Adjust MD_CONTEXT_CPU_MASK to reflect reality, fix some code so it can handle dumps using the old value for MD_CONTEXT_ARM

The value of MD_CONTEXT_CPU_MASK in use assumes that only the lower 6 bits are used for flags, and the upper 26 bits are for the CPU type. However, as of Windows 7 SP1, the 7th bit is being used as a flag (per http://msdn.microsoft.com/en-us/library/hh134238%28v=vs.85%29.aspx and the Windows SDK headers). Adjusting MD_CONTEXT_CPU_MASK works, but unfortunately that masks off the existing value of MD_CONTEXT_ARM. This patch also changes the value of MD_CONTEXT_ARM and adjusts the minidump context reading machinery to gracefully handle minidumps with the old value.
R=mark at http://breakpad.appspot.com/302001

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@831 4c0a9323-5329-0410-9bdc-e9ce6186880e

10 files changed, 658 insertions, 42 deletions

diff --git a/src/google_breakpad/common/minidump_cpu_amd64.h b/src/google_breakpad/common/minidump_cpu_amd64.h
index 75dae7dd..fa6a9961 100644
--- a/src/google_breakpad/common/minidump_cpu_amd64.h
+++ b/src/google_breakpad/common/minidump_cpu_amd64.h
@@ -201,8 +201,9 @@ typedef struct {
 } MDRawContextAMD64;  /* CONTEXT */
 
 /* For (MDRawContextAMD64).context_flags.  These values indicate the type of
- * context stored in the structure.  The high 26 bits identify the CPU, the
- * low 6 bits identify the type of context saved. */
+ * context stored in the structure.  The high 24 bits identify the CPU, the
+ * low 8 bits identify the type of context saved. */
+#define MD_CONTEXT_AMD64 0x00100000  /* CONTEXT_AMD64 */
 #define MD_CONTEXT_AMD64_CONTROL         (MD_CONTEXT_AMD64 | 0x00000001)
      /* CONTEXT_CONTROL */
 #define MD_CONTEXT_AMD64_INTEGER         (MD_CONTEXT_AMD64 | 0x00000002)
@@ -213,6 +214,9 @@ typedef struct {
      /* CONTEXT_FLOATING_POINT */
 #define MD_CONTEXT_AMD64_DEBUG_REGISTERS (MD_CONTEXT_AMD64 | 0x00000010)
      /* CONTEXT_DEBUG_REGISTERS */
+#define MD_CONTEXT_AMD64_XSTATE          (MD_CONTEXT_AMD64 | 0x00000040)
+     /* CONTEXT_XSTATE */
+
 /* WinNT.h refers to CONTEXT_MMX_REGISTERS but doesn't appear to define it
  * I think it really means CONTEXT_FLOATING_POINT.
  */
diff --git a/src/google_breakpad/common/minidump_cpu_arm.h b/src/google_breakpad/common/minidump_cpu_arm.h
index 14d81460..aa1c88f5 100644
--- a/src/google_breakpad/common/minidump_cpu_arm.h
+++ b/src/google_breakpad/common/minidump_cpu_arm.h
@@ -128,6 +128,16 @@ enum MDARMRegisterNumbers {
 
 /* For (MDRawContextARM).context_flags.  These values indicate the type of
  * context stored in the structure. */
+/* CONTEXT_ARM from the Windows CE 5.0 SDK. This value isn't correct
+ * because this bit can be used for flags. Presumably this value was
+ * never actually used in minidumps, but only in "CEDumps" which
+ * are a whole parallel minidump file format for Windows CE.
+ * Therefore, Breakpad defines its own value for ARM CPUs.
+ */
+#define MD_CONTEXT_ARM_OLD               0x00000040
+/* This value was chosen to avoid likely conflicts with MD_CONTEXT_*
+ * for other CPUs. */
+#define MD_CONTEXT_ARM                   0x40000000
 #define MD_CONTEXT_ARM_INTEGER           (MD_CONTEXT_ARM | 0x00000002)
 #define MD_CONTEXT_ARM_FLOATING_POINT    (MD_CONTEXT_ARM | 0x00000004)
 
diff --git a/src/google_breakpad/common/minidump_cpu_x86.h b/src/google_breakpad/common/minidump_cpu_x86.h
index 4dbc0e9a..32aff8a7 100644
--- a/src/google_breakpad/common/minidump_cpu_x86.h
+++ b/src/google_breakpad/common/minidump_cpu_x86.h
@@ -141,8 +141,8 @@ typedef struct {
 } MDRawContextX86;  /* CONTEXT */
 
 /* For (MDRawContextX86).context_flags.  These values indicate the type of
- * context stored in the structure.  The high 26 bits identify the CPU, the
- * low 6 bits identify the type of context saved. */
+ * context stored in the structure.  The high 24 bits identify the CPU, the
+ * low 8 bits identify the type of context saved. */
 #define MD_CONTEXT_X86                    0x00010000
      /* CONTEXT_i386, CONTEXT_i486: identifies CPU */
 #define MD_CONTEXT_X86_CONTROL            (MD_CONTEXT_X86 | 0x00000001)
@@ -157,6 +157,8 @@ typedef struct {
      /* CONTEXT_DEBUG_REGISTERS */
 #define MD_CONTEXT_X86_EXTENDED_REGISTERS (MD_CONTEXT_X86 | 0x00000020)
      /* CONTEXT_EXTENDED_REGISTERS */
+#define MD_CONTEXT_X86_XSTATE             (MD_CONTEXT_X86 | 0x00000040)
+     /* CONTEXT_XSTATE */
 
 #define MD_CONTEXT_X86_FULL              (MD_CONTEXT_X86_CONTROL | \
                                           MD_CONTEXT_X86_INTEGER | \
diff --git a/src/google_breakpad/common/minidump_format.h b/src/google_breakpad/common/minidump_format.h
index 77f28ca7..6c051305 100644
--- a/src/google_breakpad/common/minidump_format.h
+++ b/src/google_breakpad/common/minidump_format.h
@@ -90,19 +90,20 @@ typedef struct {
  * WinNT.h
  */
 
