# HG changeset patch
# User coleenp
# Date 1371826219 14400
# Node ID 9ba41a4a71fffac094801fdc686ad0ad03f0c965
# Parent  b3cd8b58b79886fc1533d7cf0db7fa60e4f300f0
8004124: Handle and/or warn about SI_KERNEL
Summary: Detect this crash in the signal handler and give a fatal error message instead of making us chase down bugs that don't reproduce
Reviewed-by: kvn, mgerdin, dholmes

diff -r b3cd8b58b798 -r 9ba41a4a71ff src/os_cpu/linux_x86/vm/os_linux_x86.cpp
--- a/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Thu Jun 20 11:53:51 2013 +0200
+++ b/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Fri Jun 21 10:50:19 2013 -0400
@@ -289,6 +289,16 @@
     }
 #endif // AMD64
 
+#ifndef AMD64
+    // Halt if SI_KERNEL before more crashes get misdiagnosed as Java bugs
+    // This can happen in any running code (currently more frequently in
+    // interpreter code but has been seen in compiled code)
+    if (sig == SIGSEGV && info->si_addr == 0 && info->si_code == SI_KERNEL) {
+      fatal("An irrecoverable SI_KERNEL SIGSEGV has occurred due "
+            "to unstable signal handling in this distribution.");
+    }
+#endif // AMD64
+
     // Handle ALL stack overflow variations here
     if (sig == SIGSEGV) {
       address addr = (address) info->si_addr;
diff -r b3cd8b58b798 -r 9ba41a4a71ff src/share/vm/runtime/sharedRuntime.cpp
--- a/src/share/vm/runtime/sharedRuntime.cpp	Thu Jun 20 11:53:51 2013 +0200
+++ b/src/share/vm/runtime/sharedRuntime.cpp	Fri Jun 21 10:50:19 2013 -0400
@@ -813,8 +813,11 @@
           // 3. Implict null exception in nmethod
 
           if (!cb->is_nmethod()) {
-            guarantee(cb->is_adapter_blob() || cb->is_method_handles_adapter_blob(),
-                      "exception happened outside interpreter, nmethods and vtable stubs (1)");
+            bool is_in_blob = cb->is_adapter_blob() || cb->is_method_handles_adapter_blob();
+            if (!is_in_blob) {
+              cb->print();
+              fatal(err_msg("exception happened outside interpreter, nmethods and vtable stubs at pc " INTPTR_FORMAT, pc));
+            }
             Events::log_exception(thread, "NullPointerException in code blob at " INTPTR_FORMAT, pc);
             // There is no handler here, so we will simply unwind.
             return StubRoutines::throw_NullPointerException_at_call_entry();