ARM support, with some build system changes to support x86-64, arm, and i386 in an autoconf style build in Linux. The O2 build for the unit tests is still broken but I'm checking this in to unblock people

A=nealsid
R=ajwong, hannahtang, ted.mielczarek



git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@541 4c0a9323-5329-0410-9bdc-e9ce6186880e

11 files changed, 290 insertions, 83 deletions

diff --git a/src/client/linux/Makefile b/src/client/linux/Makefile
index eb5a1f28..53e3b0f5 100644
--- a/src/client/linux/Makefile
+++ b/src/client/linux/Makefile
@@ -1,7 +1,7 @@
 CXX=g++
 CC=gcc
 
-CXXFLAGS=-gstabs+ -I../../ -I../../testing/gtest/include -I../../testing -I../../third_party/linux/include -I../../testing/include -I../../testing/gtest -D_REENTRANT -m32 -Wall
+CXXFLAGS=-gstabs+ -I../../ -I../../testing/gtest/include -I../../testing -I../../third_party/linux/include -I../../testing/include -I../../testing/gtest -D_REENTRANT -Wall
 CFLAGS=$(CXXFLAGS)
 LDFLAGS=-lpthread
 
@@ -37,7 +37,13 @@ LIB_C_SRC = ../../common/convert_UTF.c
 LIB_CC_OBJ=$(patsubst %.cc, $(OBJ_DIR)/%.o,$(LIB_CC_SRC))
 LIB_C_OBJ=$(patsubst %.c, $(OBJ_DIR)/%.o, $(LIB_C_SRC))
 
+DUMPER_HELPER_TEST_C_SRC=minidump_writer/linux_dumper_unittest_helper.c
+
+DUMPER_HELPER_TEST_C_OBJ=$(patsubst %.cc, $(OBJ_DIR)/%.o, \
+			   $(DUMPER_HELPER_TEST_C_SRC))
+
 # Unit tests for client library 
+
 TEST_CC_SRC=handler/exception_handler_unittest.cc \
 	    minidump_writer/directory_reader_unittest.cc \
 	    minidump_writer/line_reader_unittest.cc \
@@ -72,9 +78,11 @@ SENDER_UNITTEST_BIN=$(BIN_DIR)/google_crashdump_uploader_test
 # Sender CLI tool binary
 SENDER_CLI_TOOL_BIN=$(BIN_DIR)/google_crashdump_uploader
 
+DUMPER_HELPER_TEST_BIN=$(BIN_DIR)/linux_dumper_unittest_helper
+
 .PHONY:all clean
 
-all:$(BREAKPAD_LIBRARY) $(UNITTEST_BIN) $(SENDER_LIBRARY) $(SENDER_UNITTEST_BIN) $(SENDER_CLI_TOOL_BIN)
+all:$(BREAKPAD_LIBRARY) $(UNITTEST_BIN) #$(SENDER_LIBRARY) $(SENDER_UNITTEST_BIN) $(SENDER_CLI_TOOL_BIN)
 
 check:$(UNITTEST_BIN) $(SENDER_UNITTEST_BIN)
 	$(UNITTEST_BIN)
@@ -83,9 +91,12 @@ check:$(UNITTEST_BIN) $(SENDER_UNITTEST_BIN)
 $(BIN_DIR)/libbreakpad.a:$(LIB_CC_OBJ) $(LIB_C_OBJ)
 	$(AR) rcs $@ $^
 
-$(BIN_DIR)/linux_client_test:$(TEST_CC_OBJ) $(BREAKPAD_LIBRARY)
+$(BIN_DIR)/linux_dumper_unittest_helper:$(DUMPER_HELPER_TEST_C_OBJ)
 	$(CXX) $(CXXFLAGS) $(LDFLAGS) $^ -o $@
 
+$(BIN_DIR)/linux_client_test:$(TEST_CC_OBJ) $(BREAKPAD_LIBRARY) $(DUMPER_HELPER_TEST_BIN)
+	$(CXX) $(CXXFLAGS) $(LDFLAGS) $(TEST_CC_OBJ) $(BREAKPAD_LIBRARY) -o $@
+
 $(BIN_DIR)/libcrash_sender.a:$(SENDER_LIBRARY_OBJ)
 	$(AR) rcs $@ $^
 
