Index: asan/asan_internal.h
===================================================================
--- asan/asan_internal.h
+++ asan/asan_internal.h
@@ -62,6 +62,21 @@
 class AsanThread;
 using __sanitizer::StackTrace;
 
+// asan_posix.cc
+struct SignalContext {
+  void *context;
+  uptr addr;
+  uptr pc;
+  uptr sp;
+  uptr bp;
+
+  explicit SignalContext(void *context_, uptr addr_) {
+    internal_memset(this, 0, sizeof(SignalContext));
+    context = context_;
+    addr = addr_;
+  }
+};
+
 void AsanInitFromRtl();
 
 // asan_rtl.cc
@@ -75,7 +90,7 @@
 void AsanCheckDynamicRTPrereqs();
 void AsanCheckIncompatibleRT();
 
-void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp);
+void GetPcSpBp(struct SignalContext *sig);
 void AsanOnSIGSEGV(int, void *siginfo, void *context);
 
 void MaybeReexec();
Index: asan/asan_linux.cc
===================================================================
--- asan/asan_linux.cc
+++ asan/asan_linux.cc
@@ -148,73 +148,73 @@
 }
 #endif  // SANITIZER_ANDROID
 
-void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
+void GetPcSpBp(struct SignalContext *sig) {
 #if defined(__arm__)
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.arm_pc;
-  *bp = ucontext->uc_mcontext.arm_fp;
-  *sp = ucontext->uc_mcontext.arm_sp;
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.arm_pc;
+  sig->bp = ucontext->uc_mcontext.arm_fp;
+  sig->sp = ucontext->uc_mcontext.arm_sp;
 #elif defined(__aarch64__)
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.pc;
-  *bp = ucontext->uc_mcontext.regs[29];
-  *sp = ucontext->uc_mcontext.sp;
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.pc;
+  sig->bp = ucontext->uc_mcontext.regs[29];
+  sig->sp = ucontext->uc_mcontext.sp;
 #elif defined(__hppa__)
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.sc_iaoq[0];
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.sc_iaoq[0];
   /* GCC uses %r3 whenever a frame pointer is needed.  */
-  *bp = ucontext->uc_mcontext.sc_gr[3];
-  *sp = ucontext->uc_mcontext.sc_gr[30];
+  sig->bp = ucontext->uc_mcontext.sc_gr[3];
+  sig->sp = ucontext->uc_mcontext.sc_gr[30];
 #elif defined(__x86_64__)
 # if SANITIZER_FREEBSD
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.mc_rip;
-  *bp = ucontext->uc_mcontext.mc_rbp;
-  *sp = ucontext->uc_mcontext.mc_rsp;
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.mc_rip;
+  sig->bp = ucontext->uc_mcontext.mc_rbp;
+  sig->sp = ucontext->uc_mcontext.mc_rsp;
 # else
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.gregs[REG_RIP];
-  *bp = ucontext->uc_mcontext.gregs[REG_RBP];
-  *sp = ucontext->uc_mcontext.gregs[REG_RSP];
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.gregs[REG_RIP];
+  sig->bp = ucontext->uc_mcontext.gregs[REG_RBP];
+  sig->sp = ucontext->uc_mcontext.gregs[REG_RSP];
 # endif
 #elif defined(__i386__)
 # if SANITIZER_FREEBSD
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.mc_eip;
-  *bp = ucontext->uc_mcontext.mc_ebp;
-  *sp = ucontext->uc_mcontext.mc_esp;
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.mc_eip;
+  sig->bp = ucontext->uc_mcontext.mc_ebp;
+  sig->sp = ucontext->uc_mcontext.mc_esp;
 # else
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.gregs[REG_EIP];
-  *bp = ucontext->uc_mcontext.gregs[REG_EBP];
-  *sp = ucontext->uc_mcontext.gregs[REG_ESP];
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.gregs[REG_EIP];
+  sig->bp = ucontext->uc_mcontext.gregs[REG_EBP];
+  sig->sp = ucontext->uc_mcontext.gregs[REG_ESP];
 # endif
 #elif defined(__powerpc__) || defined(__powerpc64__)
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.regs->nip;
-  *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.regs->nip;
+  sig->sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
   // The powerpc{,64}-linux ABIs do not specify r31 as the frame
   // pointer, but GCC always uses r31 when we need a frame pointer.
-  *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
+  sig->bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
 #elif defined(__sparc__)
-  ucontext_t *ucontext = (ucontext_t*)context;
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
   uptr *stk_ptr;
 # if defined (__arch64__)
-  *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
-  *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
-  stk_ptr = (uptr *) (*sp + 2047);
-  *bp = stk_ptr[15];
+  sig->pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
+  sig->sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
+  stk_ptr = (uptr *) (sig->sp + 2047);
+  sig->bp = stk_ptr[15];
 # else
-  *pc = ucontext->uc_mcontext.gregs[REG_PC];
-  *sp = ucontext->uc_mcontext.gregs[REG_O6];
-  stk_ptr = (uptr *) *sp;
-  *bp = stk_ptr[15];
+  sig->pc = ucontext->uc_mcontext.gregs[REG_PC];
+  sig->sp = ucontext->uc_mcontext.gregs[REG_O6];
+  stk_ptr = (uptr *) sig->sp;
+  sig->bp = stk_ptr[15];
 # endif
 #elif defined(__mips__)
-  ucontext_t *ucontext = (ucontext_t*)context;
-  *pc = ucontext->uc_mcontext.gregs[31];
-  *bp = ucontext->uc_mcontext.gregs[30];
-  *sp = ucontext->uc_mcontext.gregs[29];
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
+  sig->pc = ucontext->uc_mcontext.gregs[31];
+  sig->bp = ucontext->uc_mcontext.gregs[30];
+  sig->sp = ucontext->uc_mcontext.gregs[29];
 #else
 # error "Unsupported arch"
 #endif
Index: asan/asan_mac.cc
===================================================================
--- asan/asan_mac.cc
+++ asan/asan_mac.cc
@@ -40,20 +40,19 @@
 
