Details
Major Description
Running valgrind against my own recent commit showed up many errors in the existing code.
==27992== Conditional jump or move depends on uninitialised value(s)
==27992== at 0x4388A5: _fdb_kvs_header_import (kv_instance.cc:793)
==27992== by 0x439BAA: fdb_kvs_header_read (kv_instance.cc:995)
==27992== by 0x421D33: _fdb_open (forestdb.cc:1674)
==27992== by 0x422346: fdb_open_custom_cmp (forestdb.cc:687)
==27992== by 0x43F1B0: multi_kv_test(unsigned char, unsigned long) (multi_kv_functional_test.cc:316)
==27992== by 0x402DFB: main (multi_kv_functional_test.cc:2414)
==27992== Uninitialised value was created by a stack allocation
==27992== at 0x41FF30: _fdb_open (forestdb.cc:1323)
There is a path through fdb_open which leaves the version variable un-initialised but later used.
fdb_status _fdb_open(fdb_kvs_handle *handle,
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const char *filename,
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fdb_filename_mode_t filename_mode,
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const fdb_config *config)
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{
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...
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uint64_t version; <- NOT Initialised
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...
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// If cloning from a snapshot handle, fdb_snapshot_open would have already
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// set handle->last_hdr_bid to the block id of required header, so rewind..
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if (handle->shandle && handle->last_hdr_bid) {
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status = filemgr_fetch_header(handle->file, handle->last_hdr_bid,
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header_buf, &header_len, &seqnum,
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&header_revnum, NULL, &version, <- INITIALISED
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&handle->log_callback);
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if (status != FDB_RESULT_SUCCESS) {
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free(handle->filename);
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handle->filename = NULL;
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filemgr_close(handle->file, false, handle->filename,
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&handle->log_callback);
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return status;
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}
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} else { // Normal open
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version not initialised on this path
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filemgr_get_header(handle->file, header_buf, &header_len,
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&handle->last_hdr_bid, &seqnum, &header_revnum);
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}
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...
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line 1674 passes version and it is not initialised.
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fdb_kvs_header_read(handle->file, handle->dhandle, kv_info_offset,
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version, false);
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...
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Inside fdb_kvs_header_read->_fdb_kvs_header_import the version parameter is used in an if
// Version control
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if (version == FILEMGR_MAGIC_V1) {
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is_deltasize = false;
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_deltasize = 0;
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} else {
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is_deltasize = true;
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}
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