@@ -100,4 +111,5 @@ $(BIN_DIR)/google_crashdump_uploader:$(SENDER_TOOL_OBJ) $(SENDER_LIBRARY) \
 clean:
 	rm -f $(UNITTEST_BIN) $(BREAKPAD_LIBRARY) $(LIB_CC_OBJ) $(LIB_C_OBJ) \
 	$(TEST_CC_OBJ) $(SENDER_LIBRARY_OBJ) $(SENDER_LIBRARY) \
-	$(SENDER_TOOL_OBJ) $(SENDER_CLI_TOOL_BIN) $(SENDER_UNITTEST_BIN) core
+	$(SENDER_TOOL_OBJ) $(SENDER_CLI_TOOL_BIN) $(SENDER_UNITTEST_BIN) \
+	$(DUMPER_HELPER_TEST_BIN) core
diff --git a/src/client/linux/crash_generation/crash_generation_client.cc b/src/client/linux/crash_generation/crash_generation_client.cc
index 2463f1ed..af02fdbd 100644
--- a/src/client/linux/crash_generation/crash_generation_client.cc
+++ b/src/client/linux/crash_generation/crash_generation_client.cc
@@ -27,6 +27,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+#include <stdio.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 
@@ -44,7 +45,6 @@ CrashGenerationClient::RequestDump(const void* blob, size_t blob_size)
 {
   int fds[2];
   sys_socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
-
   static const unsigned kControlMsgSize = CMSG_SPACE(sizeof(int));
 
   struct kernel_msghdr msg;
diff --git a/src/client/linux/handler/exception_handler.cc b/src/client/linux/handler/exception_handler.cc
index 01081878..038612f2 100644
--- a/src/client/linux/handler/exception_handler.cc
+++ b/src/client/linux/handler/exception_handler.cc
@@ -80,6 +80,9 @@
 #include <ucontext.h>
 #include <unistd.h>
 
+#include <algorithm>
+#include <vector>
+
 #include "common/linux/linux_libc_support.h"
 #include "common/linux/linux_syscall_support.h"
 #include "common/linux/memory.h"
@@ -88,7 +91,7 @@
 
 // A wrapper for the tgkill syscall: send a signal to a specific thread.
 static int tgkill(pid_t tgid, pid_t tid, int sig) {
-  syscall(__NR_tgkill, tgid, tid, sig);
+  return syscall(__NR_tgkill, tgid, tid, sig);
   return 0;
 }
 
@@ -145,7 +148,6 @@ void ExceptionHandler::Init(const std::string &dump_path,
                             const int server_fd)
 {
   crash_handler_ = NULL;
-
   if (0 <= server_fd)
     crash_generation_client_
       .reset(CrashGenerationClient::TryCreate(server_fd));
@@ -209,7 +211,11 @@ void ExceptionHandler::UninstallHandlers() {
     sigaction(old_handlers_[i].first, action, NULL);
     delete action;
   }
-
+  pthread_mutex_lock(&handler_stack_mutex_);
+  std::vector<ExceptionHandler*>::iterator handler =
+      std::find(handler_stack_->begin(), handler_stack_->end(), this);
+  handler_stack_->erase(handler);
+  pthread_mutex_unlock(&handler_stack_mutex_);
   old_handlers_.clear();
 }
 
@@ -231,12 +237,15 @@ void ExceptionHandler::UpdateNextID() {
   }
 }
 
+// void ExceptionHandler::set_crash_handler(HandlerCallback callback) {
+//   crash_handler_ = callback;
+// }
+
 // This function runs in a compromised context: see the top of the file.
 // Runs on the crashing thread.
 // static
 void ExceptionHandler::SignalHandler(int sig, siginfo_t* info, void* uc) {
   // All the exception signals are blocked at this point.
-
   pthread_mutex_lock(&handler_stack_mutex_);
 
   if (!handler_stack_->size()) {
@@ -288,18 +297,25 @@ bool ExceptionHandler::HandleSignal(int sig, siginfo_t* info, void* uc) {
 
   // Allow ourselves to be dumped.
   sys_prctl(PR_SET_DUMPABLE, 1);
-
   CrashContext context;
   memcpy(&context.siginfo, info, sizeof(siginfo_t));
   memcpy(&context.context, uc, sizeof(struct ucontext));
-  memcpy(&context.float_state, ((struct ucontext *)uc)->uc_mcontext.fpregs,
-         sizeof(context.float_state));
+#if !defined(__ARM_EABI__)
+  // FP state is not part of user ABI on ARM Linux.
+  struct ucontext *uc_ptr = (struct ucontext*)uc;
+  if (uc_ptr->uc_mcontext.fpregs) {
+    memcpy(&context.float_state,
+           uc_ptr->uc_mcontext.fpregs,
+           sizeof(context.float_state));
+  }
+#endif
   context.tid = sys_gettid();
-
-  if (crash_handler_ && crash_handler_(&context, sizeof(context),
-                                       callback_context_))
-    return true;
-
+  if (crash_handler_ != NULL) {
+    if (crash_handler_(&context, sizeof(context),
+                       callback_context_)) {
+      return true;
+    }
+  }
   return GenerateDump(&context);
 }
 
