# \[PATCH v2 0/9\] Improvements to memory usage by parse events

- From: Ian Rogers \<irogers@google.com\>
- Date: 2019-10-23 00:54:01 
- List: netdev
- Page: https://ratatoskr.run/netdev/2019/10/5753173
- Thread: https://ratatoskr.run/netdev/2019/10/5753173/t.md

```text
The parse events parser leaks memory for certain expressions as well as
allowing a char* to reference stack, heap or .rodata. This series of patches
improves the hygeine and adds free-ing operations to reclaim memory in
the parser in error and non-error situations.

The series of patches was generated with LLVM's address sanitizer and
libFuzzer:
https://llvm.org/docs/LibFuzzer.html
called on the parse_events function with randomly generated input. With
the patches no leaks or memory corruption issues were present.

These patches are preferable to an earlier proposed patch:
   perf tools: avoid reading out of scope array

Ian Rogers (9):
  perf tools: add parse events append error
  perf tools: splice events onto evlist even on error
  perf tools: ensure config and str in terms are unique
  perf tools: move ALLOC_LIST into a function
  perf tools: avoid a malloc for array events
  perf tools: add destructors for parse event terms
  perf tools: before yyabort-ing free components
  perf tools: if pmu configuration fails free terms
  perf tools: add a deep delete for parse event terms

 tools/perf/util/parse-events.c | 177 ++++++++++-----
 tools/perf/util/parse-events.h |   3 +
 tools/perf/util/parse-events.y | 388 ++++++++++++++++++++++++---------
 tools/perf/util/pmu.c          |  38 ++--
 4 files changed, 431 insertions(+), 175 deletions(-)

-- 
2.23.0.866.gb869b98d4c-goog

```