return btf_commit_type(btf, sz);
}
-struct btf_ext_sec_setup_param {
+struct btf_ext_sec_info_param {
__u32 off;
__u32 len;
__u32 min_rec_size;
const char *desc;
};
-static int btf_ext_setup_info(struct btf_ext *btf_ext,
- struct btf_ext_sec_setup_param *ext_sec)
+/*
+ * Parse a single info subsection of the BTF.ext info data:
+ * - validate subsection structure and elements
+ * - save info subsection start and sizing details in struct btf_ext
+ * - endian-independent operation, for calling before byte-swapping
+ */
+static int btf_ext_parse_sec_info(struct btf_ext *btf_ext,
+ struct btf_ext_sec_info_param *ext_sec,
+ bool is_native)
{
const struct btf_ext_info_sec *sinfo;
struct btf_ext_info *ext_info;
__u32 info_left, record_size;
size_t sec_cnt = 0;
- /* The start of the info sec (including the __u32 record_size). */
void *info;
if (ext_sec->len == 0)
return -EINVAL;
}
+ /* The start of the info sec (including the __u32 record_size). */
info = btf_ext->data + btf_ext->hdr->hdr_len + ext_sec->off;
info_left = ext_sec->len;
return -EINVAL;
}
- /* The record size needs to meet the minimum standard */
- record_size = *(__u32 *)info;
+ /* The record size needs to meet either the minimum standard or, when
+ * handling non-native endianness data, the exact standard so as
+ * to allow safe byte-swapping.
+ */
+ record_size = is_native ? *(__u32 *)info : bswap_32(*(__u32 *)info);
if (record_size < ext_sec->min_rec_size ||
+ (!is_native && record_size != ext_sec->min_rec_size) ||
record_size & 0x03) {
pr_debug("%s section in .BTF.ext has invalid record size %u\n",
ext_sec->desc, record_size);
return -EINVAL;
}
- num_records = sinfo->num_info;
+ num_records = is_native ? sinfo->num_info : bswap_32(sinfo->num_info);
if (num_records == 0) {
pr_debug("%s section has incorrect num_records in .BTF.ext\n",
ext_sec->desc);
return 0;
}
-static int btf_ext_setup_func_info(struct btf_ext *btf_ext)
+/* Parse all info secs in the BTF.ext info data */
+static int btf_ext_parse_info(struct btf_ext *btf_ext, bool is_native)
{
- struct btf_ext_sec_setup_param param = {
+ struct btf_ext_sec_info_param func_info = {
.off = btf_ext->hdr->func_info_off,
.len = btf_ext->hdr->func_info_len,
.min_rec_size = sizeof(struct bpf_func_info_min),
.ext_info = &btf_ext->func_info,
.desc = "func_info"
};
-
- return btf_ext_setup_info(btf_ext, ¶m);
-}
-
-static int btf_ext_setup_line_info(struct btf_ext *btf_ext)
-{
- struct btf_ext_sec_setup_param param = {
+ struct btf_ext_sec_info_param line_info = {
.off = btf_ext->hdr->line_info_off,
.len = btf_ext->hdr->line_info_len,
.min_rec_size = sizeof(struct bpf_line_info_min),
.ext_info = &btf_ext->line_info,
.desc = "line_info",
};
-
- return btf_ext_setup_info(btf_ext, ¶m);
-}
-
-static int btf_ext_setup_core_relos(struct btf_ext *btf_ext)
-{
- struct btf_ext_sec_setup_param param = {
+ struct btf_ext_sec_info_param core_relo = {
.off = btf_ext->hdr->core_relo_off,
.len = btf_ext->hdr->core_relo_len,
.min_rec_size = sizeof(struct bpf_core_relo),
.ext_info = &btf_ext->core_relo_info,
.desc = "core_relo",
};
+ int err;
+
+ err = btf_ext_parse_sec_info(btf_ext, &func_info, is_native);
+ if (err)
+ return err;
+
+ err = btf_ext_parse_sec_info(btf_ext, &line_info, is_native);
+ if (err)
+ return err;
+
+ if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len))
+ return 0; /* skip core relos parsing */
- return btf_ext_setup_info(btf_ext, ¶m);
+ err = btf_ext_parse_sec_info(btf_ext, &core_relo, is_native);
+ if (err)
+ return err;
+
+ return 0;
}
-static int btf_ext_parse_hdr(__u8 *data, __u32 data_size)
+/* Swap byte-order of BTF.ext header with any endianness */
+static void btf_ext_bswap_hdr(struct btf_ext_header *h)
{
- const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
+ bool is_native = h->magic == BTF_MAGIC;
+ __u32 hdr_len;
- if (data_size < offsetofend(struct btf_ext_header, hdr_len) ||
- data_size < hdr->hdr_len) {
- pr_debug("BTF.ext header not found\n");
+ hdr_len = is_native ? h->hdr_len : bswap_32(h->hdr_len);
+
+ h->magic = bswap_16(h->magic);
+ h->hdr_len = bswap_32(h->hdr_len);
+ h->func_info_off = bswap_32(h->func_info_off);
