[bpf-next,3/7] libbpf: factor out low-level BPF program loading helper

Message ID	20201121024616.1588175-4-andrii@kernel.org (mailing list archive)
State	New, archived
Delegated to:	BPF
Headers	show Return-Path: <bpf-owner@kernel.org> From: Andrii Nakryiko <andrii@kernel.org> To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>, <daniel@iogearbox.net> CC: <andrii@kernel.org>, <kernel-team@fb.com> Subject: [PATCH bpf-next 3/7] libbpf: factor out low-level BPF program loading helper Date: Fri, 20 Nov 2020 18:46:12 -0800 Message-ID: <20201121024616.1588175-4-andrii@kernel.org> In-Reply-To: <20201121024616.1588175-1-andrii@kernel.org> References: <20201121024616.1588175-1-andrii@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain Precedence: bulk
Series	Add kernel modules support for tracing BPF program attachments \| expand [bpf-next,0/7] Add kernel modules support for tracing BPF program attachments [bpf-next,1/7] bpf: remove hard-coded btf_vmlinux assumption from BPF verifier [bpf-next,2/7] bpf: allow to specify kernel module BTFs when attaching BPF programs [bpf-next,3/7] libbpf: factor out low-level BPF program loading helper [bpf-next,4/7] libbpf: support attachment of BPF tracing programs to kernel modules [bpf-next,5/7] selftests/bpf: add tp_btf CO-RE reloc test for modules [bpf-next,6/7] selftests/bpf: make BPF sidecar traceable function global [bpf-next,7/7] selftests/bpf: add fentry/fexit/fmod_ret selftest for kernel module

Context	Check	Description
netdev/apply	fail	Patch does not apply to bpf-next
netdev/tree_selection	success	Clearly marked for bpf-next