-/* Non-x86 CPU identifiers found in the high 26 bits of
+/* Non-x86 CPU identifiers found in the high 24 bits of
  * (MDRawContext*).context_flags.  These aren't used by Breakpad, but are
  * defined here for reference, to avoid assigning values that conflict
  * (although some values already conflict). */
 #define MD_CONTEXT_IA64  0x00080000  /* CONTEXT_IA64 */
-#define MD_CONTEXT_AMD64 0x00100000  /* CONTEXT_AMD64 */
 /* Additional values from winnt.h in the Windows CE 5.0 SDK: */
 #define MD_CONTEXT_SHX   0x000000c0  /* CONTEXT_SH4 (Super-H, includes SH3) */
-#define MD_CONTEXT_ARM   0x00000040  /* CONTEXT_ARM (0x40 bit set in SHx?) */
 #define MD_CONTEXT_MIPS  0x00010000  /* CONTEXT_R4000 (same value as x86?) */
 #define MD_CONTEXT_ALPHA 0x00020000  /* CONTEXT_ALPHA */
 
-#define MD_CONTEXT_CPU_MASK 0xffffffc0
+/* As of Windows 7 SP1, the number of flag bits has increased to
+ * include 0x40 (CONTEXT_XSTATE):
+ * http://msdn.microsoft.com/en-us/library/hh134238%28v=vs.85%29.aspx */
+#define MD_CONTEXT_CPU_MASK 0xffffff00
 
 
 /* This is a base type for MDRawContextX86 and MDRawContextPPC.  This
diff --git a/src/processor/minidump.cc b/src/processor/minidump.cc
index 9e084401..331ebd9e 100644
--- a/src/processor/minidump.cc
+++ b/src/processor/minidump.cc
@@ -410,6 +410,17 @@ bool MinidumpContext::Read(u_int32_t expected_size) {
       Swap(&context_flags);
 
     u_int32_t cpu_type = context_flags & MD_CONTEXT_CPU_MASK;
+    if (cpu_type == 0) {
+      // Unfortunately the flag for MD_CONTEXT_ARM that was taken
+      // from a Windows CE SDK header conflicts in practice with
+      // the CONTEXT_XSTATE flag. MD_CONTEXT_ARM has been renumbered,
+      // but handle dumps with the legacy value gracefully here.
+      if (context_flags & MD_CONTEXT_ARM_OLD) {
+        context_flags |= MD_CONTEXT_ARM;
+        context_flags &= ~MD_CONTEXT_ARM_OLD;
+        cpu_type = MD_CONTEXT_ARM;
+      }
+    }
 
     // Allocate the context structure for the correct CPU and fill it.  The
     // casts are slightly unorthodox, but it seems better to do that than to
diff --git a/src/processor/minidump_unittest.cc b/src/processor/minidump_unittest.cc
index 13876df5..d1c91a88 100644
--- a/src/processor/minidump_unittest.cc
+++ b/src/processor/minidump_unittest.cc
@@ -46,6 +46,7 @@ namespace {
 
 using google_breakpad::Minidump;
 using google_breakpad::MinidumpContext;
+using google_breakpad::MinidumpException;
 using google_breakpad::MinidumpMemoryInfo;
 using google_breakpad::MinidumpMemoryInfoList;
 using google_breakpad::MinidumpMemoryList;
@@ -57,6 +58,7 @@ using google_breakpad::MinidumpThread;
 using google_breakpad::MinidumpThreadList;
 using google_breakpad::SynthMinidump::Context;
 using google_breakpad::SynthMinidump::Dump;
+using google_breakpad::SynthMinidump::Exception;
 using google_breakpad::SynthMinidump::Memory;
 using google_breakpad::SynthMinidump::Module;
 using google_breakpad::SynthMinidump::Stream;
@@ -588,4 +590,318 @@ TEST(Dump, OneMemoryInfo) {
   ASSERT_EQ(kRegionSize, info2->GetSize());
 }
 
