		pr_warning("-- BEGIN DUMP LOG ---\n");
-		pr_warning("%s\n", log_buf);
+		pr_warning("\n%s\n", log_buf);
 		pr_warning("-- END LOG --\n");
 	}
 
 out:
+	free(log_buf);
+	return ret;
+}
+
+static int
+bpf_program__load(struct bpf_program *prog,
+		  char *license, u32 kern_version)
+{
+	int err, fd;
+
+	err = load_program(prog->insns, prog->insns_cnt,
+			   license, kern_version, &fd);
+	if (!err)
+		prog->fd = fd;
+
+	if (err)
+		pr_warning("failed to load program '%s'\n",
+			   prog->section_name);
 	zfree(&prog->insns);
 	prog->insns_cnt = 0;
-	free(log_buf);
 	return err;
 }
 
-- 
1.8.3.4