In ASan, we have __asan_locate_address and __asan_get_alloc_stack, which is used in LLDB/Xcode to show the allocation backtrace for a heap memory object. This patch implements the same for TSan.
Differential Revision: https://reviews.llvm.org/D27656
llvm-svn: 290119
We already have an interceptor for __shared_weak_count::__release_shared, this patch handles __shared_count::__release_shared in the same way. This should get rid of TSan false positives when using std::future.
Differential Revision: https://reviews.llvm.org/D27797
llvm-svn: 289831
Objects may move during the garbage collection, and JVM needs
to notify ThreadAnalyzer about that. The new function
__tsan_java_find eliminates the need to maintain these
objects both in ThreadAnalyzer and JVM.
Author: Alexander Smundak (asmundak)
Reviewed in https://reviews.llvm.org/D27720
llvm-svn: 289682
Summary:
The current code was sometimes attempting to release huge chunks of
memory due to undesired RoundUp/RoundDown interaction when the requested
range is fully contained within one memory page.
Reviewers: eugenis
Subscribers: kubabrecka, llvm-commits
Patch by Aleksey Shlyapnikov.
Differential Revision: https://reviews.llvm.org/D27228
llvm-svn: 288271
Summary:
In order to avoid starting a separate thread to return unused memory to
the system (the thread interferes with process startup on Android,
Zygota waits for all threads to exit before fork, but this thread never
exits), try to return it right after free.
Reviewers: eugenis
Subscribers: cryptoad, filcab, danalbert, kubabrecka, llvm-commits
Patch by Aleksey Shlyapnikov.
Differential Revision: https://reviews.llvm.org/D27003
llvm-svn: 288091
GCD queues can be suspended and resumed with dispatch_suspend and dispatch_resume. We need to add synchronization between the call to dispatch_resume and any subsequent executions of blocks in the queue that was resumed. We already have an Acquire(q) before the block executes, so this patch just adds the Release(q) in an interceptor of dispatch_resume.
Differential Revision: https://reviews.llvm.org/D27112
llvm-svn: 287902
On Darwin, we're running the TSan unit tests without interceptors. To make sure TSan observes all the pthread events (thread creating, thread join, condvar signal, etc.) in tsan_posix.cc, we should call the pthread interceptors directly, as we already do in tsan_test_util_posix.cc. This fixes some flaky failures on Darwin bots.
Differential Revision: https://reviews.llvm.org/D26639
llvm-svn: 287026
This adds support for TSan C++ exception handling, where we need to add extra calls to __tsan_func_exit when a function is exitted via exception mechanisms. Otherwise the shadow stack gets corrupted (leaked). This patch moves and enhances the existing implementation of EscapeEnumerator that finds all possible function exit points, and adds extra EH cleanup blocks where needed.
Differential Revision: https://reviews.llvm.org/D26177
llvm-svn: 286894
This patch is needed to implement the function attribute that disable TSan checking at run time.
Differential Revision: https://reviews.llvm.org/D25859
llvm-svn: 286658
Atomic stores terminate release sequences on the atomic variable,
and must use ReleaseStore primitive instead of Release.
This was broken in r192355 during a refactoring.
Restore correct behavior and add a test.
llvm-svn: 286211
TSan’s memory usage profiling currently doesn’t work on Darwin. This patch implements measuring the amount of resident and dirty memory for each memory region. I also removed the GetShadowMemoryConsumption function, which seems to be unused.
Differential Revision: https://reviews.llvm.org/D25973
llvm-svn: 285630
GCD (libdispatch) has a concept of “target queues”: Each queue has either an implicit or explicit target queue, where the task is handed over to when it’s time to execute it. For example, a concurrent queue can have a serial target queue (effectively making the first queue serial), or multiple queues can have the same serial target queue (which means tasks in all the queues are mutually excluded). Thus we need to acquire-release semantics on the full “chain” of target queues.
