diff --git a/debuggerd/Android.mk b/debuggerd/Android.mk
index dd53296..1a5f05e 100644
--- a/debuggerd/Android.mk
+++ b/debuggerd/Android.mk
@@ -1,4 +1,12 @@
-LOCAL_PATH:= $(call my-dir)
+LOCAL_PATH := $(call my-dir)
+
+common_cppflags := \
+    -std=gnu++11 \
+    -W \
+    -Wall \
+    -Wextra \
+    -Wunused \
+    -Werror \
 
 include $(CLEAR_VARS)
 
@@ -17,11 +25,7 @@
 LOCAL_SRC_FILES_x86    := x86/machine.cpp
 LOCAL_SRC_FILES_x86_64 := x86_64/machine.cpp
 
-LOCAL_CPPFLAGS := \
-    -std=gnu++11 \
-    -W -Wall -Wextra \
-    -Wunused \
-    -Werror \
+LOCAL_CPPFLAGS := $(common_cppflags)
 
 ifeq ($(TARGET_IS_64_BIT),true)
 LOCAL_CPPFLAGS += -DTARGET_IS_64_BIT
@@ -70,3 +74,47 @@
 LOCAL_MULTILIB := both
 
 include $(BUILD_EXECUTABLE)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    utility.cpp \
+    test/dump_memory_test.cpp \
+    test/log_fake.cpp \
+
+LOCAL_MODULE := debuggerd_test
+
+LOCAL_SHARED_LIBRARIES := \
+    libbacktrace \
+    libbase \
+
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/test
+LOCAL_CPPFLAGS := $(common_cppflags)
+
+LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
+LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
+LOCAL_MULTILIB := both
+
+include $(BUILD_HOST_NATIVE_TEST)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    utility.cpp \
+    test/dump_memory_test.cpp \
+    test/log_fake.cpp \
+
+LOCAL_MODULE := debuggerd_test
+
+LOCAL_SHARED_LIBRARIES := \
+    libbacktrace \
+    libbase \
+
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/test
+LOCAL_CPPFLAGS := $(common_cppflags)
+
+LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
+LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
+LOCAL_MULTILIB := both
+
+include $(BUILD_NATIVE_TEST)
diff --git a/debuggerd/arm/machine.cpp b/debuggerd/arm/machine.cpp
index 50e78c5..b7d6997 100644
--- a/debuggerd/arm/machine.cpp
+++ b/debuggerd/arm/machine.cpp
@@ -16,53 +16,39 @@
  */
 
 #include <errno.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
+#include <stdint.h>
 #include <string.h>
 #include <sys/ptrace.h>
-#include <sys/types.h>
-#include <sys/user.h>
 
-#include "../utility.h"
-#include "../machine.h"
+#include <backtrace/Backtrace.h>
 
-void dump_memory_and_code(log_t* log, pid_t tid) {
+#include "machine.h"
+#include "utility.h"
+
+void dump_memory_and_code(log_t* log, Backtrace* backtrace) {
   pt_regs regs;
-  if (ptrace(PTRACE_GETREGS, tid, 0, &regs)) {
+  if (ptrace(PTRACE_GETREGS, backtrace->Tid(), 0, &regs)) {
+    _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
     return;
   }
 
-  static const char REG_NAMES[] = "r0r1r2r3r4r5r6r7r8r9slfpipsp";
+  static const char reg_names[] = "r0r1r2r3r4r5r6r7r8r9slfpipsp";
 
   for (int reg = 0; reg < 14; reg++) {
-    // this may not be a valid way to access, but it'll do for now
-    uintptr_t addr = regs.uregs[reg];
-
-    // Don't bother if it looks like a small int or ~= null, or if
-    // it's in the kernel area.
-    if (addr < 4096 || addr >= 0xc0000000) {
-      continue;
-    }
-
-    _LOG(log, logtype::MEMORY, "\nmemory near %.2s:\n", &REG_NAMES[reg * 2]);
-    dump_memory(log, tid, addr);
+    dump_memory(log, backtrace, regs.uregs[reg], "memory near %.2s:", &reg_names[reg * 2]);
   }
 
-  // explicitly allow upload of code dump logging
-  _LOG(log, logtype::MEMORY, "\ncode around pc:\n");
-  dump_memory(log, tid, static_cast<uintptr_t>(regs.ARM_pc));
+  dump_memory(log, backtrace, static_cast<uintptr_t>(regs.ARM_pc), "code around pc:");
 
   if (regs.ARM_pc != regs.ARM_lr) {
-    _LOG(log, logtype::MEMORY, "\ncode around lr:\n");
-    dump_memory(log, tid, static_cast<uintptr_t>(regs.ARM_lr));
+    dump_memory(log, backtrace, static_cast<uintptr_t>(regs.ARM_lr), "code around lr:");
   }
 }
 
 void dump_registers(log_t* log, pid_t tid) {
   pt_regs r;
   if (ptrace(PTRACE_GETREGS, tid, 0, &r)) {
-    _LOG(log, logtype::REGISTERS, "cannot get registers: %s\n", strerror(errno));
+    _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
     return;
   }
 
@@ -82,7 +68,7 @@
 
   user_vfp vfp_regs;
   if (ptrace(PTRACE_GETVFPREGS, tid, 0, &vfp_regs)) {
-    _LOG(log, logtype::FP_REGISTERS, "cannot get FP registers: %s\n", strerror(errno));
+    _LOG(log, logtype::ERROR, "cannot get FP registers: %s\n", strerror(errno));
     return;
   }
 
diff --git a/debuggerd/arm64/machine.cpp b/debuggerd/arm64/machine.cpp
index 8b17d53..2e097da 100644
--- a/debuggerd/arm64/machine.cpp
+++ b/debuggerd/arm64/machine.cpp
@@ -17,50 +17,37 @@
 
 #include <elf.h>
 #include <errno.h>
-#include <inttypes.h>
+#include <stdint.h>
 #include <string.h>
-#include <sys/types.h>
 #include <sys/ptrace.h>
-#include <sys/user.h>
 #include <sys/uio.h>
 
-#include "../utility.h"
-#include "../machine.h"
+#include <backtrace/Backtrace.h>
 
-void dump_memory_and_code(log_t* log, pid_t tid) {
-    struct user_pt_regs regs;
-    struct iovec io;
-    io.iov_base = &regs;
-    io.iov_len = sizeof(regs);
+#include "machine.h"
+#include "utility.h"
 
-    if (ptrace(PTRACE_GETREGSET, tid, (void*)NT_PRSTATUS, &io) == -1) {
-        _LOG(log, logtype::ERROR, "%s: ptrace failed to get registers: %s\n",
-             __func__, strerror(errno));
-        return;
-    }
+void dump_memory_and_code(log_t* log, Backtrace* backtrace) {
+  struct user_pt_regs regs;
+  struct iovec io;
+  io.iov_base = &regs;
+  io.iov_len = sizeof(regs);
 
-    for (int reg = 0; reg < 31; reg++) {
-        uintptr_t addr = regs.regs[reg];
+  if (ptrace(PTRACE_GETREGSET, backtrace->Tid(), reinterpret_cast<void*>(NT_PRSTATUS), &io) == -1) {
+    _LOG(log, logtype::ERROR, "%s: ptrace failed to get registers: %s",
+         __func__, strerror(errno));
+    return;
+  }
 
-        /*
-         * Don't bother if it looks like a small int or ~= null, or if
-         * it's in the kernel area.
-         */
-        if (addr < 4096 || addr >= (1UL<<63)) {
-            continue;
-        }
+  for (int reg = 0; reg < 31; reg++) {
+    dump_memory(log, backtrace, regs.regs[reg], "memory near x%d:", reg);
+  }
 
-        _LOG(log, logtype::MEMORY, "\nmemory near x%d:\n", reg);
-        dump_memory(log, tid, addr);
-    }
+  dump_memory(log, backtrace, static_cast<uintptr_t>(regs.pc), "code around pc:");
 
