diff options
Diffstat (limited to 'kernel/bpf/btf.c')
| -rw-r--r-- | kernel/bpf/btf.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 3dad828db13c..5579ff3a5b54 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3551,6 +3551,61 @@ end: return ERR_PTR(ret); } +static int btf_field_offs_cmp(const void *_a, const void *_b, const void *priv) +{ + const u32 a = *(const u32 *)_a; + const u32 b = *(const u32 *)_b; + + if (a < b) + return -1; + else if (a > b) + return 1; + return 0; +} + +static void btf_field_offs_swap(void *_a, void *_b, int size, const void *priv) +{ + struct btf_field_offs *foffs = (void *)priv; + u32 *off_base = foffs->field_off; + u32 *a = _a, *b = _b; + u8 *sz_a, *sz_b; + + sz_a = foffs->field_sz + (a - off_base); + sz_b = foffs->field_sz + (b - off_base); + + swap(*a, *b); + swap(*sz_a, *sz_b); +} + +struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec) +{ + struct btf_field_offs *foffs; + u32 i, *off; + u8 *sz; + + BUILD_BUG_ON(ARRAY_SIZE(foffs->field_off) != ARRAY_SIZE(foffs->field_sz)); + if (IS_ERR_OR_NULL(rec) || WARN_ON_ONCE(rec->cnt > sizeof(foffs->field_off))) + return NULL; + + foffs = kzalloc(sizeof(*foffs), GFP_KERNEL | __GFP_NOWARN); + if (!foffs) + return ERR_PTR(-ENOMEM); + + off = foffs->field_off; + sz = foffs->field_sz; + for (i = 0; i < rec->cnt; i++) { + off[i] = rec->fields[i].offset; + sz[i] = btf_field_type_size(rec->fields[i].type); + } + foffs->cnt = rec->cnt; + + if (foffs->cnt == 1) + return foffs; + sort_r(foffs->field_off, foffs->cnt, sizeof(foffs->field_off[0]), + btf_field_offs_cmp, btf_field_offs_swap, foffs); + return foffs; +} + static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct btf_show *show) |