8255711: Fix and unify hotspot signal handlers

Reviewed-by: coleenp, gziemski, dholmes

Author: tstuefe

make/hotspot/symbols/symbols-aix

@@ -21,7 +21,7 @@
 # questions.
 #
 
-JVM_handle_linux_signal
+JVM_handle_aix_signal
 numa_error
 numa_warn
 sysThreadAvailableStackWithSlack

src/hotspot/os/posix/signals_posix.cpp

@@ -38,7 +38,11 @@ class PosixSignals : public AllStatic {
 
 public:
 
-  static bool are_signal_handlers_installed();
+  // The platform dependent parts of the central hotspot signal handler.
+  // Returns true if the signal had been recognized and handled, false if not. If true, caller should
+  // return from signal handling.
+  static bool pd_hotspot_signal_handler(int sig, siginfo_t* info, ucontext_t* uc, JavaThread* thread);
+
   static void install_signal_handlers();
 
   static bool is_sig_ignored(int sig);

src/hotspot/os/posix/signals_posix.hpp

@@ -2144,6 +2144,8 @@ static int check_pending_signals() {
       }
     } while (threadIsSuspended);
   }
+  ShouldNotReachHere();
+  return 0; // Satisfy compiler
 }
 
 int os::signal_wait() {

src/hotspot/os/windows/os_windows.cpp

@@ -168,43 +168,8 @@ frame os::current_frame() {
   return os::get_sender_for_C_frame(&tmp);
 }
 
-// Utility functions
-
-extern "C" JNIEXPORT int
-JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrecognized) {
-
-  ucontext_t* uc = (ucontext_t*) ucVoid;
-
-  Thread* t = Thread::current_or_null_safe();
-
-  // Note: it's not uncommon that JNI code uses signal/sigset to install
-  // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
-  // or have a SIGILL handler when detecting CPU type). When that happens,
-  // JVM_handle_aix_signal() might be invoked with junk info/ucVoid. To
-  // avoid unnecessary crash when libjsig is not preloaded, try handle signals
-  // that do not require siginfo/ucontext first.
-
-  if (sig == SIGPIPE || sig == SIGXFSZ) {
-    if (PosixSignals::chained_handler(sig, info, ucVoid)) {
-      return 1;
-    } else {
-      // Ignoring SIGPIPE - see bugs 4229104
-      return 1;
-    }
-  }
-
-  JavaThread* thread = NULL;
-  VMThread* vmthread = NULL;
-  if (PosixSignals::are_signal_handlers_installed()) {
-    if (t != NULL) {
-      if(t->is_Java_thread()) {
-        thread = t->as_Java_thread();
-      }
-      else if(t->is_VM_thread()) {
-        vmthread = (VMThread *)t;
-      }
-    }
-  }
+bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
+                                             ucontext_t* uc, JavaThread* thread) {
 
   // Decide if this trap can be handled by a stub.
   address stub = NULL;
@@ -226,8 +191,8 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
     }
   }
 
-  if (info == NULL || uc == NULL || thread == NULL && vmthread == NULL) {
-    goto run_chained_handler;
+  if (info == NULL || uc == NULL) {
+    return false; // Fatal error
   }
 
   // If we are a java thread...
@@ -237,11 +202,11 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
     if (sig == SIGSEGV && thread->is_in_full_stack(addr)) {
       // stack overflow
       if (os::Posix::handle_stack_overflow(thread, addr, pc, uc, &stub)) {
-        return 1; // continue
+        return true; // continue
       } else if (stub != NULL) {
         goto run_stub;
       } else {
-        goto report_and_die;
+        return false; // Fatal error
       }
     } // end handle SIGSEGV inside stack boundaries
 
@@ -281,17 +246,6 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
       //     happens rarely.  In heap based and disjoint base compressd oop modes also loads
       //     are used for null checks.
 