-    _LOG(log, logtype::MEMORY, "\ncode around pc:\n");
-    dump_memory(log, tid, (uintptr_t)regs.pc);
-
-    if (regs.pc != regs.sp) {
-        _LOG(log, logtype::MEMORY, "\ncode around sp:\n");
-        dump_memory(log, tid, (uintptr_t)regs.sp);
-    }
+  if (regs.pc != regs.sp) {
+    dump_memory(log, backtrace, static_cast<uintptr_t>(regs.sp), "code around sp:");
+  }
 }
 
 void dump_registers(log_t* log, pid_t tid) {
diff --git a/debuggerd/machine.h b/debuggerd/machine.h
index fca9fbe..e65b147 100644
--- a/debuggerd/machine.h
+++ b/debuggerd/machine.h
@@ -19,9 +19,11 @@
 
 #include <sys/types.h>
 
+#include <backtrace/Backtrace.h>
+
 #include "utility.h"
 
-void dump_memory_and_code(log_t* log, pid_t tid);
+void dump_memory_and_code(log_t* log, Backtrace* backtrace);
 void dump_registers(log_t* log, pid_t tid);
 
 #endif // _DEBUGGERD_MACHINE_H
diff --git a/debuggerd/mips/machine.cpp b/debuggerd/mips/machine.cpp
index 1145963..f7b8a86 100644
--- a/debuggerd/mips/machine.cpp
+++ b/debuggerd/mips/machine.cpp
@@ -14,30 +14,29 @@
  * limitations under the License.
  */
 
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
 #include <errno.h>
-#include <sys/types.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <string.h>
 #include <sys/ptrace.h>
 
-#include <sys/user.h>
+#include <backtrace/Backtrace.h>
 
-#include "../utility.h"
-#include "../machine.h"
+#include "machine.h"
+#include "utility.h"
 
-#define R(x) (static_cast<unsigned int>(x))
+#define R(x) (static_cast<uintptr_t>(x))
 
 // If configured to do so, dump memory around *all* registers
 // for the crashing thread.
-void dump_memory_and_code(log_t* log, pid_t tid) {
+void dump_memory_and_code(log_t* log, Backtrace* backtrace) {
   pt_regs r;
-  if (ptrace(PTRACE_GETREGS, tid, 0, &r)) {
+  if (ptrace(PTRACE_GETREGS, backtrace->Tid(), 0, &r)) {
+    _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
     return;
   }
 
-  static const char REG_NAMES[] = "$0atv0v1a0a1a2a3t0t1t2t3t4t5t6t7s0s1s2s3s4s5s6s7t8t9k0k1gpsps8ra";
+  static const char reg_names[] = "$0atv0v1a0a1a2a3t0t1t2t3t4t5t6t7s0s1s2s3s4s5s6s7t8t9k0k1gpsps8ra";
 
   for (int reg = 0; reg < 32; reg++) {
     // skip uninteresting registers
@@ -48,27 +47,14 @@
        )
       continue;
 
-    uintptr_t addr = R(r.regs[reg]);
-
-    // Don't bother if it looks like a small int or ~= null, or if
-    // it's in the kernel area.
-    if (addr < 4096 || addr >= 0x80000000) {
-      continue;
-    }
-
-    _LOG(log, logtype::MEMORY, "\nmemory near %.2s:\n", &REG_NAMES[reg * 2]);
-    dump_memory(log, tid, addr);
+    dump_memory(log, backtrace, R(r.regs[reg]), "memory near %.2s:", &reg_names[reg * 2]);
   }
 
-  unsigned int pc = R(r.cp0_epc);
-  unsigned int ra = R(r.regs[31]);
-
-  _LOG(log, logtype::MEMORY, "\ncode around pc:\n");
-  dump_memory(log, tid, (uintptr_t)pc);
-
+  uintptr_t pc = R(r.cp0_epc);
+  uintptr_t ra = R(r.regs[31]);
+  dump_memory(log, backtrace, pc, "code around pc:");
   if (pc != ra) {
-    _LOG(log, logtype::MEMORY, "\ncode around ra:\n");
-    dump_memory(log, tid, (uintptr_t)ra);
+    dump_memory(log, backtrace, ra, "code around ra:");
   }
 }
 
@@ -79,22 +65,31 @@
     return;
   }
 
-  _LOG(log, logtype::REGISTERS, " zr %08x  at %08x  v0 %08x  v1 %08x\n",
+  _LOG(log, logtype::REGISTERS, " zr %08" PRIxPTR "  at %08" PRIxPTR
+       "  v0 %08" PRIxPTR "  v1 %08" PRIxPTR "\n",
        R(r.regs[0]), R(r.regs[1]), R(r.regs[2]), R(r.regs[3]));
-  _LOG(log, logtype::REGISTERS, " a0 %08x  a1 %08x  a2 %08x  a3 %08x\n",
+  _LOG(log, logtype::REGISTERS, " a0 %08" PRIxPTR "  a1 %08" PRIxPTR
+       "  a2 %08" PRIxPTR "  a3 %08" PRIxPTR "\n",
        R(r.regs[4]), R(r.regs[5]), R(r.regs[6]), R(r.regs[7]));
-  _LOG(log, logtype::REGISTERS, " t0 %08x  t1 %08x  t2 %08x  t3 %08x\n",
+  _LOG(log, logtype::REGISTERS, " t0 %08" PRIxPTR "  t1 %08" PRIxPTR
+       "  t2 %08" PRIxPTR "  t3 %08" PRIxPTR "\n",
        R(r.regs[8]), R(r.regs[9]), R(r.regs[10]), R(r.regs[11]));
-  _LOG(log, logtype::REGISTERS, " t4 %08x  t5 %08x  t6 %08x  t7 %08x\n",
+  _LOG(log, logtype::REGISTERS, " t4 %08" PRIxPTR "  t5 %08" PRIxPTR
+       "  t6 %08" PRIxPTR "  t7 %08" PRIxPTR "\n",
        R(r.regs[12]), R(r.regs[13]), R(r.regs[14]), R(r.regs[15]));
-  _LOG(log, logtype::REGISTERS, " s0 %08x  s1 %08x  s2 %08x  s3 %08x\n",
+  _LOG(log, logtype::REGISTERS, " s0 %08" PRIxPTR "  s1 %08" PRIxPTR
+       "  s2 %08" PRIxPTR "  s3 %08" PRIxPTR "\n",
        R(r.regs[16]), R(r.regs[17]), R(r.regs[18]), R(r.regs[19]));
-  _LOG(log, logtype::REGISTERS, " s4 %08x  s5 %08x  s6 %08x  s7 %08x\n",
+  _LOG(log, logtype::REGISTERS, " s4 %08" PRIxPTR "  s5 %08" PRIxPTR
+       "  s6 %08" PRIxPTR "  s7 %08" PRIxPTR "\n",
        R(r.regs[20]), R(r.regs[21]), R(r.regs[22]), R(r.regs[23]));
-  _LOG(log, logtype::REGISTERS, " t8 %08x  t9 %08x  k0 %08x  k1 %08x\n",
+  _LOG(log, logtype::REGISTERS, " t8 %08" PRIxPTR "  t9 %08" PRIxPTR
+       "  k0 %08" PRIxPTR "  k1 %08" PRIxPTR "\n",
        R(r.regs[24]), R(r.regs[25]), R(r.regs[26]), R(r.regs[27]));
-  _LOG(log, logtype::REGISTERS, " gp %08x  sp %08x  s8 %08x  ra %08x\n",
+  _LOG(log, logtype::REGISTERS, " gp %08" PRIxPTR "  sp %08" PRIxPTR
+       "  s8 %08" PRIxPTR "  ra %08" PRIxPTR "\n",
        R(r.regs[28]), R(r.regs[29]), R(r.regs[30]), R(r.regs[31]));
-  _LOG(log, logtype::REGISTERS, " hi %08x  lo %08x bva %08x epc %08x\n",
+  _LOG(log, logtype::REGISTERS, " hi %08" PRIxPTR "  lo %08" PRIxPTR
+       " bva %08" PRIxPTR " epc %08" PRIxPTR "\n",
        R(r.hi), R(r.lo), R(r.cp0_badvaddr), R(r.cp0_epc));
 }
diff --git a/debuggerd/mips64/machine.cpp b/debuggerd/mips64/machine.cpp
index ef9092f..293dcf6 100644
--- a/debuggerd/mips64/machine.cpp
+++ b/debuggerd/mips64/machine.cpp
@@ -14,30 +14,29 @@
  * limitations under the License.
  */
 
