fuchsia: Capture general purpose registers in thread snapshot

Conversion to CPUContext is currently only implemented for x64.

Bug: crashpad:196
Change-Id: I3fb8541f70a6f8d6f12c02e6b17c78e07e195056
Reviewed-on: https://chromium-review.googlesource.com/1007967
Commit-Queue: Scott Graham <scottmg@chromium.org>
Reviewed-by: Joshua Peraza <jperaza@chromium.org>

snapshot/BUILD.gn

@@ -176,6 +176,8 @@ static_library("snapshot") {
 
   if (crashpad_is_fuchsia) {
     sources += [
+      "fuchsia/cpu_context_fuchsia.cc",
+      "fuchsia/cpu_context_fuchsia.h",
       "fuchsia/process_reader_fuchsia.cc",
       "fuchsia/process_reader_fuchsia.h",
       "fuchsia/process_snapshot_fuchsia.cc",

snapshot/fuchsia/cpu_context_fuchsia.cc

@@ -0,0 +1,51 @@
+// Copyright 2018 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/fuchsia/cpu_context_fuchsia.h"
+
+#include <string.h>
+
+namespace crashpad {
+namespace internal {
+
+#if defined(ARCH_CPU_X86_64)
+
+void InitializeCPUContextX86_64(
+    const zx_thread_state_general_regs_t& thread_context,
+    CPUContextX86_64* context) {
+  memset(context, 0, sizeof(*context));
+  context->rax = thread_context.rax;
+  context->rbx = thread_context.rbx;
+  context->rcx = thread_context.rcx;
+  context->rdx = thread_context.rdx;
+  context->rdi = thread_context.rdi;
+  context->rsi = thread_context.rsi;
+  context->rbp = thread_context.rbp;
+  context->rsp = thread_context.rsp;
+  context->r8 = thread_context.r8;
+  context->r9 = thread_context.r9;
+  context->r10 = thread_context.r10;
+  context->r11 = thread_context.r11;
+  context->r12 = thread_context.r12;
+  context->r13 = thread_context.r13;
+  context->r14 = thread_context.r14;
+  context->r15 = thread_context.r15;
+  context->rip = thread_context.rip;
+  context->rflags = thread_context.rflags;
+}
+
+#endif  // ARCH_CPU_X86_64
+
+}  // namespace internal
+}  // namespace crashpad

snapshot/fuchsia/cpu_context_fuchsia.h

@@ -0,0 +1,46 @@
+// Copyright 2018 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.
+
+#ifndef CRASHPAD_SNAPSHOT_FUCHSIA_CPU_CONTEXT_FUCHSIA_H_
+#define CRASHPAD_SNAPSHOT_FUCHSIA_CPU_CONTEXT_FUCHSIA_H_
+
+#include <zircon/syscall/debug.h>
+
+#include "build/build_config.h"
+#include "snapshot/cpu_context.h"
+#include "snapshot/fuchsia/process_reader_fuchsia.h"
+
+namespace crashpad {
+namespace internal {
+
+#if defined(ARCH_CPU_X86_64) || DOXYGEN
+
+//! \brief Initializes a CPUContextX86_64 structure from native context
+//!     structures on Fuchsia.
+//!
+//! Floating point registers are currently initialized to zero.
+//! Segment registers are currently initialized to zero.
+//!
+//! \param[in] thread_context The native thread context.
+//! \param[out] context The CPUContextX86_64 structure to initialize.
+void InitializeCPUContextX86_64(
+    const zx_thread_state_general_regs_t& thread_context,
+    CPUContextX86_64* context);
+
+#endif  // ARCH_CPU_X86_64 || DOXYGEN
+
+}  // namespace internal
+}  // namespace crashpad
+
+#endif  // CRASHPAD_SNAPSHOT_FUCHSIA_CPU_CONTEXT_FUCHSIA_H_

snapshot/fuchsia/process_reader_fuchsia.cc

@@ -224,6 +224,15 @@ void ProcessReaderFuchsia::InitializeThreads() {
       }
     }
 