+TEST(Dump, OneExceptionX86) {
+  Dump dump(0, kLittleEndian);
+
+  MDRawContextX86 raw_context;
+  raw_context.context_flags = MD_CONTEXT_X86_INTEGER | MD_CONTEXT_X86_CONTROL;
+  raw_context.edi = 0x3ecba80d;
+  raw_context.esi = 0x382583b9;
+  raw_context.ebx = 0x7fccc03f;
+  raw_context.edx = 0xf62f8ec2;
+  raw_context.ecx = 0x46a6a6a8;
+  raw_context.eax = 0x6a5025e2;
+  raw_context.ebp = 0xd9fabb4a;
+  raw_context.eip = 0x6913f540;
+  raw_context.cs = 0xbffe6eda;
+  raw_context.eflags = 0xb2ce1e2d;
+  raw_context.esp = 0x659caaa4;
+  raw_context.ss = 0x2e951ef7;
+  Context context(dump, raw_context);
+
+  Exception exception(dump, context,
+                      0x1234abcd, // thread id
+                      0xdcba4321, // exception code
+                      0xf0e0d0c0, // exception flags
+                      0x0919a9b9c9d9e9f9ULL); // exception address
+  
+  dump.Add(&context);
+  dump.Add(&exception);
+  dump.Finish();
+
+  string contents;
+  ASSERT_TRUE(dump.GetContents(&contents));
+
+  istringstream minidump_stream(contents);
+  Minidump minidump(minidump_stream);
+  ASSERT_TRUE(minidump.Read());
+  ASSERT_EQ(1U, minidump.GetDirectoryEntryCount());
+
+  MinidumpException *md_exception = minidump.GetException();
+  ASSERT_TRUE(md_exception != NULL);
+
+  u_int32_t thread_id;
+  ASSERT_TRUE(md_exception->GetThreadID(&thread_id));
+  ASSERT_EQ(0x1234abcd, thread_id);
+
+  const MDRawExceptionStream* raw_exception = md_exception->exception();
+  ASSERT_TRUE(raw_exception != NULL);
+  EXPECT_EQ(0xdcba4321, raw_exception->exception_record.exception_code);
+  EXPECT_EQ(0xf0e0d0c0, raw_exception->exception_record.exception_flags);
+  EXPECT_EQ(0x0919a9b9c9d9e9f9ULL,
+            raw_exception->exception_record.exception_address);
+
+  MinidumpContext *md_context = md_exception->GetContext();
+  ASSERT_TRUE(md_context != NULL);
+  ASSERT_EQ((u_int32_t) MD_CONTEXT_X86, md_context->GetContextCPU());
+  const MDRawContextX86 *md_raw_context = md_context->GetContextX86();
+  ASSERT_TRUE(md_raw_context != NULL);
+  ASSERT_EQ((u_int32_t) (MD_CONTEXT_X86_INTEGER | MD_CONTEXT_X86_CONTROL),
+            (md_raw_context->context_flags
+             & (MD_CONTEXT_X86_INTEGER | MD_CONTEXT_X86_CONTROL)));
+  EXPECT_EQ(0x3ecba80dU, raw_context.edi);
+  EXPECT_EQ(0x382583b9U, raw_context.esi);
+  EXPECT_EQ(0x7fccc03fU, raw_context.ebx);
+  EXPECT_EQ(0xf62f8ec2U, raw_context.edx);
+  EXPECT_EQ(0x46a6a6a8U, raw_context.ecx);
+  EXPECT_EQ(0x6a5025e2U, raw_context.eax);
+  EXPECT_EQ(0xd9fabb4aU, raw_context.ebp);
+  EXPECT_EQ(0x6913f540U, raw_context.eip);
+  EXPECT_EQ(0xbffe6edaU, raw_context.cs);
+  EXPECT_EQ(0xb2ce1e2dU, raw_context.eflags);
+  EXPECT_EQ(0x659caaa4U, raw_context.esp);
+  EXPECT_EQ(0x2e951ef7U, raw_context.ss);
+}
+
+TEST(Dump, OneExceptionX86XState) {
+  Dump dump(0, kLittleEndian);
+
+  MDRawContextX86 raw_context;
+  raw_context.context_flags = MD_CONTEXT_X86_INTEGER |
+    MD_CONTEXT_X86_CONTROL | MD_CONTEXT_X86_XSTATE;
+  raw_context.edi = 0x3ecba80d;
+  raw_context.esi = 0x382583b9;
+  raw_context.ebx = 0x7fccc03f;
+  raw_context.edx = 0xf62f8ec2;
+  raw_context.ecx = 0x46a6a6a8;
+  raw_context.eax = 0x6a5025e2;
+  raw_context.ebp = 0xd9fabb4a;
+  raw_context.eip = 0x6913f540;
+  raw_context.cs = 0xbffe6eda;
+  raw_context.eflags = 0xb2ce1e2d;
+  raw_context.esp = 0x659caaa4;
+  raw_context.ss = 0x2e951ef7;
+  Context context(dump, raw_context);
+
+  Exception exception(dump, context,
+                      0x1234abcd, // thread id
+                      0xdcba4321, // exception code
+                      0xf0e0d0c0, // exception flags
+                      0x0919a9b9c9d9e9f9ULL); // exception address
+  
+  dump.Add(&context);
+  dump.Add(&exception);
+  dump.Finish();
+
+  string contents;
+  ASSERT_TRUE(dump.GetContents(&contents));
+
+  istringstream minidump_stream(contents);
+  Minidump minidump(minidump_stream);
+  ASSERT_TRUE(minidump.Read());
+  ASSERT_EQ(1U, minidump.GetDirectoryEntryCount());
+
+  MinidumpException *md_exception = minidump.GetException();
+  ASSERT_TRUE(md_exception != NULL);
+
+  u_int32_t thread_id;
+  ASSERT_TRUE(md_exception->GetThreadID(&thread_id));
+  ASSERT_EQ(0x1234abcd, thread_id);
+
+  const MDRawExceptionStream* raw_exception = md_exception->exception();
+  ASSERT_TRUE(raw_exception != NULL);
+  EXPECT_EQ(0xdcba4321, raw_exception->exception_record.exception_code);
+  EXPECT_EQ(0xf0e0d0c0, raw_exception->exception_record.exception_flags);
+  EXPECT_EQ(0x0919a9b9c9d9e9f9ULL,
+            raw_exception->exception_record.exception_address);
+
+  MinidumpContext *md_context = md_exception->GetContext();
+  ASSERT_TRUE(md_context != NULL);
+  ASSERT_EQ((u_int32_t) MD_CONTEXT_X86, md_context->GetContextCPU());
+  const MDRawContextX86 *md_raw_context = md_context->GetContextX86();
+  ASSERT_TRUE(md_raw_context != NULL);
+  ASSERT_EQ((u_int32_t) (MD_CONTEXT_X86_INTEGER | MD_CONTEXT_X86_CONTROL),
+            (md_raw_context->context_flags
+             & (MD_CONTEXT_X86_INTEGER | MD_CONTEXT_X86_CONTROL)));
+  EXPECT_EQ(0x3ecba80dU, raw_context.edi);
+  EXPECT_EQ(0x382583b9U, raw_context.esi);
+  EXPECT_EQ(0x7fccc03fU, raw_context.ebx);
+  EXPECT_EQ(0xf62f8ec2U, raw_context.edx);
+  EXPECT_EQ(0x46a6a6a8U, raw_context.ecx);
+  EXPECT_EQ(0x6a5025e2U, raw_context.eax);
+  EXPECT_EQ(0xd9fabb4aU, raw_context.ebp);
+  EXPECT_EQ(0x6913f540U, raw_context.eip);
+  EXPECT_EQ(0xbffe6edaU, raw_context.cs);
+  EXPECT_EQ(0xb2ce1e2dU, raw_context.eflags);
+  EXPECT_EQ(0x659caaa4U, raw_context.esp);
+  EXPECT_EQ(0x2e951ef7U, raw_context.ss);
+}
+
+TEST(Dump, OneExceptionARM) {
+  Dump dump(0, kLittleEndian);
+
+  MDRawContextARM raw_context;
+  raw_context.context_flags = MD_CONTEXT_ARM_INTEGER;
+  raw_context.iregs[0] = 0x3ecba80d;
+  raw_context.iregs[1] = 0x382583b9;
+  raw_context.iregs[2] = 0x7fccc03f;
+  raw_context.iregs[3] = 0xf62f8ec2;
+  raw_context.iregs[4] = 0x46a6a6a8;
+  raw_context.iregs[5] = 0x6a5025e2;
+  raw_context.iregs[6] = 0xd9fabb4a;
+  raw_context.iregs[7] = 0x6913f540;
+  raw_context.iregs[8] = 0xbffe6eda;
+  raw_context.iregs[9] = 0xb2ce1e2d;
+  raw_context.iregs[10] = 0x659caaa4;
+  raw_context.iregs[11] = 0xf0e0d0c0;
+  raw_context.iregs[12] = 0xa9b8c7d6;