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
 #include <errno.h>
-#include <sys/types.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <string.h>
 #include <sys/ptrace.h>
 
-#include <sys/user.h>
+#include <backtrace/Backtrace.h>
 
-#include "../utility.h"
-#include "../machine.h"
+#include "machine.h"
+#include "utility.h"
 
-#define R(x) (static_cast<unsigned long>(x))
+#define R(x) (static_cast<uintptr_t>(x))
 
 // If configured to do so, dump memory around *all* registers
 // for the crashing thread.
-void dump_memory_and_code(log_t* log, pid_t tid) {
+void dump_memory_and_code(log_t* log, Backtrace* backtrace) {
   pt_regs r;
-  if (ptrace(PTRACE_GETREGS, tid, 0, &r)) {
+  if (ptrace(PTRACE_GETREGS, backtrace->Tid(), 0, &r)) {
+    _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
     return;
   }
 
-  static const char REG_NAMES[] = "$0atv0v1a0a1a2a3a4a5a6a7t0t1t2t3s0s1s2s3s4s5s6s7t8t9k0k1gpsps8ra";
+  static const char reg_names[] = "$0atv0v1a0a1a2a3a4a5a6a7t0t1t2t3s0s1s2s3s4s5s6s7t8t9k0k1gpsps8ra";
 
   for (int reg = 0; reg < 32; reg++) {
     // skip uninteresting registers
@@ -48,27 +47,14 @@
        )
       continue;
 
-    uintptr_t addr = R(r.regs[reg]);
-
-    // Don't bother if it looks like a small int or ~= null, or if
-    // it's in the kernel area.
-    if (addr < 4096 || addr >= 0x4000000000000000) {
-      continue;
-    }
-
-    _LOG(log, logtype::MEMORY, "\nmemory near %.2s:\n", &REG_NAMES[reg * 2]);
-    dump_memory(log, tid, addr);
+    dump_memory(log, backtrace, R(r.regs[reg]), "memory near %.2s:", &reg_names[reg * 2]);
   }
 
-  unsigned long pc = R(r.cp0_epc);
-  unsigned long ra = R(r.regs[31]);
-
-  _LOG(log, logtype::MEMORY, "\ncode around pc:\n");
-  dump_memory(log, tid, (uintptr_t)pc);
-
+  uintptr_t pc = R(r.cp0_epc);
+  uintptr_t ra = R(r.regs[31]);
+  dump_memory(log, backtrace, pc, "code around pc:");
   if (pc != ra) {
-    _LOG(log, logtype::MEMORY, "\ncode around ra:\n");
-    dump_memory(log, tid, (uintptr_t)ra);
+    dump_memory(log, backtrace, ra, "code around ra:");
   }
 }
 
