[ASan] Move the SIGSEGV/SIGBUS handling to sanitizer_common

This change is a part of refactoring intended to have common signal handling behavior in all tools.
This particular CL moves InstallSignalHandlers() into sanitizer_common (making it InstallDeadlySignalHandlers()), but doesn't enable default signal handlers for any tool other than ASan.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@200542 91177308-0d34-0410-b5e6-96231b3b80d8

12 files changed, 77 insertions, 31 deletions

diff --git a/lib/asan/asan_interceptors.cc b/lib/asan/asan_interceptors.cc
index c63de35c3..f5efbd3f6 100644
--- a/lib/asan/asan_interceptors.cc
+++ b/lib/asan/asan_interceptors.cc
@@ -202,6 +202,13 @@ INTERCEPTOR(int, sigaction, int signum, const struct sigaction *act,
   }
   return 0;
 }
+
+extern "C"
+int __sanitizer_sigaction_f(int signum, const void *act, void *oldact) {
+  return REAL(sigaction)(signum,
+                         (struct sigaction *)act, (struct sigaction *)oldact);
+}
+
 #elif SANITIZER_POSIX
 // We need to have defined REAL(sigaction) on posix systems.
 DEFINE_REAL(int, sigaction, int signum, const struct sigaction *act,
diff --git a/lib/asan/asan_internal.h b/lib/asan/asan_internal.h
index f0c9a49a6..3914fbbd1 100644
--- a/lib/asan/asan_internal.h
+++ b/lib/asan/asan_internal.h
@@ -71,10 +71,10 @@ void ReplaceSystemMalloc();
 void *AsanDoesNotSupportStaticLinkage();
 
 void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp);
+void AsanOnSIGSEGV(int, void *siginfo, void *context);
 
 void MaybeReexec();
 bool AsanInterceptsSignal(int signum);
-void InstallSignalHandlers();
 void ReadContextStack(void *context, uptr *stack, uptr *ssize);
 void AsanPlatformThreadInit();
 void StopInitOrderChecking();
diff --git a/lib/asan/asan_posix.cc b/lib/asan/asan_posix.cc
index 9a306309a..d4bf84f8e 100644
--- a/lib/asan/asan_posix.cc
+++ b/lib/asan/asan_posix.cc
@@ -32,21 +32,8 @@
 
 namespace __asan {
 
-static void MaybeInstallSigaction(int signum,
-                                  void (*handler)(int, siginfo_t *, void *)) {
-  if (!AsanInterceptsSignal(signum))
-    return;
-  struct sigaction sigact;
-  REAL(memset)(&sigact, 0, sizeof(sigact));
-  sigact.sa_sigaction = handler;
-  sigact.sa_flags = SA_SIGINFO;
-  if (common_flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
-  CHECK_EQ(0, REAL(sigaction)(signum, &sigact, 0));
-  VReport(1, "Installed the sigaction for signal %d\n", signum);
-}
-
-static void     ASAN_OnSIGSEGV(int, siginfo_t *siginfo, void *context) {
-  uptr addr = (uptr)siginfo->si_addr;
+void AsanOnSIGSEGV(int, void *siginfo, void *context) {
+  uptr addr = (uptr)((siginfo_t*)siginfo)->si_addr;
   // Write the first message using the bullet-proof write.
   if (13 != internal_write(2, "ASAN:SIGSEGV\n", 13)) Die();
   uptr pc, sp, bp;
@@ -54,15 +41,6 @@ static void     ASAN_OnSIGSEGV(int, siginfo_t *siginfo, void *context) {
   ReportSIGSEGV(pc, sp, bp, addr);
 }
 
-void InstallSignalHandlers() {
-  // Set the alternate signal stack for the main thread.
-  // This will cause SetAlternateSignalStack to be called twice, but the stack
-  // will be actually set only once.
-  if (common_flags()->use_sigaltstack) SetAlternateSignalStack();
-  MaybeInstallSigaction(SIGSEGV, ASAN_OnSIGSEGV);
-  MaybeInstallSigaction(SIGBUS, ASAN_OnSIGSEGV);
-}
-
 // ---------------------- TSD ---------------- {{{1
 
 static pthread_key_t tsd_key;
diff --git a/lib/asan/asan_rtl.cc b/lib/asan/asan_rtl.cc
index 3d8ed9f84..2a97ed595 100644
--- a/lib/asan/asan_rtl.cc
+++ b/lib/asan/asan_rtl.cc
@@ -486,7 +486,7 @@ static void AsanInitInternal() {
   }
 