+  raw_context.iregs[13] = 0x12345678;
+  raw_context.iregs[14] = 0xabcd1234;
+  raw_context.iregs[15] = 0x10203040;
+  raw_context.cpsr = 0x2e951ef7;
+  Context context(dump, raw_context);
+
+  Exception exception(dump, context,
+                      0x1234abcd, // thread id
+                      0xdcba4321, // exception code
+                      0xf0e0d0c0, // exception flags
+                      0x0919a9b9c9d9e9f9ULL); // exception address
+  
+  dump.Add(&context);
+  dump.Add(&exception);
+  dump.Finish();
+
+  string contents;
+  ASSERT_TRUE(dump.GetContents(&contents));
+
+  istringstream minidump_stream(contents);
+  Minidump minidump(minidump_stream);
+  ASSERT_TRUE(minidump.Read());
+  ASSERT_EQ(1U, minidump.GetDirectoryEntryCount());
+
+  MinidumpException *md_exception = minidump.GetException();
+  ASSERT_TRUE(md_exception != NULL);
+
+  u_int32_t thread_id;
+  ASSERT_TRUE(md_exception->GetThreadID(&thread_id));
+  ASSERT_EQ(0x1234abcd, thread_id);
+
+  const MDRawExceptionStream* raw_exception = md_exception->exception();
+  ASSERT_TRUE(raw_exception != NULL);
+  EXPECT_EQ(0xdcba4321, raw_exception->exception_record.exception_code);
+  EXPECT_EQ(0xf0e0d0c0, raw_exception->exception_record.exception_flags);
+  EXPECT_EQ(0x0919a9b9c9d9e9f9ULL,
+            raw_exception->exception_record.exception_address);
+
+  MinidumpContext *md_context = md_exception->GetContext();
+  ASSERT_TRUE(md_context != NULL);
+  ASSERT_EQ((u_int32_t) MD_CONTEXT_ARM, md_context->GetContextCPU());
+  const MDRawContextARM *md_raw_context = md_context->GetContextARM();
+  ASSERT_TRUE(md_raw_context != NULL);
+  ASSERT_EQ((u_int32_t) MD_CONTEXT_ARM_INTEGER,
+            (md_raw_context->context_flags
+             & MD_CONTEXT_ARM_INTEGER));
+  EXPECT_EQ(0x3ecba80dU, raw_context.iregs[0]);
+  EXPECT_EQ(0x382583b9U, raw_context.iregs[1]);
+  EXPECT_EQ(0x7fccc03fU, raw_context.iregs[2]);
+  EXPECT_EQ(0xf62f8ec2U, raw_context.iregs[3]);
+  EXPECT_EQ(0x46a6a6a8U, raw_context.iregs[4]);
+  EXPECT_EQ(0x6a5025e2U, raw_context.iregs[5]);
+  EXPECT_EQ(0xd9fabb4aU, raw_context.iregs[6]);
+  EXPECT_EQ(0x6913f540U, raw_context.iregs[7]);
+  EXPECT_EQ(0xbffe6edaU, raw_context.iregs[8]);
+  EXPECT_EQ(0xb2ce1e2dU, raw_context.iregs[9]);
+  EXPECT_EQ(0x659caaa4U, raw_context.iregs[10]);
+  EXPECT_EQ(0xf0e0d0c0U, raw_context.iregs[11]);
+  EXPECT_EQ(0xa9b8c7d6U, raw_context.iregs[12]);
+  EXPECT_EQ(0x12345678U, raw_context.iregs[13]);
+  EXPECT_EQ(0xabcd1234U, raw_context.iregs[14]);
+  EXPECT_EQ(0x10203040U, raw_context.iregs[15]);
+  EXPECT_EQ(0x2e951ef7U, raw_context.cpsr);
+}
+
+TEST(Dump, OneExceptionARMOldFlags) {
+  Dump dump(0, kLittleEndian);
+
+  MDRawContextARM raw_context;
+  // MD_CONTEXT_ARM_INTEGER, but with _OLD
+  raw_context.context_flags = MD_CONTEXT_ARM_OLD | 0x00000002;
+  raw_context.iregs[0] = 0x3ecba80d;
+  raw_context.iregs[1] = 0x382583b9;
+  raw_context.iregs[2] = 0x7fccc03f;
+  raw_context.iregs[3] = 0xf62f8ec2;
+  raw_context.iregs[4] = 0x46a6a6a8;
+  raw_context.iregs[5] = 0x6a5025e2;
+  raw_context.iregs[6] = 0xd9fabb4a;
+  raw_context.iregs[7] = 0x6913f540;
+  raw_context.iregs[8] = 0xbffe6eda;
+  raw_context.iregs[9] = 0xb2ce1e2d;
+  raw_context.iregs[10] = 0x659caaa4;
+  raw_context.iregs[11] = 0xf0e0d0c0;
+  raw_context.iregs[12] = 0xa9b8c7d6;
+  raw_context.iregs[13] = 0x12345678;
+  raw_context.iregs[14] = 0xabcd1234;
+  raw_context.iregs[15] = 0x10203040;
+  raw_context.cpsr = 0x2e951ef7;
+  Context context(dump, raw_context);
+
+  Exception exception(dump, context,
+                      0x1234abcd, // thread id
+                      0xdcba4321, // exception code
+                      0xf0e0d0c0, // exception flags
+                      0x0919a9b9c9d9e9f9ULL); // exception address
+  
+  dump.Add(&context);
+  dump.Add(&exception);
+  dump.Finish();
+
+  string contents;
+  ASSERT_TRUE(dump.GetContents(&contents));
+
+  istringstream minidump_stream(contents);
+  Minidump minidump(minidump_stream);
+  ASSERT_TRUE(minidump.Read());
+  ASSERT_EQ(1U, minidump.GetDirectoryEntryCount());
+
+  MinidumpException *md_exception = minidump.GetException();
+  ASSERT_TRUE(md_exception != NULL);
+
+  u_int32_t thread_id;
+  ASSERT_TRUE(md_exception->GetThreadID(&thread_id));
+  ASSERT_EQ(0x1234abcd, thread_id);
+
+  const MDRawExceptionStream* raw_exception = md_exception->exception();
+  ASSERT_TRUE(raw_exception != NULL);
+  EXPECT_EQ(0xdcba4321, raw_exception->exception_record.exception_code);
+  EXPECT_EQ(0xf0e0d0c0, raw_exception->exception_record.exception_flags);
+  EXPECT_EQ(0x0919a9b9c9d9e9f9ULL,
+            raw_exception->exception_record.exception_address);
+
+  MinidumpContext *md_context = md_exception->GetContext();
+  ASSERT_TRUE(md_context != NULL);
+  ASSERT_EQ((u_int32_t) MD_CONTEXT_ARM, md_context->GetContextCPU());
+  const MDRawContextARM *md_raw_context = md_context->GetContextARM();
+  ASSERT_TRUE(md_raw_context != NULL);
+  ASSERT_EQ((u_int32_t) MD_CONTEXT_ARM_INTEGER,
+            (md_raw_context->context_flags
+             & MD_CONTEXT_ARM_INTEGER));
+  EXPECT_EQ(0x3ecba80dU, raw_context.iregs[0]);
+  EXPECT_EQ(0x382583b9U, raw_context.iregs[1]);
+  EXPECT_EQ(0x7fccc03fU, raw_context.iregs[2]);
+  EXPECT_EQ(0xf62f8ec2U, raw_context.iregs[3]);
+  EXPECT_EQ(0x46a6a6a8U, raw_context.iregs[4]);
+  EXPECT_EQ(0x6a5025e2U, raw_context.iregs[5]);
+  EXPECT_EQ(0xd9fabb4aU, raw_context.iregs[6]);
+  EXPECT_EQ(0x6913f540U, raw_context.iregs[7]);
+  EXPECT_EQ(0xbffe6edaU, raw_context.iregs[8]);
+  EXPECT_EQ(0xb2ce1e2dU, raw_context.iregs[9]);
+  EXPECT_EQ(0x659caaa4U, raw_context.iregs[10]);
+  EXPECT_EQ(0xf0e0d0c0U, raw_context.iregs[11]);
+  EXPECT_EQ(0xa9b8c7d6U, raw_context.iregs[12]);
+  EXPECT_EQ(0x12345678U, raw_context.iregs[13]);
+  EXPECT_EQ(0xabcd1234U, raw_context.iregs[14]);
+  EXPECT_EQ(0x10203040U, raw_context.iregs[15]);
+  EXPECT_EQ(0x2e951ef7U, raw_context.cpsr);
+}
+
 }  // namespace
diff --git a/src/processor/synth_minidump.cc b/src/processor/synth_minidump.cc
index cebc0a6a..b207c0d9 100644
--- a/src/processor/synth_minidump.cc
+++ b/src/processor/synth_minidump.cc
@@ -170,6 +170,25 @@ Context::Context(const Dump &dump, const MDRawContextX86 &context)
   assert(Size() == sizeof(MDRawContextX86));
 }
 
