// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif #include #include #include #include #include #include "bpf-utils.h" #include "debug.h" struct bpil_array_desc { int array_offset; /* e.g. offset of jited_prog_insns */ int count_offset; /* e.g. offset of jited_prog_len */ int size_offset; /* > 0: offset of rec size, * < 0: fix size of -size_offset */ }; static const struct bpil_array_desc bpil_array_desc[] = { [PERF_BPIL_JITED_INSNS] = { offsetof(struct bpf_prog_info, jited_prog_insns), offsetof(struct bpf_prog_info, jited_prog_len), -1, }, [PERF_BPIL_XLATED_INSNS] = { offsetof(struct bpf_prog_info, xlated_prog_insns), offsetof(struct bpf_prog_info, xlated_prog_len), -1, }, [PERF_BPIL_MAP_IDS] = { offsetof(struct bpf_prog_info, map_ids), offsetof(struct bpf_prog_info, nr_map_ids), -(int)sizeof(__u32), }, [PERF_BPIL_JITED_KSYMS] = { offsetof(struct bpf_prog_info, jited_ksyms), offsetof(struct bpf_prog_info, nr_jited_ksyms), -(int)sizeof(__u64), }, [PERF_BPIL_JITED_FUNC_LENS] = { offsetof(struct bpf_prog_info, jited_func_lens), offsetof(struct bpf_prog_info, nr_jited_func_lens), -(int)sizeof(__u32), }, [PERF_BPIL_FUNC_INFO] = { offsetof(struct bpf_prog_info, func_info), offsetof(struct bpf_prog_info, nr_func_info), offsetof(struct bpf_prog_info, func_info_rec_size), }, [PERF_BPIL_LINE_INFO] = { offsetof(struct bpf_prog_info, line_info), offsetof(struct bpf_prog_info, nr_line_info), offsetof(struct bpf_prog_info, line_info_rec_size), }, [PERF_BPIL_JITED_LINE_INFO] = { offsetof(struct bpf_prog_info, jited_line_info), offsetof(struct bpf_prog_info, nr_jited_line_info), offsetof(struct bpf_prog_info, jited_line_info_rec_size), }, [PERF_BPIL_PROG_TAGS] = { offsetof(struct bpf_prog_info, prog_tags), offsetof(struct bpf_prog_info, nr_prog_tags), -(int)sizeof(__u8) * BPF_TAG_SIZE, }, }; static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info, int offset) { __u32 *array = (__u32 *)info; if (offset >= 0) return array[offset / sizeof(__u32)]; return -(int)offset; } static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info, int offset) { __u64 *array = (__u64 *)info; if (offset >= 0) return array[offset / sizeof(__u64)]; return -(int)offset; } static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset, __u32 val) { __u32 *array = (__u32 *)info; if (offset >= 0) array[offset / sizeof(__u32)] = val; } static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset, __u64 val) { __u64 *array = (__u64 *)info; if (offset >= 0) array[offset / sizeof(__u64)] = val; } struct perf_bpil * get_bpf_prog_info_linear(int fd, __u64 arrays) { struct bpf_prog_info info = {}; struct perf_bpil *info_linear; __u32 info_len = sizeof(info); __u32 data_len = 0; int i, err; __u8 *ptr; if (arrays >> PERF_BPIL_LAST_ARRAY) return ERR_PTR(-EINVAL); /* step 1: get array dimensions */ err = bpf_obj_get_info_by_fd(fd, &info, &info_len); if (err) { pr_debug("can't get prog info: %s", strerror(errno)); return ERR_PTR(-EFAULT); } if (info.type >= __MAX_BPF_PROG_TYPE) pr_debug("%s:%d: unexpected program type %u\n", __func__, __LINE__, info.type); /* step 2: calculate total size of all arrays */ for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) { const struct bpil_array_desc *desc = &bpil_array_desc[i]; bool include_array = (arrays & (1UL << i)) > 0; __u32 count, size; /* kernel is too old to support this field */ if (info_len < desc->array_offset + sizeof(__u32) || info_len < desc->count_offset + sizeof(__u32) || (desc->size_offset > 0 && info_len < (__u32)desc->size_offset)) include_array = false; if (!include_array) { arrays &= ~(1UL << i); /* clear the bit */ continue; } count = bpf_prog_info_read_offset_u32(&info, desc->count_offset); size = bpf_prog_info_read_offset_u32(&info, desc->size_offset); data_len += roundup(count * size, sizeof(__u64)); } /* step 3: allocate continuous memory */ info_linear = malloc(sizeof(struct perf_bpil) + data_len); if (!info_linear) return ERR_PTR(-ENOMEM); /* step 4: fill data to info_linear->info */ info_linear->arrays = arrays; memset(&info_linear->info, 0, sizeof(info)); ptr = info_linear->data; for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) { const struct bpil_array_desc *desc = &bpil_array_desc[i]; __u32 count, size; if ((arrays & (1UL << i)) == 0) continue; count = bpf_prog_info_read_offset_u32(&info, desc->count_offset); size = bpf_prog_info_read_offset_u32(&info, desc->size_offset); bpf_prog_info_set_offset_u32(&info_linear->info, desc->count_offset, count); bpf_prog_info_set_offset_u32(&info_linear->info, desc->size_offset, size); assert(ptr >= info_linear->data); assert(ptr < &info_linear->data[data_len]); bpf_prog_info_set_offset_u64(&info_linear->info, desc->array_offset, ptr_to_u64(ptr)); ptr += roundup(count * size, sizeof(__u64)); } /* step 5: call syscall again to get required arrays */ err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len); if (err) { pr_debug("can't get prog info: %s", strerror(errno)); free(info_linear); return ERR_PTR(-EFAULT); } if (info_linear->info.type >= __MAX_BPF_PROG_TYPE) { pr_debug("%s:%d: unexpected program type %u\n", __func__, __LINE__, info_linear->info.type); } /* step 6: verify the data */ ptr = info_linear->data; for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) { const struct bpil_array_desc *desc = &bpil_array_desc[i]; __u32 count1, count2, size1, size2; __u64 ptr2; if ((arrays & (1UL << i)) == 0) continue; count1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset); count2 = bpf_prog_info_read_offset_u32(&info_linear->info, desc->count_offset); if (count1 != count2) { pr_warning("%s: mismatch in element count %u vs %u\n", __func__, count1, count2); free(info_linear); return ERR_PTR(-ERANGE); } size1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset); size2 = bpf_prog_info_read_offset_u32(&info_linear->info, desc->size_offset); if (size1 != size2) { pr_warning("%s: mismatch in rec size %u vs %u\n", __func__, size1, size2); free(info_linear); return ERR_PTR(-ERANGE); } ptr2 = bpf_prog_info_read_offset_u64(&info_linear->info, desc->array_offset); if (ptr_to_u64(ptr) != ptr2) { pr_warning("%s: mismatch in array %p vs %llx\n", __func__, ptr, ptr2); free(info_linear); return ERR_PTR(-ERANGE); } ptr += roundup(count1 * size1, sizeof(__u64)); } /* step 7: update info_len and data_len */ info_linear->info_len = sizeof(struct bpf_prog_info); info_linear->data_len = data_len; return info_linear; } void bpil_addr_to_offs(struct perf_bpil *info_linear) { int i; for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) { const struct bpil_array_desc *desc = &bpil_array_desc[i]; __u64 addr, offs; if ((info_linear->arrays & (1UL << i)) == 0) continue; addr = bpf_prog_info_read_offset_u64(&info_linear->info, desc->array_offset); offs = addr - ptr_to_u64(info_linear->data); bpf_prog_info_set_offset_u64(&info_linear->info, desc->array_offset, offs); } } void bpil_offs_to_addr(struct perf_bpil *info_linear) { int i; for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) { const struct bpil_array_desc *desc = &bpil_array_desc[i]; __u64 addr, offs; if ((info_linear->arrays & (1UL << i)) == 0) continue; offs = bpf_prog_info_read_offset_u64(&info_linear->info, desc->array_offset); addr = offs + ptr_to_u64(info_linear->data); bpf_prog_info_set_offset_u64(&info_linear->info, desc->array_offset, addr); } }