@@ -79,22 +65,31 @@
     return;
   }
 
-  _LOG(log, logtype::REGISTERS, " zr %016lx  at %016lx  v0 %016lx  v1 %016lx\n",
+  _LOG(log, logtype::REGISTERS, " zr %016" PRIxPTR "  at %016" PRIxPTR
+       "  v0 %016" PRIxPTR "  v1 %016" PRIxPTR "\n",
        R(r.regs[0]), R(r.regs[1]), R(r.regs[2]), R(r.regs[3]));
-  _LOG(log, logtype::REGISTERS, " a0 %016lx  a1 %016lx  a2 %016lx  a3 %016lx\n",
+  _LOG(log, logtype::REGISTERS, " a0 %016" PRIxPTR "  a1 %016" PRIxPTR
+       "  a2 %016" PRIxPTR "  a3 %016" PRIxPTR "\n",
        R(r.regs[4]), R(r.regs[5]), R(r.regs[6]), R(r.regs[7]));
-  _LOG(log, logtype::REGISTERS, " a4 %016lx  a5 %016lx  a6 %016lx  a7 %016lx\n",
+  _LOG(log, logtype::REGISTERS, " a4 %016" PRIxPTR "  a5 %016" PRIxPTR
+       "  a6 %016" PRIxPTR "  a7 %016" PRIxPTR "\n",
        R(r.regs[8]), R(r.regs[9]), R(r.regs[10]), R(r.regs[11]));
-  _LOG(log, logtype::REGISTERS, " t0 %016lx  t1 %016lx  t2 %016lx  t3 %016lx\n",
+  _LOG(log, logtype::REGISTERS, " t0 %016" PRIxPTR "  t1 %016" PRIxPTR
+       "  t2 %016" PRIxPTR "  t3 %016" PRIxPTR "\n",
        R(r.regs[12]), R(r.regs[13]), R(r.regs[14]), R(r.regs[15]));
-  _LOG(log, logtype::REGISTERS, " s0 %016lx  s1 %016lx  s2 %016lx  s3 %016lx\n",
+  _LOG(log, logtype::REGISTERS, " s0 %016" PRIxPTR "  s1 %016" PRIxPTR
+       "  s2 %016" PRIxPTR "  s3 %016" PRIxPTR "\n",
        R(r.regs[16]), R(r.regs[17]), R(r.regs[18]), R(r.regs[19]));
-  _LOG(log, logtype::REGISTERS, " s4 %016lx  s5 %016lx  s6 %016lx  s7 %016lx\n",
+  _LOG(log, logtype::REGISTERS, " s4 %016" PRIxPTR "  s5 %016" PRIxPTR
+       "  s6 %016" PRIxPTR "  s7 %016" PRIxPTR "\n",
        R(r.regs[20]), R(r.regs[21]), R(r.regs[22]), R(r.regs[23]));
-  _LOG(log, logtype::REGISTERS, " t8 %016lx  t9 %016lx  k0 %016lx  k1 %016lx\n",
+  _LOG(log, logtype::REGISTERS, " t8 %016" PRIxPTR "  t9 %016" PRIxPTR
+       "  k0 %016" PRIxPTR "  k1 %016" PRIxPTR "\n",
        R(r.regs[24]), R(r.regs[25]), R(r.regs[26]), R(r.regs[27]));
-  _LOG(log, logtype::REGISTERS, " gp %016lx  sp %016lx  s8 %016lx  ra %016lx\n",
+  _LOG(log, logtype::REGISTERS, " gp %016" PRIxPTR "  sp %016" PRIxPTR
+       "  s8 %016" PRIxPTR "  ra %016" PRIxPTR "\n",
        R(r.regs[28]), R(r.regs[29]), R(r.regs[30]), R(r.regs[31]));
-  _LOG(log, logtype::REGISTERS, " hi %016lx  lo %016lx bva %016lx epc %016lx\n",
+  _LOG(log, logtype::REGISTERS, " hi %016" PRIxPTR "  lo %016" PRIxPTR
+       " bva %016" PRIxPTR " epc %016" PRIxPTR "\n",
        R(r.hi), R(r.lo), R(r.cp0_badvaddr), R(r.cp0_epc));
 }
diff --git a/debuggerd/test/BacktraceMock.h b/debuggerd/test/BacktraceMock.h
new file mode 100644
index 0000000..05ad12b
--- /dev/null
+++ b/debuggerd/test/BacktraceMock.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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 _DEBUGGERD_TEST_BACKTRACE_MOCK_H
+#define _DEBUGGERD_TEST_BACKTRACE_MOCK_H
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ucontext.h>
+
+#include <string>
+#include <vector>
+
+#include <backtrace/Backtrace.h>
+#include <backtrace/BacktraceMap.h>
+
+class BacktraceMapMock : public BacktraceMap {
+ public:
+  BacktraceMapMock() : BacktraceMap(0) {}
+  virtual ~BacktraceMapMock() {}
+};
+
+
+class BacktraceMock : public Backtrace {
+ public:
+  BacktraceMock(BacktraceMapMock* map) : Backtrace(0, 0, map) {
+    if (map_ == nullptr) {
+      abort();
+    }
+  }
+  virtual ~BacktraceMock() {}
+
+  virtual bool Unwind(size_t, ucontext_t*) { return false; }
+  virtual bool ReadWord(uintptr_t, word_t*) { return false;}
+
+  virtual std::string GetFunctionNameRaw(uintptr_t, uintptr_t*) { return ""; }
+
+  virtual size_t Read(uintptr_t addr, uint8_t* buffer, size_t bytes) {
+    size_t offset = 0;
+    if (last_read_addr_ > 0) {
+      offset = addr - last_read_addr_;
+    }
+    size_t bytes_available = buffer_.size() - offset;
+
+    if (bytes_partial_read_ > 0) {
+      // Do a partial read.
+      if (bytes > bytes_partial_read_) {
+        bytes = bytes_partial_read_;
+      }
+      bytes_partial_read_ -= bytes;
+    } else if (bytes > bytes_available) {
+      bytes = bytes_available;
+    }
+
+    if (bytes > 0) {
+      memcpy(buffer, buffer_.data() + offset, bytes);
+    }
+
+    last_read_addr_ = addr;
+    return bytes;
+  }
+
+  void SetReadData(uint8_t* buffer, size_t bytes) {
+    buffer_.resize(bytes);
+    memcpy(buffer_.data(), buffer, bytes);
+    bytes_partial_read_ = 0;
+    last_read_addr_ = 0;
+  }
+
+  void SetPartialReadAmount(size_t bytes) {
+    if (bytes > buffer_.size()) {
+      abort();
+    }
+    bytes_partial_read_ = bytes;
+  }
+
+ private:
+  std::vector<uint8_t> buffer_;
+  size_t bytes_partial_read_ = 0;
+  uintptr_t last_read_addr_ = 0;
+};
+
+#endif //  _DEBUGGERD_TEST_BACKTRACE_MOCK_H
diff --git a/debuggerd/test/dump_memory_test.cpp b/debuggerd/test/dump_memory_test.cpp
new file mode 100644
index 0000000..fcb0108
--- /dev/null
+++ b/debuggerd/test/dump_memory_test.cpp
@@ -0,0 +1,504 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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 <stdlib.h>
+
+#include <memory>
+#include <string>
+
+#include <gtest/gtest.h>
+#include <base/file.h>
+
+#include "BacktraceMock.h"
+#include "log_fake.h"
+#include "utility.h"
+
+const char g_expected_full_dump[] =
+"\nmemory near r1:\n"
+#if defined(__LP64__)
+"    0000000012345658 0706050403020100 0f0e0d0c0b0a0908  ................\n"
+"    0000000012345668 1716151413121110 1f1e1d1c1b1a1918  ................\n"
+"    0000000012345678 2726252423222120 2f2e2d2c2b2a2928   !\"#$%&'()*+,-./\n"
+"    0000000012345688 3736353433323130 3f3e3d3c3b3a3938  0123456789:;<=>?\n"
+"    0000000012345698 4746454443424140 4f4e4d4c4b4a4948  @ABCDEFGHIJKLMNO\n"
+"    00000000123456a8 5756555453525150 5f5e5d5c5b5a5958  PQRSTUVWXYZ[\\]^_\n"
+"    00000000123456b8 6766656463626160 6f6e6d6c6b6a6968  `abcdefghijklmno\n"
+"    00000000123456c8 7776757473727170 7f7e7d7c7b7a7978  pqrstuvwxyz{|}~.\n"
+"    00000000123456d8 8786858483828180 8f8e8d8c8b8a8988  ................\n"
+"    00000000123456e8 9796959493929190 9f9e9d9c9b9a9998  ................\n"
+"    00000000123456f8 a7a6a5a4a3a2a1a0 afaeadacabaaa9a8  ................\n"
+"    0000000012345708 b7b6b5b4b3b2b1b0 bfbebdbcbbbab9b8  ................\n"
+"    0000000012345718 c7c6c5c4c3c2c1c0 cfcecdcccbcac9c8  ................\n"
+"    0000000012345728 d7d6d5d4d3d2d1d0 dfdedddcdbdad9d8  ................\n"
+"    0000000012345738 e7e6e5e4e3e2e1e0 efeeedecebeae9e8  ................\n"
+"    0000000012345748 f7f6f5f4f3f2f1f0 fffefdfcfbfaf9f8  ................\n";
+#else
+"    12345658 03020100 07060504 0b0a0908 0f0e0d0c  ................\n"
+"    12345668 13121110 17161514 1b1a1918 1f1e1d1c  ................\n"
+"    12345678 23222120 27262524 2b2a2928 2f2e2d2c   !\"#$%&'()*+,-./\n"
+"    12345688 33323130 37363534 3b3a3938 3f3e3d3c  0123456789:;<=>?\n"
+"    12345698 43424140 47464544 4b4a4948 4f4e4d4c  @ABCDEFGHIJKLMNO\n"
+"    123456a8 53525150 57565554 5b5a5958 5f5e5d5c  PQRSTUVWXYZ[\\]^_\n"
+"    123456b8 63626160 67666564 6b6a6968 6f6e6d6c  `abcdefghijklmno\n"
+"    123456c8 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.\n"
+"    123456d8 83828180 87868584 8b8a8988 8f8e8d8c  ................\n"
+"    123456e8 93929190 97969594 9b9a9998 9f9e9d9c  ................\n"
+"    123456f8 a3a2a1a0 a7a6a5a4 abaaa9a8 afaeadac  ................\n"
+"    12345708 b3b2b1b0 b7b6b5b4 bbbab9b8 bfbebdbc  ................\n"
+"    12345718 c3c2c1c0 c7c6c5c4 cbcac9c8 cfcecdcc  ................\n"
+"    12345728 d3d2d1d0 d7d6d5d4 dbdad9d8 dfdedddc  ................\n"
+"    12345738 e3e2e1e0 e7e6e5e4 ebeae9e8 efeeedec  ................\n"
+"    12345748 f3f2f1f0 f7f6f5f4 fbfaf9f8 fffefdfc  ................\n";
+#endif
+
+const char g_expected_partial_dump[] = \
+"\nmemory near pc:\n"
+#if defined(__LP64__)
+"    00000000123455e0 0706050403020100 0f0e0d0c0b0a0908  ................\n"
+"    00000000123455f0 1716151413121110 1f1e1d1c1b1a1918  ................\n"
+"    0000000012345600 2726252423222120 2f2e2d2c2b2a2928   !\"#$%&'()*+,-./\n"
+"    0000000012345610 3736353433323130 3f3e3d3c3b3a3938  0123456789:;<=>?\n"
+"    0000000012345620 4746454443424140 4f4e4d4c4b4a4948  @ABCDEFGHIJKLMNO\n"
+"    0000000012345630 5756555453525150 5f5e5d5c5b5a5958  PQRSTUVWXYZ[\\]^_\n"
+"    0000000012345640 6766656463626160 ----------------  `abcdefg........\n"
+"    0000000012345650 ---------------- ----------------  ................\n"
+"    0000000012345660 ---------------- ----------------  ................\n"
+"    0000000012345670 ---------------- ----------------  ................\n"
+"    0000000012345680 ---------------- ----------------  ................\n"
+"    0000000012345690 ---------------- ----------------  ................\n"
+"    00000000123456a0 ---------------- ----------------  ................\n"
+"    00000000123456b0 ---------------- ----------------  ................\n"
+"    00000000123456c0 ---------------- ----------------  ................\n"
+"    00000000123456d0 ---------------- ----------------  ................\n";