+Context::Context(const Dump &dump, const MDRawContextARM &context)
+  : Section(dump) {
+  // The caller should have properly set the CPU type flag.
+  assert((context.context_flags & MD_CONTEXT_ARM) ||
+         (context.context_flags & MD_CONTEXT_ARM_OLD));
+  // It doesn't make sense to store ARM registers in big-endian form.
+  assert(dump.endianness() == kLittleEndian);
+  D32(context.context_flags);
+  for (int i = 0; i < MD_CONTEXT_ARM_GPR_COUNT; ++i)
+    D32(context.iregs[i]);
+  D32(context.cpsr);
+  D64(context.float_save.fpscr);
+  for (int i = 0; i < MD_FLOATINGSAVEAREA_ARM_FPR_COUNT; ++i)
+    D64(context.float_save.regs[i]);
+  for (int i = 0; i < MD_FLOATINGSAVEAREA_ARM_FPEXTRA_COUNT; ++i)
+    D32(context.float_save.extra[i]);
+  assert(Size() == sizeof(MDRawContextARM));
+}
+
 Thread::Thread(const Dump &dump,
                u_int32_t thread_id, const Memory &stack, const Context &context,
                u_int32_t suspend_count, u_int32_t priority_class,
@@ -231,7 +250,28 @@ const MDVSFixedFileInfo Module::stock_version_info = {
   MD_VSFIXEDFILEINFO_FILE_SUBTYPE_UNKNOWN, // file_subtype
   0,                                    // file_date_hi
   0                                     // file_date_lo
-};  
+};
+
+Exception::Exception(const Dump &dump,
+                     const Context &context,
+                     u_int32_t thread_id,
+                     u_int32_t exception_code,
+                     u_int32_t exception_flags,
+                     u_int64_t exception_address)
+  : Stream(dump, MD_EXCEPTION_STREAM) {
+  D32(thread_id);
+  D32(0);  // __align
+  D32(exception_code);
+  D32(exception_flags);
+  D64(0);  // exception_record
+  D64(exception_address);
+  D32(0);  // number_parameters
+  D32(0);  // __align
+  for (int i = 0; i < MD_EXCEPTION_MAXIMUM_PARAMETERS; ++i)
+    D64(0);  // exception_information
+  context.CiteLocationIn(this);
+  assert(Size() == sizeof(MDRawExceptionStream));
+}
 
