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sed -i '' -E -e 's/Copyright (.+) The Crashpad Authors\. All rights reserved\.$/Copyright \1 The Crashpad Authors/' $(git grep -El 'Copyright (.+) The Crashpad Authors\. All rights reserved\.$') Bug: chromium:1098010 Change-Id: I8d6138469ddbe3d281a5d83f64cf918ec2491611 Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3878262 Reviewed-by: Joshua Peraza <jperaza@chromium.org> Commit-Queue: Mark Mentovai <mark@chromium.org>
106 lines
3.1 KiB
C++
106 lines
3.1 KiB
C++
// Copyright 2017 The Crashpad Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include <sys/mman.h>
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#include <dlfcn.h>
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#include <errno.h>
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#include <stdint.h>
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#include <unistd.h>
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#include "dlfcn_internal.h"
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#include "util/misc/no_cfi_icall.h"
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#if defined(__USE_FILE_OFFSET64) && __ANDROID_API__ < 21
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// Bionic has provided a wrapper for __mmap2() since the beginning of time. See
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// bionic/libc/SYSCALLS.TXT in any Android version.
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extern "C" void* __mmap2(void* addr,
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size_t size,
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int prot,
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int flags,
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int fd,
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size_t pgoff);
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namespace {
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template <typename T>
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T Align(T value, size_t alignment) {
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return (value + alignment - 1) & ~(alignment - 1);
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}
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// Adapted from Android 8.0.0 bionic/libc/bionic/mmap.cpp.
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void* LocalMmap64(void* addr,
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size_t size,
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int prot,
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int flags,
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int fd,
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off64_t offset) {
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constexpr int kMmap2Shift = 12;
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if (offset < 0 || (offset & ((1UL << kMmap2Shift) - 1)) != 0) {
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errno = EINVAL;
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return MAP_FAILED;
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}
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const size_t rounded = Align(size, getpagesize());
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if (rounded < size || rounded > PTRDIFF_MAX) {
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errno = ENOMEM;
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return MAP_FAILED;
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}
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const bool is_private_anonymous =
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(flags & (MAP_PRIVATE | MAP_ANONYMOUS)) == (MAP_PRIVATE | MAP_ANONYMOUS);
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const bool is_stack_or_grows_down =
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(flags & (MAP_STACK | MAP_GROWSDOWN)) != 0;
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void* const result =
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__mmap2(addr, size, prot, flags, fd, offset >> kMmap2Shift);
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static bool kernel_has_MADV_MERGEABLE = true;
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if (result != MAP_FAILED && kernel_has_MADV_MERGEABLE &&
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is_private_anonymous && !is_stack_or_grows_down) {
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const int saved_errno = errno;
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const int rc = madvise(result, size, MADV_MERGEABLE);
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if (rc == -1 && errno == EINVAL) {
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kernel_has_MADV_MERGEABLE = false;
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}
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errno = saved_errno;
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}
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return result;
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}
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} // namespace
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extern "C" {
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void* mmap(void* addr, size_t size, int prot, int flags, int fd, off_t offset) {
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// Use the system’s mmap64() wrapper if available. It will be available on
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// Android 5.0 (“Lollipop”) and later.
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static const crashpad::NoCfiIcall<decltype(LocalMmap64)*> mmap64(
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crashpad::internal::Dlsym(RTLD_DEFAULT, "mmap64"));
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if (mmap64) {
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return mmap64(addr, size, prot, flags, fd, offset);
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}
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// Otherwise, use the local implementation, which should amount to exactly the
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// same thing.
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return LocalMmap64(addr, size, prot, flags, fd, offset);
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}
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} // extern "C"
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#endif // defined(__USE_FILE_OFFSET64) && __ANDROID_API__ < 21
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