This patch changes the way we Acquire() and Release() when executing tasks in queues. Now we’ll walk the chain of target queues and synchronize on each queue that is serial (or when dealing with a barrier block). This should avoid false positives when using dispatch_set_target_queue().
Differential Revision: https://reviews.llvm.org/D25835
llvm-svn: 285613
There is a corner case reported in Go issue tracker:
https://github.com/golang/go/issues/17065
On darwin data/bss segments may not be aligned to page bounary
and mmap seems to be behaving differently than on linux
(shrinks instead of enlarge unaligned regions).
Explicitly round shadow to page bounary before mapping
to avoid any such problems.
llvm-svn: 285454
Currently we either define SANITIZER_GO for Go or don't define it at all for C++.
This works fine with preprocessor (ifdef/ifndef/defined), but does not work
for C++ if statements (e.g. if (SANITIZER_GO) {...}). Also this is different
from majority of SANITIZER_FOO macros which are always defined to either 0 or 1.
Always define SANITIZER_GO to either 0 or 1.
This allows to use SANITIZER_GO in expressions and in flag default values.
Also remove kGoMode and kCppMode, which were meant to be used in expressions,
but they are not defined in sanitizer_common code, so SANITIZER_GO become prevalent.
Also convert some preprocessor checks to C++ if's or ternary expressions.
Majority of this change is done mechanically with:
sed "s#ifdef SANITIZER_GO#if SANITIZER_GO#g"
sed "s#ifndef SANITIZER_GO#if \!SANITIZER_GO#g"
sed "s#defined(SANITIZER_GO)#SANITIZER_GO#g"
llvm-svn: 285443
Currently windows fails on startup with:
CHECK failed: gotsan.cc:3077 "(((m - prev_m) / kMetaShadowSize)) == (((p - prev) / kMetaShadowCell))" (0x3ffffffeffffff7e, 0x6ffffff7e)
Make MemToMeta do the same MemToShadow does on windows: add offset instead of or'ing it.
llvm-svn: 285420
Looks like we are missing these flags only in tsan and sanitizer-common.
This results in linker warnings in some settings as it can cause the Unit
tests to be built with a different SDK version than that was used to build
the runtime. For example, we are not setting the minimal deployment target
on the tests but are setting the minimal deployment target for the sanitizer
library, which leads to the following warning on some bots: ld: warning:
object file (sanitizer_posix_test.cc.i386.o) was built for newer OSX version
(10.12) than being linked (10.11).
Differential Revision: https://reviews.llvm.org/D25860https://reviews.llvm.org/D25352
llvm-svn: 285255
This is a follow up to r282152.
A more extensive testing on real apps revealed a subtle bug in r282152.
The revision made shadow mapping non-linear even within a single
user region. But there are lots of code in runtime that processes
memory ranges and assumes that mapping is linear. For example,
region memory access handling simply increments shadow address
to advance to the next shadow cell group. Similarly, DontNeedShadowFor,
java memory mover, search of heap memory block header, etc
make similar assumptions.
To trigger the bug user range would need to cross 0x008000000000 boundary.
This was observed for a module data section.
Make shadow mapping linear within a single user range again.
Add a startup CHECK for linearity.
llvm-svn: 282405
Don't xor user address with kAppMemXor in meta mapping.
The only purpose of kAppMemXor is to raise shadow for ~0 user addresses,
so that they don't map to ~0 (which would cause overlap between
user memory and shadow).
For meta mapping we explicitly add kMetaShadowBeg offset,
so we don't need to additionally raise meta shadow.
llvm-svn: 282403
In ShadowToMem we call MemToShadow potentially for incorrect addresses.
So DCHECK(IsAppMem(p)) can fire in debug mode.
Fix this by swapping range and MemToShadow checks.
llvm-svn: 282157
4.1+ Linux kernels map pie binaries at 0x55:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d1fd836dcf00d2028c700c7e44d2c23404062c90
Currently tsan does not support app memory at 0x55 (https://github.com/google/sanitizers/issues/503).