 Dump::Dump(u_int64_t flags,
            Endianness endianness,
diff --git a/src/processor/synth_minidump.h b/src/processor/synth_minidump.h
index f09a68fc..245afe66 100644
--- a/src/processor/synth_minidump.h
+++ b/src/processor/synth_minidump.h
@@ -196,7 +196,7 @@ class SystemInfo: public Stream {
   static const string windows_x86_csd_version;
 };
 
-// An MDString: a string predeced by a 32-bit length.
+// An MDString: a string preceded by a 32-bit length.
 class String: public Section {
  public:
   String(const Dump &dump, const string &value);
@@ -227,6 +227,7 @@ class Context: public Section {
  public:
   // Create a context belonging to DUMP whose contents are a copy of CONTEXT.
   Context(const Dump &dump, const MDRawContextX86 &context);
+  Context(const Dump &dump, const MDRawContextARM &context);
   // Add constructors for other architectures here. Remember to byteswap.
 };
 
@@ -266,6 +267,16 @@ class Module: public Section {
   static const MDVSFixedFileInfo stock_version_info;
 };
 
+class Exception : public Stream {
+public:
+  Exception(const Dump &dump,
+            const Context &context,
+            u_int32_t thread_id = 0,
+            u_int32_t exception_code = 0,
+            u_int32_t exception_flags = 0,
+            u_int64_t exception_address = 0);
+};
+
 // A list of entries starting with a 32-bit count, like a memory list
 // or a thread list.
 template<typename Element>
diff --git a/src/processor/synth_minidump_unittest.cc b/src/processor/synth_minidump_unittest.cc
index adad4ae8..b5ae3357 100644
--- a/src/processor/synth_minidump_unittest.cc
+++ b/src/processor/synth_minidump_unittest.cc
@@ -42,6 +42,7 @@
 
 using google_breakpad::SynthMinidump::Context;
 using google_breakpad::SynthMinidump::Dump;
+using google_breakpad::SynthMinidump::Exception;
 using google_breakpad::SynthMinidump::List;
 using google_breakpad::SynthMinidump::Memory;
 using google_breakpad::SynthMinidump::Module;
@@ -133,6 +134,17 @@ TEST(Context, X86) {
               == 0);
 }
 
+TEST(Context, ARM) {
+  Dump dump(0, kLittleEndian);
+  assert(arm_raw_context.context_flags & MD_CONTEXT_ARM);
+  Context context(dump, arm_raw_context);
+  string contents;
+  ASSERT_TRUE(context.GetContents(&contents));
+  EXPECT_EQ(sizeof(arm_expected_contents), contents.size());
+  EXPECT_TRUE(memcmp(contents.data(), arm_expected_contents, contents.size())
+              == 0);
+}
+
 TEST(ContextDeathTest, X86BadFlags) {
   Dump dump(0, kLittleEndian);
   MDRawContextX86 raw;
@@ -179,6 +191,49 @@ TEST(Thread, Simple) {
   EXPECT_TRUE(memcmp(contents.data(), expected_bytes, contents.size()) == 0);
 }
 
+TEST(Exception, Simple) {
+  Dump dump(0, kLittleEndian);
+  Context context(dump, x86_raw_context);
+  context.Finish(0x8665da0c);
+  
+  Exception exception(dump, context,
+                      0x1234abcd, // thread id
+                      0xdcba4321, // exception code
+                      0xf0e0d0c0, // exception flags
+                      0x0919a9b9c9d9e9f9ULL); // exception address
+  string contents;
+  ASSERT_TRUE(exception.GetContents(&contents));
+  static const u_int8_t expected_bytes[] = {
+    0xcd, 0xab, 0x34, 0x12, // thread id
+    0x00, 0x00, 0x00, 0x00, // __align
+    0x21, 0x43, 0xba, 0xdc, // exception code
+    0xc0, 0xd0, 0xe0, 0xf0, // exception flags
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception record
+    0xf9, 0xe9, 0xd9, 0xc9, 0xb9, 0xa9, 0x19, 0x09, // exception address
+    0x00, 0x00, 0x00, 0x00, // number parameters
+    0x00, 0x00, 0x00, 0x00, // __align
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exception_information
+    0xcc, 0x02, 0x00, 0x00, // context size
+    0x0c, 0xda, 0x65, 0x86  // context MDRVA
+  };
+  EXPECT_EQ(sizeof(expected_bytes), contents.size());
+  EXPECT_TRUE(memcmp(contents.data(), expected_bytes, contents.size()) == 0);
+}
+
 TEST(String, Simple) {
   Dump dump(0, kBigEndian);
   String s(dump, "All mimsy were the borogoves");
diff --git a/src/processor/synth_minidump_unittest_data.h b/src/processor/synth_minidump_unittest_data.h
index 7036d2cb..f7ff925c 100644
--- a/src/processor/synth_minidump_unittest_data.h
+++ b/src/processor/synth_minidump_unittest_data.h
@@ -43,7 +43,7 @@ static const MDRawContextX86 x86_raw_context = {
 
