TSAN_SHADOW_COUNT is defined to 4 in all environments.
Other values of TSAN_SHADOW_COUNT were never tested and
were broken by recent changes to shadow mapping.
Remove it as there is no reason to fix nor maintain it.
llvm-svn: 226466
Summary:
This change removes `__tsan::StackTrace` class. There are
now three alternatives:
# Lightweight `__sanitizer::StackTrace`, which doesn't own a buffer
of PCs. It is used in functions that need stack traces in read-only
mode, and helps to prevent unnecessary allocations/copies (e.g.
for StackTraces fetched from StackDepot).
# `__sanitizer::BufferedStackTrace`, which stores buffer of PCs in
a constant array. It is used in TraceHeader (non-Go version)
# `__tsan::VarSizeStackTrace`, which owns buffer of PCs, dynamically
allocated via TSan internal allocator.
Test Plan: compiler-rt test suite
Reviewers: dvyukov, kcc
Reviewed By: kcc
Subscribers: llvm-commits, kcc
Differential Revision: http://reviews.llvm.org/D6004
llvm-svn: 221194
Vector clocks is the most actively allocated object in tsan runtime.
Current internal allocator is not scalable enough to handle allocation
of clocks in scalable way (too small caches). This changes transforms
clocks to 2-level array with 512-byte blocks. Since all blocks are of
the same size, it's possible to cache them more efficiently in per-thread caches.
llvm-svn: 214912
The bug happens in the following case:
Mutex is located at heap block beginning,
when we call MutexDestroy, s->next is set to 0,
so free can't find the MBlock related to the block.
llvm-svn: 212531
Introduce new public header <sanitizer/allocator_interface.h> and a set
of functions __sanitizer_get_ownership(), __sanitizer_malloc_hook() etc.
that will eventually replace their tool-specific equivalents
(__asan_get_ownership(), __msan_get_ownership() etc.). Tool-specific
functions are now deprecated and implemented as stubs redirecting
to __sanitizer_ versions (which are implemented differently in each tool).
Replace all uses of __xsan_ versions with __sanitizer_ versions in unit
and lit tests.
llvm-svn: 212469
The former used to crash with a null deref if it was given a not owned pointer,
while the latter returned 0. Now they both return 0. This is still not the best possible
behavior: it is better to print an error report with a stack trace, pointing
to the error in user code, as we do in ASan.
llvm-svn: 212112
The optimization is two-fold:
First, the algorithm now uses SSE instructions to
handle all 4 shadow slots at once. This makes processing
faster.
Second, if shadow contains the same access, we do not
store the event into trace. This increases effective
trace size, that is, tsan can remember up to 10x more
previous memory accesses.
Perofrmance impact:
Before:
[ OK ] DISABLED_BENCH.Mop8Read (2461 ms)
[ OK ] DISABLED_BENCH.Mop8Write (1836 ms)
After:
[ OK ] DISABLED_BENCH.Mop8Read (1204 ms)
[ OK ] DISABLED_BENCH.Mop8Write (976 ms)
But this measures only fast-path.
On large real applications the speedup is ~20%.
Trace size impact:
On app1:
Memory accesses : 1163265870
Including same : 791312905 (68%)
on app2:
Memory accesses : 166875345
Including same : 150449689 (90%)
90% of filtered events means that trace size is effectively 10x larger.
llvm-svn: 209897
The new storage (MetaMap) is based on direct shadow (instead of a hashmap + per-block lists).
This solves a number of problems:
- eliminates quadratic behaviour in SyncTab::GetAndLock (https://code.google.com/p/thread-sanitizer/issues/detail?id=26)
- eliminates contention in SyncTab
- eliminates contention in internal allocator during allocation of sync objects
- removes a bunch of ad-hoc code in java interface
- reduces java shadow from 2x to 1/2x
- allows to memorize heap block meta info for Java and Go
- allows to cleanup sync object meta info for Go
- which in turn enabled deadlock detector for Go
llvm-svn: 209810
Make vector clock operations O(1) for several important classes of use cases.
See comments for details.
Below are stats from a large server app, 77% of all clock operations are handled as O(1).
Clock acquire : 25983645
empty clock : 6288080
fast from release-store : 14917504
contains my tid : 4515743
repeated (fast) : 2141428
full (slow) : 2636633
acquired something : 1426863
Clock release : 2544216
resize : 6241
fast1 : 197693
fast2 : 1016293
fast3 : 2007
full (slow) : 1797488
was acquired : 709227
clear tail : 1
last overflow : 0
Clock release store : 3446946
resize : 200516
fast : 469265
slow : 2977681
clear tail : 0
Clock acquire-release : 820028
llvm-svn: 204656
Make behavior introduced in r202820 conditional (under legacy_pthread_cond flag).
The new issue that we've hit with the satellite pthread_cond_t struct is
that pthread_condattr_getpshared does not work (satellite data is not shared between processes).
The idea is that most processes do not use pthread 2.2.5.
The rare ones that use (2.2.5 is dated by 2002) must specify legacy_pthread_cond=1
on their own risk.
llvm-svn: 204032
Currently correct programs can deadlock after fork, because atomic operations and async-signal-safe calls are not async-signal-safe under tsan.
With this change:
- if a single-threaded program forks, the child continues running with verification enabled (the tsan background thread is recreated as well)
- if a multi-threaded program forks, then the child runs with verification disabled (memory accesses, atomic operations and interceptors are disabled); it's expected that it will exec soon anyway
- if the child tries to create more threads after multi-threaded fork, the program aborts with error message
- die_after_fork flag is added that allows to continue running, but all bets are off
http://llvm-reviews.chandlerc.com/D2614
llvm-svn: 199993
This is intended to address the following problem.
Episodically we see CHECK-failures when recursive interceptors call back into user code. Effectively we are not "in_rtl" at this point, but it's very complicated and fragile to properly maintain in_rtl property. Instead get rid of it. It was used mostly for sanity CHECKs, which basically never uncover real problems.
Instead introduce ignore_interceptors flag, which is used in very few narrow places to disable recursive interceptors (e.g. during runtime initialization).
llvm-svn: 197979
This allows to increase max shadow stack size to 64K,
and reliably catch shadow stack overflows instead of silently
corrupting memory.
llvm-svn: 192797
Move this function to sanitizer_common because LSan uses it too. Also, fix a bug
where the TLS range reported for main thread was off by the size of the thread
descriptor from libc (TSan doesn't care much, but for LSan it's critical).
llvm-svn: 181322
Mohit K. Bhakkad