diff options
| -rw-r--r-- | src/liblzma/common/stream_decoder_mt.c | 51 |
1 files changed, 35 insertions, 16 deletions
diff --git a/src/liblzma/common/stream_decoder_mt.c b/src/liblzma/common/stream_decoder_mt.c index 32e0b892..e8939254 100644 --- a/src/liblzma/common/stream_decoder_mt.c +++ b/src/liblzma/common/stream_decoder_mt.c @@ -711,16 +711,29 @@ read_output_and_wait(struct lzma_stream_coder *coder, // Check if any thread has indicated an error. if (coder->thread_error != LZMA_OK) { - if (coder->pending_error == LZMA_OK) - coder->pending_error - = coder->thread_error; - // If LZMA_FAIL_FAST was used, report errors // from worker threads immediately. if (coder->fail_fast) { ret = coder->thread_error; break; } + + // Otherwise set pending_error. The value we + // set here will not actually get used other + // than working as a flag that an error has + // occurred. This is because in SEQ_ERROR + // all output before the error will be read + // first by calling this function, and once we + // reach the location of the (first) error the + // error code from the above lzma_outq_read() + // will be returned to the application. + // + // Use LZMA_PROG_ERROR since the value should + // never leak to the application. It's + // possible that pending_error has already + // been set but that doesn't matter: if we get + // here, pending_error only works as a flag. + coder->pending_error = LZMA_PROG_ERROR; } // Check if decoding of the next Block can be started. @@ -1150,9 +1163,18 @@ stream_decode_mt(void *coder_ptr, const lzma_allocator *allocator, // See if an error occurred. if (ret != LZMA_STREAM_END) { - if (coder->pending_error == LZMA_OK) - coder->pending_error = ret; - + // NOTE: Here and in all other places where + // pending_error is set, it may overwrite the value + // (LZMA_PROG_ERROR) set by read_output_and_wait(). + // That function might overwrite value set here too. + // These are fine because when read_output_and_wait() + // sets pending_error, it actually works as a flag + // variable only ("some error has occurred") and the + // actual value of pending_error is not used in + // SEQ_ERROR. In such cases SEQ_ERROR will eventually + // get the correct error code from the return value of + // a later read_output_and_wait() call. + coder->pending_error = ret; coder->sequence = SEQ_ERROR; break; } @@ -1163,9 +1185,7 @@ stream_decode_mt(void *coder_ptr, const lzma_allocator *allocator, if (coder->mem_next_filters == UINT64_MAX) { // One or more unknown Filter IDs. - if (coder->pending_error == LZMA_OK) - coder->pending_error = LZMA_OPTIONS_ERROR; - + coder->pending_error = LZMA_OPTIONS_ERROR; coder->sequence = SEQ_ERROR; break; } @@ -1254,9 +1274,7 @@ stream_decode_mt(void *coder_ptr, const lzma_allocator *allocator, &coder->block_options), coder->block_options.uncompressed_size); if (ret != LZMA_OK) { - if (coder->pending_error == LZMA_OK) - coder->pending_error = ret; - + coder->pending_error = ret; coder->sequence = SEQ_ERROR; break; } @@ -1425,9 +1443,7 @@ stream_decode_mt(void *coder_ptr, const lzma_allocator *allocator, // Check if memory usage calculation and Block encoder // initialization succeeded. if (ret != LZMA_OK) { - if (coder->pending_error == LZMA_OK) - coder->pending_error = ret; - + coder->pending_error = ret; coder->sequence = SEQ_ERROR; break; } @@ -1712,6 +1728,9 @@ stream_decode_mt(void *coder_ptr, const lzma_allocator *allocator, return LZMA_OK; } + // We only get here if no errors were detected by the worker + // threads. Errors from worker threads would have already been + // returned by the call to read_output_and_wait() above. return coder->pending_error; default: |