src/os_cpu/linux_x86/vm/os_linux_x86.cpp

rev 7968 : 8074552:  SafeFetch32 and SafeFetchN do not work in error handling
Summary: handle SafeFetch faults in secondary signal handlers
Reviewed-by: dholmes
Contributed-by: Thomas Stuefe

@@ -120,10 +120,14 @@
 
 address os::Linux::ucontext_get_pc(ucontext_t * uc) {
   return (address)uc->uc_mcontext.gregs[REG_PC];
 }
 
+void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
+  uc->uc_mcontext.gregs[REG_PC] = (intptr_t)pc;
+}
+
 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
   return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
 }
 
 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {

@@ -277,11 +281,11 @@
   //%note os_trap_1
   if (info != NULL && uc != NULL && thread != NULL) {
     pc = (address) os::Linux::ucontext_get_pc(uc);
 
     if (StubRoutines::is_safefetch_fault(pc)) {
-      uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
+      os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
       return 1;
     }
 
 #ifndef AMD64
     // Halt if SI_KERNEL before more crashes get misdiagnosed as Java bugs

@@ -512,11 +516,11 @@
 
   if (stub != NULL) {
     // save all thread context in case we need to restore it
     if (thread != NULL) thread->set_saved_exception_pc(pc);
 
-    uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
+    os::Linux::ucontext_set_pc(uc, stub);
     return true;
   }
 
   // signal-chaining
   if (os::Linux::chained_handler(sig, info, ucVoid)) {