 namespace __asan {
 
-void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
-  ucontext_t *ucontext = (ucontext_t*)context;
+void GetPcSpBp(struct SignalContext *sig) {
+  ucontext_t *ucontext = (ucontext_t*)sig->context;
 # if SANITIZER_WORDSIZE == 64
-  *pc = ucontext->uc_mcontext->__ss.__rip;
-  *bp = ucontext->uc_mcontext->__ss.__rbp;
-  *sp = ucontext->uc_mcontext->__ss.__rsp;
+  sig->pc = ucontext->uc_mcontext->__ss.__rip;
+  sig->bp = ucontext->uc_mcontext->__ss.__rbp;
+  sig->sp = ucontext->uc_mcontext->__ss.__rsp;
 # else
-  *pc = ucontext->uc_mcontext->__ss.__eip;
-  *bp = ucontext->uc_mcontext->__ss.__ebp;
-  *sp = ucontext->uc_mcontext->__ss.__esp;
+  sig->pc = ucontext->uc_mcontext->__ss.__eip;
+  sig->bp = ucontext->uc_mcontext->__ss.__ebp;
+  sig->sp = ucontext->uc_mcontext->__ss.__esp;
 # endif  // SANITIZER_WORDSIZE
 }
 
-
 bool PlatformHasDifferentMemcpyAndMemmove() {
   // On OS X 10.7 memcpy() and memmove() are both resolved
   // into memmove$VARIANT$sse42.
Index: asan/asan_posix.cc
===================================================================
--- asan/asan_posix.cc
+++ asan/asan_posix.cc
@@ -37,8 +37,8 @@
   int code = (int)((siginfo_t*)siginfo)->si_code;
   // Write the first message using the bullet-proof write.
   if (13 != internal_write(2, "ASAN:SIGSEGV\n", 13)) Die();
-  uptr pc, sp, bp;
-  GetPcSpBp(context, &pc, &sp, &bp);
+  struct SignalContext sig(context, addr);
+  GetPcSpBp(&sig);
 
   // Access at a reasonable offset above SP, or slightly below it (to account
   // for x86_64 redzone, ARM push of multiple registers, etc) is probably a
@@ -46,11 +46,11 @@
   // We also check si_code to filter out SEGV caused by something else other
   // then hitting the guard page or unmapped memory, like, for example,
   // unaligned memory access.
-  if (addr + 128 > sp && addr < sp + 0xFFFF &&
+  if (addr + 128 > sig.sp && addr < sig.sp + 0xFFFF &&
       (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR))
-    ReportStackOverflow(pc, sp, bp, context, addr);
+    ReportStackOverflow(&sig);
   else
-    ReportSIGSEGV("SEGV", pc, sp, bp, context, addr);
+    ReportSIGSEGV("SEGV", &sig);
 }
 
