Atomic RMW is not necessary in InitializeGuardArray.
It is supposed to run when no user code runs.
And if user code runs concurrently, then the atomic
RMW won't help anyway. So replace it with non-atomic RMW.
InitializeGuardArray takes more than 50% of time during re2 fuzzing:
real 0m47.215s
51.56% a.out a.out [.] __sanitizer_reset_coverage
6.68% a.out a.out [.] __sanitizer_cov
3.41% a.out a.out [.] __sanitizer::internal_bzero_aligned16(void*, unsigned long)
1.79% a.out a.out [.] __asan::Allocator::Allocate(unsigned long, unsigned long,
With this change:
real 0m31.661s
26.21% a.out a.out [.] sanitizer_reset_coverage
10.12% a.out a.out [.] sanitizer_cov
5.38% a.out a.out [.] __sanitizer::internal_bzero_aligned16(void*, unsigned long)
2.53% a.out a.out [.] __asan::Allocator::Allocate(unsigned long, unsigned long,
That's 33% speedup.
Reviewed in http://reviews.llvm.org/D14537
llvm-svn: 252715
- Trim spaces.
- Use nullptr in place of 0 for pointer variables.
- Use '!p' in place of 'p == 0' for null pointer checks.
Patch by Eugene Zelenko!
Differential Revision: http://reviews.llvm.org/D13310
llvm-svn: 248964
Previously we had to call __sanitizer_cov_dump() from tool-specific
callbacks - instead, let sanitizer_common library handle this in a
single place.
This is a re-application of r245770, with slightly different approach
taken.
llvm-svn: 245890
These changes break both autoconf Mac OS X buildbot (linker errors
due to wrong Makefiles) and CMake buildbot (safestack test failures).
llvm-svn: 245784
Previously we had to call __sanitizer_cov_dump() from tool-specific
callbacks - instead, let sanitizer_common library handle this in a single place.
llvm-svn: 245770
On Windows, we have to know if a memory to be protected is mapped or not.
On POSIX, Mprotect was semantically different from mprotect most people know.
llvm-svn: 234602
The experiments can be used to evaluate potential optimizations that remove
instrumentation (assess false negatives). Instead of completely removing
some instrumentation, you set Exp to a non-zero value (mask of optimization
experiments that want to remove instrumentation of this instruction).
If Exp is non-zero, this pass will emit special calls into runtime
(e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
make runtime terminate the program in a special way (with a different
exit status). Then you run the new compiler on a buggy corpus, collect
the special terminations (ideally, you don't see them at all -- no false
negatives) and make the decision on the optimization.
The exact reaction to experiments in runtime is not implemented in this patch.
It will be defined and implemented in a subsequent patch.
http://reviews.llvm.org/D8198
llvm-svn: 232501
Introduce -mllvm -sanitizer-coverage-8bit-counters=1
which adds imprecise thread-unfriendly 8-bit coverage counters.
The run-time library maps these 8-bit counters to 8-bit bitsets in the same way
AFL (http://lcamtuf.coredump.cx/afl/technical_details.txt) does:
counter values are divided into 8 ranges and based on the counter
value one of the bits in the bitset is set.
The AFL ranges are used here: 1, 2, 3, 4-7, 8-15, 16-31, 32-127, 128+.
These counters provide a search heuristic for single-threaded
coverage-guided fuzzers, we do not expect them to be useful for other purposes.
Depending on the value of -fsanitize-coverage=[123] flag,
these counters will be added to the function entry blocks (=1),
every basic block (=2), or every edge (=3).
Use these counters as an optional search heuristic in the Fuzzer library.
Add a test where this heuristic is critical.
llvm-svn: 231166
pc_fd was not initialized to (-1) on some code paths, resulting in the program
erroneously closing stdin when reinitializing coverage.
llvm-svn: 225637
This increases the limit from 4M locations to 16M, reserving
64Mb virtual memory. Chrome has >5M unique coverage locations with coverage=3.
llvm-svn: 224855
Kostya Serebryany