Similar to previous bpf_prog_load() and bpf_map_create() APIs, add bpf_btf_load() API which is taking optional OPTS struct. Schedule bpf_load_btf() for deprecation in v0.8 ([0]). This makes naming consistent with BPF_BTF_LOAD command, sets up an API for extensibility in the future, moves options parameters (log-related fields) into optional options, and also allows to pass log_level directly. It also removes log buffer auto-allocation logic from low-level API (consistent with bpf_prog_load() behavior), but preserves a special treatment of log_level == 0 with non-NULL log_buf, which matches low-level bpf_prog_load() and high-level libbpf APIs for BTF and program loading behaviors. [0] Closes: https://github.com/libbpf/libbpf/issues/419 Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> --- tools/lib/bpf/bpf.c | 59 +++++++++++++++++++++++++++++------ tools/lib/bpf/bpf.h | 19 +++++++++-- tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/libbpf_probes.c | 2 +- 4 files changed, 69 insertions(+), 12 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index c7627fc18952..61931efc4fc1 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -1047,24 +1047,65 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd) return libbpf_err_errno(fd); } -int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size, - bool do_log) +int bpf_btf_load(const void *btf_data, size_t btf_size, const struct bpf_btf_load_opts *opts) { - union bpf_attr attr = {}; + const size_t attr_sz = offsetofend(union bpf_attr, btf_log_level); + union bpf_attr attr; + char *log_buf; + size_t log_size; + __u32 log_level; int fd; - attr.btf = ptr_to_u64(btf); + memset(&attr, 0, attr_sz); + + if (!OPTS_VALID(opts, bpf_btf_load_opts)) + return libbpf_err(-EINVAL); + + log_buf = OPTS_GET(opts, log_buf, NULL); + log_size = OPTS_GET(opts, log_size, 0); + log_level = OPTS_GET(opts, log_level, 0); + + if (log_size > UINT_MAX) + return libbpf_err(-EINVAL); + if (log_size && !log_buf) + return libbpf_err(-EINVAL); + + attr.btf = ptr_to_u64(btf_data); attr.btf_size = btf_size; + /* log_level == 0 and log_buf != NULL means "try loading without + * log_buf, but retry with log_buf and log_level=1 on error", which is + * consistent across low-level and high-level BTF and program loading + * APIs within libbpf and provides a sensible behavior in practice + */ + if (log_level) { + attr.btf_log_buf = ptr_to_u64(log_buf); + attr.btf_log_size = (__u32)log_size; + attr.btf_log_level = log_level; + } -retry: - if (do_log && log_buf && log_buf_size) { - attr.btf_log_level = 1; - attr.btf_log_size = log_buf_size; + fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); + if (fd < 0 && log_buf && log_level == 0) { attr.btf_log_buf = ptr_to_u64(log_buf); + attr.btf_log_size = (__u32)log_size; + attr.btf_log_level = log_level; + fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); } + return libbpf_err_errno(fd); +} + +int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size, bool do_log) +{ + LIBBPF_OPTS(bpf_btf_load_opts, opts); + int fd; - fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, sizeof(attr)); +retry: + if (do_log && log_buf && log_buf_size) { + opts.log_buf = log_buf; + opts.log_size = log_buf_size; + opts.log_level = 1; + } + fd = bpf_btf_load(btf, btf_size, &opts); if (fd < 0 && !do_log && log_buf && log_buf_size) { do_log = true; goto retry; diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index f79e5fbcf1c1..5f7d9636643d 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -213,6 +213,23 @@ LIBBPF_API int bpf_verify_program(enum bpf_prog_type type, char *log_buf, size_t log_buf_sz, int log_level); +struct bpf_btf_load_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ + + /* kernel log options */ + char *log_buf; + __u32 log_level; + __u32 log_size; +}; +#define bpf_btf_load_opts__last_field log_size + +LIBBPF_API int bpf_btf_load(const void *btf_data, size_t btf_size, + const struct bpf_btf_load_opts *opts); + +LIBBPF_DEPRECATED_SINCE(0, 8, "use bpf_btf_load() instead") +LIBBPF_API int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, + __u32 log_buf_size, bool do_log); + LIBBPF_API int bpf_map_update_elem(int fd, const void *key, const void *value, __u64 flags); @@ -340,8 +357,6 @@ LIBBPF_API int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt); LIBBPF_API int bpf_raw_tracepoint_open(const char *name, int prog_fd); -LIBBPF_API int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, - __u32 log_buf_size, bool do_log); LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, __u64 *probe_addr); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 715df3a27389..08cdfe840436 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -422,6 +422,7 @@ LIBBPF_0.6.0 { LIBBPF_0.7.0 { global: + bpf_btf_load; bpf_program__log_level; bpf_program__set_log_level; }; diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index 41f2be47c2ea..4bdec69523a7 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -164,7 +164,7 @@ int libbpf__load_raw_btf(const char *raw_types, size_t types_len, memcpy(raw_btf + hdr.hdr_len, raw_types, hdr.type_len); memcpy(raw_btf + hdr.hdr_len + hdr.type_len, str_sec, hdr.str_len); - btf_fd = bpf_load_btf(raw_btf, btf_len, NULL, 0, false); + btf_fd = bpf_btf_load(raw_btf, btf_len, NULL); free(raw_btf); return btf_fd; -- 2.30.2