@@ -364,6 +380,7 @@ bool ExceptionHandler::WriteMinidump(const std::string &dump_path,
 }
 
 bool ExceptionHandler::WriteMinidump() {
+#if !defined(__ARM_EABI__)
   // Allow ourselves to be dumped.
   sys_prctl(PR_SET_DUMPABLE, 1);
 
@@ -378,6 +395,9 @@ bool ExceptionHandler::WriteMinidump() {
   bool success = GenerateDump(&context);
   UpdateNextID();
   return success;
+#else
+  return false;
+#endif  // !defined(__ARM_EABI__)
 }
 
 }  // namespace google_breakpad
diff --git a/src/client/linux/handler/exception_handler.h b/src/client/linux/handler/exception_handler.h
index 6182a6c1..2a497037 100644
--- a/src/client/linux/handler/exception_handler.h
+++ b/src/client/linux/handler/exception_handler.h
@@ -34,6 +34,7 @@
 #include <string>
 
 #include <signal.h>
+#include <stdio.h>
 
 #include "client/linux/crash_generation/crash_generation_client.h"
 #include "processor/scoped_ptr.h"
@@ -42,6 +43,8 @@ struct sigaction;
 
 namespace google_breakpad {
 
+class ExceptionHandler;
+
 // ExceptionHandler
 //
 // ExceptionHandler can write a minidump file when an exception occurs,
@@ -163,7 +166,10 @@ class ExceptionHandler {
     siginfo_t siginfo;
     pid_t tid;  // the crashing thread.
     struct ucontext context;
+#if !defined(__ARM_EABI__)
+    // #ifdef this out because FP state is not part of user ABI for Linux ARM.
     struct _libc_fpstate float_state;
+#endif
   };
 
   // Returns whether out-of-process dump generation is used or not.
diff --git a/src/client/linux/handler/exception_handler_unittest.cc b/src/client/linux/handler/exception_handler_unittest.cc
index 2e8a6dbe..9747fe71 100644
--- a/src/client/linux/handler/exception_handler_unittest.cc
+++ b/src/client/linux/handler/exception_handler_unittest.cc
@@ -36,7 +36,7 @@
 #include <sys/socket.h>
 #include <sys/uio.h>
 
-#include "client/linux/handler//exception_handler.h"
+#include "client/linux/handler/exception_handler.h"
 #include "client/linux/minidump_writer/minidump_writer.h"
 #include "common/linux/eintr_wrapper.h"
 #include "common/linux/linux_libc_support.h"
@@ -112,8 +112,8 @@ TEST(ExceptionHandlerTest, ChildCrash) {
   ASSERT_TRUE(pfd.revents & POLLIN);
 
   uint32_t len;
-  ASSERT_EQ(read(fds[0], &len, sizeof(len)), sizeof(len));
-  ASSERT_LT(len, 2048);
+  ASSERT_EQ(read(fds[0], &len, sizeof(len)), (ssize_t)sizeof(len));
+  ASSERT_LT(len, (uint32_t)2048);
   char* filename = reinterpret_cast<char*>(malloc(len + 1));
   ASSERT_EQ(read(fds[0], filename, len), len);
   filename[len] = 0;
@@ -137,12 +137,10 @@ CrashHandler(const void* crash_context, size_t crash_context_size,
   const int fd = (intptr_t) context;
   int fds[2];
   pipe(fds);
-
   struct kernel_msghdr msg = {0};
   struct kernel_iovec iov;
   iov.iov_base = const_cast<void*>(crash_context);
   iov.iov_len = crash_context_size;
-
   msg.msg_iov = &iov;
   msg.msg_iovlen = 1;
   char cmsg[kControlMsgSize];
@@ -183,11 +181,10 @@ TEST(ExceptionHandlerTest, ExternalDumper) {
   const pid_t child = fork();
   if (child == 0) {
     close(fds[0]);
-    ExceptionHandler handler("/tmp", NULL, NULL, (void*) fds[1], true);
+    ExceptionHandler handler("/tmp1", NULL, NULL, (void*) fds[1], true);
     handler.set_crash_handler(CrashHandler);
     *reinterpret_cast<int*>(NULL) = 0;
   }
-
   close(fds[1]);
   struct msghdr msg = {0};
   struct iovec iov;
diff --git a/src/client/linux/minidump_writer/line_reader_unittest.cc b/src/client/linux/minidump_writer/line_reader_unittest.cc
index 222a098e..7c4c3ced 100644
--- a/src/client/linux/minidump_writer/line_reader_unittest.cc
+++ b/src/client/linux/minidump_writer/line_reader_unittest.cc
@@ -69,9 +69,9 @@ TEST(LineReaderTest, OneLineTerminated) {
   LineReader reader(fd);
 
