Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 334 insertions, 0 deletions

diff --git a/js/src/jit/ExecutableAllocator.cpp b/js/src/jit/ExecutableAllocator.cpp
new file mode 100644
index 0000000000..700ffe57f6
--- /dev/null
+++ b/js/src/jit/ExecutableAllocator.cpp
@@ -0,0 +1,334 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ *
+ * Copyright (C) 2008 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "jit/ExecutableAllocator.h"
+
+#include "js/MemoryMetrics.h"
+#include "util/Poison.h"
+
+using namespace js::jit;
+
+ExecutablePool::~ExecutablePool() {
+#ifdef DEBUG
+  for (size_t bytes : m_codeBytes) {
+    MOZ_ASSERT(bytes == 0);
+  }
+#endif
+
+  MOZ_ASSERT(!isMarked());
+
+  m_allocator->releasePoolPages(this);
+}
+
+void ExecutablePool::release(bool willDestroy) {
+  MOZ_ASSERT(m_refCount != 0);
+  MOZ_ASSERT_IF(willDestroy, m_refCount == 1);
+  if (--m_refCount == 0) {
+    js_delete(this);
+  }
+}
+
+void ExecutablePool::release(size_t n, CodeKind kind) {
+  m_codeBytes[kind] -= n;
+  MOZ_ASSERT(m_codeBytes[kind] < m_allocation.size);  // Shouldn't underflow.
+
+  release();
+}
+
+void ExecutablePool::addRef() {
+  // It should be impossible for us to roll over, because only small
+  // pools have multiple holders, and they have one holder per chunk
+  // of generated code, and they only hold 16KB or so of code.
+  MOZ_ASSERT(m_refCount);
+  ++m_refCount;
+  MOZ_ASSERT(m_refCount, "refcount overflow");
+}
+
+void* ExecutablePool::alloc(size_t n, CodeKind kind) {
+  MOZ_ASSERT(n <= available());
+  void* result = m_freePtr;
+  m_freePtr += n;
+
+  m_codeBytes[kind] += n;
+
+  MOZ_MAKE_MEM_UNDEFINED(result, n);
+  return result;
+}
+
+size_t ExecutablePool::available() const {
+  MOZ_ASSERT(m_end >= m_freePtr);
+  return m_end - m_freePtr;
+}
+
+ExecutableAllocator::~ExecutableAllocator() {
+  for (size_t i = 0; i < m_smallPools.length(); i++) {
+    m_smallPools[i]->release(/* willDestroy = */ true);
+  }
+
+  // If this asserts we have a pool leak.
+  MOZ_ASSERT(m_pools.empty());
+}
+
+ExecutablePool* ExecutableAllocator::poolForSize(size_t n) {
+  // Try to fit in an existing small allocator.  Use the pool with the
+  // least available space that is big enough (best-fit).  This is the
+  // best strategy because (a) it maximizes the chance of the next
+  // allocation fitting in a small pool, and (b) it minimizes the
+  // potential waste when a small pool is next abandoned.
+  ExecutablePool* minPool = nullptr;
+  for (size_t i = 0; i < m_smallPools.length(); i++) {
+    ExecutablePool* pool = m_smallPools[i];
+    if (n <= pool->available() &&
+        (!minPool || pool->available() < minPool->available())) {
+      minPool = pool;
+    }
+  }
+  if (minPool) {
+    minPool->addRef();
+    return minPool;
+  }
+
+  // If the request is large, we just provide a unshared allocator
+  if (n > ExecutableCodePageSize) {
+    return createPool(n);
+  }
+
+  // Create a new allocator
+  ExecutablePool* pool = createPool(ExecutableCodePageSize);
+  if (!pool) {
+    return nullptr;
+  }
+  // At this point, local |pool| is the owner.
+
+  if (m_smallPools.length() < maxSmallPools) {
+    // We haven't hit the maximum number of live pools; add the new pool.
