src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp

rev 54204 : 8220794: PPC64: Fix signal handler for SIGSEGV on branch to illegal address
Reviewed-by:

*** 130,139 ****
--- 130,143 ----
  
  intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
    return NULL;
  }
  
+ static unsigned long ucontext_get_trap(const ucontext_t * uc) {
+   return uc->uc_mcontext.regs->trap;
+ }
+ 
  ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                      intptr_t** ret_sp, intptr_t** ret_fp) {
  
    ExtendedPC  epc;
    const ucontext_t* uc = (const ucontext_t*)ucVoid;
*** 302,314 ****
    if (info != NULL && uc != NULL && thread != NULL) {
      pc = (address) os::Linux::ucontext_get_pc(uc);
  
      // Handle ALL stack overflow variations here
      if (sig == SIGSEGV) {
!       // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see
        // comment below). Use get_stack_bang_address instead of si_addr.
!       address addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc);
  
        // Check if fault address is within thread stack.
        if (thread->on_local_stack(addr)) {
          // stack overflow
          if (thread->in_stack_yellow_reserved_zone(addr)) {
--- 306,331 ----
    if (info != NULL && uc != NULL && thread != NULL) {
      pc = (address) os::Linux::ucontext_get_pc(uc);
  
      // Handle ALL stack overflow variations here
      if (sig == SIGSEGV) {
!       // si_addr may not be valid due to a bug in the linux-ppc64 kernel (see
        // comment below). Use get_stack_bang_address instead of si_addr.
!       // If SIGSEGV is caused due to a branch to an invalid address an
!       // "Instruction Storage" interruption is generated and 'pc' (NIP) already
!       // contains the invalid address. Otherwise, the SIGSEGV is caused due to
!       // load/store instruction trying to load/store from/to an invalid address
!       // and causing a "Data Storage" interruption, so we inspect the intruction
!       // in order to extract the faulty data addresss.
!       address addr;
!       if ((ucontext_get_trap(uc) & 0x0F00 /* no IRQ reply bits */) == 0x0400) {
!         // Instruction interruption
!         addr = pc;
!       } else {
!         // Data interruption (0x0300): extract faulty data address
!         addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc);
!       }
  
        // Check if fault address is within thread stack.
        if (thread->on_local_stack(addr)) {
          // stack overflow
          if (thread->in_stack_yellow_reserved_zone(addr)) {