   AsanTSDInit(PlatformTSDDtor);
-  InstallSignalHandlers();
+  InstallDeadlySignalHandlers(AsanOnSIGSEGV);
 
   // Allocator should be initialized before starting external symbolizer, as
   // fork() on Mac locks the allocator.
diff --git a/lib/asan/asan_win.cc b/lib/asan/asan_win.cc
index f06e74030..80d70b9c0 100644
--- a/lib/asan/asan_win.cc
+++ b/lib/asan/asan_win.cc
@@ -70,10 +70,6 @@ void *AsanDoesNotSupportStaticLinkage() {
   return 0;
 }
 
-void InstallSignalHandlers() {
-  // FIXME: Decide what to do on Windows.
-}
-
 void AsanPlatformThreadInit() {
   // Nothing here for now.
 }
diff --git a/lib/sanitizer_common/sanitizer_common.h b/lib/sanitizer_common/sanitizer_common.h
index 1398f75a6..a5c8df0c3 100644
--- a/lib/sanitizer_common/sanitizer_common.h
+++ b/lib/sanitizer_common/sanitizer_common.h
@@ -214,6 +214,10 @@ typedef void (*CheckFailedCallbackType)(const char *, int, const char *,
 void SetCheckFailedCallback(CheckFailedCallbackType callback);
 
 // Functions related to signal handling.
+typedef void (*SignalHandlerType)(int, void *, void *);
+bool IsDeadlySignal(int signum);
+void InstallDeadlySignalHandlers(SignalHandlerType handler);
+// Alternative signal stack (POSIX-only).
 void SetAlternateSignalStack();
 void UnsetAlternateSignalStack();
 
diff --git a/lib/sanitizer_common/sanitizer_libc.h b/lib/sanitizer_common/sanitizer_libc.h
index 9a1b4b539..0768ae16e 100644
--- a/lib/sanitizer_common/sanitizer_libc.h
+++ b/lib/sanitizer_common/sanitizer_libc.h
@@ -97,6 +97,8 @@ uptr internal_sched_yield();
 // Error handling
 bool internal_iserror(uptr retval, int *rverrno = 0);
 
+int internal_sigaction(int signum, const void *act, void *oldact);
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_LIBC_H
diff --git a/lib/sanitizer_common/sanitizer_linux.cc b/lib/sanitizer_common/sanitizer_linux.cc
index 03d3dc5d6..2a954772b 100644
--- a/lib/sanitizer_common/sanitizer_linux.cc
+++ b/lib/sanitizer_common/sanitizer_linux.cc
@@ -16,6 +16,7 @@
 #if SANITIZER_LINUX
 
 #include "sanitizer_common.h"
+#include "sanitizer_flags.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_libc.h"
 #include "sanitizer_linux.h"
@@ -698,6 +699,10 @@ void AndroidLogWrite(const char *buffer) {
 }
 #endif
 
+bool IsDeadlySignal(int signum) {
+  return (signum == SIGSEGV) && common_flags()->handle_segv;
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_LINUX
diff --git a/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index 0b951bd3e..d64a89293 100644
--- a/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -24,6 +24,7 @@
 
 #include <dlfcn.h>
 #include <pthread.h>
+#include <signal.h>
 #include <sys/prctl.h>
 #include <sys/resource.h>
 #include <unwind.h>
@@ -39,7 +40,6 @@ extern "C" SANITIZER_WEAK_ATTRIBUTE int
 __sanitizer_pthread_attr_getstack(void *attr, void **addr, size_t *size);
 
 static int my_pthread_attr_getstack(void *attr, void **addr, size_t *size) {
-#
   if (__sanitizer_pthread_attr_getstack)
     return __sanitizer_pthread_attr_getstack((pthread_attr_t *)attr, addr,
                                              size);
@@ -50,6 +50,15 @@ static int my_pthread_attr_getstack(void *attr, void **addr, size_t *size) {
 