+#else
+"    123455e0 03020100 07060504 0b0a0908 0f0e0d0c  ................\n"
+"    123455f0 13121110 17161514 1b1a1918 1f1e1d1c  ................\n"
+"    12345600 23222120 27262524 2b2a2928 2f2e2d2c   !\"#$%&'()*+,-./\n"
+"    12345610 33323130 37363534 3b3a3938 3f3e3d3c  0123456789:;<=>?\n"
+"    12345620 43424140 47464544 4b4a4948 4f4e4d4c  @ABCDEFGHIJKLMNO\n"
+"    12345630 53525150 57565554 5b5a5958 5f5e5d5c  PQRSTUVWXYZ[\\]^_\n"
+"    12345640 63626160 67666564 -------- --------  `abcdefg........\n"
+"    12345650 -------- -------- -------- --------  ................\n"
+"    12345660 -------- -------- -------- --------  ................\n"
+"    12345670 -------- -------- -------- --------  ................\n"
+"    12345680 -------- -------- -------- --------  ................\n"
+"    12345690 -------- -------- -------- --------  ................\n"
+"    123456a0 -------- -------- -------- --------  ................\n"
+"    123456b0 -------- -------- -------- --------  ................\n"
+"    123456c0 -------- -------- -------- --------  ................\n"
+"    123456d0 -------- -------- -------- --------  ................\n";
+#endif
+
+class DumpMemoryTest : public ::testing::Test {
+ protected:
+  virtual void SetUp() {
+    map_mock_.reset(new BacktraceMapMock());
+    backtrace_mock_.reset(new BacktraceMock(map_mock_.get()));
+
+    char tmp_file[256];
+    const char data_template[] = "/data/local/tmp/debuggerd_memory_testXXXXXX";
+    memcpy(tmp_file, data_template, sizeof(data_template));
+    int tombstone_fd = mkstemp(tmp_file);
+    if (tombstone_fd == -1) {
+      const char tmp_template[] = "/tmp/debuggerd_memory_testXXXXXX";
+      memcpy(tmp_file, tmp_template, sizeof(tmp_template));
+      tombstone_fd = mkstemp(tmp_file);
+      if (tombstone_fd == -1) {
+        abort();
+      }
+    }
+    if (unlink(tmp_file) == -1) {
+      abort();
+    }
+
+    log_.tfd = tombstone_fd;
+    log_.amfd = -1;
+    log_.crashed_tid = 12;
+    log_.current_tid = 12;
+    log_.should_retrieve_logcat = false;
+
+    resetLogs();
+  }
+
+  virtual void TearDown() {
+    if (log_.tfd >= 0) {
+      close(log_.tfd);
+    }
+  }
+
+  std::unique_ptr<BacktraceMapMock> map_mock_;
+  std::unique_ptr<BacktraceMock> backtrace_mock_;
+
+  log_t log_;
+};
+
+TEST_F(DumpMemoryTest, aligned_addr) {
+  uint8_t buffer[256];
+  for (size_t i = 0; i < sizeof(buffer); i++) {
+    buffer[i] = i;
+  }
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+  dump_memory(&log_, backtrace_mock_.get(), 0x12345678, "memory near %.2s:", "r1");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ(g_expected_full_dump, tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, partial_read) {
+  uint8_t buffer[256];
+  for (size_t i = 0; i < sizeof(buffer); i++) {
+    buffer[i] = i;
+  }
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+  backtrace_mock_->SetPartialReadAmount(96);
+
+  dump_memory(&log_, backtrace_mock_.get(), 0x12345679, "memory near %.2s:", "r1");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ(g_expected_full_dump, tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, unaligned_addr) {
+  uint8_t buffer[256];
+  for (size_t i = 0; i < sizeof(buffer); i++) {
+    buffer[i] = i;
+  }
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+  dump_memory(&log_, backtrace_mock_.get(), 0x12345679, "memory near %.2s:", "r1");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ(g_expected_full_dump, tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_unreadable) {
+  dump_memory(&log_, backtrace_mock_.get(), 0xa2345678, "memory near pc:");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  const char* expected_dump = \
+"\nmemory near pc:\n"
+#if defined(__LP64__)
+"    00000000a2345658 ---------------- ----------------  ................\n"
+"    00000000a2345668 ---------------- ----------------  ................\n"
+"    00000000a2345678 ---------------- ----------------  ................\n"
+"    00000000a2345688 ---------------- ----------------  ................\n"
+"    00000000a2345698 ---------------- ----------------  ................\n"
+"    00000000a23456a8 ---------------- ----------------  ................\n"
+"    00000000a23456b8 ---------------- ----------------  ................\n"
+"    00000000a23456c8 ---------------- ----------------  ................\n"
+"    00000000a23456d8 ---------------- ----------------  ................\n"
+"    00000000a23456e8 ---------------- ----------------  ................\n"
+"    00000000a23456f8 ---------------- ----------------  ................\n"
+"    00000000a2345708 ---------------- ----------------  ................\n"
+"    00000000a2345718 ---------------- ----------------  ................\n"
+"    00000000a2345728 ---------------- ----------------  ................\n"
+"    00000000a2345738 ---------------- ----------------  ................\n"
+"    00000000a2345748 ---------------- ----------------  ................\n";
+#else
+"    a2345658 -------- -------- -------- --------  ................\n"
+"    a2345668 -------- -------- -------- --------  ................\n"
+"    a2345678 -------- -------- -------- --------  ................\n"
+"    a2345688 -------- -------- -------- --------  ................\n"
+"    a2345698 -------- -------- -------- --------  ................\n"
+"    a23456a8 -------- -------- -------- --------  ................\n"
+"    a23456b8 -------- -------- -------- --------  ................\n"
+"    a23456c8 -------- -------- -------- --------  ................\n"
+"    a23456d8 -------- -------- -------- --------  ................\n"
+"    a23456e8 -------- -------- -------- --------  ................\n"
+"    a23456f8 -------- -------- -------- --------  ................\n"
+"    a2345708 -------- -------- -------- --------  ................\n"
+"    a2345718 -------- -------- -------- --------  ................\n"
+"    a2345728 -------- -------- -------- --------  ................\n"
+"    a2345738 -------- -------- -------- --------  ................\n"
+"    a2345748 -------- -------- -------- --------  ................\n";
+#endif
+  ASSERT_STREQ(expected_dump, tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_partially_unreadable) {
+  uint8_t buffer[104];
+  for (size_t i = 0; i < sizeof(buffer); i++) {
+    buffer[i] = i;
+  }
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+  dump_memory(&log_, backtrace_mock_.get(), 0x12345600, "memory near pc:");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ(g_expected_partial_dump, tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_partially_unreadable_unaligned_return) {
+  uint8_t buffer[104];
+  for (size_t i = 0; i < sizeof(buffer); i++) {
+    buffer[i] = i;
+  }
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+  backtrace_mock_->SetPartialReadAmount(102);
+
+  dump_memory(&log_, backtrace_mock_.get(), 0x12345600, "memory near pc:");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ(g_expected_partial_dump, tombstone_contents.c_str());
+
+#if defined(__LP64__)
+  ASSERT_STREQ("DEBUG Bytes read 102, is not a multiple of 8\n", getFakeLogPrint().c_str());
+#else
+  ASSERT_STREQ("DEBUG Bytes read 102, is not a multiple of 4\n", getFakeLogPrint().c_str());
+#endif
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_partially_unreadable_two_unaligned_reads) {
+  uint8_t buffer[106];
+  for (size_t i = 0; i < sizeof(buffer); i++) {
+    buffer[i] = i;
+  }
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+  backtrace_mock_->SetPartialReadAmount(45);
+
+  dump_memory(&log_, backtrace_mock_.get(), 0x12345600, "memory near pc:");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ(g_expected_partial_dump, tombstone_contents.c_str());
+
+#if defined(__LP64__)
+  ASSERT_STREQ("DEBUG Bytes read 45, is not a multiple of 8\n"
+               "DEBUG Bytes after second read 106, is not a multiple of 8\n",
+               getFakeLogPrint().c_str());
+#else
+  ASSERT_STREQ("DEBUG Bytes read 45, is not a multiple of 4\n"
+               "DEBUG Bytes after second read 106, is not a multiple of 4\n",
+               getFakeLogPrint().c_str());
+#endif
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+}
+
+TEST_F(DumpMemoryTest, address_low_fence) {
+  uint8_t buffer[256];
+  memset(buffer, 0, sizeof(buffer));
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+  dump_memory(&log_, backtrace_mock_.get(), 0x1000, "memory near %.2s:", "r1");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  const char* expected_dump = \
+"\nmemory near r1:\n"
+#if defined(__LP64__)
+"    0000000000001000 0000000000000000 0000000000000000  ................\n"
+"    0000000000001010 0000000000000000 0000000000000000  ................\n"
+"    0000000000001020 0000000000000000 0000000000000000  ................\n"
+"    0000000000001030 0000000000000000 0000000000000000  ................\n"
+"    0000000000001040 0000000000000000 0000000000000000  ................\n"
+"    0000000000001050 0000000000000000 0000000000000000  ................\n"
