Bug 942290 - Merge ARM exidx info with DWARF if both are present. r=ted

toolkit/crashreporter/breakpad-patches/19-bug942290-breakpad-exidx-merge.patch

@@ -0,0 +1,93 @@
+commit 8885dea3716170ec7f3b213421c330f31cd5ac4b
+Author: Jed Davis <jld@mozilla.com>
+Date:   Mon May 19 15:41:28 2014 -0700
+
+    Bug 942290: Merge ARM exidx info with DWARF if both are present.
+
+diff --git a/toolkit/crashreporter/google-breakpad/src/common/arm_ex_reader.cc b/toolkit/crashreporter/google-breakpad/src/common/arm_ex_reader.cc
+index 5d87ab4..97f99e4 100644
+--- a/toolkit/crashreporter/google-breakpad/src/common/arm_ex_reader.cc
++++ b/toolkit/crashreporter/google-breakpad/src/common/arm_ex_reader.cc
+@@ -487,14 +487,16 @@ void ExceptionTableInfo::Start()
+     // create CFI entries that Breakpad can use.  This can also fail.
+     // First, add a new stack frame entry, into which ExtabEntryDecode
+     // will write the CFI entries.
+-    handler_->AddStackFrame(addr, next_addr - addr);
+-    int ret = ExtabEntryDecode(buf, buf_used);
+-    if (ret < 0) {
+-      handler_->DeleteStackFrame();
+-      BPLOG(INFO) << "ExtabEntryDecode: failed with error code: " << ret;
+-      continue;
++    if (!handler_->HasStackFrame(addr, next_addr - addr)) {
++      handler_->AddStackFrame(addr, next_addr - addr);
++      int ret = ExtabEntryDecode(buf, buf_used);
++      if (ret < 0) {
++	handler_->DeleteStackFrame();
++	BPLOG(INFO) << "ExtabEntryDecode: failed with error code: " << ret;
++	continue;
++      }
++      handler_->SubmitStackFrame();
+     }
+-    handler_->SubmitStackFrame();
+ 
+   } /* iterating over .exidx */
+ }
+diff --git a/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.cc b/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.cc
+index f8535b7..b5e3b06 100644
+--- a/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.cc
++++ b/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.cc
+@@ -162,6 +162,21 @@ int ARMExToModule::TranslateCmd(const struct extab_data* edata,
+   return ret;
+ }
+ 
++bool ARMExToModule::HasStackFrame(uintptr_t addr, size_t size) {
++  // Invariant: the range [addr,covered) is covered by existing stack
++  // frame entries.
++  uintptr_t covered = addr;
++  while (covered < addr + size) {
++    const Module::StackFrameEntry *old_entry =
++      module_->FindStackFrameEntryByAddress(covered);
++    if (!old_entry) {
++      return false;
++    }
++    covered = old_entry->address + old_entry->size;
++  }
++  return true;
++}
++
+ void ARMExToModule::AddStackFrame(uintptr_t addr, size_t size) {
+   stack_frame_entry_ = new Module::StackFrameEntry;
+   stack_frame_entry_->address = addr;
+diff --git a/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.h b/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.h
+index 73c936c..9d6a879 100644
+--- a/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.h
++++ b/toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.h
+@@ -108,6 +108,7 @@ class ARMExToModule {
+   ARMExToModule(Module* module)
+       : module_(module) { }
+   ~ARMExToModule() { }
++  bool HasStackFrame(uintptr_t addr, size_t size);
+   void AddStackFrame(uintptr_t addr, size_t size);
+   int ImproveStackFrame(const struct extab_data* edata);
+   void DeleteStackFrame();
+diff --git a/toolkit/crashreporter/google-breakpad/src/common/linux/dump_symbols.cc b/toolkit/crashreporter/google-breakpad/src/common/linux/dump_symbols.cc
+index d59832c..9a54bab 100644
+--- a/toolkit/crashreporter/google-breakpad/src/common/linux/dump_symbols.cc
++++ b/toolkit/crashreporter/google-breakpad/src/common/linux/dump_symbols.cc
+@@ -695,10 +695,12 @@ bool LoadSymbols(const string& obj_file,
+       FindElfSectionByName<ElfClass>(".ARM.extab", SHT_PROGBITS,
+                                      sections, names, names_end,
+                                      elf_header->e_shnum);
+-  // Only load information from this section if there isn't a .debug_info
+-  // section.
+-  if (!found_debug_info_section
+-      && arm_exidx_section && arm_extab_section && symbol_data != NO_CFI) {
++  // Load information from these sections even if there is
++  // .debug_info, because some functions (e.g., hand-written or
++  // script-generated assembly) could have exidx entries but no DWARF.
++  // (For functions with both, the DWARF info that has already been
++  // parsed will take precedence.)
++  if (arm_exidx_section && arm_extab_section && symbol_data != NO_CFI) {
+     info->LoadedSection(".ARM.exidx");
+     info->LoadedSection(".ARM.extab");
+     bool result = LoadARMexidx<ElfClass>(elf_header,

