[ASan] Add SIGFPE by default as deadly signal

[skomski]

Summary

Adds the flag handle_sigfpe that is default true to handle SIGFPE crashes same as SIGSEV crashes

https://groups.google.com/forum/#!topic/llvm-dev/4EMk1qijC84

[kcc]

Looks almost good!
May I ask you to add a lit-style test, probably similar to projects/compiler-rt/test/sanitizer_common/TestCases/Linux/assert.cc?

lib/asan/tests/asan_test.cc

262

Just in case, I would use volatile instead of attribute((optnone)
e.g.
volatile int one = 1;
volatile int zero = 0;
volatile int sink;
sink = one/zero

[skomski]

Added and fixed lit test

[kcc]

LGTM
Thanks!

[kcc]

r244136.

lib/asan/asan_internal.h

 void AsanCheckDynamicRTPrereqs();
 void AsanCheckIncompatibleRT();
 
-void AsanOnSIGSEGV(int, void *siginfo, void *context);
+void AsanOnDeadlySignal(int, void *siginfo, void *context);
 
 void DisableReexec();
 void MaybeReexec();

lib/asan/asan_posix.cc

 
 namespace __asan {
 
-void AsanOnSIGSEGV(int, void *siginfo, void *context) {
+void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   ScopedDeadlySignal signal_scope(GetCurrentThread());
   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();
+  if (18 != internal_write(2, "ASAN:DEADLYSIGNAL\n", 18)) Die();
   SignalContext sig = SignalContext::Create(siginfo, context);
 
   // Access at a reasonable offset above SP, or slightly below it (to account

   // unaligned memory access.
   if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR))
     ReportStackOverflow(sig);
+  else if (signo == SIGFPE)
+    ReportDeadlySignal("FPE", sig);
   else
-    ReportSIGSEGV("SEGV", sig);
+    ReportDeadlySignal("SEGV", sig);
 }
 
 // ---------------------- TSD ---------------- {{{1

lib/asan/asan_report.h

 
 // Different kinds of error reports.
 void NORETURN ReportStackOverflow(const SignalContext &sig);
-void NORETURN ReportSIGSEGV(const char *description, const SignalContext &sig);
+void NORETURN ReportDeadlySignal(const char* description,
+                                 const SignalContext &sig);
 void NORETURN ReportNewDeleteSizeMismatch(uptr addr, uptr delete_size,
                                           BufferedStackTrace *free_stack);
 void NORETURN ReportDoubleFree(uptr addr, BufferedStackTrace *free_stack);

lib/asan/asan_report.cc

   ReportErrorSummary("stack-overflow", &stack);
 }
 
-void ReportSIGSEGV(const char *description, const SignalContext &sig) {
+void ReportDeadlySignal(const char *description, const SignalContext &sig) {
   ScopedInErrorReport in_report;
   Decorator d;
   Printf("%s", d.Warning());

   stack.Print();
   MaybeDumpInstructionBytes(sig.pc);
   Printf("AddressSanitizer can not provide additional info.\n");
-  ReportErrorSummary("SEGV", &stack);
+  ReportErrorSummary(description, &stack);
 }
 
 void ReportDoubleFree(uptr addr, BufferedStackTrace *free_stack) {

lib/asan/asan_rtl.cc

   }
 
   AsanTSDInit(PlatformTSDDtor);
-  InstallDeadlySignalHandlers(AsanOnSIGSEGV);
+  InstallDeadlySignalHandlers(AsanOnDeadlySignal);
 
   AllocatorOptions allocator_options;
   allocator_options.SetFrom(flags(), common_flags());

lib/asan/asan_win.cc

   UNIMPLEMENTED();
 }
 
-void AsanOnSIGSEGV(int, void *siginfo, void *context) {
+void AsanOnDeadlySignal(int, void *siginfo, void *context) {
   UNIMPLEMENTED();
 }
 

             ? "access-violation"
             : "in-page-error";
     SignalContext sig = SignalContext::Create(exception_record, context);
-    ReportSIGSEGV(description, sig);
+    ReportDeadlySignal(description, sig);
   }
 
   // FIXME: Handle EXCEPTION_STACK_OVERFLOW here.