+"    0000000000001060 0000000000000000 0000000000000000  ................\n"
+"    0000000000001070 0000000000000000 0000000000000000  ................\n"
+"    0000000000001080 0000000000000000 0000000000000000  ................\n"
+"    0000000000001090 0000000000000000 0000000000000000  ................\n"
+"    00000000000010a0 0000000000000000 0000000000000000  ................\n"
+"    00000000000010b0 0000000000000000 0000000000000000  ................\n"
+"    00000000000010c0 0000000000000000 0000000000000000  ................\n"
+"    00000000000010d0 0000000000000000 0000000000000000  ................\n"
+"    00000000000010e0 0000000000000000 0000000000000000  ................\n"
+"    00000000000010f0 0000000000000000 0000000000000000  ................\n";
+#else
+"    00001000 00000000 00000000 00000000 00000000  ................\n"
+"    00001010 00000000 00000000 00000000 00000000  ................\n"
+"    00001020 00000000 00000000 00000000 00000000  ................\n"
+"    00001030 00000000 00000000 00000000 00000000  ................\n"
+"    00001040 00000000 00000000 00000000 00000000  ................\n"
+"    00001050 00000000 00000000 00000000 00000000  ................\n"
+"    00001060 00000000 00000000 00000000 00000000  ................\n"
+"    00001070 00000000 00000000 00000000 00000000  ................\n"
+"    00001080 00000000 00000000 00000000 00000000  ................\n"
+"    00001090 00000000 00000000 00000000 00000000  ................\n"
+"    000010a0 00000000 00000000 00000000 00000000  ................\n"
+"    000010b0 00000000 00000000 00000000 00000000  ................\n"
+"    000010c0 00000000 00000000 00000000 00000000  ................\n"
+"    000010d0 00000000 00000000 00000000 00000000  ................\n"
+"    000010e0 00000000 00000000 00000000 00000000  ................\n"
+"    000010f0 00000000 00000000 00000000 00000000  ................\n";
+#endif
+  ASSERT_STREQ(expected_dump, tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_address_too_low) {
+  uint8_t buffer[256];
+  memset(buffer, 0, sizeof(buffer));
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+  dump_memory(&log_, backtrace_mock_.get(), 0, "memory near %.2s:", "r1");
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ("", tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_address_too_high) {
+  uint8_t buffer[256];
+  memset(buffer, 0, sizeof(buffer));
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+#if defined(__LP64__)
+  dump_memory(&log_, backtrace_mock_.get(), 0x4000000000000000UL, "memory near %.2s:", "r1");
+  dump_memory(&log_, backtrace_mock_.get(), 0x4000000000000000UL - 32, "memory near %.2s:", "r1");
+  dump_memory(&log_, backtrace_mock_.get(), 0x4000000000000000UL - 216, "memory near %.2s:", "r1");
+#else
+  dump_memory(&log_, backtrace_mock_.get(), 0xffff0000, "memory near %.2s:", "r1");
+  dump_memory(&log_, backtrace_mock_.get(), 0xffff0000 - 32, "memory near %.2s:", "r1");
+  dump_memory(&log_, backtrace_mock_.get(), 0xffff0000 - 220, "memory near %.2s:", "r1");
+#endif
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ("", tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_address_would_overflow) {
+  uint8_t buffer[256];
+  memset(buffer, 0, sizeof(buffer));
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+#if defined(__LP64__)
+  dump_memory(&log_, backtrace_mock_.get(), 0xfffffffffffffff0, "memory near %.2s:", "r1");
+#else
+  dump_memory(&log_, backtrace_mock_.get(), 0xfffffff0, "memory near %.2s:", "r1");
+#endif
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_STREQ("", tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(DumpMemoryTest, memory_address_nearly_too_high) {
+  uint8_t buffer[256];
+  for (size_t i = 0; i < sizeof(buffer); i++) {
+    buffer[i] = i;
+  }
+  backtrace_mock_->SetReadData(buffer, sizeof(buffer));
+
+#if defined(__LP64__)
+  dump_memory(&log_, backtrace_mock_.get(), 0x4000000000000000UL - 224, "memory near %.2s:", "r4");
+#else
+  dump_memory(&log_, backtrace_mock_.get(), 0xffff0000 - 224, "memory near %.2s:", "r4");
+#endif
+
+  std::string tombstone_contents;
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  const char* expected_dump = \
+"\nmemory near r4:\n"
+#if defined(__LP64__)
+"    3fffffffffffff00 0706050403020100 0f0e0d0c0b0a0908  ................\n"
+"    3fffffffffffff10 1716151413121110 1f1e1d1c1b1a1918  ................\n"
+"    3fffffffffffff20 2726252423222120 2f2e2d2c2b2a2928   !\"#$%&'()*+,-./\n"
+"    3fffffffffffff30 3736353433323130 3f3e3d3c3b3a3938  0123456789:;<=>?\n"
+"    3fffffffffffff40 4746454443424140 4f4e4d4c4b4a4948  @ABCDEFGHIJKLMNO\n"
+"    3fffffffffffff50 5756555453525150 5f5e5d5c5b5a5958  PQRSTUVWXYZ[\\]^_\n"
+"    3fffffffffffff60 6766656463626160 6f6e6d6c6b6a6968  `abcdefghijklmno\n"
+"    3fffffffffffff70 7776757473727170 7f7e7d7c7b7a7978  pqrstuvwxyz{|}~.\n"
+"    3fffffffffffff80 8786858483828180 8f8e8d8c8b8a8988  ................\n"
+"    3fffffffffffff90 9796959493929190 9f9e9d9c9b9a9998  ................\n"
+"    3fffffffffffffa0 a7a6a5a4a3a2a1a0 afaeadacabaaa9a8  ................\n"
+"    3fffffffffffffb0 b7b6b5b4b3b2b1b0 bfbebdbcbbbab9b8  ................\n"
+"    3fffffffffffffc0 c7c6c5c4c3c2c1c0 cfcecdcccbcac9c8  ................\n"
+"    3fffffffffffffd0 d7d6d5d4d3d2d1d0 dfdedddcdbdad9d8  ................\n"
+"    3fffffffffffffe0 e7e6e5e4e3e2e1e0 efeeedecebeae9e8  ................\n"
+"    3ffffffffffffff0 f7f6f5f4f3f2f1f0 fffefdfcfbfaf9f8  ................\n";
+#else
+"    fffeff00 03020100 07060504 0b0a0908 0f0e0d0c  ................\n"
+"    fffeff10 13121110 17161514 1b1a1918 1f1e1d1c  ................\n"
+"    fffeff20 23222120 27262524 2b2a2928 2f2e2d2c   !\"#$%&'()*+,-./\n"
+"    fffeff30 33323130 37363534 3b3a3938 3f3e3d3c  0123456789:;<=>?\n"
+"    fffeff40 43424140 47464544 4b4a4948 4f4e4d4c  @ABCDEFGHIJKLMNO\n"
+"    fffeff50 53525150 57565554 5b5a5958 5f5e5d5c  PQRSTUVWXYZ[\\]^_\n"
+"    fffeff60 63626160 67666564 6b6a6968 6f6e6d6c  `abcdefghijklmno\n"
+"    fffeff70 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.\n"
+"    fffeff80 83828180 87868584 8b8a8988 8f8e8d8c  ................\n"
+"    fffeff90 93929190 97969594 9b9a9998 9f9e9d9c  ................\n"
+"    fffeffa0 a3a2a1a0 a7a6a5a4 abaaa9a8 afaeadac  ................\n"
+"    fffeffb0 b3b2b1b0 b7b6b5b4 bbbab9b8 bfbebdbc  ................\n"
+"    fffeffc0 c3c2c1c0 c7c6c5c4 cbcac9c8 cfcecdcc  ................\n"
+"    fffeffd0 d3d2d1d0 d7d6d5d4 dbdad9d8 dfdedddc  ................\n"
+"    fffeffe0 e3e2e1e0 e7e6e5e4 ebeae9e8 efeeedec  ................\n"
+"    fffefff0 f3f2f1f0 f7f6f5f4 fbfaf9f8 fffefdfc  ................\n";
+#endif
+  ASSERT_STREQ(expected_dump, tombstone_contents.c_str());
+
+  // Verify that the log buf is empty, and no error messages.
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
diff --git a/debuggerd/test/log_fake.cpp b/debuggerd/test/log_fake.cpp
new file mode 100644
index 0000000..1161afe
--- /dev/null
+++ b/debuggerd/test/log_fake.cpp
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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 <stdarg.h>
+
+#include <string>
+
+#include <base/stringprintf.h>
+
+std::string g_fake_log_buf;
+
+std::string g_fake_log_print;
+
+void resetLogs() {
+  g_fake_log_buf = "";
+  g_fake_log_print = "";
+}
+
+extern "C" int __android_log_buf_write(int, int, const char* tag, const char* msg) {
+  g_fake_log_buf += tag;
+  g_fake_log_buf += ' ';
+  g_fake_log_buf += msg;
+  return 1;
+}
+
+std::string getFakeLogBuf() {
+  return g_fake_log_buf;
+}
+
+extern "C" int __android_log_print(int, const char* tag, const char* fmt, ...) {
+  g_fake_log_print += tag;
+  g_fake_log_print += ' ';
+
+  va_list ap;
+  va_start(ap, fmt);
+  android::base::StringAppendV(&g_fake_log_print, fmt, ap);
+  va_end(ap);
+
+  g_fake_log_print += '\n';
+
+  return 1;
+}
+
+std::string getFakeLogPrint() {
+  return g_fake_log_print;
+}
diff --git a/debuggerd/test/log_fake.h b/debuggerd/test/log_fake.h
new file mode 100644
index 0000000..5418fce
--- /dev/null
+++ b/debuggerd/test/log_fake.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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 _DEBUGGERD_TEST_LOG_FAKE_H
+#define _DEBUGGERD_TEST_LOG_FAKE_H
+
+#include <string>
+
+void resetLogs();
+std::string getFakeLogBuf();
+std::string getFakeLogPrint();
+
+#endif // _DEBUGGERD_TEST_LOG_FAKE_H
diff --git a/debuggerd/tombstone.cpp b/debuggerd/tombstone.cpp
index ccdfe85..614edb6 100644
--- a/debuggerd/tombstone.cpp
+++ b/debuggerd/tombstone.cpp
@@ -654,7 +654,7 @@
   } else {
     ALOGE("Unwind failed: pid = %d, tid = %d", pid, tid);
   }
-  dump_memory_and_code(log, tid);
+  dump_memory_and_code(log, backtrace.get());
   if (map.get() != nullptr) {
     dump_all_maps(backtrace.get(), map.get(), log, tid);
   }
diff --git a/debuggerd/utility.cpp b/debuggerd/utility.cpp
index e722f82..9f340a8 100644
--- a/debuggerd/utility.cpp
+++ b/debuggerd/utility.cpp
@@ -27,6 +27,7 @@
 
