mbox series

[v2,0/9] Improvements to memory usage by parse events

Message ID 20191023005337.196160-1-irogers@google.com
Headers show
Series Improvements to memory usage by parse events | expand

Message

Ian Rogers Oct. 23, 2019, 12:53 a.m. UTC 
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(-)

Comments

Ian Rogers Oct. 24, 2019, 7:01 p.m. UTC | #1 
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.

The v3 patches address review comments from Jiri Olsa improving commit
messages, handling ENOMEM errors from strdup better, and removing a
printed warning if an invalid event is passed.

The v2 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 | 193 +++++++++++-----
 tools/perf/util/parse-events.h |   3 +
 tools/perf/util/parse-events.y | 388 ++++++++++++++++++++++++---------
 tools/perf/util/pmu.c          |  32 +--
 4 files changed, 449 insertions(+), 167 deletions(-)