lib/asan/tests/asan_test.cc

 #if ASAN_NEEDS_SEGV
 namespace {
 
-const char kUnknownCrash[] = "AddressSanitizer: SEGV on unknown address";
+const char kSEGVCrash[] = "AddressSanitizer: SEGV on unknown address";
+const char kFPECrash[] = "AddressSanitizer: FPE on unknown address";
 const char kOverriddenHandler[] = "ASan signal handler has been overridden\n";
 
 TEST(AddressSanitizer, WildAddressTest) {
   char *c = (char*)0x123;
-  EXPECT_DEATH(*c = 0, kUnknownCrash);
+  EXPECT_DEATH(*c = 0, kSEGVCrash);
+}
+
+void division_by_zero() {
+  volatile int one = 1;
+  volatile int zero = 0;
+  volatile int sink;
+  sink = one / zero;
+}
+
+TEST(AddressSanitizer, FPECrashTest) {
+  EXPECT_DEATH(division_by_zero(), kFPECrash);
 }
 
 void my_sigaction_sighandler(int, siginfo_t*, void*) {

   EXPECT_EQ(0, sigaction(SIGBUS, &sigact, 0));
 #endif
   char *c = (char*)0x123;
-  EXPECT_DEATH(*c = 0, kUnknownCrash);
+  EXPECT_DEATH(*c = 0, kSEGVCrash);
   // ... and signal().
   EXPECT_EQ(0, signal(SIGSEGV, my_signal_sighandler));
-  EXPECT_DEATH(*c = 0, kUnknownCrash);
+  EXPECT_DEATH(*c = 0, kSEGVCrash);
 }
 }  // namespace
 #endif

lib/sanitizer_common/sanitizer_flags.inc

             "If set, registers the tool's custom SIGSEGV/SIGBUS handler.")
 COMMON_FLAG(bool, handle_abort, false,
             "If set, registers the tool's custom SIGABRT handler.")
+COMMON_FLAG(bool, handle_sigfpe, true,
+            "If set, registers the tool's custom SIGFPE handler.")
 COMMON_FLAG(bool, allow_user_segv_handler, false,
             "If set, allows user to register a SEGV handler even if the tool "
             "registers one.")

lib/sanitizer_common/sanitizer_linux.cc

 bool IsDeadlySignal(int signum) {
   if (common_flags()->handle_abort && signum == SIGABRT)
     return true;
+  if (common_flags()->handle_sigfpe && signum == SIGFPE)
+    return true;
   return (signum == SIGSEGV || signum == SIGBUS) && common_flags()->handle_segv;
 }
 

lib/sanitizer_common/sanitizer_posix_libcdep.cc

   MaybeInstallSigaction(SIGSEGV, handler);
   MaybeInstallSigaction(SIGBUS, handler);
   MaybeInstallSigaction(SIGABRT, handler);
+  MaybeInstallSigaction(SIGFPE, handler);
 }
 #endif  // SANITIZER_GO
 

test/asan/TestCases/Posix/allow_user_segv.cc

 
 // CHECK: User sigaction installed
 // CHECK-NEXT: User sigaction called
-// CHECK-NEXT: ASAN:SIGSEGV
+// CHECK-NEXT: ASAN:DEADLYSIGNAL
 // CHECK: AddressSanitizer: SEGV on unknown address

test/sanitizer_common/TestCases/Linux/fpe.cc

+// Test the handle_sigfpe option.
+// RUN: %clang %s -o %t
+// RUN:                               not         %run %t 2>&1 | FileCheck --check-prefix=CHECK1 %s
+// RUN: %tool_options=handle_sigfpe=0 not --crash %run %t 2>&1 | FileCheck --check-prefix=CHECK0 %s
+// RUN: %tool_options=handle_sigfpe=1 not         %run %t 2>&1 | FileCheck --check-prefix=CHECK1 %s
+// FIXME: implement in other sanitizers, not just asan.
+// XFAIL: msan
+// XFAIL: lsan
+// XFAIL: tsan
+#include <assert.h>
+#include <stdio.h>
+#include <sanitizer/asan_interface.h>
+
+void death() {
+  fprintf(stderr, "DEATH CALLBACK\n");
+}
+
+int main(int argc, char **argv) {
+  __sanitizer_set_death_callback(death);
+  volatile int one = 1;
+  volatile int zero = 0;
+  volatile int sink;
+  sink = one / zero;
+}
+// CHECK1: ERROR: {{.*}}Sanitizer:
+// CHECK1: DEATH CALLBACK
+// CHECK0-NOT: Sanitizer