[lttng-dev] [RFC PATCH babeltrace-1.5] Fix: report truncated files while reading (v2)
Jérémie Galarneau
jeremie.galarneau at efficios.com
Tue Feb 20 15:25:16 EST 2018
Merged in master, stable-1.5, and stable-1.4.
Thanks!
Jérémie
On Tue, Feb 06, 2018 at 03:40:19PM -0500, Mathieu Desnoyers wrote:
> When index files are available, this ensures we report the issue
> properly before mapping a truncated packet rather than hitting a
> SIGBUS.
>
> For traces without index files, remove the check that was done at
> index creation, and use the new check done when mapping the packet
> instead. This ensures babeltrace can print stream data prior to the
> truncated packet for this stream.
>
> TODO: What is _not_ done in this patch is changing handling of truncated
> packets: this should be treated as a warning rather than an error, so
> processing of other streams continue.
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> CC: Jonathan Rajotte-Julien <jonathan.rajotte-julien at efficios.com>
> CC: Jérémie Galarneau <jeremie.galarneau at efficios.com>
> ---
> formats/ctf/ctf.c | 44 +++++++++++++++++++-----------------------
> include/babeltrace/ctf/types.h | 1 +
> 2 files changed, 21 insertions(+), 24 deletions(-)
>
> diff --git a/formats/ctf/ctf.c b/formats/ctf/ctf.c
> index ab98b288..b74cddd7 100644
> --- a/formats/ctf/ctf.c
> +++ b/formats/ctf/ctf.c
> @@ -1180,6 +1180,14 @@ void ctf_packet_seek(struct bt_stream_pos *stream_pos, size_t index, int whence)
> goto end;
> }
> }
> +
> + if (packet_index->packet_size > ((uint64_t) pos->file_length - packet_index->offset) * CHAR_BIT) {
> + fprintf(stderr, "[error] Packet size (%" PRIu64 " bits) is larger than remaining file size (%" PRIu64 " bits).\n",
> + packet_index->packet_size, ((uint64_t) pos->file_length - packet_index->offset) * CHAR_BIT);
> + ret = -1;
> + goto end;
> + }
> +
> pos->content_size = packet_index->content_size;
> pos->packet_size = packet_index->packet_size;
> pos->mmap_offset = packet_index->offset;
> @@ -1708,8 +1716,7 @@ int stream_assign_class(struct ctf_trace *td,
> static
> int create_stream_one_packet_index(struct ctf_stream_pos *pos,
> struct ctf_trace *td,
> - struct ctf_file_stream *file_stream,
> - size_t filesize)
> + struct ctf_file_stream *file_stream)
> {
> struct packet_index packet_index;
> uint64_t stream_id = 0;
> @@ -1724,8 +1731,8 @@ begin:
> first_packet = 1;
> }
>
> - if (filesize - pos->mmap_offset < (packet_map_len >> LOG2_CHAR_BIT)) {
> - packet_map_len = (filesize - pos->mmap_offset) << LOG2_CHAR_BIT;
> + if (pos->file_length - pos->mmap_offset < (packet_map_len >> LOG2_CHAR_BIT)) {
> + packet_map_len = (pos->file_length - pos->mmap_offset) << LOG2_CHAR_BIT;
> }
>
> if (pos->base_mma) {
> @@ -1843,7 +1850,7 @@ begin:
> packet_index.packet_size = bt_get_unsigned_int(field);
> } else {
> /* Use file size for packet size */
> - packet_index.packet_size = filesize * CHAR_BIT;
> + packet_index.packet_size = pos->file_length * CHAR_BIT;
> }
>
> /* read content size from header */
> @@ -1855,7 +1862,7 @@ begin:
> packet_index.content_size = bt_get_unsigned_int(field);
> } else {
> /* Use packet size if non-zero, else file size */
> - packet_index.content_size = packet_index.packet_size ? : filesize * CHAR_BIT;