Older kernels also map pie binaries at 0x55 when ASLR is disables (most notably under gdb).
This change extends tsan mapping for linux/x86_64 to cover 0x554-0x568 app range and fixes both 4.1+ kernels and gdb.
This required to slightly shrink low and high app ranges and move heap. The mapping become even more non-linear, since now we xor lower bits. Now even a continuous app range maps to split, intermixed shadow ranges. This breaks ShadowToMemImpl as it assumes linear mapping at least within a continuous app range (however it turned out to be already broken at least on arm64/42-bit vma as uncovered by r281970). So also change ShadowToMemImpl to hopefully a more robust implementation that does not assume a linear mapping.
llvm-svn: 282152
The definitions in sanitizer_common may conflict with definitions from system headers because:
The runtime includes the system headers after the project headers (as per LLVM coding guidelines).
lib/sanitizer_common/sanitizer_internal_defs.h pollutes the namespace of everything defined after it, which is all/most of the sanitizer .h and .cc files and the included system headers with: using namespace __sanitizer; // NOLINT
This patch solves the problem by introducing the namespace only within the sanitizer namespaces as proposed by Dmitry.
Differential Revision: https://reviews.llvm.org/D21947
llvm-svn: 281657
This patch adds a wrapper for call_once, which uses an already-compiled helper __call_once with an atomic release which is invisible to TSan. To avoid false positives, the interceptor performs an explicit atomic release in the callback wrapper.
Differential Revision: https://reviews.llvm.org/D24188
llvm-svn: 280920
This patch builds on LLVM r279776.
In this patch I've done some cleanup and abstracted three common steps runtime components have in their CMakeLists files, and added a fourth.
The three steps I abstract are:
(1) Add a top-level target (i.e asan, msan, ...)
(2) Set the target properties for sorting files in IDE generators
(3) Make the compiler-rt target depend on the top-level target
The new step is to check if a command named "runtime_register_component" is defined, and to call it with the component name.
The runtime_register_component command is defined in llvm/runtimes/CMakeLists.txt, and presently just adds the component to a list of sub-components, which later gets used to generate target mappings.
With this patch a new workflow for runtimes builds is supported. The new workflow when building runtimes from the LLVM runtimes directory is:
> cmake [...]
> ninja runtimes-configure
> ninja asan
The "runtimes-configure" target builds all the dependencies for configuring the runtimes projects, and runs CMake on the runtimes projects. Running the runtimes CMake generates a list of targets to bind into the top-level CMake so subsequent build invocations will have access to some of Compiler-RT's targets through the top-level build.
Note: This patch does exclude some top-level targets from compiler-rt libraries because they either don't install files (sanitizer_common), or don't have a cooresponding `check` target (stats).
llvm-svn: 279863
When compiler-rt's CMake is not directly invoked, it will currently not call
project() and thus ASM will not be enabled.
We also don't need to put the .S files through the C compiler then.
Differential Revision: https://reviews.llvm.org/D23656
llvm-svn: 279215
Current AArch64 {sig}{set,long}jmp interposing requires accessing glibc
private __pointer_chk_guard to get process xor mask to demangled the
internal {sig}jmp_buf function pointers.
It causes some packing issues, as described in gcc PR#71042 [1], and is
is not a godd practice to rely on a private glibc namespace (since ABI is
not meant to be stable).
This patch fixes it by changing how libtsan obtains the guarded pointer
value: at initialization a specific routine issues a setjmp call and
using the mangled function pointer and the original value derive the
random guarded pointer.
Checked on aarch64 39-bit VMA.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71042
llvm-svn: 278292
The system implementation of OSAtomicTestAndClear returns the original bit, but the TSan interceptor has a bug which always returns zero from the function. This patch fixes this and adds a test.
