diff options
Diffstat (limited to 'tools/lib/bpf/bpf.c')
| -rw-r--r-- | tools/lib/bpf/bpf.c | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 03f9bcc4ef50..ce1822194590 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -177,6 +177,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, char *log_buf, size_t log_buf_sz) { union bpf_attr attr; + void *finfo = NULL; __u32 name_len; int fd; @@ -196,6 +197,10 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.log_level = 0; attr.kern_version = load_attr->kern_version; attr.prog_ifindex = load_attr->prog_ifindex; + attr.prog_btf_fd = load_attr->prog_btf_fd; + 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); memcpy(attr.prog_name, load_attr->name, min(name_len, BPF_OBJ_NAME_LEN - 1)); @@ -203,12 +208,55 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, if (fd >= 0 || !log_buf || !log_buf_sz) return fd; + /* After bpf_prog_load, the kernel may modify certain attributes + * to give user space a hint how to deal with loading failure. + * Check to see whether we can make some changes and load again. + */ + if (errno == E2BIG && attr.func_info_cnt && + attr.func_info_rec_size < load_attr->func_info_rec_size) { + __u32 actual_rec_size = load_attr->func_info_rec_size; + __u32 expected_rec_size = attr.func_info_rec_size; + __u32 finfo_cnt = load_attr->func_info_cnt; + __u64 finfo_len = actual_rec_size * finfo_cnt; + const void *orecord; + void *nrecord; + int i; + + finfo = malloc(finfo_len); + if (!finfo) + /* further try with log buffer won't help */ + return fd; + + /* zero out bytes kernel does not understand */ + orecord = load_attr->func_info; + nrecord = finfo; + for (i = 0; i < load_attr->func_info_cnt; i++) { + memcpy(nrecord, orecord, expected_rec_size); + memset(nrecord + expected_rec_size, 0, + actual_rec_size - expected_rec_size); + orecord += actual_rec_size; + nrecord += actual_rec_size; + } + + /* try with corrected func info records */ + attr.func_info = ptr_to_u64(finfo); + attr.func_info_rec_size = load_attr->func_info_rec_size; + + fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + + if (fd >= 0 || !log_buf || !log_buf_sz) + goto done; + } + /* Try again with log */ attr.log_buf = ptr_to_u64(log_buf); attr.log_size = log_buf_sz; attr.log_level = 1; log_buf[0] = 0; - return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); +done: + free(finfo); + return fd; } int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, |