Add m-esr52 at 52.6.0

1 files changed, 390 insertions, 0 deletions

diff --git a/js/src/jit/ExecutableAllocator.cpp b/js/src/jit/ExecutableAllocator.cpp
new file mode 100644
index 000000000..20ca74183
--- /dev/null
+++ b/js/src/jit/ExecutableAllocator.cpp
@@ -0,0 +1,390 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ *
+ * 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 "jit/JitCompartment.h"
+#include "js/MemoryMetrics.h"
+
+using namespace js::jit;
+
+ExecutablePool::~ExecutablePool()
+{
+    MOZ_ASSERT(m_ionCodeBytes == 0);
+    MOZ_ASSERT(m_baselineCodeBytes == 0);
+    MOZ_ASSERT(m_regexpCodeBytes == 0);
+    MOZ_ASSERT(m_otherCodeBytes == 0);
+
+    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)
+{
+    switch (kind) {
+      case ION_CODE:
+        m_ionCodeBytes -= n;
+        MOZ_ASSERT(m_ionCodeBytes < m_allocation.size); // Shouldn't underflow.
+        break;
+      case BASELINE_CODE:
+        m_baselineCodeBytes -= n;
+        MOZ_ASSERT(m_baselineCodeBytes < m_allocation.size);
+        break;
+      case REGEXP_CODE:
+        m_regexpCodeBytes -= n;
+        MOZ_ASSERT(m_regexpCodeBytes < m_allocation.size);
+        break;
+      case OTHER_CODE:
+        m_otherCodeBytes -= n;
+        MOZ_ASSERT(m_otherCodeBytes < m_allocation.size);
+        break;
+      default:
+        MOZ_CRASH("bad code kind");
+    }
+
+    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;
+
+    switch (kind) {
+      case ION_CODE:      m_ionCodeBytes      += n;        break;
+      case BASELINE_CODE: m_baselineCodeBytes += n;        break;
+      case REGEXP_CODE:   m_regexpCodeBytes   += n;        break;
+      case OTHER_CODE:    m_otherCodeBytes    += n;        break;
+      default:            MOZ_CRASH("bad code kind");
+    }
+
+    return result;
+}
+
+size_t
+ExecutablePool::available() const
+{
+    MOZ_ASSERT(m_end >= m_freePtr);
+    return m_end - m_freePtr;
+}
+
+ExecutableAllocator::ExecutableAllocator(JSRuntime* rt)
+  : rt_(rt)
+{
+    MOZ_ASSERT(m_smallPools.empty());
+}
+
+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_IF(m_pools.initialized(), 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)
+{
+    // Something included via windows.h defines a macro with this name,
+    // which causes the function below to fail to compile.
+#ifdef _MSC_VER
+# undef max
+#endif
+
+    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)
+{
+    MOZ_ASSERT(rt_->jitRuntime()->preventBackedgePatching());
+
+    size_t allocSize = roundUpAllocationSize(n, ExecutableCodePageSize);
+    if (allocSize == OVERSIZE_ALLOCATION)
+        return nullptr;
+
+    if (!m_pools.initialized() && !m_pools.init())
+        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(size_t n, ExecutablePool** poolp, CodeKind type)
+{
+    // Don't race with reprotectAll called from the signal handler.
+    JitRuntime::AutoPreventBackedgePatching apbp(rt_);
+
+    // 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)
+{
+    // Don't race with reprotectAll called from the signal handler.
+    JitRuntime::AutoPreventBackedgePatching apbp(rt_);
+
+    MOZ_ASSERT(pool->m_allocation.pages);
+    systemRelease(pool->m_allocation);
+
+    MOZ_ASSERT(m_pools.initialized());
+
+    // 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()
+{
+    // Don't race with reprotectAll called from the signal handler.
+    JitRuntime::AutoPreventBackedgePatching apbp(rt_);
+
+    for (size_t i = 0; i < m_smallPools.length(); i++)
+        m_smallPools[i]->release();
+    m_smallPools.clear();
+}
+
+void
+ExecutableAllocator::addSizeOfCode(JS::CodeSizes* sizes) const
+{
+    if (m_pools.initialized()) {
+        for (ExecPoolHashSet::Range r = m_pools.all(); !r.empty(); r.popFront()) {
+            ExecutablePool* pool = r.front();
+            sizes->ion      += pool->m_ionCodeBytes;
+            sizes->baseline += pool->m_baselineCodeBytes;
+            sizes->regexp   += pool->m_regexpCodeBytes;
+            sizes->other    += pool->m_otherCodeBytes;
+            sizes->unused   += pool->m_allocation.size - pool->m_ionCodeBytes
+                                                       - pool->m_baselineCodeBytes
+                                                       - pool->m_regexpCodeBytes
+                                                       - pool->m_otherCodeBytes;
+        }
+    }
+}
+
+void
+ExecutableAllocator::reprotectAll(ProtectionSetting protection)
+{
+    if (!m_pools.initialized())
+        return;
+
+    for (ExecPoolHashSet::Range r = m_pools.all(); !r.empty(); r.popFront())
+        reprotectPool(rt_, r.front(), protection);
+}
+
+/* static */ void
+ExecutableAllocator::reprotectPool(JSRuntime* rt, ExecutablePool* pool, ProtectionSetting protection)
+{
+    // Don't race with reprotectAll called from the signal handler.
+    MOZ_ASSERT(rt->jitRuntime()->preventBackedgePatching() || rt->handlingJitInterrupt());
+
+    char* start = pool->m_allocation.pages;
+    if (!ReprotectRegion(start, pool->m_freePtr - start, protection))
+        MOZ_CRASH();
+}
+
+/* static */ void
+ExecutableAllocator::poisonCode(JSRuntime* rt, JitPoisonRangeVector& ranges)
+{
+    MOZ_ASSERT(CurrentThreadCanAccessRuntime(rt));
+
+    // Don't race with reprotectAll called from the signal handler.
+    JitRuntime::AutoPreventBackedgePatching apbp(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
+
+    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);
+            pool->mark();
+        }
+
+        memset(ranges[i].start, JS_SWEPT_CODE_PATTERN, ranges[i].size);
+    }
+
+    // Make the pools executable again and drop references.
+    for (size_t i = 0; i < ranges.length(); i++) {
+        ExecutablePool* pool = ranges[i].pool;
+        if (pool->isMarked()) {
+            reprotectPool(rt, pool, ProtectionSetting::Executable);
+            pool->unmark();
+        }
+        pool->release();
+    }
+}
+
+ExecutablePool::Allocation
+ExecutableAllocator::systemAlloc(size_t n)
+{
+    void* allocation = AllocateExecutableMemory(n, ProtectionSetting::Executable);
+    ExecutablePool::Allocation alloc = { reinterpret_cast<char*>(allocation), n };
+    return alloc;
+}
+
+void
+ExecutableAllocator::systemRelease(const ExecutablePool::Allocation& alloc)
+{
+    DeallocateExecutableMemory(alloc.pages, alloc.size);
+}