+ h->func_info_len = bswap_32(h->func_info_len);
+ h->line_info_off = bswap_32(h->line_info_off);
+ h->line_info_len = bswap_32(h->line_info_len);
+
+ if (hdr_len < offsetofend(struct btf_ext_header, core_relo_len))
+ return;
+
+ h->core_relo_off = bswap_32(h->core_relo_off);
+ h->core_relo_len = bswap_32(h->core_relo_len);
+}
+
+/* Swap byte-order of generic info subsection */
+static void btf_ext_bswap_info_sec(void *info, __u32 len, bool is_native,
+ info_rec_bswap_fn bswap_fn)
+{
+ struct btf_ext_info_sec *sec;
+ __u32 info_left, rec_size, *rs;
+
+ if (len == 0)
+ return;
+
+ rs = info; /* info record size */
+ rec_size = is_native ? *rs : bswap_32(*rs);
+ *rs = bswap_32(*rs);
+
+ sec = info + sizeof(__u32); /* info sec #1 */
+ info_left = len - sizeof(__u32);
+ while (info_left) {
+ unsigned int sec_hdrlen = sizeof(struct btf_ext_info_sec);
+ __u32 i, num_recs;
+ void *p;
+
+ num_recs = is_native ? sec->num_info : bswap_32(sec->num_info);
+ sec->sec_name_off = bswap_32(sec->sec_name_off);
+ sec->num_info = bswap_32(sec->num_info);
+ p = sec->data; /* info rec #1 */
+ for (i = 0; i < num_recs; i++, p += rec_size)
+ bswap_fn(p);
+ sec = p;
+ info_left -= sec_hdrlen + (__u64)rec_size * num_recs;
+ }
+}
+
+/*
+ * Swap byte-order of all info data in a BTF.ext section
+ * - requires BTF.ext hdr in native endianness
+ */
+static void btf_ext_bswap_info(struct btf_ext *btf_ext, void *data)
+{
+ const bool is_native = btf_ext->swapped_endian;
+ const struct btf_ext_header *h = data;
+ void *info;
+
+ /* Swap func_info subsection byte-order */
+ info = data + h->hdr_len + h->func_info_off;
+ btf_ext_bswap_info_sec(info, h->func_info_len, is_native,
+ (info_rec_bswap_fn)bpf_func_info_bswap);
+
+ /* Swap line_info subsection byte-order */
+ info = data + h->hdr_len + h->line_info_off;
+ btf_ext_bswap_info_sec(info, h->line_info_len, is_native,
+ (info_rec_bswap_fn)bpf_line_info_bswap);
+
+ /* Swap core_relo subsection byte-order (if present) */
+ if (h->hdr_len < offsetofend(struct btf_ext_header, core_relo_len))
+ return;
+
+ info = data + h->hdr_len + h->core_relo_off;
+ btf_ext_bswap_info_sec(info, h->core_relo_len, is_native,
+ (info_rec_bswap_fn)bpf_core_relo_bswap);
+}
+
+/* Parse hdr data and info sections: check and convert to native endianness */
+static int btf_ext_parse(struct btf_ext *btf_ext)
+{
+ __u32 hdr_len, data_size = btf_ext->data_size;
+ struct btf_ext_header *hdr = btf_ext->hdr;
+ bool swapped_endian = false;
+ int err;
+
+ if (data_size < offsetofend(struct btf_ext_header, hdr_len)) {
+ pr_debug("BTF.ext header too short\n");
return -EINVAL;
}
+ hdr_len = hdr->hdr_len;
if (hdr->magic == bswap_16(BTF_MAGIC)) {
- pr_warn("BTF.ext in non-native endianness is not supported\n");
- return -ENOTSUP;
+ swapped_endian = true;
+ hdr_len = bswap_32(hdr_len);
} else if (hdr->magic != BTF_MAGIC) {
pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic);
return -EINVAL;
}
- if (hdr->version != BTF_VERSION) {
+ /* Ensure known version of structs, current BTF_VERSION == 1 */
+ if (hdr->version != 1) {
pr_debug("Unsupported BTF.ext version:%u\n", hdr->version);
return -ENOTSUP;
}
return -ENOTSUP;
}
- if (data_size == hdr->hdr_len) {
+ if (data_size < hdr_len) {
+ pr_debug("BTF.ext header not found\n");
+ return -EINVAL;
+ } else if (data_size == hdr_len) {
pr_debug("BTF.ext has no data\n");
return -EINVAL;
}
+ /* Verify mandatory hdr info details present */
+ if (hdr_len < offsetofend(struct btf_ext_header, line_info_len)) {
+ pr_warn("BTF.ext header missing func_info, line_info\n");
+ return -EINVAL;
+ }
+
+ /* Keep hdr native byte-order in memory for introspection */
+ if (swapped_endian)
+ btf_ext_bswap_hdr(btf_ext->hdr);
+
+ /* Validate info subsections and cache key metadata */
+ err = btf_ext_parse_info(btf_ext, !swapped_endian);
+ if (err)
+ return err;
+
+ /* Keep infos native byte-order in memory for introspection */
+ if (swapped_endian)
+ btf_ext_bswap_info(btf_ext, btf_ext->data);
+
+ /*
+ * Set btf_ext->swapped_endian only after all header and info data has
+ * been swapped, helping bswap functions determine if their data are
+ * in native byte-order when called.