+    // If append() OOMs, we just return an unshared allocator.
+    if (m_smallPools.append(pool)) {
+      pool->addRef();
+    }
+  } else {
+    // Find the pool with the least space.
+    int iMin = 0;
+    for (size_t i = 1; i < m_smallPools.length(); i++) {
+      if (m_smallPools[i]->available() < m_smallPools[iMin]->available()) {
+        iMin = i;
+      }
+    }
+
+    // If the new allocator will result in more free space than the small
+    // pool with the least space, then we will use it instead
+    ExecutablePool* minPool = m_smallPools[iMin];
+    if ((pool->available() - n) > minPool->available()) {
+      minPool->release();
+      m_smallPools[iMin] = pool;
+      pool->addRef();
+    }
+  }
+
+  // Pass ownership to the caller.
+  return pool;
+}
+
+/* static */
+size_t ExecutableAllocator::roundUpAllocationSize(size_t request,
+                                                  size_t granularity) {
+  if ((std::numeric_limits<size_t>::max() - granularity) <= request) {
+    return OVERSIZE_ALLOCATION;
+  }
+
+  // Round up to next page boundary
+  size_t size = request + (granularity - 1);
+  size = size & ~(granularity - 1);
+  MOZ_ASSERT(size >= request);
+  return size;
+}
+
+ExecutablePool* ExecutableAllocator::createPool(size_t n) {
+  size_t allocSize = roundUpAllocationSize(n, ExecutableCodePageSize);
+  if (allocSize == OVERSIZE_ALLOCATION) {
+    return nullptr;
+  }
+
+  ExecutablePool::Allocation a = systemAlloc(allocSize);
+  if (!a.pages) {
+    return nullptr;
+  }
+
+  ExecutablePool* pool = js_new<ExecutablePool>(this, a);
+  if (!pool) {
+    systemRelease(a);
+    return nullptr;
+  }
+
+  if (!m_pools.put(pool)) {
+    // Note: this will call |systemRelease(a)|.
+    js_delete(pool);
+    return nullptr;
+  }
+
+  return pool;
+}
+
+void* ExecutableAllocator::alloc(JSContext* cx, size_t n,
+                                 ExecutablePool** poolp, CodeKind type) {
+  // Caller must ensure 'n' is word-size aligned. If all allocations are
+  // of word sized quantities, then all subsequent allocations will be
+  // aligned.
+  MOZ_ASSERT(roundUpAllocationSize(n, sizeof(void*)) == n);
+
+  if (n == OVERSIZE_ALLOCATION) {
+    *poolp = nullptr;
+    return nullptr;
+  }
+
+  *poolp = poolForSize(n);
+  if (!*poolp) {
+    return nullptr;
+  }
+
+  // This alloc is infallible because poolForSize() just obtained
+  // (found, or created if necessary) a pool that had enough space.
+  void* result = (*poolp)->alloc(n, type);
+  MOZ_ASSERT(result);
+
+  return result;
+}
+
+void ExecutableAllocator::releasePoolPages(ExecutablePool* pool) {
+  MOZ_ASSERT(pool->m_allocation.pages);
+  systemRelease(pool->m_allocation);
+
+  // Pool may not be present in m_pools if we hit OOM during creation.
+  if (auto ptr = m_pools.lookup(pool)) {
+    m_pools.remove(ptr);
+  }
+}
+
+void ExecutableAllocator::purge() {
+  for (size_t i = 0; i < m_smallPools.length();) {
+    ExecutablePool* pool = m_smallPools[i];
+    if (pool->m_refCount > 1) {
+      // Releasing this pool is not going to deallocate it, so we might as
+      // well hold on to it and reuse it for future allocations.