> + packet_index.content_size = packet_index.packet_size ? : pos->file_length * CHAR_BIT;
> }
>
> /* read timestamp begin from header */
> @@ -1912,9 +1919,9 @@ begin:
> }
> } else {
> /* Use file size for packet size */
> - packet_index.packet_size = filesize * CHAR_BIT;
> + packet_index.packet_size = pos->file_length * CHAR_BIT;
> /* Use packet size if non-zero, else file size */
> - packet_index.content_size = packet_index.packet_size ? : filesize * CHAR_BIT;
> + packet_index.content_size = packet_index.packet_size ? : pos->file_length * CHAR_BIT;
> }
>
> /* Validate content size and packet size values */
> @@ -1924,12 +1931,6 @@ begin:
> return -EINVAL;
> }
>
> - if (packet_index.packet_size > ((uint64_t) filesize - packet_index.offset) * CHAR_BIT) {
> - fprintf(stderr, "[error] Packet size (%" PRIu64 " bits) is larger than remaining file size (%" PRIu64 " bits).\n",
> - packet_index.packet_size, ((uint64_t) filesize - packet_index.offset) * CHAR_BIT);
> - return -EINVAL;
> - }
> -
> if (packet_index.content_size < pos->offset) {
> fprintf(stderr, "[error] Invalid CTF stream: content size is smaller than packet headers.\n");
> return -EINVAL;
> @@ -1952,7 +1953,7 @@ begin:
>
> /* Retry with larger mapping */
> retry:
> - if (packet_map_len == ((filesize - pos->mmap_offset) << LOG2_CHAR_BIT)) {
> + if (packet_map_len == ((pos->file_length - pos->mmap_offset) << LOG2_CHAR_BIT)) {
> /*
> * Reached EOF, but still expecting header/context data.
> */
> @@ -1975,17 +1976,12 @@ int create_stream_packet_index(struct ctf_trace *td,
> struct ctf_file_stream *file_stream)
> {
> struct ctf_stream_pos *pos;
> - struct stat filestats;
> int ret;
>
> pos = &file_stream->pos;
>
> - ret = fstat(pos->fd, &filestats);
> - if (ret < 0)
> - return ret;
> -
> /* Deal with empty files */
> - if (!filestats.st_size) {
> + if (!pos->file_length) {
> if (file_stream->parent.trace_packet_header
> || file_stream->parent.stream_packet_context) {
> /*
> @@ -2008,9 +2004,8 @@ int create_stream_packet_index(struct ctf_trace *td,
> }
> }
>
> - for (pos->mmap_offset = 0; pos->mmap_offset < filestats.st_size; ) {
> - ret = create_stream_one_packet_index(pos, td, file_stream,
> - filestats.st_size);
> + for (pos->mmap_offset = 0; pos->mmap_offset < pos->file_length; ) {
> + ret = create_stream_one_packet_index(pos, td, file_stream);
> if (ret)
> return ret;
> }
> @@ -2195,6 +2190,7 @@ int ctf_open_file_stream_read(struct ctf_trace *td, const char *path, int flags,
> file_stream->pos.last_offset = LAST_OFFSET_POISON;
> file_stream->pos.fd = -1;
> file_stream->pos.index_fp = NULL;
> + file_stream->pos.file_length = statbuf.st_size;
>
> strncpy(file_stream->parent.path, path, PATH_MAX);
> file_stream->parent.path[PATH_MAX - 1] = '\0';
> diff --git a/include/babeltrace/ctf/types.h b/include/babeltrace/ctf/types.h
> index 59ce9981..0bc003c8 100644
> --- a/include/babeltrace/ctf/types.h
> +++ b/include/babeltrace/ctf/types.h
> @@ -92,6 +92,7 @@ struct ctf_stream_pos {
>
> int dummy; /* dummy position, for length calculation */
> struct bt_stream_callbacks *cb; /* Callbacks registered for iterator. */
> + size_t file_length; /* length of backing file, in bytes. */
> void *priv;
> };
>
> --
> 2.11.0
>
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