+ */
+ btf_ext->swapped_endian = swapped_endian;
return 0;
}
free(btf_ext->line_info.sec_idxs);
free(btf_ext->core_relo_info.sec_idxs);
free(btf_ext->data);
+ free(btf_ext->data_swapped);
free(btf_ext);
}
}
memcpy(btf_ext->data, data, size);
- err = btf_ext_parse_hdr(btf_ext->data, size);
- if (err)
- goto done;
-
- if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, line_info_len)) {
- err = -EINVAL;
- goto done;
- }
-
- err = btf_ext_setup_func_info(btf_ext);
- if (err)
- goto done;
-
- err = btf_ext_setup_line_info(btf_ext);
- if (err)
- goto done;
-
- if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len))
- goto done; /* skip core relos parsing */
-
- err = btf_ext_setup_core_relos(btf_ext);
- if (err)
- goto done;
+ err = btf_ext_parse(btf_ext);
done:
if (err) {
return btf_ext;
}
+static void *btf_ext_raw_data(const struct btf_ext *btf_ext_ro, bool swap_endian)
+{
+ struct btf_ext *btf_ext = (struct btf_ext *)btf_ext_ro;
+ const __u32 data_sz = btf_ext->data_size;
+ void *data;
+
+ /* Return native data (always present) or swapped data if present */
+ if (!swap_endian)
+ return btf_ext->data;
+ else if (btf_ext->data_swapped)
+ return btf_ext->data_swapped;
+
+ /* Recreate missing swapped data, then cache and return */
+ data = calloc(1, data_sz);
+ if (!data)
+ return NULL;
+ memcpy(data, btf_ext->data, data_sz);
+
+ btf_ext_bswap_info(btf_ext, data);
+ btf_ext_bswap_hdr(data);
+ btf_ext->data_swapped = data;
+ return data;
+}
+
const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size)
{
+ void *data;
+
+ data = btf_ext_raw_data(btf_ext, btf_ext->swapped_endian);
+ if (!data)
+ return errno = ENOMEM, NULL;
+
*size = btf_ext->data_size;
- return btf_ext->data;
+ return data;
}
__attribute__((alias("btf_ext__raw_data")))
const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size);
+enum btf_endianness btf_ext__endianness(const struct btf_ext *btf_ext)
+{
+ if (is_host_big_endian())
+ return btf_ext->swapped_endian ? BTF_LITTLE_ENDIAN : BTF_BIG_ENDIAN;
+ else
+ return btf_ext->swapped_endian ? BTF_BIG_ENDIAN : BTF_LITTLE_ENDIAN;
+}
+
+int btf_ext__set_endianness(struct btf_ext *btf_ext, enum btf_endianness endian)
+{
+ if (endian != BTF_LITTLE_ENDIAN && endian != BTF_BIG_ENDIAN)
+ return libbpf_err(-EINVAL);
+
+ btf_ext->swapped_endian = is_host_big_endian() != (endian == BTF_BIG_ENDIAN);
+
+ if (!btf_ext->swapped_endian) {
+ free(btf_ext->data_swapped);
+ btf_ext->data_swapped = NULL;
+ }
+ return 0;
+}
struct btf_dedup;
projects / linux-block.git / commitdiff