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index d27e34133973..e371ef91f5e8 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -214,59 +214,52 @@ alloc_zero_tailing_info(const void *orecord, __u32 cnt, return info; } -int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, - char *log_buf, size_t log_buf_sz) +int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr) { void *finfo = NULL, *linfo = NULL; union bpf_attr attr; - __u32 log_level; int fd; - if (!load_attr || !log_buf != !log_buf_sz) + if (!load_attr->log_buf != !load_attr->log_buf_sz) return -EINVAL; - log_level = load_attr->log_level; - if (log_level > (4 | 2 | 1) || (log_level && !log_buf)) + if (load_attr->log_level > (4 | 2 | 1) || (load_attr->log_level && !load_attr->log_buf)) return -EINVAL; memset(&attr, 0, sizeof(attr)); attr.prog_type = load_attr->prog_type; attr.expected_attach_type = load_attr->expected_attach_type; - if (attr.prog_type == BPF_PROG_TYPE_STRUCT_OPS || - attr.prog_type == BPF_PROG_TYPE_LSM) { - attr.attach_btf_id = load_attr->attach_btf_id; - } else if (attr.prog_type == BPF_PROG_TYPE_TRACING || - attr.prog_type == BPF_PROG_TYPE_EXT) { - attr.attach_btf_id = load_attr->attach_btf_id; - attr.attach_prog_fd = load_attr->attach_prog_fd; - } else { - attr.prog_ifindex = load_attr->prog_ifindex; - attr.kern_version = load_attr->kern_version; - } - attr.insn_cnt = (__u32)load_attr->insns_cnt; + + attr.attach_btf_id = load_attr->attach_btf_id; + attr.attach_prog_fd = load_attr->attach_prog_fd; + + attr.prog_ifindex = load_attr->prog_ifindex; + attr.kern_version = load_attr->kern_version; + + attr.insn_cnt = (__u32)load_attr->insn_cnt; attr.insns = ptr_to_u64(load_attr->insns); attr.license = ptr_to_u64(load_attr->license); - attr.log_level = log_level; - if (log_level) { - attr.log_buf = ptr_to_u64(log_buf); - attr.log_size = log_buf_sz; - } else { - attr.log_buf = ptr_to_u64(NULL); - attr.log_size = 0; + attr.log_level = load_attr->log_level; + if (attr.log_level) { + attr.log_buf = ptr_to_u64(load_attr->log_buf); + attr.log_size = load_attr->log_buf_sz; } attr.prog_btf_fd = load_attr->prog_btf_fd; + attr.prog_flags = load_attr->prog_flags; + attr.func_info_rec_size = load_attr->func_info_rec_size; attr.func_info_cnt = load_attr->func_info_cnt; attr.func_info = ptr_to_u64(load_attr->func_info); + attr.line_info_rec_size = load_attr->line_info_rec_size; attr.line_info_cnt = load_attr->line_info_cnt; attr.line_info = ptr_to_u64(load_attr->line_info); + if (load_attr->name) memcpy(attr.prog_name, load_attr->name, - min(strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1)); - attr.prog_flags = load_attr->prog_flags; + min(strlen(load_attr->name), (size_t)BPF_OBJ_NAME_LEN - 1)); fd = sys_bpf_prog_load(&attr, sizeof(attr)); if (fd >= 0) @@ -306,19 +299,19 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, } fd = sys_bpf_prog_load(&attr, sizeof(attr)); - if (fd >= 0) goto done; } - if (log_level || !log_buf) + if (load_attr->log_level || !load_attr->log_buf) goto done; /* Try again with log */ - attr.log_buf = ptr_to_u64(log_buf); - attr.log_size = log_buf_sz; + attr.log_buf = ptr_to_u64(load_attr->log_buf); + attr.log_size = load_attr->log_buf_sz; attr.log_level = 1; - log_buf[0] = 0; + load_attr->log_buf[0] = 0; + fd = sys_bpf_prog_load(&attr, sizeof(attr)); done: free(finfo); @@ -326,6 +319,49 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, return fd; } +int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, + char *log_buf, size_t log_buf_sz) +{ + struct bpf_prog_load_params p = {}; + + if (!load_attr || !log_buf != !log_buf_sz) + return -EINVAL; + + p.prog_type = load_attr->prog_type; + p.expected_attach_type = load_attr->expected_attach_type; + switch (p.prog_type) { + case BPF_PROG_TYPE_STRUCT_OPS: + case BPF_PROG_TYPE_LSM: + p.attach_btf_id = load_attr->attach_btf_id; + break; + case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_EXT: + p.attach_btf_id = load_attr->attach_btf_id; + p.attach_prog_fd = load_attr->attach_prog_fd; + break; + default: + p.prog_ifindex = load_attr->prog_ifindex; + p.kern_version = load_attr->kern_version; + } + p.insn_cnt = load_attr->insns_cnt; + p.insns = load_attr->insns; + p.license = load_attr->license; + p.log_level = load_attr->log_level; + p.log_buf = log_buf; + p.log_buf_sz = log_buf_sz; + p.prog_btf_fd = load_attr->prog_btf_fd; + p.func_info_rec_size = load_attr->func_info_rec_size; + p.func_info_cnt = load_attr->func_info_cnt; + p.func_info = load_attr->func_info; + p.line_info_rec_size = load_attr->line_info_rec_size; + p.line_info_cnt = load_attr->line_info_cnt; + p.line_info = load_attr->line_info; + p.name = load_attr->name; + p.prog_flags = load_attr->prog_flags; + + return libbpf__bpf_prog_load(&p); +} + int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, size_t insns_cnt, const char *license, __u32 kern_version, char *log_buf, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ac1ff4e7741a..3425e594132b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -6809,7 +6809,7 @@ static int load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, char *license, __u32 kern_version, int *pfd) { - struct bpf_load_program_attr load_attr; + struct bpf_prog_load_params load_attr = {}; char *cp, errmsg[STRERR_BUFSIZE]; size_t log_buf_size = 0; char *log_buf = NULL; @@ -6818,7 +6818,6 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, if (!insns || !insns_cnt) return -EINVAL; - memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); load_attr.prog_type = prog->type; /* old kernels might not support specifying expected_attach_type */ if (!kernel_supports(FEAT_EXP_ATTACH_TYPE) && prog->sec_def && @@ -6829,19 +6828,14 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, if (kernel_supports(FEAT_PROG_NAME)) load_attr.name = prog->name; load_attr.insns = insns; - load_attr.insns_cnt = insns_cnt; + load_attr.insn_cnt = insns_cnt; load_attr.license = license; - if (prog->type == BPF_PROG_TYPE_STRUCT_OPS || - prog->type == BPF_PROG_TYPE_LSM) { - load_attr.attach_btf_id = prog->attach_btf_id; - } else if (prog->type == BPF_PROG_TYPE_TRACING || - prog->type == BPF_PROG_TYPE_EXT) { - load_attr.attach_prog_fd = prog->attach_prog_fd; - load_attr.attach_btf_id = prog->attach_btf_id; - } else { - load_attr.kern_version = kern_version; - load_attr.prog_ifindex = prog->prog_ifindex; - } + load_attr.attach_btf_id = prog->attach_btf_id; + load_attr.attach_prog_fd = prog->attach_prog_fd; + load_attr.attach_btf_id = prog->attach_btf_id; + load_attr.kern_version = kern_version; + load_attr.prog_ifindex = prog->prog_ifindex; + /* specify func_info/line_info only if kernel supports them */ btf_fd = bpf_object__btf_fd(prog->obj); if (btf_fd >= 0 && kernel_supports(FEAT_BTF_FUNC)) { @@ -6865,7 +6859,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, *log_buf = 0; } - ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size); + load_attr.log_buf = log_buf; + load_attr.log_buf_sz = log_buf_size; + ret = libbpf__bpf_prog_load(&load_attr); if (ret >= 0) { if (log_buf && load_attr.log_level) @@ -6906,9 +6902,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, pr_warn("-- BEGIN DUMP LOG ---\n"); pr_warn("\n%s\n", log_buf); pr_warn("-- END LOG --\n"); - } else if (load_attr.insns_cnt >= BPF_MAXINSNS) { + } else if (load_attr.insn_cnt >= BPF_MAXINSNS) { pr_warn("Program too large (%zu insns), at most %d insns\n", - load_attr.insns_cnt, BPF_MAXINSNS); + load_attr.insn_cnt, BPF_MAXINSNS); ret = -LIBBPF_ERRNO__PROG2BIG; } else if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) { /* Wrong program type? */ @@ -6916,7 +6912,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.prog_type = BPF_PROG_TYPE_KPROBE; load_attr.expected_attach_type = 0; - fd = bpf_load_program_xattr(&load_attr, NULL, 0); + load_attr.log_buf = NULL; + load_attr.log_buf_sz = 0; + fd = libbpf__bpf_prog_load(&load_attr); if (fd >= 0) { close(fd); ret = -LIBBPF_ERRNO__PROGTYPE; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index e569ae63808e..681073a67ae3 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -151,6 +151,35 @@ int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); int libbpf__load_raw_btf(const char *raw_types, size_t types_len, const char *str_sec, size_t str_len); +struct bpf_prog_load_params { + enum bpf_prog_type prog_type; + enum bpf_attach_type expected_attach_type; + const char *name; + const struct bpf_insn *insns; + size_t insn_cnt; + const char *license; + __u32 kern_version; + __u32 attach_prog_fd; + __u32 attach_btf_id; + __u32 prog_ifindex; + __u32 prog_btf_fd; + __u32 prog_flags; + + __u32 func_info_rec_size; + const void *func_info; + __u32 func_info_cnt; + + __u32 line_info_rec_size; + const void *line_info; + __u32 line_info_cnt; + + __u32 log_level; + char *log_buf; + size_t log_buf_sz; +}; + +int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr); + int bpf_object__section_size(const struct bpf_object *obj, const char *name, __u32 *size); int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,

[bpf-next,3/7] libbpf: factor out low-level BPF program loading helper

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