   const char *line;
-  unsigned len;
+  unsigned int len;
   ASSERT_TRUE(reader.GetNextLine(&line, &len));
-  ASSERT_EQ(len, 1);
+  ASSERT_EQ(len, (unsigned int)1);
   ASSERT_EQ(line[0], 'a');
   ASSERT_EQ(line[1], 0);
   reader.PopLine(len);
@@ -90,7 +90,7 @@ TEST(LineReaderTest, OneLine) {
   const char *line;
   unsigned len;
   ASSERT_TRUE(reader.GetNextLine(&line, &len));
-  ASSERT_EQ(len, 1);
+  ASSERT_EQ(len, (unsigned)1);
   ASSERT_EQ(line[0], 'a');
   ASSERT_EQ(line[1], 0);
   reader.PopLine(len);
@@ -109,13 +109,13 @@ TEST(LineReaderTest, TwoLinesTerminated) {
   const char *line;
   unsigned len;
   ASSERT_TRUE(reader.GetNextLine(&line, &len));
-  ASSERT_EQ(len, 1);
+  ASSERT_EQ(len, (unsigned)1);
   ASSERT_EQ(line[0], 'a');
   ASSERT_EQ(line[1], 0);
   reader.PopLine(len);
 
   ASSERT_TRUE(reader.GetNextLine(&line, &len));
-  ASSERT_EQ(len, 1);
+  ASSERT_EQ(len, (unsigned)1);
   ASSERT_EQ(line[0], 'b');
   ASSERT_EQ(line[1], 0);
   reader.PopLine(len);
@@ -134,13 +134,13 @@ TEST(LineReaderTest, TwoLines) {
   const char *line;
   unsigned len;
   ASSERT_TRUE(reader.GetNextLine(&line, &len));
-  ASSERT_EQ(len, 1);
+  ASSERT_EQ(len, (unsigned)1);
   ASSERT_EQ(line[0], 'a');
   ASSERT_EQ(line[1], 0);
   reader.PopLine(len);
 
   ASSERT_TRUE(reader.GetNextLine(&line, &len));
-  ASSERT_EQ(len, 1);
+  ASSERT_EQ(len, (unsigned)1);
   ASSERT_EQ(line[0], 'b');
   ASSERT_EQ(line[1], 0);
   reader.PopLine(len);
diff --git a/src/client/linux/minidump_writer/linux_dumper.cc b/src/client/linux/minidump_writer/linux_dumper.cc
index 41929b8a..be199f7b 100644
--- a/src/client/linux/minidump_writer/linux_dumper.cc
+++ b/src/client/linux/minidump_writer/linux_dumper.cc
@@ -85,7 +85,7 @@ namespace google_breakpad {
 
 LinuxDumper::LinuxDumper(int pid)
     : pid_(pid),
-      threads_suspened_(false),
+      threads_suspended_(false),
       threads_(&allocator_, 8),
       mappings_(&allocator_) {
 }
@@ -96,22 +96,22 @@ bool LinuxDumper::Init() {
 }
 
 bool LinuxDumper::ThreadsSuspend() {
-  if (threads_suspened_)
+  if (threads_suspended_)
     return true;
   bool good = true;
   for (size_t i = 0; i < threads_.size(); ++i)
     good &= SuspendThread(threads_[i]);
-  threads_suspened_ = true;
+  threads_suspended_ = true;
   return good;
 }
 
 bool LinuxDumper::ThreadsResume() {
-  if (!threads_suspened_)
+  if (!threads_suspended_)
     return false;
   bool good = true;
   for (size_t i = 0; i < threads_.size(); ++i)
     good &= ResumeThread(threads_[i]);
-  threads_suspened_ = false;
+  threads_suspended_ = false;
   return good;
 }
 
@@ -312,9 +312,9 @@ bool LinuxDumper::EnumerateThreads(wasteful_vector<pid_t>* result) const {
 }
 
