src/os_cpu/bsd_x86/vm/os_bsd_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

*** 307,316 ****
--- 307,320 ----
  
  address os::Bsd::ucontext_get_pc(ucontext_t * uc) {
    return (address)uc->context_pc;
  }
  
+ void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) {
+   uc->context_pc = (intptr_t)pc ;
+ }
+ 
  intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) {
    return (intptr_t*)uc->context_sp;
  }
  
  intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) {
*** 461,471 ****
    //%note os_trap_1
    if (info != NULL && uc != NULL && thread != NULL) {
      pc = (address) os::Bsd::ucontext_get_pc(uc);
  
      if (StubRoutines::is_safefetch_fault(pc)) {
!       uc->context_pc = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
        return 1;
      }
  
      // Handle ALL stack overflow variations here
      if (sig == SIGSEGV || sig == SIGBUS) {
--- 465,475 ----
    //%note os_trap_1
    if (info != NULL && uc != NULL && thread != NULL) {
      pc = (address) os::Bsd::ucontext_get_pc(uc);
  
      if (StubRoutines::is_safefetch_fault(pc)) {
!       os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
        return 1;
      }
  
      // Handle ALL stack overflow variations here
      if (sig == SIGSEGV || sig == SIGBUS) {
*** 701,711 ****
  
    if (stub != NULL) {
      // save all thread context in case we need to restore it
      if (thread != NULL) thread->set_saved_exception_pc(pc);
  
!     uc->context_pc = (intptr_t)stub;
      return true;
    }
  
    // signal-chaining
    if (os::Bsd::chained_handler(sig, info, ucVoid)) {
--- 705,715 ----
  
    if (stub != NULL) {
      // save all thread context in case we need to restore it
      if (thread != NULL) thread->set_saved_exception_pc(pc);
  
!     os::Bsd::ucontext_set_pc(uc, stub);
      return true;
    }
  
    // signal-chaining
    if (os::Bsd::chained_handler(sig, info, ucVoid)) {