 #include <backtrace/Backtrace.h>
 #include <base/file.h>
+#include <base/stringprintf.h>
 #include <log/log.h>
 
 const int SLEEP_TIME_USEC = 50000;         // 0.05 seconds
@@ -118,68 +119,91 @@
   return -1;
 }
 
-void dump_memory(log_t* log, pid_t tid, uintptr_t addr) {
-    char code_buffer[64];
-    char ascii_buffer[32];
-    uintptr_t p, end;
+#define MEMORY_BYTES_TO_DUMP 256
+#define MEMORY_BYTES_PER_LINE 16
 
-    p = addr & ~(sizeof(long) - 1);
-    /* Dump 32 bytes before addr */
-    p -= 32;
-    if (p > addr) {
-        /* catch underflow */
-        p = 0;
-    }
-    /* Dump 256 bytes */
-    end = p + 256;
-    /* catch overflow; 'end - p' has to be multiples of 16 */
-    while (end < p) {
-        end -= 16;
-    }
+void dump_memory(log_t* log, Backtrace* backtrace, uintptr_t addr, const char* fmt, ...) {
+  std::string log_msg;
+  va_list ap;
+  va_start(ap, fmt);
+  android::base::StringAppendV(&log_msg, fmt, ap);
+  va_end(ap);
 
-    /* Dump the code around PC as:
-     *  addr             contents                           ascii
-     *  0000000000008d34 ef000000e8bd0090 e1b00000512fff1e  ............../Q
-     *  0000000000008d44 ea00b1f9e92d0090 e3a070fcef000000  ......-..p......
-     * On 32-bit machines, there are still 16 bytes per line but addresses and
-     * words are of course presented differently.
-     */
-    while (p < end) {
-        char* asc_out = ascii_buffer;
+  // Align the address to sizeof(long) and start 32 bytes before the address.
+  addr &= ~(sizeof(long) - 1);
+  if (addr >= 4128) {
+    addr -= 32;
+  }
 
-        int len = snprintf(code_buffer, sizeof(code_buffer), "%" PRIPTR " ", p);
-
-        for (size_t i = 0; i < 16/sizeof(long); i++) {
-            long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL);
-            if (data == -1 && errno != 0) {
-                // ptrace failed, probably because we're dumping memory in an
-                // unmapped or inaccessible page.
-#ifdef __LP64__
-                len += sprintf(code_buffer + len, "---------------- ");
+  // Don't bother if the address looks too low, or looks too high.
+  if (addr < 4096 ||
+#if defined(__LP64__)
+      addr > 0x4000000000000000UL - MEMORY_BYTES_TO_DUMP) {
 #else
-                len += sprintf(code_buffer + len, "-------- ");
+      addr > 0xffff0000 - MEMORY_BYTES_TO_DUMP) {
 #endif
-            } else {
-                len += sprintf(code_buffer + len, "%" PRIPTR " ",
-                               static_cast<uintptr_t>(data));
-            }
+    return;
+  }
 
-            for (size_t j = 0; j < sizeof(long); j++) {
-                /*
-                 * Our isprint() allows high-ASCII characters that display
-                 * differently (often badly) in different viewers, so we
-                 * just use a simpler test.
-                 */
-                char val = (data >> (j*8)) & 0xff;
-                if (val >= 0x20 && val < 0x7f) {
-                    *asc_out++ = val;
-                } else {
-                    *asc_out++ = '.';
-                }
-            }
-            p += sizeof(long);
-        }
-        *asc_out = '\0';
-        _LOG(log, logtype::MEMORY, "    %s %s\n", code_buffer, ascii_buffer);
+  _LOG(log, logtype::MEMORY, "\n%s\n", log_msg.c_str());
+
+  // Dump 256 bytes
+  uintptr_t data[MEMORY_BYTES_TO_DUMP/sizeof(uintptr_t)];
+  memset(data, 0, MEMORY_BYTES_TO_DUMP);
+  size_t bytes = backtrace->Read(addr, reinterpret_cast<uint8_t*>(data), sizeof(data));
+  if (bytes % sizeof(uintptr_t) != 0) {
+    // This should never happen, but just in case.
+    ALOGE("Bytes read %zu, is not a multiple of %zu", bytes, sizeof(uintptr_t));
+    bytes &= ~(sizeof(uintptr_t) - 1);
+  }
+
+  if (bytes < MEMORY_BYTES_TO_DUMP && bytes > 0) {
+    // Try to do one more read. This could happen if a read crosses a map, but
+    // the maps do not have any break between them. Only requires one extra
+    // read because a map has to contain at least one page, and the total
+    // number of bytes to dump is smaller than a page.
+    size_t bytes2 = backtrace->Read(addr + bytes, reinterpret_cast<uint8_t*>(data) + bytes,
+                                    sizeof(data) - bytes);
+    bytes += bytes2;
+    if (bytes2 > 0 && bytes % sizeof(uintptr_t) != 0) {
+      // This should never happen, but we'll try and continue any way.
+      ALOGE("Bytes after second read %zu, is not a multiple of %zu", bytes, sizeof(uintptr_t));
+      bytes &= ~(sizeof(uintptr_t) - 1);
     }
+  }
+
+  // Dump the code around memory as:
+  //  addr             contents                           ascii
+  //  0000000000008d34 ef000000e8bd0090 e1b00000512fff1e  ............../Q
+  //  0000000000008d44 ea00b1f9e92d0090 e3a070fcef000000  ......-..p......
+  // On 32-bit machines, there are still 16 bytes per line but addresses and
+  // words are of course presented differently.
+  uintptr_t* data_ptr = data;
+  for (size_t line = 0; line < MEMORY_BYTES_TO_DUMP / MEMORY_BYTES_PER_LINE; line++) {
+    std::string logline;
+    android::base::StringAppendF(&logline, "    %" PRIPTR, addr);
+
+    addr += MEMORY_BYTES_PER_LINE;
+    std::string ascii;
+    for (size_t i = 0; i < MEMORY_BYTES_PER_LINE / sizeof(uintptr_t); i++, data_ptr++) {
+      if (bytes >= sizeof(uintptr_t)) {
+        bytes -= sizeof(uintptr_t);
+        android::base::StringAppendF(&logline, " %" PRIPTR, *data_ptr);
+
+        // Fill out the ascii string from the data.
+        uint8_t* ptr = reinterpret_cast<uint8_t*>(data_ptr);
+        for (size_t val = 0; val < sizeof(uintptr_t); val++, ptr++) {
+          if (*ptr >= 0x20 && *ptr < 0x7f) {
+            ascii += *ptr;
+          } else {
+            ascii += '.';
+          }
+        }
+      } else {
+        logline += ' ' + std::string(sizeof(uintptr_t) * 2, '-');
+        ascii += std::string(sizeof(uintptr_t), '.');
+      }
+    }
+    _LOG(log, logtype::MEMORY, "%s  %s\n", logline.c_str(), ascii.c_str());
+  }
 }
diff --git a/debuggerd/utility.h b/debuggerd/utility.h
index 49b46e8..263374d 100644
--- a/debuggerd/utility.h
+++ b/debuggerd/utility.h
@@ -21,6 +21,8 @@
 #include <stdbool.h>
 #include <sys/types.h>
 