 // Read thread info from /proc/$pid/status.
-// Fill out the |tgid|, |ppid| and |pid| members of |info|. If unavailible,
+// Fill out the |tgid|, |ppid| and |pid| members of |info|. If unavailable,
 // these members are set to -1. Returns true iff all three members are
-// availible.
+// available.
 bool LinuxDumper::ThreadInfoGet(pid_t tid, ThreadInfo* info) {
   assert(info != NULL);
   char status_path[80];
@@ -371,6 +371,8 @@ bool LinuxDumper::ThreadInfoGet(pid_t tid, ThreadInfo* info) {
   memcpy(&stack_pointer, &info->regs.esp, sizeof(info->regs.esp));
 #elif defined(__x86_64)
   memcpy(&stack_pointer, &info->regs.rsp, sizeof(info->regs.rsp));
+#elif defined(__ARM_EABI__)
+  memcpy(&stack_pointer, &info->regs.uregs[R13], sizeof(info->regs.uregs[R13]));
 #else
 #error "This code hasn't been ported to your platform yet."
 #endif
@@ -387,13 +389,9 @@ bool LinuxDumper::ThreadInfoGet(pid_t tid, ThreadInfo* info) {
 // unwind. So we just grab, up to, 32k of stack.
 bool LinuxDumper::GetStackInfo(const void** stack, size_t* stack_len,
                                uintptr_t int_stack_pointer) {
-#if defined(__i386) || defined(__x86_64)
-  static const bool stack_grows_down = true;
-  static const uintptr_t page_size = 4096;
-#else
-#error "This code has not been ported to your platform yet."
-#endif
   // Move the stack pointer to the bottom of the page that it's in.
+  const uintptr_t page_size = getpagesize();
+
   uint8_t* const stack_pointer =
       reinterpret_cast<uint8_t*>(int_stack_pointer & ~(page_size - 1));
 
@@ -403,26 +401,19 @@ bool LinuxDumper::GetStackInfo(const void** stack, size_t* stack_len,
   const MappingInfo* mapping = FindMapping(stack_pointer);
   if (!mapping)
     return false;
-  if (stack_grows_down) {
-    const ptrdiff_t offset = stack_pointer - (uint8_t*) mapping->start_addr;
-    const ptrdiff_t distance_to_end =
-        static_cast<ptrdiff_t>(mapping->size) - offset;
-    *stack_len = distance_to_end > kStackToCapture ?
-                 kStackToCapture : distance_to_end;
-    *stack = stack_pointer;
-  } else {
-    const ptrdiff_t offset = stack_pointer - (uint8_t*) mapping->start_addr;
-    *stack_len = offset > kStackToCapture ? kStackToCapture : offset;
-    *stack = stack_pointer - *stack_len;
-  }
-
+  const ptrdiff_t offset = stack_pointer - (uint8_t*) mapping->start_addr;
+  const ptrdiff_t distance_to_end =
+      static_cast<ptrdiff_t>(mapping->size) - offset;
+  *stack_len = distance_to_end > kStackToCapture ?
+      kStackToCapture : distance_to_end;
+  *stack = stack_pointer;
   return true;
 }
 
 // static
 void LinuxDumper::CopyFromProcess(void* dest, pid_t child, const void* src,
                                   size_t length) {
-  unsigned long tmp;
+  unsigned long tmp = 55;
   size_t done = 0;
   static const size_t word_size = sizeof(tmp);
   uint8_t* const local = (uint8_t*) dest;
@@ -430,8 +421,9 @@ void LinuxDumper::CopyFromProcess(void* dest, pid_t child, const void* src,
 
   while (done < length) {
     const size_t l = length - done > word_size ? word_size : length - done;
-    if (sys_ptrace(PTRACE_PEEKDATA, child, remote + done, &tmp) == -1)
+    if (sys_ptrace(PTRACE_PEEKDATA, child, remote + done, &tmp) == -1) {
       tmp = 0;
+    }
     memcpy(local + done, &tmp, l);
     done += l;
   }
diff --git a/src/client/linux/minidump_writer/linux_dumper.h b/src/client/linux/minidump_writer/linux_dumper.h
index 3e8869b5..7a4cd3a3 100644
--- a/src/client/linux/minidump_writer/linux_dumper.h
+++ b/src/client/linux/minidump_writer/linux_dumper.h
@@ -44,7 +44,7 @@ namespace google_breakpad {
 typedef typeof(((struct user*) 0)->u_debugreg[0]) debugreg_t;
 
