Users can call HwasanThreadList::GetRingBufferSize rather than RingBufferSize
to prevent having to do the calculation in RingBufferSize. This will be useful
for Fuchsia where we plan to initialize the stack ring buffer separately from
the rest of thread initialization.
Differential Revision: https://reviews.llvm.org/D104823
Similar to InitOptions in asan, we can use this optional struct for
initializing some members thread objects before they are created. On
linux, this is unused and can remain undefined. On fuchsia, this will
just be the stack bounds.
Differential Revision: https://reviews.llvm.org/D104553
The problem was introduced in D100348.
It's really hard to trigger the bug in a stress test - the race is just too
narrow - but the new checks in Thread::Init should at least provide usable
diagnostic if the problem ever returns.
Differential Revision: https://reviews.llvm.org/D101881
Do not hold the free/live thread list lock longer than necessary.
This change speeds up the following benchmark 10x.
constexpr int kTopThreads = 50;
constexpr int kChildThreads = 20;
constexpr int kChildIterations = 8;
void Thread() {
for (int i = 0; i < kChildIterations; ++i) {
std::vector<std::thread> threads;
for (int i = 0; i < kChildThreads; ++i)
threads.emplace_back([](){});
for (auto& t : threads)
t.join();
}
}
int main() {
std::vector<std::thread> threads;
for (int i = 0; i < kTopThreads; ++i)
threads.emplace_back(Thread);
for (auto& t : threads)
t.join();
}
Differential Revision: https://reviews.llvm.org/D100348
HwasanThreadList::DontNeedThread clobbers Thread::next_,
Breaking the freelist. As a result, only the top of the freelist ever
gets reused, and the rest of it is lost.
Since the Thread object with its associated ring buffer is only 8Kb, this is
typically only noticable in long running processes, such as fuzzers.
Fix the problem by switching from an intrusive linked list to a vector.
Differential Revision: https://reviews.llvm.org/D91392
HwasanThreadList::DontNeedThread clobbers Thread::next_, breaking the
freelist. As a result, only the top of the freelist ever gets reused,
and the rest of it is lost.
Since the Thread object its associated ring buffer is only 8Kb, this is
typically only noticable in long running processes, such as fuzzers.
Fix the problem by switching from an intrusive linked list to a vector.
Differential Revision: https://reviews.llvm.org/D91208
Summary:
Release memory pages for thread data (allocator cache, stack allocations
ring buffer, etc) when a thread exits. We can not simply munmap them
because this memory is custom allocated within a limited address range,
and it needs to stay "reserved".
This change alters thread storage layout by putting the ring buffer
before Thread instead of after it. This makes it possible to find the
start of the thread aux allocation given only the Thread pointer.
Reviewers: kcc, pcc
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D56621
llvm-svn: 352151
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
Display a list of recent stack frames (not a stack trace!) when
tag-mismatch is detected on a stack address.
The implementation uses alignment tricks to get both the address of
the history buffer, and the base address of the shadow with a single
8-byte load. See the comment in hwasan_thread_list.h for more
details.
Developed in collaboration with Kostya Serebryany.
Reviewers: kcc
Subscribers: srhines, kubamracek, mgorny, hiraditya, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D52249
llvm-svn: 342923
Summary:
Display a list of recent stack frames (not a stack trace!) when
tag-mismatch is detected on a stack address.
The implementation uses alignment tricks to get both the address of
the history buffer, and the base address of the shadow with a single
8-byte load. See the comment in hwasan_thread_list.h for more
details.
Developed in collaboration with Kostya Serebryany.
Reviewers: kcc
Subscribers: srhines, kubamracek, mgorny, hiraditya, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D52249
llvm-svn: 342921
Leonard Chan