 // ---------------------- TSD ---------------- {{{1
Index: asan/asan_report.h
===================================================================
--- asan/asan_report.h
+++ asan/asan_report.h
@@ -52,10 +52,8 @@
 void DescribeThread(AsanThreadContext *context);
 
 // Different kinds of error reports.
-void NORETURN
-    ReportStackOverflow(uptr pc, uptr sp, uptr bp, void *context, uptr addr);
-void NORETURN ReportSIGSEGV(const char *description, uptr pc, uptr sp, uptr bp,
-                            void *context, uptr addr);
+void NORETURN ReportStackOverflow(struct SignalContext *sig);
+void NORETURN ReportSIGSEGV(const char *description, struct SignalContext *sig);
 void NORETURN ReportNewDeleteSizeMismatch(uptr addr, uptr delete_size,
                                           BufferedStackTrace *free_stack);
 void NORETURN ReportDoubleFree(uptr addr, BufferedStackTrace *free_stack);
Index: asan/asan_report.cc
===================================================================
--- asan/asan_report.cc
+++ asan/asan_report.cc
@@ -643,38 +643,37 @@
   }
 };
 
-void ReportStackOverflow(uptr pc, uptr sp, uptr bp, void *context, uptr addr) {
+void ReportStackOverflow(struct SignalContext *sig) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());
   Report(
       "ERROR: AddressSanitizer: stack-overflow on address %p"
       " (pc %p bp %p sp %p T%d)\n",
-      (void *)addr, (void *)pc, (void *)bp, (void *)sp,
+      (void *)sig->addr, (void *)sig->pc, (void *)sig->bp, (void *)sig->sp,
       GetCurrentTidOrInvalid());
   Printf("%s", d.EndWarning());
-  GET_STACK_TRACE_SIGNAL(pc, bp, context);
+  GET_STACK_TRACE_SIGNAL(sig);
   stack.Print();
   ReportErrorSummary("stack-overflow", &stack);
 }
 
-void ReportSIGSEGV(const char *description, uptr pc, uptr sp, uptr bp,
-                   void *context, uptr addr) {
+void ReportSIGSEGV(const char *description, struct SignalContext *sig) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());
   Report(
       "ERROR: AddressSanitizer: %s on unknown address %p"
       " (pc %p bp %p sp %p T%d)\n",
-      description, (void *)addr, (void *)pc, (void *)bp, (void *)sp,
-      GetCurrentTidOrInvalid());
-  if (pc < GetPageSizeCached()) {
+      description, (void *)sig->addr, (void *)sig->pc, (void *)sig->bp,
+      (void *)sig->sp, GetCurrentTidOrInvalid());
+  if (sig->pc < GetPageSizeCached()) {
     Report("Hint: pc points to the zero page.\n");
   }
   Printf("%s", d.EndWarning());
-  GET_STACK_TRACE_SIGNAL(pc, bp, context);
+  GET_STACK_TRACE_SIGNAL(sig);
   stack.Print();
-  MaybeDumpInstructionBytes(pc);
+  MaybeDumpInstructionBytes(sig->pc);
   Printf("AddressSanitizer can not provide additional info.\n");
   ReportErrorSummary("SEGV", &stack);
 }
Index: asan/asan_stack.h
===================================================================
--- asan/asan_stack.h
+++ asan/asan_stack.h
@@ -74,9 +74,10 @@
   GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, 0,           \
                                   common_flags()->fast_unwind_on_fatal)
 
-#define GET_STACK_TRACE_SIGNAL(pc, bp, context)                                \
+#define GET_STACK_TRACE_SIGNAL(sig)                                            \
   BufferedStackTrace stack;                                                    \
-  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, context,     \
+  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax,                      \
+                                  sig->pc, sig->bp, sig->context,              \
                                   common_flags()->fast_unwind_on_fatal)
 
 #define GET_STACK_TRACE_FATAL_HERE                                \
Index: asan/asan_win.cc
===================================================================
--- asan/asan_win.cc
+++ asan/asan_win.cc
@@ -106,7 +106,11 @@
             ? "access-violation"
             : "in-page-error";
     uptr access_addr = exception_record->ExceptionInformation[1];
-    ReportSIGSEGV(description, pc, sp, bp, context, access_addr);
+    struct SignalContext sig(context, access_addr);
+    sig.pc = pc;
+    sig.sp = sp;
+    sig.bp = bp;
+    ReportSIGSEGV(description, &sig);
   }
 
   // FIXME: Handle EXCEPTION_STACK_OVERFLOW here.