Use general instruction/stack pointer convenience method instead of manually

src/processor/exploitability_linux.cc

 // Copyright (c) 2013 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
@@ skipping 19 matching lines @@
 // exploitability_linux.cc: Linux specific exploitability engine.
 //
 // Provides a guess at the exploitability of the crash for the Linux
 // platform given a minidump and process_state.
 //
 // Author: Matthew Riley
 
 #include "processor/exploitability_linux.h"
 
 #include "google_breakpad/common/minidump_exception_linux.h"
+#include "google_breakpad/processor/call_stack.h"
 #include "google_breakpad/processor/process_state.h"
-#include "google_breakpad/processor/call_stack.h"
 #include "google_breakpad/processor/stack_frame.h"
 #include "processor/logging.h"
 
 namespace {
 
 // This function in libc is called if the program was compiled with
 // -fstack-protector and a function's stack canary changes.
 const char kStackCheckFailureFunction[] = "__stack_chk_fail";
 
 // This function in libc is called if the program was compiled with
@@ skipping 39 matching lines @@
   if (exception == NULL) {
     BPLOG(INFO) << "No exception record.";
     return EXPLOITABILITY_ERR_PROCESSING;
   }
   const MinidumpContext *context = exception->GetContext();
   if (context == NULL) {
     BPLOG(INFO) << "No exception context.";
     return EXPLOITABILITY_ERR_PROCESSING;
   }
 
-  // Getting instruction pointer based off architecture.
-  uint32_t architecture = context->GetContextCPU();
-  switch (architecture) {
-    case MD_CONTEXT_X86:
-      instruction_ptr = context->GetContextX86()->eip;
-      break;
-    case MD_CONTEXT_AMD64:
-      instruction_ptr = context->GetContextAMD64()->rip;
-      break;
-    case MD_CONTEXT_ARM:
-      instruction_ptr =
-          context->GetContextARM()->iregs[MD_CONTEXT_ARM_REG_PC];
-      break;
-    case MD_CONTEXT_ARM64:
-      instruction_ptr =
-          context->GetContextARM64()->iregs[MD_CONTEXT_ARM64_REG_PC];
-      break;
-    default:
-      BPLOG(INFO) << "Unsupported architecture.";
-      return EXPLOITABILITY_ERR_PROCESSING;
+  // Getting the instruction pointer.
+  if (!context->GetInstructionPointer(&instruction_ptr)) {
+    return EXPLOITABILITY_ERR_PROCESSING;
   }
 
   // Checking for the instruction pointer in a valid instruction region.
   if (!this->InstructionPointerInCode(instruction_ptr)) {
     return EXPLOITABILITY_HIGH;
   }
 
   const MDRawExceptionStream *raw_exception_stream = exception->exception();
   if (raw_exception_stream == NULL) {
     BPLOG(INFO) << "No raw exception stream.";
@@ skipping 67 matching lines @@
     case MD_EXCEPTION_CODE_LIN_DUMP_REQUESTED:
       return true;
       break;
     default:
       return false;
       break;
   }
 }
 
 }  // namespace google_breakpad