-      // A VM-related SIGILL may only occur if we are not in the zero page.
-      // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
-      // in the zero page, because it is filled with 0x0. We ignore
-      // explicit SIGILLs in the zero page.
-      if (sig == SIGILL && (pc < (address) 0x200)) {
-        if (TraceTraps) {
-          tty->print_raw_cr("SIGILL happened inside zero page.");
-        }
-        goto report_and_die;
-      }
-
       int stop_type = -1;
       // Handle signal from NativeJump::patch_verified_entry().
       if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) {
@@ -384,10 +338,7 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
           tty->print_cr("trap: %s: %s (SIGTRAP, stop type %d)", msg, detail_msg, stop_type);
         }
 
-        va_list detail_args;
-        VMError::report_and_die(INTERNAL_ERROR, msg, detail_msg, detail_args, thread,
-                                pc, info, ucVoid, NULL, 0, 0);
-        va_end(detail_args);
+        return false; // Fatal error
       }
 
       else if (sig == SIGBUS) {
@@ -403,7 +354,7 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
           }
           next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
           os::Aix::ucontext_set_pc(uc, next_pc);
-          return 1;
+          return true;
         }
       }
     }
@@ -428,7 +379,7 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
         }
         next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
         os::Aix::ucontext_set_pc(uc, next_pc);
-        return 1;
+        return true;
       }
     }
 
@@ -450,32 +401,10 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
     // Save all thread context in case we need to restore it.
     if (thread != NULL) thread->set_saved_exception_pc(pc);
     os::Aix::ucontext_set_pc(uc, stub);
-    return 1;
-  }
-
-run_chained_handler:
-
-  // signal-chaining
-  if (PosixSignals::chained_handler(sig, info, ucVoid)) {
-    return 1;
+    return true;
   }
-  if (!abort_if_unrecognized) {
-    // caller wants another chance, so give it to him
-    return 0;
-  }
-
-report_and_die:
 
-  // Use sigthreadmask instead of sigprocmask on AIX and unmask current signal.
-  sigset_t newset;
-  sigemptyset(&newset);
-  sigaddset(&newset, sig);
-  sigthreadmask(SIG_UNBLOCK, &newset, NULL);
-
-  VMError::report_and_die(t, sig, pc, info, ucVoid);
-
-  ShouldNotReachHere();
-  return 0;
+  return false; // Fatal error
 }
 
 void os::Aix::init_thread_fpu_state(void) {

src/hotspot/os_cpu/aix_ppc/os_aix_ppc.cpp

@@ -385,56 +385,14 @@ frame os::current_frame() {
   }
 }
 
-// Utility functions
-
 // From IA32 System Programming Guide
 enum {
   trap_page_fault = 0xE
 };
 
-extern "C" JNIEXPORT int
-JVM_handle_bsd_signal(int sig,
-                        siginfo_t* info,
-                        void* ucVoid,
-                        int abort_if_unrecognized) {
-  ucontext_t* uc = (ucontext_t*) ucVoid;
-
-  Thread* t = Thread::current_or_null_safe();
-
-  // If crash protection is installed we may longjmp away and no destructors
-  // for objects in this scope will be run.
-  // So don't use any RAII utilities before crash protection is checked.
-  os::ThreadCrashProtection::check_crash_protection(sig, t);
-
-  // Note: it's not uncommon that JNI code uses signal/sigset to install
-  // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
-  // or have a SIGILL handler when detecting CPU type). When that happens,
-  // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To
-  // avoid unnecessary crash when libjsig is not preloaded, try handle signals
-  // that do not require siginfo/ucontext first.
-
-  if (sig == SIGPIPE || sig == SIGXFSZ) {
-    // allow chained handler to go first
-    if (PosixSignals::chained_handler(sig, info, ucVoid)) {
-      return true;
-    } else {
-      // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
-      return true;
-    }
-  }
+bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
+                                             ucontext_t* uc, JavaThread* thread) {
 
-  JavaThread* thread = NULL;
-  VMThread* vmthread = NULL;
-  if (PosixSignals::are_signal_handlers_installed()) {
-    if (t != NULL ){
-      if(t->is_Java_thread()) {
-        thread = t->as_Java_thread();
-      }
-      else if(t->is_VM_thread()){
-        vmthread = (VMThread *)t;
-      }
-    }
-  }
 /*
   NOTE: does not seem to work on bsd.
   if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
@@ -455,7 +413,7 @@ JVM_handle_bsd_signal(int sig,
 
     if (StubRoutines::is_safefetch_fault(pc)) {
       os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
-      return 1;
+      return true;
     }
 