toolkit/crashreporter/google-breakpad/src/common/arm_ex_reader.cc

@@ -487,14 +487,16 @@ void ExceptionTableInfo::Start()
     // create CFI entries that Breakpad can use.  This can also fail.
     // First, add a new stack frame entry, into which ExtabEntryDecode
     // will write the CFI entries.
-    handler_->AddStackFrame(addr, next_addr - addr);
-    int ret = ExtabEntryDecode(buf, buf_used);
-    if (ret < 0) {
-      handler_->DeleteStackFrame();
-      BPLOG(INFO) << "ExtabEntryDecode: failed with error code: " << ret;
-      continue;
+    if (!handler_->HasStackFrame(addr, next_addr - addr)) {
+      handler_->AddStackFrame(addr, next_addr - addr);
+      int ret = ExtabEntryDecode(buf, buf_used);
+      if (ret < 0) {
+	handler_->DeleteStackFrame();
+	BPLOG(INFO) << "ExtabEntryDecode: failed with error code: " << ret;
+	continue;
+      }
+      handler_->SubmitStackFrame();
     }
-    handler_->SubmitStackFrame();
 
   } /* iterating over .exidx */
 }

toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.cc

@@ -162,6 +162,21 @@ int ARMExToModule::TranslateCmd(const struct extab_data* edata,
   return ret;
 }
 
+bool ARMExToModule::HasStackFrame(uintptr_t addr, size_t size) {
+  // Invariant: the range [addr,covered) is covered by existing stack
+  // frame entries.
+  uintptr_t covered = addr;
+  while (covered < addr + size) {
+    const Module::StackFrameEntry *old_entry =
+      module_->FindStackFrameEntryByAddress(covered);
+    if (!old_entry) {
+      return false;
+    }
+    covered = old_entry->address + old_entry->size;
+  }
+  return true;
+}
+
 void ARMExToModule::AddStackFrame(uintptr_t addr, size_t size) {
   stack_frame_entry_ = new Module::StackFrameEntry;
   stack_frame_entry_->address = addr;

toolkit/crashreporter/google-breakpad/src/common/arm_ex_to_module.h

@@ -108,6 +108,7 @@ class ARMExToModule {
   ARMExToModule(Module* module)
       : module_(module) { }
   ~ARMExToModule() { }
+  bool HasStackFrame(uintptr_t addr, size_t size);
   void AddStackFrame(uintptr_t addr, size_t size);
   int ImproveStackFrame(const struct extab_data* edata);
   void DeleteStackFrame();

toolkit/crashreporter/google-breakpad/src/common/linux/dump_symbols.cc

@@ -695,10 +695,12 @@ bool LoadSymbols(const string& obj_file,
       FindElfSectionByName<ElfClass>(".ARM.extab", SHT_PROGBITS,
                                      sections, names, names_end,
                                      elf_header->e_shnum);
-  // Only load information from this section if there isn't a .debug_info
-  // section.
-  if (!found_debug_info_section
-      && arm_exidx_section && arm_extab_section && symbol_data != NO_CFI) {
+  // Load information from these sections even if there is
+  // .debug_info, because some functions (e.g., hand-written or
+  // script-generated assembly) could have exidx entries but no DWARF.
+  // (For functions with both, the DWARF info that has already been
+  // parsed will take precedence.)
+  if (arm_exidx_section && arm_extab_section && symbol_data != NO_CFI) {
     info->LoadedSection(".ARM.exidx");
     info->LoadedSection(".ARM.extab");
     bool result = LoadARMexidx<ElfClass>(elf_header,