Differential Revision: https://reviews.llvm.org/D23061
llvm-svn: 277461
On Darwin, there are some apps that rely on realloc(nullptr, 0) returning a valid pointer. TSan currently returns nullptr in this case, let's fix it to avoid breaking binary compatibility.
Differential Revision: https://reviews.llvm.org/D22800
llvm-svn: 277458
This patch adds 48-bits VMA support for tsan on aarch64. As current
mappings for aarch64, 48-bit VMA also supports PIE executable. This
limits the mapping mechanism because the PIE address bits
(usually 0aaaaXXXXXXXX) makes it harder to create a mask/xor value
to include all memory regions. I think it is possible to create a
large application VAM range by either dropping PIE support or tune
current range.
It also changes slight the way addresses are packed in SyncVar structure:
previously it assumes x86_64 as the maximum VMA range. Since ID is 14 bits
wide, shifting 48 bits should be ok.
Tested on x86_64, ppc64le and aarch64 (39 and 48 bits VMA).
llvm-svn: 277137
When we delay signals we can deliver them when the signal
is blocked. This can be surprising to the program.
Intercept signal blocking functions merely to process
pending signals. As the result, at worst we will delay
a signal till return from the signal blocking function.
llvm-svn: 276876
Summary:
This patch is a refactoring of the way cmake 'targets' are grouped.
It won't affect non-UI cmake-generators.
Clang/LLVM are using a structured way to group targets which ease
navigation through Visual Studio UI. The Compiler-RT projects
differ from the way Clang/LLVM are grouping targets.
This patch doesn't contain behavior changes.
Reviewers: kubabrecka, rnk
Subscribers: wang0109, llvm-commits, kubabrecka, chrisha
Differential Revision: http://reviews.llvm.org/D21952
llvm-svn: 275111
This patch adds interceptors for dispatch_io_*, dispatch_read and dispatch_write functions. This avoids false positives when using GCD IO. Adding several test cases.
Differential Revision: http://reviews.llvm.org/D21889
llvm-svn: 275071
This patch adds synchronization between the creation of the GCD data object and destructor’s execution. It’s far from perfect, because ideally we’d want to synchronize the destruction of the last reference (via dispatch_release) and the destructor’s execution, but intercepting objc_release is problematic.
Differential Revision: http://reviews.llvm.org/D21990
llvm-svn: 274749
We already have interceptors for dispatch_source API (e.g. dispatch_source_set_event_handler), but they currently only handle submission synchronization. We also need to synchronize based on the target queue (serial, concurrent), in other words, we need to use dispatch_callback_wrap. This patch implements that.
Differential Revision: http://reviews.llvm.org/D21999
llvm-svn: 274619
In the patch that introduced support for GCD barrier blocks, I removed releasing a group when leaving it (in dispatch_group_leave). However, this is necessary to synchronize leaving a group and a notification callback (dispatch_group_notify). Adding this back, simplifying dispatch_group_notify_f and adding a test case.
Differential Revision: http://reviews.llvm.org/D21927
llvm-svn: 274549
Because we use SCOPED_TSAN_INTERCEPTOR in the dispatch_once interceptor, the original dispatch_once can also be sometimes called (when ignores are enabled or when thr->is_inited is false). However the original dispatch_once function doesn’t expect to find “2” in the storage and it will spin forever (but we use “2” to indicate that the initialization is already done, so no waiting is necessary). This patch makes sure we never call the original dispatch_once.
Differential Revision: http://reviews.llvm.org/D21976
llvm-svn: 274548
The dispatch_group_async interceptor actually extends the lifetime of the executed block. This means the destructor of the block (and captured variables) is called *after* dispatch_group_leave, which changes the semantics of dispatch_group_async. This patch fixes that.
Differential Revision: http://reviews.llvm.org/D21816
llvm-svn: 274117
Adding support for GCD barrier blocks in concurrent queues. This uses two sync object in the same way as read-write locks do. This also simplifies the use of dispatch groups (the notifications act as barrier blocks).