 // Typedef for our parsing of the auxv variables in /proc/pid/auxv.
-#if defined(__i386)
+#if defined(__i386) || defined(__ARM_EABI__)
 typedef Elf32_auxv_t elf_aux_entry;
 #elif defined(__x86_64__)
 typedef Elf64_auxv_t elf_aux_entry;
@@ -64,16 +64,20 @@ struct ThreadInfo {
   const void* stack;  // pointer to the stack area
   size_t stack_len;  // length of the stack to copy
 
+
+#if defined(__i386) || defined(__x86_64)
   user_regs_struct regs;
   user_fpregs_struct fpregs;
+  static const unsigned kNumDebugRegisters = 8;
+  debugreg_t dregs[8];
 #if defined(__i386)
   user_fpxregs_struct fpxregs;
-#endif
-
-#if defined(__i386) || defined(__x86_64)
+#endif  // defined(__i386)
 
-  static const unsigned kNumDebugRegisters = 8;
-  debugreg_t dregs[8];
+#elif defined(__ARM_EABI__)
+  // Mimicking how strace does this(see syscall.c, search for GETREGS)
+  struct user_regs regs;
+  struct user_fpregs fpregs;
 #endif
 };
 
@@ -141,7 +145,7 @@ class LinuxDumper {
 
   mutable PageAllocator allocator_;
 
-  bool threads_suspened_;
+  bool threads_suspended_;
   wasteful_vector<pid_t> threads_;  // the ids of all the threads
   wasteful_vector<MappingInfo*> mappings_;  // info from /proc/<pid>/maps
 };
diff --git a/src/client/linux/minidump_writer/linux_dumper_unittest.cc b/src/client/linux/minidump_writer/linux_dumper_unittest.cc
index e060e53e..6f1043c3 100644
--- a/src/client/linux/minidump_writer/linux_dumper_unittest.cc
+++ b/src/client/linux/minidump_writer/linux_dumper_unittest.cc
@@ -29,10 +29,13 @@
 
 #include <limits.h>
 #include <unistd.h>
+#include <signal.h>
+#include <sys/types.h>
 
+#include "breakpad_googletest_includes.h"
 #include "client/linux/minidump_writer/linux_dumper.h"
 #include "common/linux/file_id.h"
-#include "breakpad_googletest_includes.h"
+#include "common/linux/memory.h"
 
 using namespace google_breakpad;
 
@@ -67,7 +70,7 @@ TEST(LinuxDumperTest, ThreadList) {
   LinuxDumper dumper(getpid());
   ASSERT_TRUE(dumper.Init());
 
-  ASSERT_GE(dumper.threads().size(), 1);
+  ASSERT_GE(dumper.threads().size(), (size_t)1);
   bool found = false;
   for (size_t i = 0; i < dumper.threads().size(); ++i) {
     if (dumper.threads()[i] == getpid()) {
@@ -77,6 +80,55 @@ TEST(LinuxDumperTest, ThreadList) {
   }
 }
 
+TEST(LinuxDumperTest, VerifyStackReadWithMultipleThreads) {
+  static const int kNumberOfThreadsInHelperProgram = 5;
+  char kNumberOfThreadsArgument[2];
+  sprintf(kNumberOfThreadsArgument, "%d", kNumberOfThreadsInHelperProgram);
+
+  pid_t child_pid = fork();
+  if (child_pid == 0) {
+    // Set the number of threads
+    execl("src/client/linux/linux_dumper_unittest_helper",
+          "linux_dumper_unittest_helper",
+          kNumberOfThreadsArgument,
+          NULL);
+    // Kill if we get here.
+    printf("Errno from exec: %d", errno);
+    FAIL() << "Exec failed: " << strerror(errno);
+    exit(0);
+  }
+  // The sleep is flaky, but prevents us from reading
+  // the child process before all threads have been created.
+  sleep(1);
+  LinuxDumper dumper(child_pid);
+  EXPECT_TRUE(dumper.Init());
+  EXPECT_EQ((size_t)kNumberOfThreadsInHelperProgram, dumper.threads().size());
+  EXPECT_TRUE(dumper.ThreadsSuspend());
+
+  ThreadInfo one_thread;
+  for(size_t i = 0; i < dumper.threads().size(); ++i) {
+    EXPECT_TRUE(dumper.ThreadInfoGet(dumper.threads()[i], &one_thread));
+    // We know the threads are in a function which has allocated exactly
+    // one word off the stack to store its thread id.
+#if defined(__ARM_EABI__)
+    void* process_tid_location = (void *)(one_thread.regs.uregs[11] - 8);
+#elif defined(__i386)
+    void* process_tid_location = (void *)(one_thread.regs.ebp - 4);
+#elif defined(__x86_64)
+    void* process_tid_location = (void *)(one_thread.regs.rbp - 4);
+#else
+#error Platform not supported!
+#endif
+    pid_t one_thread_id;
+    dumper.CopyFromProcess(&one_thread_id,
+                           dumper.threads()[i],
+                           process_tid_location,
+                           4);
+    EXPECT_EQ(dumper.threads()[i], one_thread_id);
+  }
+  kill(child_pid, SIGKILL);
+}
+
 TEST(LinuxDumperTest, BuildProcPath) {
   const pid_t pid = getpid();
   LinuxDumper dumper(pid);
@@ -106,28 +158,29 @@ TEST(LinuxDumperTest, BuildProcPath) {
 #endif
 }
 
