abe7f841ca
Backed out changeset 3e8d2c47138c (bug 1454816) Backed out changeset 80ff20241831 (bug 1454816) Backed out changeset 28c2d6d2a683 (bug 1454816) Backed out changeset 236943ab4142 (bug 1454816)
54 lines
1.5 KiB
C++
54 lines
1.5 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include <sys/mman.h> // mprotect
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#include <unistd.h> // sysconf
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#include "mozilla/ipc/SharedMemory.h"
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#if defined(XP_MACOSX) && defined(__x86_64__)
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# include "prenv.h"
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#endif
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namespace mozilla::ipc {
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#if defined(XP_MACOSX) && defined(__x86_64__)
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std::atomic<size_t> sPageSizeOverride = 0;
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#endif
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void SharedMemory::SystemProtect(char* aAddr, size_t aSize, int aRights) {
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if (!SystemProtectFallible(aAddr, aSize, aRights)) {
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MOZ_CRASH("can't mprotect()");
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}
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}
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bool SharedMemory::SystemProtectFallible(char* aAddr, size_t aSize,
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int aRights) {
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int flags = 0;
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if (aRights & RightsRead) flags |= PROT_READ;
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if (aRights & RightsWrite) flags |= PROT_WRITE;
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if (RightsNone == aRights) flags = PROT_NONE;
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return 0 == mprotect(aAddr, aSize, flags);
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}
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size_t SharedMemory::SystemPageSize() {
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#if defined(XP_MACOSX) && defined(__x86_64__)
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if (sPageSizeOverride == 0) {
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if (PR_GetEnv("MOZ_SHMEM_PAGESIZE_16K")) {
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sPageSizeOverride = 16 * 1024;
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} else {
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sPageSizeOverride = sysconf(_SC_PAGESIZE);
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}
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}
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return sPageSizeOverride;
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#else
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return sysconf(_SC_PAGESIZE);
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#endif
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}
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} // namespace mozilla::ipc
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