Fix: don't attempt to mmap packet at end of file

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/plugins/ctf/fs/data-stream.c b/plugins/ctf/fs/data-stream.c
index 949c2c3acd04b6ca0d95412e11554b5907d51583..a71cc00744d89f86f226adb4ff575632515852e4 100644 (file)
--- a/plugins/ctf/fs/data-stream.c
+++ b/plugins/ctf/fs/data-stream.c
@@ -66,9 +66,10 @@ end:
 }
 
 static
-int mmap_next(struct ctf_fs_stream *stream)
+enum bt_ctf_notif_iter_medium_status mmap_next(struct ctf_fs_stream *stream)
 {
-       int ret = 0;
+       enum bt_ctf_notif_iter_medium_status ret =
+                       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK;
        struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
 
        /* Unmap old region */
@@ -83,10 +84,15 @@ int mmap_next(struct ctf_fs_stream *stream)
 
        stream->mmap_valid_len = MIN(stream->file->size - stream->mmap_offset,
                        stream->mmap_max_len);
+       if (stream->mmap_valid_len == 0) {
+               ret = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF;
+               goto end;
+       }
        /* Round up to next page, assuming page size being a power of 2. */
        stream->mmap_len = (stream->mmap_valid_len + ctf_fs->page_size - 1)
                        & ~(ctf_fs->page_size - 1);
        /* Map new region */
+       assert(stream->mmap_len);
        stream->mmap_addr = mmap((void *) 0, stream->mmap_len,
                        PROT_READ, MAP_PRIVATE, fileno(stream->file->fp),
                        stream->mmap_offset);
@@ -101,7 +107,7 @@ int mmap_next(struct ctf_fs_stream *stream)
        goto end;
 error:
        stream_munmap(stream);
-       ret = -1;
+       ret = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR;
 end:
        return ret;
 }
@@ -123,16 +129,23 @@ enum bt_ctf_notif_iter_medium_status medop_request_bytes(
        /* Check if we have at least one memory-mapped byte left */
        if (remaining_mmap_bytes(stream) == 0) {
                /* Are we at the end of the file? */
-               if (stream->request_offset >= stream->file->size) {
+               if (stream->mmap_offset >= stream->file->size) {
                        PDBG("Reached end of file \"%s\" (%p)\n",
                                stream->file->path->str, stream->file->fp);
                        status = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF;
                        goto end;
                }
 
-               if (mmap_next(stream)) {
+               status = mmap_next(stream);
+               switch (status) {
+               case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK:
+                       break;
+               case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF:
+                       goto end;
+               default:
                        PERR("Cannot memory-map next region of file \"%s\" (%p)\n",
-                               stream->file->path->str, stream->file->fp);
+                                       stream->file->path->str,
+                                       stream->file->fp);
                        goto error;
                }
        }