diff options
| -rw-r--r-- | tools/lib/bpf/bpf.h | 3 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 24 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 41 |
3 files changed, 65 insertions, 3 deletions
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 5f7d9636643d..94e553a0ff9d 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -195,8 +195,9 @@ struct bpf_load_program_attr { /* Flags to direct loading requirements */ #define MAPS_RELAX_COMPAT 0x01 -/* Recommend log buffer size */ +/* Recommended log buffer size */ #define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */ + LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_prog_load() instead") LIBBPF_API int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, char *log_buf, size_t log_buf_sz); diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6db0b5e8540e..38999e9c08e0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -573,6 +573,11 @@ struct bpf_object { size_t btf_module_cnt; size_t btf_module_cap; + /* optional log settings passed to BPF_BTF_LOAD and BPF_PROG_LOAD commands */ + char *log_buf; + size_t log_size; + __u32 log_level; + void *priv; bpf_object_clear_priv_t clear_priv; @@ -3017,7 +3022,9 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) */ btf__set_fd(kern_btf, 0); } else { - err = btf__load_into_kernel(kern_btf); + /* currently BPF_BTF_LOAD only supports log_level 1 */ + err = btf_load_into_kernel(kern_btf, obj->log_buf, obj->log_size, + obj->log_level ? 1 : 0); } if (sanitize) { if (!err) { @@ -6932,6 +6939,9 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, struct bpf_object *obj; char tmp_name[64]; int err; + char *log_buf; + size_t log_size; + __u32 log_level; if (elf_version(EV_CURRENT) == EV_NONE) { pr_warn("failed to init libelf for %s\n", @@ -6954,10 +6964,22 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, pr_debug("loading object '%s' from buffer\n", obj_name); } + log_buf = OPTS_GET(opts, kernel_log_buf, NULL); + log_size = OPTS_GET(opts, kernel_log_size, 0); + log_level = OPTS_GET(opts, kernel_log_level, 0); + if (log_size > UINT_MAX) + return ERR_PTR(-EINVAL); + if (log_size && !log_buf) + return ERR_PTR(-EINVAL); + obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name); if (IS_ERR(obj)) return obj; + obj->log_buf = log_buf; + obj->log_size = log_size; + obj->log_level = log_level; + btf_tmp_path = OPTS_GET(opts, btf_custom_path, NULL); if (btf_tmp_path) { if (strlen(btf_tmp_path) >= PATH_MAX) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 4802c1e736c3..5c984c63859f 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -108,8 +108,47 @@ struct bpf_object_open_opts { * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. */ const char *btf_custom_path; + /* Pointer to a buffer for storing kernel logs for applicable BPF + * commands. Valid kernel_log_size has to be specified as well and are + * passed-through to bpf() syscall. Keep in mind that kernel might + * fail operation with -ENOSPC error if provided buffer is too small + * to contain entire log output. + * See the comment below for kernel_log_level for interaction between + * log_buf and log_level settings. + * + * If specified, this log buffer will be passed for: + * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden + * with bpf_program__set_log() on per-program level, to get + * BPF verifier log output. + * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get + * BTF sanity checking log. + * + * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite + * previous contents, so if you need more fine-grained control, set + * per-program buffer with bpf_program__set_log_buf() to preserve each + * individual program's verification log. Keep using kernel_log_buf + * for BTF verification log, if necessary. + */ + char *kernel_log_buf; + size_t kernel_log_size; + /* + * Log level can be set independently from log buffer. Log_level=0 + * means that libbpf will attempt loading BTF or program without any + * logging requested, but will retry with either its own or custom log + * buffer, if provided, and log_level=1 on any error. + * And vice versa, setting log_level>0 will request BTF or prog + * loading with verbose log from the first attempt (and as such also + * for successfully loaded BTF or program), and the actual log buffer + * could be either libbpf's own auto-allocated log buffer, if + * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf. + * If user didn't provide custom log buffer, libbpf will emit captured + * logs through its print callback. + */ + __u32 kernel_log_level; + + size_t :0; }; -#define bpf_object_open_opts__last_field btf_custom_path +#define bpf_object_open_opts__last_field kernel_log_level LIBBPF_API struct bpf_object *bpf_object__open(const char *path); |