Differential Revision: http://reviews.llvm.org/D21604
llvm-svn: 273893
The non-barrier versions of OSAtomic* functions are semantically mo_relaxed, but the two variants (e.g. OSAtomicAdd32 and OSAtomicAdd32Barrier) are actually aliases of each other, and we cannot have different interceptors for them, because they're actually the same function. Thus, we have to stay conservative and treat the non-barrier versions as mo_acq_rel.
Differential Revision: http://reviews.llvm.org/D21733
llvm-svn: 273890
There is a "well-known" TSan false positive when using C++ weak_ptr/shared_ptr and code in destructors, e.g. described at <https://llvm.org/bugs/show_bug.cgi?id=22324>. The "standard" solution is to build and use a TSan-instrumented version of libcxx, which is not trivial for end-users. This patch tries a different approach (on OS X): It adds an interceptor for the specific function in libc++.dylib, which implements the atomic operation that needs to be visible to TSan.
Differential Revision: http://reviews.llvm.org/D21609
llvm-svn: 273806
This patch replaces all uses of __libc_malloc and friends with the internal allocator.
It seems that the only reason why we have calls to __libc_malloc in the first place was the lack of the internal allocator at the time. Using the internal allocator will also make sure that the system allocator is never used (this is the same behavior as ASan), and we don’t have to worry about working with unknown pointers coming from the system allocator.
Differential Revision: http://reviews.llvm.org/D21025
llvm-svn: 271916
This is a very simple optimization that gets about 10% speedup for certain programs. We’re currently storing the pointer to the main thread’s ThreadState, but we can store the state directly in a static variable, which avoid the load acquire.
Differential Revision: http://reviews.llvm.org/D20910
llvm-svn: 271906
We're not building the Go runtime with -mmacosx-version-min, which means it'll have a minimum deployment target set to the system you're building on. Let's make the code compile (and link) with -mmacosx-version-min=10.7.
Differential Revision: http://reviews.llvm.org/D20670
llvm-svn: 271833
The new annotation was added a while ago, but was not actually used.
Use the annotation to detect linker-initialized mutexes instead
of the broken IsGlobalVar which has both false positives and false
negatives. Remove IsGlobalVar mess.
llvm-svn: 271663
Currently the added test produces false race reports with glibc 2.19,
because DLTS memory is reused by pthread under the hood.
Use the DTLS machinery to intercept new DTLS ranges.
__tls_get_addr known to cause issues for tsan in the past,
so write the interceptor more carefully.
Reviewed in http://reviews.llvm.org/D20927
llvm-svn: 271568
Summary:
As suggested by kcc@ in http://reviews.llvm.org/D20084#441418, move the CheckFailed and Die functions, and their associated callback functionalities in their own separate file.
I expended the build rules to include a new rule that would not include those termination functions, so that another project can define their own.
The tests check-{a,t,m,ub,l,e,df}san are all passing.
Reviewers: llvm-commits, kcc
Subscribers: kubabrecka
Differential Revision: http://reviews.llvm.org/D20742
llvm-svn: 271055
We're missing interceptors for dispatch_after and dispatch_after_f. Let's add them to avoid false positives. Added a test case.
Differential Revision: http://reviews.llvm.org/D20426
llvm-svn: 270071
Summary:
Adds *fstat to the common interceptors.
Removes the now-duplicate fstat interceptor from msan/tsan
This adds fstat to asan/esan, which previously did not intercept it.
Resubmit of http://reviews.llvm.org/D20318 with ios build fixes.
Reviewers: eugenis, vitalybuka, aizatsky
Subscribers: zaks.anna, kcc, bruening, kubabrecka, srhines, danalbert, tberghammer
Differential Revision: http://reviews.llvm.org/D20350
llvm-svn: 269981
The previous patch (r269291) was reverted (commented out) because the patch caused leaks that
were detected by LSan and they broke some lit tests. The actual reason was that dlsym allocates
an error string buffer in TLS, and some LSan lit tests are intentionally not scanning TLS for
root pointers. This patch simply makes LSan ignore the allocation from dlsym, because it's
not interesting anyway.
llvm-svn: 269917
Summary:
Adds *fstat to the common interceptors.
