[PATCH v4 0/9] Improvements to memory usage by parse events

From: Ian Rogers
Date: Fri Oct 25 2019 - 14:09:02 EST

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
called on the parse_events function with randomly generated input. With
the patches no leaks or memory corruption issues were present.

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 (9):
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

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 | 32 +--
4 files changed, 433 insertions(+), 167 deletions(-)