[PATCH v3 2/5] bpf: Simplify bpf_load_program() error handling in the library

[Mickaël Salaün]

Do not call a second time bpf(2) when a program load failed.

Signed-off-by: Mickaël Salaün <m...@digikod.net>
Cc: Alexei Starovoitov <a...@fb.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Cc: Wang Nan <wangn...@huawei.com>
---
 tools/lib/bpf/bpf.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 3ddb58a36d3c..fda3f494f1cd 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -73,7 +73,6 @@ int bpf_load_program(enum bpf_prog_type type, struct bpf_insn 
*insns,
                     size_t insns_cnt, char *license,
                     __u32 kern_version, char *log_buf, size_t log_buf_sz)
 {
-       int fd;
        union bpf_attr attr;
 
        bzero(&attr, sizeof(attr));
@@ -81,20 +80,15 @@ int bpf_load_program(enum bpf_prog_type type, struct 
bpf_insn *insns,
        attr.insn_cnt = (__u32)insns_cnt;
        attr.insns = ptr_to_u64(insns);
        attr.license = ptr_to_u64(license);
-       attr.log_buf = ptr_to_u64(NULL);
-       attr.log_size = 0;
-       attr.log_level = 0;
+       attr.log_buf = ptr_to_u64(log_buf);
+       attr.log_size = log_buf_sz;
        attr.kern_version = kern_version;
 
-       fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
-       if (fd >= 0 || !log_buf || !log_buf_sz)
-               return fd;
+       if (log_buf && log_buf_sz > 0) {
+               attr.log_level = 1;
+               log_buf[0] = 0;
+       }
 
-       /* Try again with log */
-       attr.log_buf = ptr_to_u64(log_buf);
-       attr.log_size = log_buf_sz;
-       attr.log_level = 1;
-       log_buf[0] = 0;
        return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
 }
 
-- 
2.11.0