     // Handle ALL stack overflow variations here
@@ -466,7 +424,7 @@ JVM_handle_bsd_signal(int sig,
       if (thread->is_in_full_stack(addr)) {
         // stack overflow
         if (os::Posix::handle_stack_overflow(thread, addr, pc, uc, &stub)) {
-          return 1; // continue
+          return true; // continue
         }
       }
     }
@@ -678,29 +636,6 @@ JVM_handle_bsd_signal(int sig,
     return true;
   }
 
-  // signal-chaining
-  if (PosixSignals::chained_handler(sig, info, ucVoid)) {
-     return true;
-  }
-
-  if (!abort_if_unrecognized) {
-    // caller wants another chance, so give it to him
-    return false;
-  }
-
-  if (pc == NULL && uc != NULL) {
-    pc = os::Bsd::ucontext_get_pc(uc);
-  }
-
-  // unmask current signal
-  sigset_t newset;
-  sigemptyset(&newset);
-  sigaddset(&newset, sig);
-  sigprocmask(SIG_UNBLOCK, &newset, NULL);
-
-  VMError::report_and_die(t, sig, pc, info, ucVoid);
-
-  ShouldNotReachHere();
   return false;
 }
 

src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp

@@ -115,54 +115,17 @@ frame os::fetch_frame_from_context(const void* ucVoid) {
   return frame();
 }
 
-extern "C" JNIEXPORT int
-JVM_handle_bsd_signal(int sig,
-                        siginfo_t* info,
-                        void* ucVoid,
-                        int abort_if_unrecognized) {
-  ucontext_t* uc = (ucontext_t*) ucVoid;
+bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
+                                             ucontext_t* uc, JavaThread* thread) {
 
-  Thread* t = Thread::current_or_null_safe();
-
-  // handle SafeFetch faults
+  // handle SafeFetch faults the zero way
   if (sig == SIGSEGV || sig == SIGBUS) {
     sigjmp_buf* const pjb = get_jmp_buf_for_continuation();
     if (pjb) {
       siglongjmp(*pjb, 1);
     }
   }
 
-  // Note: it's not uncommon that JNI code uses signal/sigset to
-  // install then restore certain signal handler (e.g. to temporarily
-  // block SIGPIPE, or have a SIGILL handler when detecting CPU
-  // type). When that happens, JVM_handle_bsd_signal() might be
-  // invoked with junk info/ucVoid. To avoid unnecessary crash when
-  // libjsig is not preloaded, try handle signals that do not require
-  // siginfo/ucontext first.
-
-  if (sig == SIGPIPE || sig == SIGXFSZ) {
-    // allow chained handler to go first
-    if (PosixSignals::chained_handler(sig, info, ucVoid)) {
-      return true;
-    } else {
-      // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
-      return true;
-    }
-  }
-
-  JavaThread* thread = NULL;
-  VMThread* vmthread = NULL;
-  if (PosixSignals::are_signal_handlers_installed()) {
-    if (t != NULL ){
-      if(t->is_Java_thread()) {
-        thread = t->as_Java_thread();
-      }
-      else if(t->is_VM_thread()){
-        vmthread = (VMThread *)t;
-      }
-    }
-  }
-
   if (info != NULL && thread != NULL) {
     // Handle ALL stack overflow variations here
     if (sig == SIGSEGV || sig == SIGBUS) {
@@ -202,36 +165,6 @@ JVM_handle_bsd_signal(int sig,
     }*/
   }
 
-  // signal-chaining
-  if (PosixSignals::chained_handler(sig, info, ucVoid)) {
-     return true;
-  }
-
-  if (!abort_if_unrecognized) {
-    // caller wants another chance, so give it to him
-    return false;
-  }
-
-#ifndef PRODUCT
-  if (sig == SIGSEGV) {
-    fatal("\n#"
-          "\n#    /--------------------\\"
-          "\n#    | segmentation fault |"
-          "\n#    \\---\\ /--------------/"
-          "\n#        /"
-          "\n#    [-]        |\\_/|    "
-          "\n#    (+)=C      |o o|__  "
-          "\n#    | |        =-*-=__\\ "
-          "\n#    OOO        c_c_(___)");
-  }
-#endif // !PRODUCT
-
-  const char *fmt =
-      "caught unhandled signal " INT32_FORMAT " at address " PTR_FORMAT;
-  char buf[128];
-
-  sprintf(buf, fmt, sig, info->si_addr);
-  fatal(buf);
   return false;
 }