+#if !defined(__ARM_EABI__)
 TEST(LinuxDumperTest, MappingsIncludeLinuxGate) {
   LinuxDumper dumper(getpid());
   ASSERT_TRUE(dumper.Init());
 
   void* linux_gate_loc = dumper.FindBeginningOfLinuxGateSharedLibrary(getpid());
-  if (linux_gate_loc) {
-    bool found_linux_gate = false;
-
-    const wasteful_vector<MappingInfo*> mappings = dumper.mappings();
-    const MappingInfo* mapping;
-    for (unsigned i = 0; i < mappings.size(); ++i) {
-      mapping = mappings[i];
-      if (!strcmp(mapping->name, kLinuxGateLibraryName)) {
-        found_linux_gate = true;
-        break;
-      }
+  ASSERT_TRUE(linux_gate_loc);
+  bool found_linux_gate = false;
+
+  const wasteful_vector<MappingInfo*> mappings = dumper.mappings();
+  const MappingInfo* mapping;
+  for (unsigned i = 0; i < mappings.size(); ++i) {
+    mapping = mappings[i];
+    if (!strcmp(mapping->name, kLinuxGateLibraryName)) {
+      found_linux_gate = true;
+      break;
     }
-    EXPECT_TRUE(found_linux_gate);
-    EXPECT_EQ(linux_gate_loc, reinterpret_cast<void*>(mapping->start_addr));
-    EXPECT_EQ(0, memcmp(linux_gate_loc, ELFMAG, SELFMAG));
   }
+  EXPECT_TRUE(found_linux_gate);
+  EXPECT_EQ(linux_gate_loc, reinterpret_cast<void*>(mapping->start_addr));
+  EXPECT_EQ(0, memcmp(linux_gate_loc, ELFMAG, SELFMAG));
 }
+#endif
 
 TEST(LinuxDumperTest, FileIDsMatch) {
   // Calculate the File ID of our binary using both
diff --git a/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc b/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
new file mode 100644
index 00000000..f744d72c
--- /dev/null
+++ b/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
@@ -0,0 +1,64 @@
+// Copyright (c) 2010, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Helper program for the linux_dumper class, which creates a bunch of
+// threads. The first word of each thread's stack is set to the thread
+// id.
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#pragma GCC optimize ("O0")
+void *thread_function(void *data) __attribute__((noinline, optimize("O2")));
+
+void *thread_function(void *data) {
+  pid_t thread_id = syscall(SYS_gettid);
+  while (true) ;
+  asm("");
+}
+
+int main(int argc, char *argv[]) {
+  int num_threads = atoi(argv[1]);
+  if (num_threads < 1) {
+    fprintf(stderr, "ERROR: number of threads is 0");
+    return 1;
+  }
+  pthread_t threads[num_threads];
+  pthread_attr_t thread_attributes;
+  pthread_attr_init(&thread_attributes);
+  pthread_attr_setdetachstate(&thread_attributes, PTHREAD_CREATE_DETACHED);
+  for (int i = 1; i < num_threads; i++) {
+    pthread_create(&threads[i], &thread_attributes, &thread_function, NULL);
+  }
+  thread_function(NULL);
+  return 0;
+}
diff --git a/src/client/linux/minidump_writer/minidump_writer.cc b/src/client/linux/minidump_writer/minidump_writer.cc
index 166b8e5c..1ee90981 100644
--- a/src/client/linux/minidump_writer/minidump_writer.cc
+++ b/src/client/linux/minidump_writer/minidump_writer.cc
@@ -61,7 +61,7 @@
 
