| Index: third_party/crashpad/crashpad/snapshot/cpu_context.cc
|
| diff --git a/third_party/crashpad/crashpad/snapshot/cpu_context.cc b/third_party/crashpad/crashpad/snapshot/cpu_context.cc
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..1ff2b459242eff8cc4574ac97be65bd2ad310f07
|
| --- /dev/null
|
| +++ b/third_party/crashpad/crashpad/snapshot/cpu_context.cc
|
| @@ -0,0 +1,101 @@
|
| +// Copyright 2014 The Crashpad Authors. All rights reserved.
|
| +//
|
| +// Licensed under the Apache License, Version 2.0 (the "License");
|
| +// you may not use this file except in compliance with the License.
|
| +// You may obtain a copy of the License at
|
| +//
|
| +// http://www.apache.org/licenses/LICENSE-2.0
|
| +//
|
| +// Unless required by applicable law or agreed to in writing, software
|
| +// distributed under the License is distributed on an "AS IS" BASIS,
|
| +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
| +// See the License for the specific language governing permissions and
|
| +// limitations under the License.
|
| +
|
| +#include "snapshot/cpu_context.h"
|
| +
|
| +#include "base/basictypes.h"
|
| +#include "base/logging.h"
|
| +#include "util/misc/implicit_cast.h"
|
| +
|
| +namespace crashpad {
|
| +
|
| +// static
|
| +uint16_t CPUContextX86::FxsaveToFsaveTagWord(
|
| + uint16_t fsw,
|
| + uint8_t fxsave_tag,
|
| + const CPUContextX86::X87OrMMXRegister st_mm[8]) {
|
| + enum {
|
| + kX87TagValid = 0,
|
| + kX87TagZero,
|
| + kX87TagSpecial,
|
| + kX87TagEmpty,
|
| + };
|
| +
|
| + // The x87 tag word (in both abridged and full form) identifies physical
|
| + // registers, but |st_mm| is arranged in logical stack order. In order to map
|
| + // physical tag word bits to the logical stack registers they correspond to,
|
| + // the “stack top” value from the x87 status word is necessary.
|
| + int stack_top = (fsw >> 11) & 0x7;
|
| +
|
| + uint16_t fsave_tag = 0;
|
| + for (int physical_index = 0; physical_index < 8; ++physical_index) {
|
| + bool fxsave_bit = (fxsave_tag & (1 << physical_index)) != 0;
|
| + uint8_t fsave_bits;
|
| +
|
| + if (fxsave_bit) {
|
| + int st_index = (physical_index + 8 - stack_top) % 8;
|
| + const CPUContextX86::X87Register& st = st_mm[st_index].st;
|
| +
|
| + uint32_t exponent = ((st[9] & 0x7f) << 8) | st[8];
|
| + if (exponent == 0x7fff) {
|
| + // Infinity, NaN, pseudo-infinity, or pseudo-NaN. If it was important to
|
| + // distinguish between these, the J bit and the M bit (the most
|
| + // significant bit of |fraction|) could be consulted.
|
| + fsave_bits = kX87TagSpecial;
|
| + } else {
|
| + // The integer bit the “J bit”.
|
| + bool integer_bit = (st[7] & 0x80) != 0;
|
| + if (exponent == 0) {
|
| + uint64_t fraction = ((implicit_cast<uint64_t>(st[7]) & 0x7f) << 56) |
|
| + (implicit_cast<uint64_t>(st[6]) << 48) |
|
| + (implicit_cast<uint64_t>(st[5]) << 40) |
|
| + (implicit_cast<uint64_t>(st[4]) << 32) |
|
| + (implicit_cast<uint32_t>(st[3]) << 24) |
|
| + (st[2] << 16) | (st[1] << 8) | st[0];
|
| + if (!integer_bit && fraction == 0) {
|
| + fsave_bits = kX87TagZero;
|
| + } else {
|
| + // Denormal (if the J bit is clear) or pseudo-denormal.
|
| + fsave_bits = kX87TagSpecial;
|
| + }
|
| + } else if (integer_bit) {
|
| + fsave_bits = kX87TagValid;
|
| + } else {
|
| + // Unnormal.
|
| + fsave_bits = kX87TagSpecial;
|
| + }
|
| + }
|
| + } else {
|
| + fsave_bits = kX87TagEmpty;
|
| + }
|
| +
|
| + fsave_tag |= (fsave_bits << (physical_index * 2));
|
| + }
|
| +
|
| + return fsave_tag;
|
| +}
|
| +
|
| +uint64_t CPUContext::InstructionPointer() const {
|
| + switch (architecture) {
|
| + case kCPUArchitectureX86:
|
| + return x86->eip;
|
| + case kCPUArchitectureX86_64:
|
| + return x86_64->rip;
|
| + default:
|
| + NOTREACHED();
|
| + return ~0ull;
|
| + }
|
| +}
|
| +
|
| +} // namespace crashpad
|
|
|