Add Arm64 version of breakpad_getcontext for Android.

This CL adds breakpad_getcontext support for Arm64 to Android. The assembly
is based on getcontext.S in glibc.

BUG=354405,335641
R=mark@chromium.org

Review URL: https://breakpad.appspot.com/1384002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1302 4c0a9323-5329-0410-9bdc-e9ce6186880e

2 files changed, 13 insertions, 6 deletions

diff --git a/src/client/linux/handler/exception_handler.cc b/src/client/linux/handler/exception_handler.cc
index 9d081ca8..e5aaecd8 100644
--- a/src/client/linux/handler/exception_handler.cc
+++ b/src/client/linux/handler/exception_handler.cc
@@ -398,8 +398,15 @@ bool ExceptionHandler::HandleSignal(int sig, siginfo_t* info, void* uc) {
   CrashContext context;
   memcpy(&context.siginfo, info, sizeof(siginfo_t));
   memcpy(&context.context, uc, sizeof(struct ucontext));
-#if !defined(__ARM_EABI__) && !defined(__aarch64__) && !defined(__mips__)
-  // FP state is not part of user ABI on ARM or ARM64 Linux.
+#if defined(__aarch64__)
+  struct ucontext *uc_ptr = (struct ucontext*)uc;
+  struct fpsimd_context *fp_ptr =
+      (struct fpsimd_context*)&uc_ptr->uc_mcontext.__reserved;
+  if (fp_ptr->head.magic == FPSIMD_MAGIC) {
+    memcpy(&context.float_state, fp_ptr, sizeof(context.float_state));
+  }
+#elif !defined(__ARM_EABI__)  && !defined(__mips__)
+  // FP state is not part of user ABI on ARM Linux.
   // In case of MIPS Linux FP state is already part of struct ucontext
   // and 'float_state' is not a member of CrashContext.
   struct ucontext *uc_ptr = (struct ucontext*)uc;
diff --git a/src/client/linux/handler/exception_handler.h b/src/client/linux/handler/exception_handler.h
index 2e842d83..e906e7a7 100644
--- a/src/client/linux/handler/exception_handler.h
+++ b/src/client/linux/handler/exception_handler.h
@@ -190,11 +190,11 @@ class ExceptionHandler {
     siginfo_t siginfo;
     pid_t tid;  // the crashing thread.
     struct ucontext context;
-#if !defined(__ARM_EABI__) && !defined(__aarch64__) && !defined(__mips__)
-    // #ifdef this out because FP state is not part of user ABI for Linux ARM
-    // or ARM64. In case of MIPS Linux FP state is already part of struct
+#if !defined(__ARM_EABI__) && !defined(__mips__)
+    // #ifdef this out because FP state is not part of user ABI for Linux ARM.
+    // In case of MIPS Linux FP state is already part of struct
     // ucontext so 'float_state' is not required.
-    struct _libc_fpstate float_state;
+    fpstate_t float_state;
 #endif
   };