 #include "client/linux/handler/exception_handler.h"
 #include "client/linux/minidump_writer/line_reader.h"
-#include "client/linux/minidump_writer//linux_dumper.h"
+#include "client/linux/minidump_writer/linux_dumper.h"
 #include "common/linux/linux_libc_support.h"
 #include "common/linux/linux_syscall_support.h"
 
@@ -307,6 +307,54 @@ static void CPUFillFromUContext(MDRawContextAMD64 *out, const ucontext *uc,
   memcpy(&out->flt_save.xmm_registers, &fpregs->_xmm, 16 * 16);
 }
 
+#elif defined(__ARMEL__)
+typedef MDRawContextARM RawContextCPU;
+
+static void CPUFillFromThreadInfo(MDRawContextARM *out,
+                                  const google_breakpad::ThreadInfo &info) {
+  out->context_flags = MD_CONTEXT_ARM_FULL;
+
+  for (int i = 0; i < MD_CONTEXT_ARM_GPR_COUNT; ++i)
+    out->iregs[i] = info.regs.uregs[i];
+  // No CPSR register in ThreadInfo(it's not accessible via ptrace)
+  out->cpsr = 0;
+  out->float_save.fpscr = info.fpregs.fpsr |
+    (static_cast<u_int64_t>(info.fpregs.fpcr) << 32);
+  //TODO: sort this out, actually collect floating point registers
+  memset(&out->float_save.regs, 0, sizeof(out->float_save.regs));
+  memset(&out->float_save.extra, 0, sizeof(out->float_save.extra));
+}
+
+static void CPUFillFromUContext(MDRawContextARM *out, const ucontext *uc,
+                                const struct _libc_fpstate* fpregs) {
+  out->context_flags = MD_CONTEXT_ARM_FULL;
+
+  out->iregs[0] = uc->uc_mcontext.arm_r0;
+  out->iregs[1] = uc->uc_mcontext.arm_r1;
+  out->iregs[2] = uc->uc_mcontext.arm_r2;
+  out->iregs[3] = uc->uc_mcontext.arm_r3;
+  out->iregs[4] = uc->uc_mcontext.arm_r4;
+  out->iregs[5] = uc->uc_mcontext.arm_r5;
+  out->iregs[6] = uc->uc_mcontext.arm_r6;
+  out->iregs[7] = uc->uc_mcontext.arm_r7;
+  out->iregs[8] = uc->uc_mcontext.arm_r8;
+  out->iregs[9] = uc->uc_mcontext.arm_r9;
+  out->iregs[10] = uc->uc_mcontext.arm_r10;
+
+  out->iregs[11] = uc->uc_mcontext.arm_fp;
+  out->iregs[12] = uc->uc_mcontext.arm_ip;
+  out->iregs[13] = uc->uc_mcontext.arm_sp;
+  out->iregs[14] = uc->uc_mcontext.arm_lr;
+  out->iregs[15] = uc->uc_mcontext.arm_pc;
+
+  out->cpsr = uc->uc_mcontext.arm_cpsr;
+
+  //TODO: fix this after fixing ExceptionHandler
+  out->float_save.fpscr = 0;
+  memset(&out->float_save.regs, 0, sizeof(out->float_save.regs));
+  memset(&out->float_save.extra, 0, sizeof(out->float_save.extra));
+}
+
 #else
 #error "This code has not been ported to your platform yet."
 #endif
@@ -321,7 +369,12 @@ class MinidumpWriter {
       : filename_(filename),
         siginfo_(&context->siginfo),
         ucontext_(&context->context),
+#if !defined(__ARM_EABI__)
         float_state_(&context->float_state),
+#else
+        //TODO: fix this after fixing ExceptionHandler
+        float_state_(NULL),
+#endif
         crashing_tid_(context->tid),
         dumper_(crashing_pid) {
   }
@@ -612,6 +665,10 @@ class MinidumpWriter {
   uintptr_t GetStackPointer() {
     return ucontext_->uc_mcontext.gregs[REG_RSP];
   }
+#elif defined(__ARM_EABI__)
+  uintptr_t GetStackPointer() {
+    return ucontext_->uc_mcontext.arm_sp;
+  }
 #else
 #error "This code has not been ported to your platform yet."
 #endif
@@ -644,6 +701,8 @@ class MinidumpWriter {
         MD_CPU_ARCHITECTURE_X86;
 #elif defined(__x86_64)
         MD_CPU_ARCHITECTURE_AMD64;
+#elif defined(__arm__)
+        MD_CPU_ARCHITECTURE_ARM;
 #else
 #error "Unknown CPU arch"
 #endif