a62586846f
Summary: Forewarning: This patch looks big in #LOC changed. I promise it's not that bad, it just moves a lot of content from one file to another. I've gone ahead and left inline comments on Phabricator for sections where this has happened. This patch: 1. Introduces the crash handler API (crash_handler_api.h). 2. Moves information required for out-of-process crash handling into an AllocatorState. This is a trivially-copied POD struct that designed to be recovered from a deceased process, and used by the crash handler to create a GWP-ASan report (along with the other trivially-copied Metadata struct). 3. Implements the crash handler API using the AllocatorState and Metadata. 4. Adds tests for the crash handler. 5. Reimplements the (now optionally linked by the supporting allocator) in-process crash handler (i.e. the segv handler) using the new crash handler API. 6. Minor updates Scudo & Scudo Standalone to fix compatibility. 7. Changed capitalisation of errors (e.g. /s/Use after free/Use After Free). Reviewers: cryptoad, eugenis, jfb Reviewed By: eugenis Subscribers: merge_guards_bot, pcc, jfb, dexonsmith, mgorny, cryptoad, #sanitizers, llvm-commits Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D73557
70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
//===-- thread_contention.cpp -----------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "gwp_asan/tests/harness.h"
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// Note: Compilation of <atomic> and <thread> are extremely expensive for
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// non-opt builds of clang.
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#include <atomic>
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#include <cstdlib>
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#include <thread>
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#include <vector>
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void asyncTask(gwp_asan::GuardedPoolAllocator *GPA,
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std::atomic<bool> *StartingGun, unsigned NumIterations) {
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while (!*StartingGun) {
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// Wait for starting gun.
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}
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// Get ourselves a new allocation.
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for (unsigned i = 0; i < NumIterations; ++i) {
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volatile char *Ptr = reinterpret_cast<volatile char *>(
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GPA->allocate(GPA->getAllocatorState()->maximumAllocationSize()));
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// Do any other threads have access to this page?
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EXPECT_EQ(*Ptr, 0);
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// Mark the page as from malloc. Wait to see if another thread also takes
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// this page.
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*Ptr = 'A';
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std::this_thread::sleep_for(std::chrono::nanoseconds(10000));
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// Check we still own the page.
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EXPECT_EQ(*Ptr, 'A');
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// And now release it.
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*Ptr = 0;
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GPA->deallocate(const_cast<char *>(Ptr));
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}
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}
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void runThreadContentionTest(unsigned NumThreads, unsigned NumIterations,
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gwp_asan::GuardedPoolAllocator *GPA) {
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std::atomic<bool> StartingGun{false};
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std::vector<std::thread> Threads;
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if (std::thread::hardware_concurrency() < NumThreads) {
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NumThreads = std::thread::hardware_concurrency();
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}
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for (unsigned i = 0; i < NumThreads; ++i) {
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Threads.emplace_back(asyncTask, GPA, &StartingGun, NumIterations);
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}
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StartingGun = true;
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for (auto &T : Threads)
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T.join();
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}
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TEST_F(CustomGuardedPoolAllocator, ThreadContention) {
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unsigned NumThreads = 4;
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unsigned NumIterations = 10000;
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InitNumSlots(NumThreads);
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runThreadContentionTest(NumThreads, NumIterations, &GPA);
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}
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