 namespace __sanitizer {
 
+extern "C" SANITIZER_WEAK_ATTRIBUTE int
+__sanitizer_sigaction_f(int signum, const void *act, void *oldact);
+
+int internal_sigaction(int signum, const void *act, void *oldact) {
+  if (__sanitizer_sigaction_f)
+    return __sanitizer_sigaction_f(signum, act, oldact);
+  return sigaction(signum, (struct sigaction *)act, (struct sigaction *)oldact);
+}
+
 #ifndef SANITIZER_GO
 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
                                 uptr *stack_bottom) {
diff --git a/lib/sanitizer_common/sanitizer_mac.cc b/lib/sanitizer_common/sanitizer_mac.cc
index 3cc3a6b5b..e6c95bb69 100644
--- a/lib/sanitizer_common/sanitizer_mac.cc
+++ b/lib/sanitizer_common/sanitizer_mac.cc
@@ -23,6 +23,7 @@
 #include <stdio.h>
 
 #include "sanitizer_common.h"
+#include "sanitizer_flags.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_libc.h"
 #include "sanitizer_placement_new.h"
@@ -32,6 +33,7 @@
 #include <fcntl.h>
 #include <pthread.h>
 #include <sched.h>
+#include <signal.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
@@ -118,6 +120,11 @@ uptr internal_getpid() {
   return getpid();
 }
 
+int internal_sigaction(int signum, const void *act, void *oldact) {
+  return sigaction(signum,
+                   (struct sigaction *)act, (struct sigaction *)oldact);
+}
+
 // ----------------- sanitizer_common.h
 bool FileExists(const char *filename) {
   struct stat st;
@@ -238,6 +245,10 @@ uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
   return memory_mapping.DumpListOfModules(modules, max_modules, filter);
 }
 
+bool IsDeadlySignal(int signum) {
+  return (signum == SIGSEGV || signum == SIGBUS) && common_flags()->handle_segv;
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_MAC
diff --git a/lib/sanitizer_common/sanitizer_posix_libcdep.cc b/lib/sanitizer_common/sanitizer_posix_libcdep.cc
index 73b7886c2..feabc6096 100644
--- a/lib/sanitizer_common/sanitizer_posix_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_posix_libcdep.cc
@@ -16,6 +16,8 @@
 
 #if SANITIZER_LINUX || SANITIZER_MAC
 #include "sanitizer_common.h"
+#include "sanitizer_flags.h"
+#include "sanitizer_platform_limits_posix.h"
 #include "sanitizer_stacktrace.h"
 
 #include <errno.h>
@@ -117,6 +119,29 @@ void UnsetAlternateSignalStack() {
   UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
 }
 
+typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
+static void MaybeInstallSigaction(int signum,
+                                  SignalHandlerType handler) {
+  if (!IsDeadlySignal(signum))
+    return;
+  struct sigaction sigact;
+  internal_memset(&sigact, 0, sizeof(sigact));
+  sigact.sa_sigaction = (sa_sigaction_t)handler;
+  sigact.sa_flags = SA_SIGINFO;
+  if (common_flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
+  CHECK_EQ(0, internal_sigaction(signum, &sigact, 0));
+  VReport(1, "Installed the sigaction for signal %d\n", signum);
+}
+
+void InstallDeadlySignalHandlers(SignalHandlerType handler) {
+  // Set the alternate signal stack for the main thread.
+  // This will cause SetAlternateSignalStack to be called twice, but the stack
+  // will be actually set only once.
+  if (common_flags()->use_sigaltstack) SetAlternateSignalStack();
+  MaybeInstallSigaction(SIGSEGV, handler);
+  MaybeInstallSigaction(SIGBUS, handler);
+}
+
 }  // namespace __sanitizer
 
 #endif
diff --git a/lib/sanitizer_common/sanitizer_win.cc b/lib/sanitizer_common/sanitizer_win.cc
index e3ef578a8..0424e97ee 100644
--- a/lib/sanitizer_common/sanitizer_win.cc
+++ b/lib/sanitizer_common/sanitizer_win.cc
@@ -421,6 +421,15 @@ void UnsetAlternateSignalStack() {
   // FIXME: Decide what to do on Windows.
 }
 
+void InstallDeadlySignalHandlers() {
+  // FIXME: Decide what to do on Windows.
+}
+
+bool IsDeadlySignal(int signum) {
+  // FIXME: Decide what to do on Windows.
+  return false;
+}
+
 }  // namespace __sanitizer
 
 #endif  // _WIN32