From bb180fb2401dfed0ba85699064e60d62af351ff9 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 18 Aug 2020 14:33:52 -0700 Subject: [PATCH] libbpf: Factor out common logic of testing and closing FD Factor out common piece of logic that detects support for a feature based on successfully created FD. Also take care of closing FD, if it was created. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200818213356.2629020-4-andriin@fb.com --- tools/lib/bpf/libbpf.c | 70 ++++++++++++-------------------------------------- 1 file changed, 17 insertions(+), 53 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2ee168822d33..08875ab9fe35 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3431,6 +3431,13 @@ bpf_object__probe_loading(struct bpf_object *obj) return 0; } +static int probe_fd(int fd) +{ + if (fd >= 0) + close(fd); + return fd >= 0; +} + static int probe_kern_prog_name(void) { struct bpf_load_program_attr attr; @@ -3449,12 +3456,7 @@ static int probe_kern_prog_name(void) attr.license = "GPL"; attr.name = "test"; ret = bpf_load_program_xattr(&attr, NULL, 0); - if (ret >= 0) { - close(ret); - return 1; - } - - return 0; + return probe_fd(ret); } static int probe_kern_global_data(void) @@ -3495,12 +3497,7 @@ static int probe_kern_global_data(void) ret = bpf_load_program_xattr(&prg_attr, NULL, 0); close(map); - if (ret >= 0) { - close(ret); - return 1; - } - - return 0; + return probe_fd(ret); } static int probe_kern_btf_func(void) @@ -3516,16 +3513,9 @@ static int probe_kern_btf_func(void) /* FUNC x */ /* [3] */ BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2), }; - int btf_fd; - btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types), - strs, sizeof(strs)); - if (btf_fd >= 0) { - close(btf_fd); - return 1; - } - - return 0; + return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types), + strs, sizeof(strs))); } static int probe_kern_btf_func_global(void) @@ -3541,16 +3531,9 @@ static int probe_kern_btf_func_global(void) /* FUNC x BTF_FUNC_GLOBAL */ /* [3] */ BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, BTF_FUNC_GLOBAL), 2), }; - int btf_fd; - btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types), - strs, sizeof(strs)); - if (btf_fd >= 0) { - close(btf_fd); - return 1; - } - - return 0; + return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types), + strs, sizeof(strs))); } static int probe_kern_btf_datasec(void) @@ -3567,16 +3550,9 @@ static int probe_kern_btf_datasec(void) BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4), BTF_VAR_SECINFO_ENC(2, 0, 4), }; - int btf_fd; - btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types), - strs, sizeof(strs)); - if (btf_fd >= 0) { - close(btf_fd); - return 1; - } - - return 0; + return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types), + strs, sizeof(strs))); } static int probe_kern_array_mmap(void) @@ -3588,14 +3564,8 @@ static int probe_kern_array_mmap(void) .value_size = sizeof(int), .max_entries = 1, }; - int fd; - fd = bpf_create_map_xattr(&attr); - if (fd >= 0) { - close(fd); - return 1; - } - return 0; + return probe_fd(bpf_create_map_xattr(&attr)); } static int probe_kern_exp_attach_type(void) @@ -3605,7 +3575,6 @@ static int probe_kern_exp_attach_type(void) BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }; - int fd; memset(&attr, 0, sizeof(attr)); /* use any valid combination of program type and (optional) @@ -3619,12 +3588,7 @@ static int probe_kern_exp_attach_type(void) attr.insns_cnt = ARRAY_SIZE(insns); attr.license = "GPL"; - fd = bpf_load_program_xattr(&attr, NULL, 0); - if (fd >= 0) { - close(fd); - return 1; - } - return 0; + return probe_fd(bpf_load_program_xattr(&attr, NULL, 0)); } enum kern_feature_result { -- 2.11.0