Hello Alexei Starovoitov,
Commit d510296d331a ("bpftool: Use syscall/loader program in "prog
load" and "gen skeleton" command.") from May 13, 2021 (linux-next),
leads to the following Smatch static checker warning:
./tools/bpf/bpftool/prog.c:1925 do_loader()
warn: missing error code here? 'bpf_object__open_file()' failed. 'err' = '0'
./tools/bpf/bpftool/prog.c
1906 static int do_loader(int argc, char **argv)
1907 {
1908 DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts);
1909 DECLARE_LIBBPF_OPTS(gen_loader_opts, gen);
1910 struct bpf_object *obj;
1911 const char *file;
1912 int err = 0;
1913
1914 if (!REQ_ARGS(1))
1915 return -1;
1916 file = GET_ARG();
1917
1918 if (verifier_logs)
1919 /* log_level1 + log_level2 + stats, but not stable UAPI */
1920 open_opts.kernel_log_level = 1 + 2 + 4;
1921
1922 obj = bpf_object__open_file(file, &open_opts);
1923 if (!obj) {
1924 p_err("failed to open object file");
--> 1925 goto err_close_obj;
set the error code?
1926 }
1927
1928 err = bpf_object__gen_loader(obj, &gen);
1929 if (err)
1930 goto err_close_obj;
1931
1932 err = bpf_object__load(obj);
1933 if (err) {
1934 p_err("failed to load object file");
1935 goto err_close_obj;
1936 }
1937
1938 if (verifier_logs) {
1939 struct dump_data dd = {};
1940
1941 kernel_syms_load(&dd);
1942 dump_xlated_plain(&dd, (void *)gen.insns, gen.insns_sz, false, false);
1943 kernel_syms_destroy(&dd);
1944 }
1945 err = try_loader(&gen);
1946 err_close_obj:
1947 bpf_object__close(obj);
1948 return err;
1949 }
regards,
dan carpenter