     0x84c53a90,                         // cr0_npx_state
   },
-    
+
   0x79f71e76,                           // gs
   0x8107bd25,                           // fs
   0x452d2921,                           // es
@@ -131,20 +131,20 @@ static const MDRawContextX86 x86_raw_context = {
 };
 
 static const u_int8_t x86_expected_contents[] = {
-  0x1b, 0xd7, 0xd5, 0xde, 
-  0x2e, 0x43, 0xdb, 0x9f, 
-  0x1a, 0xa8, 0xb7, 0x26, 
-  0x48, 0xe3, 0xc7, 0xca, 
-  0x09, 0xec, 0x99, 0xcf, 
-  0xcd, 0xc2, 0xc8, 0x7d, 
-  0x80, 0xb8, 0xde, 0x21, 
-  0xb0, 0x2b, 0x5d, 0x8a, 
-  0xc9, 0xc4, 0x86, 0x02, 
-  0x21, 0xea, 0xfe, 0xf1, 
-  0x76, 0x05, 0xd4, 0xb2, 
-  0xde, 0x6c, 0x14, 0x48, 
-  0x21, 0x9b, 0x3f, 0x98, 
-  0x2c, 0xe1, 0x5b, 0x47, 
+  0x1b, 0xd7, 0xd5, 0xde,
+  0x2e, 0x43, 0xdb, 0x9f,
+  0x1a, 0xa8, 0xb7, 0x26,
+  0x48, 0xe3, 0xc7, 0xca,
+  0x09, 0xec, 0x99, 0xcf,
+  0xcd, 0xc2, 0xc8, 0x7d,
+  0x80, 0xb8, 0xde, 0x21,
+  0xb0, 0x2b, 0x5d, 0x8a,
+  0xc9, 0xc4, 0x86, 0x02,
+  0x21, 0xea, 0xfe, 0xf1,
+  0x76, 0x05, 0xd4, 0xb2,
+  0xde, 0x6c, 0x14, 0x48,
+  0x21, 0x9b, 0x3f, 0x98,
+  0x2c, 0xe1, 0x5b, 0x47,
 
   // float_save.register_area --- unswapped
   0xd9, 0x04, 0x20, 0x6b, 0x88, 0x3a, 0x3f, 0xd5,
@@ -158,23 +158,23 @@ static const u_int8_t x86_expected_contents[] = {
   0xc7, 0x8d, 0x17, 0xb6, 0xe5, 0x0b, 0x94, 0xf7,
   0x78, 0x9b, 0x63, 0x49, 0xba, 0xfc, 0x08, 0x4d,
 
-  0x90, 0x3a, 0xc5, 0x84, 
-  0x76, 0x1e, 0xf7, 0x79, 
-  0x25, 0xbd, 0x07, 0x81, 
-  0x21, 0x29, 0x2d, 0x45, 
-  0x75, 0x28, 0xec, 0x87, 
-  0xf5, 0x73, 0xbb, 0xf8, 
-  0x88, 0xbb, 0x3e, 0xa6, 
-  0xbe, 0x5e, 0xd3, 0x95, 
-  0x56, 0x24, 0xaa, 0x17, 
-  0x08, 0xa2, 0x5f, 0x13, 
-  0xe6, 0x15, 0x06, 0x50, 
-  0x05, 0x42, 0xd1, 0x66, 
-  0xa5, 0x19, 0x07, 0x00, 
-  0x1b, 0x48, 0x7b, 0x47, 
-  0xba, 0xdf, 0x84, 0x86, 
-  0xdf, 0xcd, 0x3c, 0xe3, 
-  0x33, 0x5d, 0xe6, 0xc0, 
+  0x90, 0x3a, 0xc5, 0x84,
+  0x76, 0x1e, 0xf7, 0x79,
+  0x25, 0xbd, 0x07, 0x81,
+  0x21, 0x29, 0x2d, 0x45,
+  0x75, 0x28, 0xec, 0x87,
+  0xf5, 0x73, 0xbb, 0xf8,
+  0x88, 0xbb, 0x3e, 0xa6,
+  0xbe, 0x5e, 0xd3, 0x95,
+  0x56, 0x24, 0xaa, 0x17,
+  0x08, 0xa2, 0x5f, 0x13,
+  0xe6, 0x15, 0x06, 0x50,
+  0x05, 0x42, 0xd1, 0x66,
+  0xa5, 0x19, 0x07, 0x00,
+  0x1b, 0x48, 0x7b, 0x47,
+  0xba, 0xdf, 0x84, 0x86,
+  0xdf, 0xcd, 0x3c, 0xe3,
+  0x33, 0x5d, 0xe6, 0xc0,
 
   // extended_registers --- unswapped
   0x68, 0x63, 0xdf, 0x50, 0xf7, 0x3b, 0xe8, 0xe5,
@@ -243,4 +243,170 @@ static const u_int8_t x86_expected_contents[] = {
   0xb2, 0xc7, 0x3a, 0x6c, 0x8a, 0x35, 0xe1, 0xba
 };
 
