[PATCH v5 00/10] Improvements to memory usage by parse events

Ian Rogers
2019-10-30T22:34:55Z

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 v5 patches add initial error print to the set, as requested by
Jiri Olsa. They also fix additional 2 missed frees in the patch
'before yyabort-ing free components' and remove a redundant new_str
variable from the patch 'add parse events handle error' as spotted by
Stephane Eranian.

The v4 patches address review comments from Jiri Olsa, turning a long
error message into a single warning, fixing the data type in a list
iterator and reordering patches.

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 (10):
perf tools: add parse events handle error
perf tools: move ALLOC_LIST into a function
perf tools: avoid a malloc for array events
perf tools: splice events onto evlist even on error
perf tools: ensure config and str in terms are unique
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
perf tools: report initial event parsing error

tools/perf/arch/powerpc/util/kvm-stat.c | 9 +-
tools/perf/builtin-stat.c | 2 +
tools/perf/builtin-trace.c | 16 +-
tools/perf/tests/parse-events.c | 3 +-
tools/perf/util/metricgroup.c | 2 +-
tools/perf/util/parse-events.c | 236 ++++++++++----
tools/perf/util/parse-events.h | 7 +
tools/perf/util/parse-events.y | 390 +++++++++++++++++-------
tools/perf/util/pmu.c | 32 +-
9 files changed, 509 insertions(+), 188 deletions(-)

--
2.24.0.rc1.363.gb1bccd3e3d-goog