diff options
| -rw-r--r-- | kernel/bpf/btf.c | 62 |
1 files changed, 58 insertions, 4 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 2ce61c3a7e28..4fefa27d5aea 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3494,6 +3494,41 @@ end: #undef field_mask_test_name +/* Repeat a field for a specified number of times. + * + * Copy and repeat the first field for repeat_cnt + * times. The field is repeated by adding the offset of each field + * with + * (i + 1) * elem_size + * where i is the repeat index and elem_size is the size of an element. + */ +static int btf_repeat_field(struct btf_field_info *info, + u32 repeat_cnt, u32 elem_size) +{ + u32 i; + u32 cur; + + /* Ensure not repeating fields that should not be repeated. */ + switch (info[0].type) { + case BPF_KPTR_UNREF: + case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: + case BPF_LIST_HEAD: + case BPF_RB_ROOT: + break; + default: + return -EINVAL; + } + + cur = 1; + for (i = 0; i < repeat_cnt; i++) { + memcpy(&info[cur], &info[0], sizeof(info[0])); + info[cur++].off += (i + 1) * elem_size; + } + + return 0; +} + static int btf_find_field_one(const struct btf *btf, const struct btf_type *var, const struct btf_type *var_type, @@ -3504,6 +3539,21 @@ static int btf_find_field_one(const struct btf *btf, { int ret, align, sz, field_type; struct btf_field_info tmp; + const struct btf_array *array; + u32 i, nelems = 1; + + /* Walk into array types to find the element type and the number of + * elements in the (flattened) array. + */ + for (i = 0; i < MAX_RESOLVE_DEPTH && btf_type_is_array(var_type); i++) { + array = btf_array(var_type); + nelems *= array->nelems; + var_type = btf_type_by_id(btf, array->type); + } + if (i == MAX_RESOLVE_DEPTH) + return -E2BIG; + if (nelems == 0) + return 0; field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off), field_mask, seen_mask, &align, &sz); @@ -3512,7 +3562,7 @@ static int btf_find_field_one(const struct btf *btf, if (field_type < 0) return field_type; - if (expected_size && expected_size != sz) + if (expected_size && expected_size != sz * nelems) return 0; if (off % align) return 0; @@ -3552,10 +3602,14 @@ static int btf_find_field_one(const struct btf *btf, if (ret == BTF_FIELD_IGNORE) return 0; - if (!info_cnt) + if (nelems > info_cnt) return -E2BIG; - - return 1; + if (nelems > 1) { + ret = btf_repeat_field(info, nelems - 1, sz); + if (ret < 0) + return ret; + } + return nelems; } static int btf_find_struct_field(const struct btf *btf, |