+static const MDRawContextARM arm_raw_context = {
+  // context_flags
+  0x591b9e6a,
+  // iregs
+  0xa21594de,
+  0x820d8a25,
+  0xc4e133b2,
+  0x173a1c02,
+  0x105fb175,
+  0xe871793f,
+  0x5def70b3,
+  0xcee3a623,
+  0x7b3aa9b8,
+  0x52518537,
+  0x627012c5,
+  0x22723dcc,
+  0x16fcc971,
+  0x20988bcb,
+  0xf1ab806b,
+  0x99d5fc03,
+  // cpsr
+  0xb70df511,
+  // float_save
+  {
+    // fpscr
+    0xa1e1f7ce1077e6b5,
+    // regs
+    0xbcb8d002eed7fbde,
+    0x4dd26a43b96ae97f,
+    0x8eec22db8b31741c,
+    0xfd634bd7c5ad66a0,
+    0x1681da0daeb3debe,
+    0x474a32bdf72d0b71,
+    0xcaf464f8b1044834,
+    0xcaa6592ae5c7582a,
+    0x4ee46889d877c3db,
+    0xf8930cf301645cf5,
+    0x4da7e9ebba27f7c7,
+    0x69a7b02761944da3,
+    0x2cda2b2e78195c06,
+    0x66b227ab9b460a42,
+    0x7e77e49e52ee0849,
+    0xd62cd9663e76f255,
+    0xe9370f082451514b,
+    0x50a1c674dd1b6029,
+    0x405db4575829eac4,
+    0x67b948764649eee7,
+    0x93731885419229d4,
+    0xdb0338bad72a4ce7,
+    0xa0a451f996fca4c8,
+    0xb4508ea668400a45,
+    0xbff28c5c7a142423,
+    0x4f31b42b96f3a431,
+    0x2ce6789d4ea1ff37,
+    0xfa150b52e4f82a3c,
+    0xe9ec40449e6ed4f3,
+    0x5ceca87836fe2251,
+    0x66f50de463ee238c,
+    0x42823efcd59ab511,
+    // extra
+    0xe9e14cd2,
+    0x865bb640,
+    0x9f3f0b3e,
+    0x94a71c52,
+    0x3c012f19,
+    0x6436637c,
+    0x46ccedcb,
+    0x7b341be7
+  }
+};
+
+static const u_int8_t arm_expected_contents[] = {
+  0x6a, 0x9e, 0x1b, 0x59,
+  0xde, 0x94, 0x15, 0xa2,
+  0x25, 0x8a, 0x0d, 0x82,
+  0xb2, 0x33, 0xe1, 0xc4,
+  0x02, 0x1c, 0x3a, 0x17,
+  0x75, 0xb1, 0x5f, 0x10,
+  0x3f, 0x79, 0x71, 0xe8,
+  0xb3, 0x70, 0xef, 0x5d,
+  0x23, 0xa6, 0xe3, 0xce,
+  0xb8, 0xa9, 0x3a, 0x7b,
+  0x37, 0x85, 0x51, 0x52,
+  0xc5, 0x12, 0x70, 0x62,
+  0xcc, 0x3d, 0x72, 0x22,
+  0x71, 0xc9, 0xfc, 0x16,
+  0xcb, 0x8b, 0x98, 0x20,
+  0x6b, 0x80, 0xab, 0xf1,
+  0x03, 0xfc, 0xd5, 0x99,
+  0x11, 0xf5, 0x0d, 0xb7,
+  0xb5, 0xe6, 0x77, 0x10,
+  0xce, 0xf7, 0xe1, 0xa1,
+  0xde, 0xfb, 0xd7, 0xee,
+  0x02, 0xd0, 0xb8, 0xbc,
+  0x7f, 0xe9, 0x6a, 0xb9,
+  0x43, 0x6a, 0xd2, 0x4d,
+  0x1c, 0x74, 0x31, 0x8b,
+  0xdb, 0x22, 0xec, 0x8e,
+  0xa0, 0x66, 0xad, 0xc5,
+  0xd7, 0x4b, 0x63, 0xfd,
+  0xbe, 0xde, 0xb3, 0xae,
+  0x0d, 0xda, 0x81, 0x16,
+  0x71, 0x0b, 0x2d, 0xf7,
+  0xbd, 0x32, 0x4a, 0x47,
+  0x34, 0x48, 0x04, 0xb1,
+  0xf8, 0x64, 0xf4, 0xca,
+  0x2a, 0x58, 0xc7, 0xe5,
+  0x2a, 0x59, 0xa6, 0xca,
+  0xdb, 0xc3, 0x77, 0xd8,
+  0x89, 0x68, 0xe4, 0x4e,
+  0xf5, 0x5c, 0x64, 0x01,
+  0xf3, 0x0c, 0x93, 0xf8,
+  0xc7, 0xf7, 0x27, 0xba,
+  0xeb, 0xe9, 0xa7, 0x4d,
+  0xa3, 0x4d, 0x94, 0x61,
+  0x27, 0xb0, 0xa7, 0x69,
+  0x06, 0x5c, 0x19, 0x78,
+  0x2e, 0x2b, 0xda, 0x2c,
+  0x42, 0x0a, 0x46, 0x9b,
+  0xab, 0x27, 0xb2, 0x66,
+  0x49, 0x08, 0xee, 0x52,
+  0x9e, 0xe4, 0x77, 0x7e,
+  0x55, 0xf2, 0x76, 0x3e,
+  0x66, 0xd9, 0x2c, 0xd6,
+  0x4b, 0x51, 0x51, 0x24,
+  0x08, 0x0f, 0x37, 0xe9,
+  0x29, 0x60, 0x1b, 0xdd,
+  0x74, 0xc6, 0xa1, 0x50,
+  0xc4, 0xea, 0x29, 0x58,
+  0x57, 0xb4, 0x5d, 0x40,
+  0xe7, 0xee, 0x49, 0x46,
+  0x76, 0x48, 0xb9, 0x67,
+  0xd4, 0x29, 0x92, 0x41,
+  0x85, 0x18, 0x73, 0x93,
+  0xe7, 0x4c, 0x2a, 0xd7,
+  0xba, 0x38, 0x03, 0xdb,
+  0xc8, 0xa4, 0xfc, 0x96,
+  0xf9, 0x51, 0xa4, 0xa0,
+  0x45, 0x0a, 0x40, 0x68,
+  0xa6, 0x8e, 0x50, 0xb4,
+  0x23, 0x24, 0x14, 0x7a,
+  0x5c, 0x8c, 0xf2, 0xbf,
+  0x31, 0xa4, 0xf3, 0x96,
+  0x2b, 0xb4, 0x31, 0x4f,
+  0x37, 0xff, 0xa1, 0x4e,
+  0x9d, 0x78, 0xe6, 0x2c,
+  0x3c, 0x2a, 0xf8, 0xe4,
+  0x52, 0x0b, 0x15, 0xfa,
+  0xf3, 0xd4, 0x6e, 0x9e,
+  0x44, 0x40, 0xec, 0xe9,
+  0x51, 0x22, 0xfe, 0x36,
+  0x78, 0xa8, 0xec, 0x5c,
+  0x8c, 0x23, 0xee, 0x63,
+  0xe4, 0x0d, 0xf5, 0x66,
+  0x11, 0xb5, 0x9a, 0xd5,
+  0xfc, 0x3e, 0x82, 0x42,
+  0xd2, 0x4c, 0xe1, 0xe9,
+  0x40, 0xb6, 0x5b, 0x86,
+  0x3e, 0x0b, 0x3f, 0x9f,
+  0x52, 0x1c, 0xa7, 0x94,
+  0x19, 0x2f, 0x01, 0x3c,
+  0x7c, 0x63, 0x36, 0x64,
+  0xcb, 0xed, 0xcc, 0x46,
+  0xe7, 0x1b, 0x34, 0x7b
+};
+
 #endif // PROCESSOR_SYNTH_MINIDUMP_UNITTEST_DATA_H_