Removes the now-duplicate fstat interceptor from msan/tsan
This adds fstat to asan/esan, which previously did not intercept it.
Reviewers: eugenis, vitalybuka, aizatsky
Subscribers: tberghammer, danalbert, srhines, kubabrecka, bruening, kcc
Differential Revision: http://reviews.llvm.org/D20318
llvm-svn: 269856
The ignore_interceptors_accesses setting did not have an effect on mmap, so
let's change that. It helps in cases user code is accessing the memory
written to by mmap when the synchronization is ensured by the code that
does not get rebuilt.
(This effects Swift interoperability since it's runtime is mapping memory
which gets accessed by the code emitted into the Swift application by the
compiler.)
Differential Revision: http://reviews.llvm.org/D20294
llvm-svn: 269855
http://reviews.llvm.org/rL269291 introduced a memory leak.
Disabling offending call temprorary rather than rolling back the chain
of CLs.
llvm-svn: 269799
To invoke the Swift demangler, we use dlsym to locate swift_demangle. However, dlsym malloc's storage and stores it in thread-local storage. Since allocations from the symbolizer are done with the system allocator (at least in TSan, interceptors are skipped when inside the symbolizer), we will crash when we try to deallocate later using the sanitizer allocator again.
To fix this, let's just not call dlsym from the demangler, and call it during initialization. The dlsym function calls malloc, so it needs to be only used after our allocator is initialized. Adding a Symbolizer::LateInitialize call that is only invoked after all other initializations.
Differential Revision: http://reviews.llvm.org/D20015
llvm-svn: 269291
Adds *stat to the common interceptors.
Removes the now-duplicate *stat interceptor from msan/tsan/esan.
This adds *stat to asan, which previously did not intercept it.
Patch by Qin Zhao.
llvm-svn: 269223
Another stack where we try to free sync objects,
but don't have a processors is:
// ResetRange
// __interceptor_munmap
// __deallocate_stack
// start_thread
// clone
Again, it is a latent bug that lead to memory leaks.
Also, increase amount of memory we scan in MetaMap::ResetRange.
Without that the test does not fail, as we fail to free
the sync objects on stack.
llvm-svn: 269041
Fixes crash reported in:
https://bugs.chromium.org/p/v8/issues/detail?id=4995
The problem is that we don't have a processor in a free interceptor
during thread exit.
The crash was introduced by introduction of Processors.
However, previously we silently leaked memory which wasn't any better.
llvm-svn: 268782
Summary:
Adds stat/__xstat to the common interceptors.
Removes the now-duplicate stat/__xstat interceptor from msan/tsan/esan.
This adds stat/__xstat to asan, which previously did not intercept it.
Resubmit of http://reviews.llvm.org/D19875 with win build fixes.
Reviewers: aizatsky, eugenis
Subscribers: tberghammer, llvm-commits, danalbert, vitalybuka, bruening, srhines, kubabrecka, kcc
Differential Revision: http://reviews.llvm.org/D19890
llvm-svn: 268466
Summary:
Adds stat/__xstat to the common interceptors.
Removes the now-duplicate stat/__xstat interceptor from msan/tsan/esan.
This adds stat/__xstat to asan, which previously did not intercept it.
Reviewers: aizatsky, eugenis
Subscribers: tberghammer, danalbert, srhines, kubabrecka, llvm-commits, vitalybuka, eugenis, kcc, bruening
Differential Revision: http://reviews.llvm.org/D19875
llvm-svn: 268440
We used to depend on host gcc. But some distributions got
new gcc recently which broke the check. Generally, we can't
depend that an arbitrary host gcc generates something stable.
Switch to clang.