+#include <backtrace/Backtrace.h>
+
 // Figure out the abi based on defined macros.
 #if defined(__arm__)
 #define ABI_STRING "arm"
@@ -75,6 +77,6 @@
 
 int wait_for_sigstop(pid_t, int*, bool*);
 
-void dump_memory(log_t* log, pid_t tid, uintptr_t addr);
+void dump_memory(log_t* log, Backtrace* backtrace, uintptr_t addr, const char* fmt, ...);
 
 #endif // _DEBUGGERD_UTILITY_H
diff --git a/debuggerd/x86/machine.cpp b/debuggerd/x86/machine.cpp
index 57330c1..c5f9259 100644
--- a/debuggerd/x86/machine.cpp
+++ b/debuggerd/x86/machine.cpp
@@ -14,18 +14,31 @@
  * limitations under the License.
  */
 
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
 #include <errno.h>
-#include <sys/types.h>
+#include <stdint.h>
+#include <string.h>
 #include <sys/ptrace.h>
 
-#include "../utility.h"
-#include "../machine.h"
+#include <backtrace/Backtrace.h>
 
-void dump_memory_and_code(log_t*, pid_t) {
+#include "machine.h"
+#include "utility.h"
+
+void dump_memory_and_code(log_t* log, Backtrace* backtrace) {
+  struct pt_regs r;
+  if (ptrace(PTRACE_GETREGS, backtrace->Tid(), 0, &r) == -1) {
+    _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
+    return;
+  }
+
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.eax), "memory near eax:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.ebx), "memory near ebx:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.ecx), "memory near ecx:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.edx), "memory near edx:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.esi), "memory near esi:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.edi), "memory near edi:");
+
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.eip), "code around eip:");
 }
 
 void dump_registers(log_t* log, pid_t tid) {
@@ -34,6 +47,7 @@
     _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
     return;
   }
+
   _LOG(log, logtype::REGISTERS, "    eax %08lx  ebx %08lx  ecx %08lx  edx %08lx\n",
        r.eax, r.ebx, r.ecx, r.edx);
   _LOG(log, logtype::REGISTERS, "    esi %08lx  edi %08lx\n",
diff --git a/debuggerd/x86_64/machine.cpp b/debuggerd/x86_64/machine.cpp
old mode 100755
new mode 100644
index af4f35a..4f09a5d
--- a/debuggerd/x86_64/machine.cpp
+++ b/debuggerd/x86_64/machine.cpp
@@ -14,38 +14,51 @@
 ** limitations under the License.
 */
 
-#include <stddef.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
 #include <errno.h>
-#include <sys/types.h>
+#include <stdint.h>
 #include <sys/ptrace.h>
+#include <string.h>
 #include <sys/user.h>
 
-#include "../utility.h"
-#include "../machine.h"
+#include <backtrace/Backtrace.h>
 
-void dump_memory_and_code(log_t*, pid_t) {
+#include "machine.h"
+#include "utility.h"
+
+void dump_memory_and_code(log_t* log, Backtrace* backtrace) {
+  struct user_regs_struct r;
+  if (ptrace(PTRACE_GETREGS, backtrace->Tid(), 0, &r) == -1) {
+    _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
+    return;
+  }
+
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.rax), "memory near rax:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.rbx), "memory near rbx:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.rcx), "memory near rcx:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.rdx), "memory near rdx:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.rsi), "memory near rsi:");
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.rdi), "memory near rdi:");
+
+  dump_memory(log, backtrace, static_cast<uintptr_t>(r.rip), "code around rip:");
 }
 
 void dump_registers(log_t* log, pid_t tid) {
-    struct user_regs_struct r;
-    if (ptrace(PTRACE_GETREGS, tid, 0, &r) == -1) {
-        _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
-        return;
-    }
-    _LOG(log, logtype::REGISTERS, "    rax %016lx  rbx %016lx  rcx %016lx  rdx %016lx\n",
-         r.rax, r.rbx, r.rcx, r.rdx);
-    _LOG(log, logtype::REGISTERS, "    rsi %016lx  rdi %016lx\n",
-         r.rsi, r.rdi);
-    _LOG(log, logtype::REGISTERS, "    r8  %016lx  r9  %016lx  r10 %016lx  r11 %016lx\n",
-         r.r8, r.r9, r.r10, r.r11);
-    _LOG(log, logtype::REGISTERS, "    r12 %016lx  r13 %016lx  r14 %016lx  r15 %016lx\n",
-         r.r12, r.r13, r.r14, r.r15);
-    _LOG(log, logtype::REGISTERS, "    cs  %016lx  ss  %016lx\n",
-         r.cs, r.ss);
-    _LOG(log, logtype::REGISTERS, "    rip %016lx  rbp %016lx  rsp %016lx  eflags %016lx\n",
-         r.rip, r.rbp, r.rsp, r.eflags);
+  struct user_regs_struct r;
+  if (ptrace(PTRACE_GETREGS, tid, 0, &r) == -1) {
+    _LOG(log, logtype::ERROR, "cannot get registers: %s\n", strerror(errno));
+    return;
+  }
+
+  _LOG(log, logtype::REGISTERS, "    rax %016lx  rbx %016lx  rcx %016lx  rdx %016lx\n",
+       r.rax, r.rbx, r.rcx, r.rdx);
+  _LOG(log, logtype::REGISTERS, "    rsi %016lx  rdi %016lx\n",
+       r.rsi, r.rdi);
+  _LOG(log, logtype::REGISTERS, "    r8  %016lx  r9  %016lx  r10 %016lx  r11 %016lx\n",
+       r.r8, r.r9, r.r10, r.r11);
+  _LOG(log, logtype::REGISTERS, "    r12 %016lx  r13 %016lx  r14 %016lx  r15 %016lx\n",
+       r.r12, r.r13, r.r14, r.r15);
+  _LOG(log, logtype::REGISTERS, "    cs  %016lx  ss  %016lx\n",
+       r.cs, r.ss);
+  _LOG(log, logtype::REGISTERS, "    rip %016lx  rbp %016lx  rsp %016lx  eflags %016lx\n",
+       r.rip, r.rbp, r.rsp, r.eflags);
 }