+    zx_thread_state_general_regs_t regs;
+    status = zx_thread_read_state(
+        thread_handle.get(), ZX_THREAD_STATE_GENERAL_REGS, &regs, sizeof(regs));
+    if (status != ZX_OK) {
+      ZX_LOG(WARNING, status) << "zx_thread_read_state";
+    } else {
+      thread.general_registers = regs;
+    }
+
     threads_.push_back(thread);
   }
 }

snapshot/fuchsia/process_reader_fuchsia.h

@@ -15,6 +15,8 @@
 #ifndef CRASHPAD_SNAPSHOT_FUCHSIA_PROCESS_READER_H_
 #define CRASHPAD_SNAPSHOT_FUCHSIA_PROCESS_READER_H_
 
+#include <zircon/syscalls/debug.h>
+
 #include <memory>
 #include <vector>
 
@@ -68,6 +70,10 @@ class ProcessReaderFuchsia {
 
     //! \brief The `ZX_PROP_NAME` property of the thread. This may be empty.
     std::string name;
+
+    //! \brief The raw architecture-specific `zx_thread_state_general_regs_t` as
+    //!     returned by `zx_thread_read_state()`.
+    zx_thread_state_general_regs_t general_registers = {};
   };
 
   ProcessReaderFuchsia();

snapshot/fuchsia/thread_snapshot_fuchsia.cc

@@ -15,6 +15,7 @@
 #include "snapshot/fuchsia/thread_snapshot_fuchsia.h"
 
 #include "base/logging.h"
+#include "snapshot/fuchsia/cpu_context_fuchsia.h"
 
 namespace crashpad {
 namespace internal {
@@ -38,11 +39,13 @@ bool ThreadSnapshotFuchsia::Initialize(
 #if defined(ARCH_CPU_X86_64)
   context_.architecture = kCPUArchitectureX86_64;
   context_.x86_64 = &context_arch_;
-// TODO(scottmg): Implement context capture for x64.
+  // TODO(scottmg): Float context, once Fuchsia has a debug API to capture
+  // floating point registers. ZX-1750 upstream.
+  InitializeCPUContextX86_64(thread.general_registers, context_.x86_64);
 #elif defined(ARCH_CPU_ARM64)
   context_.architecture = kCPUArchitectureARM64;
   context_.arm64 = &context_arch_;
-// TODO(scottmg): Implement context capture for arm64.
+  // TODO(scottmg): Implement context capture for arm64.
 #else
 #error Port.
 #endif

snapshot/linux/cpu_context_linux.h

@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef CRASHPAD_SNAPSHOT_LINUX_SNAPSHOT_CPU_CONTEXT_LINUX_H_
-#define CRASHPAD_SNAPSHOT_LINUX_SNAPSHOT_CPU_CONTEXT_LINUX_H_
+#ifndef CRASHPAD_SNAPSHOT_LINUX_CPU_CONTEXT_LINUX_H_
+#define CRASHPAD_SNAPSHOT_LINUX_CPU_CONTEXT_LINUX_H_
 
 #include "build/build_config.h"
 #include "snapshot/cpu_context.h"
@@ -141,4 +141,4 @@ void InitializeCPUContextARM64_OnlyFPSIMD(
 }  // namespace internal
 }  // namespace crashpad
 
-#endif  // CRASHPAD_SNAPSHOT_LINUX_SNAPSHOT_CPU_CONTEXT_LINUX_H_
+#endif  // CRASHPAD_SNAPSHOT_LINUX_CPU_CONTEXT_LINUX_H_

snapshot/mac/cpu_context_mac.h

@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef CRASHPAD_SNAPSHOT_MAC_SNAPSHOT_CPU_CONTEXT_MAC_H_
-#define CRASHPAD_SNAPSHOT_MAC_SNAPSHOT_CPU_CONTEXT_MAC_H_
+#ifndef CRASHPAD_SNAPSHOT_MAC_CPU_CONTEXT_MAC_H_
+#define CRASHPAD_SNAPSHOT_MAC_CPU_CONTEXT_MAC_H_
 
 #include <mach/mach.h>
 
@@ -113,4 +113,4 @@ void InitializeCPUContextX86_64(CPUContextX86_64* context,
 }  // namespace internal
 }  // namespace crashpad
 
-#endif  // CRASHPAD_SNAPSHOT_MAC_SNAPSHOT_CPU_CONTEXT_MAC_H_
+#endif  // CRASHPAD_SNAPSHOT_MAC_CPU_CONTEXT_MAC_H_