This has an additional advantage of catching regressions in
clang codegen.
llvm-svn: 268382
In http://reviews.llvm.org/D19100, I introduced a bug: On OS X, existing programs rely on malloc_size() to detect whether a pointer comes from heap memory (malloc_size returns non-zero) or not. We have to distinguish between a zero-sized allocation (where we need to return 1 from malloc_size, due to other binary compatibility reasons, see http://reviews.llvm.org/D19100), and pointers that are not returned from malloc at all.
Differential Revision: http://reviews.llvm.org/D19653
llvm-svn: 268157
Recent TSan changes (r267678) which factor out parts of ThreadState into a Processor structure broke worker threads on OS X. This fixes it by properly calling ProcCreate for GCD worker threads and by replacing some CHECKs with RAW_CHECK in early process initialization. CHECK() in TSan calls the allocator, which requires a valid Processor.
llvm-svn: 267864
On linux, some architectures had an ABI transition from 64-bit long double
(ie. same as double) to 128-bit long double. On those, glibc symbols
involving long doubles come in two versions, and we need to pass the
correct one to dlvsym when intercepting them.
A few more functions we intercept are also versioned (all printf, scanf,
strtold variants), but there's no need to fix these, as the REAL() versions
are never called.
Differential Revision: http://reviews.llvm.org/D19555
llvm-svn: 267794
In short, CVE-2016-2143 will crash the machine if a process uses both >4TB
virtual addresses and fork(). ASan, TSan, and MSan will, by necessity, map
a sizable chunk of virtual address space, which is much larger than 4TB.
Even worse, sanitizers will always use fork() for llvm-symbolizer when a bug
is detected. Disable all three by aborting on process initialization if
the running kernel version is not known to contain a fix.
Unfortunately, there's no reliable way to detect the fix without crashing
the kernel. So, we rely on whitelisting - I've included a list of upstream
kernel versions that will work. In case someone uses a distribution kernel
or applied the fix themselves, an override switch is also included.
Differential Revision: http://reviews.llvm.org/D19576
llvm-svn: 267747
Current interface assumes that Go calls ProcWire/ProcUnwire
to establish the association between thread and proc.
With the wisdom of hindsight, this interface does not work
very well. I had to sprinkle Go scheduler with wire/unwire
calls, and any mistake leads to hard to debug crashes.
This is not something one wants to maintian.
Fortunately, there is a simpler solution. We can ask Go
runtime as to what is the current Processor, and that
question is very easy to answer on Go side.
Switch to such interface.
llvm-svn: 267703
tsan_debugging.cc: In function ‘void* __tsan_get_current_report()’:
tsan_debugging.cc:61:18: warning: cast from type ‘const __tsan::ReportDesc*’
to type ‘void*’ casts away qualifiers [-Wcast-qual]
return (void *)rep;
llvm-svn: 267679
This is reincarnation of http://reviews.llvm.org/D17648 with the bug fix pointed out by Adhemerval (zatrazz).
Currently ThreadState holds both logical state (required for race-detection algorithm, user-visible)
and physical state (various caches, most notably malloc cache). Move physical state in a new
Process entity. Besides just being the right thing from abstraction point of view, this solves several
problems:
Cache everything on P level in Go. Currently we cache on a mix of goroutine and OS thread levels.
This unnecessary increases memory consumption.
Properly handle free operations in Go. Frees are issue by GC which don't have goroutine context.
As the result we could not do anything more than just clearing shadow. For example, we leaked
sync objects and heap block descriptors.
This will allow to get rid of libc malloc in Go (now we have Processor context for internal allocator cache).
This in turn will allow to get rid of dependency on libc entirely.
Potentially we can make Processor per-CPU in C++ mode instead of per-thread, which will
reduce resource consumption.
The distinction between Thread and Processor is currently used only by Go, C++ creates Processor per OS thread,
which is equivalent to the current scheme.
llvm-svn: 267678
Kuba Mracek