+      i++;
+      continue;
+    }
+
+    MOZ_ASSERT(pool->m_refCount == 1);
+    pool->release();
+    m_smallPools.erase(&m_smallPools[i]);
+  }
+}
+
+void ExecutableAllocator::addSizeOfCode(JS::CodeSizes* sizes) const {
+  for (ExecPoolHashSet::Range r = m_pools.all(); !r.empty(); r.popFront()) {
+    ExecutablePool* pool = r.front();
+    sizes->ion += pool->m_codeBytes[CodeKind::Ion];
+    sizes->baseline += pool->m_codeBytes[CodeKind::Baseline];
+    sizes->regexp += pool->m_codeBytes[CodeKind::RegExp];
+    sizes->other += pool->m_codeBytes[CodeKind::Other];
+    sizes->unused += pool->m_allocation.size - pool->usedCodeBytes();
+  }
+}
+
+/* static */
+void ExecutableAllocator::reprotectPool(JSRuntime* rt, ExecutablePool* pool,
+                                        ProtectionSetting protection,
+                                        MustFlushICache flushICache) {
+  char* start = pool->m_allocation.pages;
+  AutoEnterOOMUnsafeRegion oomUnsafe;
+  if (!ReprotectRegion(start, pool->m_freePtr - start, protection,
+                       flushICache)) {
+    oomUnsafe.crash("ExecutableAllocator::reprotectPool");
+  }
+}
+
+/* static */
+void ExecutableAllocator::poisonCode(JSRuntime* rt,
+                                     JitPoisonRangeVector& ranges) {
+  MOZ_ASSERT(CurrentThreadCanAccessRuntime(rt));
+
+#ifdef DEBUG
+  // Make sure no pools have the mark bit set.
+  for (size_t i = 0; i < ranges.length(); i++) {
+    MOZ_ASSERT(!ranges[i].pool->isMarked());
+  }
+#endif
+
+  {
+    AutoMarkJitCodeWritableForThread writable;
+
+    for (size_t i = 0; i < ranges.length(); i++) {
+      ExecutablePool* pool = ranges[i].pool;
+      if (pool->m_refCount == 1) {
+        // This is the last reference so the release() call below will
+        // unmap the memory. Don't bother poisoning it.
+        continue;
+      }
+
+      MOZ_ASSERT(pool->m_refCount > 1);
+
+      // Use the pool's mark bit to indicate we made the pool writable.
+      // This avoids reprotecting a pool multiple times.
+      if (!pool->isMarked()) {
+        reprotectPool(rt, pool, ProtectionSetting::Writable,
+                      MustFlushICache::No);
+        pool->mark();
+      }
+
+      // Note: we use memset instead of js::Poison because we want to poison
+      // JIT code in release builds too. Furthermore, we don't want the
+      // invalid-ObjectValue poisoning js::Poison does in debug builds.
+      memset(ranges[i].start, JS_SWEPT_CODE_PATTERN, ranges[i].size);
+      MOZ_MAKE_MEM_NOACCESS(ranges[i].start, ranges[i].size);
+    }
+  }
+
+  // Make the pools executable again and drop references. We don't flush the
+  // ICache here to not add extra overhead.
+  for (size_t i = 0; i < ranges.length(); i++) {
+    ExecutablePool* pool = ranges[i].pool;
+    if (pool->isMarked()) {
+      reprotectPool(rt, pool, ProtectionSetting::Executable,
+                    MustFlushICache::No);
+      pool->unmark();
+    }
+    pool->release();
+  }
+}
+
+ExecutablePool::Allocation ExecutableAllocator::systemAlloc(size_t n) {
+  void* allocation = AllocateExecutableMemory(n, ProtectionSetting::Executable,
+                                              MemCheckKind::MakeNoAccess);
+  ExecutablePool::Allocation alloc = {reinterpret_cast<char*>(allocation), n};
+  return alloc;
+}
+
+void ExecutableAllocator::systemRelease(
+    const ExecutablePool::Allocation& alloc) {
+  DeallocateExecutableMemory(alloc.pages, alloc.size);
+}