# HG changeset patch
# User stuefe
# Date 1450078151 18000
# Node ID 8b86440d3bf1330c99cf58c8c3d3d0f1ff6104f2
# Parent  14858721b3b3ffa0c523d5b2ae7a7b5a1084a7f8
8145114: const-correctness for ucontext_t* reading functions
Reviewed-by: dholmes, coleenp

diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/aix/vm/os_aix.cpp
--- a/hotspot/src/os/aix/vm/os_aix.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/aix/vm/os_aix.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -1216,7 +1216,7 @@
 // Note: os::abort() might be called very early during initialization, or
 // called from signal handler. Before adding something to os::abort(), make
 // sure it is async-safe and can handle partially initialized VM.
-void os::abort(bool dump_core, void* siginfo, void* context) {
+void os::abort(bool dump_core, void* siginfo, const void* context) {
   os::shutdown();
   if (dump_core) {
 #ifndef PRODUCT
@@ -3815,7 +3815,7 @@
   Thread* thread = context.thread();
   OSThread* osthread = thread->osthread();
   if (osthread->ucontext() != NULL) {
-    _epc = os::Aix::ucontext_get_pc((ucontext_t *) context.ucontext());
+    _epc = os::Aix::ucontext_get_pc((const ucontext_t *) context.ucontext());
   } else {
     // NULL context is unexpected, double-check this is the VMThread.
     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/aix/vm/os_aix.hpp
--- a/hotspot/src/os/aix/vm/os_aix.hpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/aix/vm/os_aix.hpp	Mon Dec 14 02:29:11 2015 -0500
@@ -123,8 +123,8 @@
   static int vm_default_page_size(void ) { return 8*K; }
 
   static address   ucontext_get_pc(const ucontext_t* uc);
-  static intptr_t* ucontext_get_sp(ucontext_t* uc);
-  static intptr_t* ucontext_get_fp(ucontext_t* uc);
+  static intptr_t* ucontext_get_sp(const ucontext_t* uc);
+  static intptr_t* ucontext_get_fp(const ucontext_t* uc);
   // Set PC into context. Needed for continuation after signal.
   static void ucontext_set_pc(ucontext_t* uc, address pc);
 
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/bsd/vm/os_bsd.cpp
--- a/hotspot/src/os/bsd/vm/os_bsd.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/bsd/vm/os_bsd.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -1077,7 +1077,7 @@
 // Note: os::abort() might be called very early during initialization, or
 // called from signal handler. Before adding something to os::abort(), make
 // sure it is async-safe and can handle partially initialized VM.
-void os::abort(bool dump_core, void* siginfo, void* context) {
+void os::abort(bool dump_core, void* siginfo, const void* context) {
   os::shutdown();
   if (dump_core) {
 #ifndef PRODUCT
@@ -3643,7 +3643,7 @@
   Thread* thread = context.thread();
   OSThread* osthread = thread->osthread();
   if (osthread->ucontext() != NULL) {
-    _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
+    _epc = os::Bsd::ucontext_get_pc((const ucontext_t *) context.ucontext());
   } else {
     // NULL context is unexpected, double-check this is the VMThread
     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/bsd/vm/os_bsd.hpp
--- a/hotspot/src/os/bsd/vm/os_bsd.hpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/bsd/vm/os_bsd.hpp	Mon Dec 14 02:29:11 2015 -0500
@@ -86,17 +86,17 @@
   static int page_size(void)                                        { return _page_size; }
   static void set_page_size(int val)                                { _page_size = val; }
 
-  static address   ucontext_get_pc(ucontext_t* uc);
+  static address   ucontext_get_pc(const ucontext_t* uc);
   static void ucontext_set_pc(ucontext_t* uc, address pc);
-  static intptr_t* ucontext_get_sp(ucontext_t* uc);
-  static intptr_t* ucontext_get_fp(ucontext_t* uc);
+  static intptr_t* ucontext_get_sp(const ucontext_t* uc);
+  static intptr_t* ucontext_get_fp(const ucontext_t* uc);
 
   // For Analyzer Forte AsyncGetCallTrace profiling support:
   //
   // This interface should be declared in os_bsd_i486.hpp, but
   // that file provides extensions to the os class and not the
   // Bsd class.
-  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
+  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, const ucontext_t* uc,
                                               intptr_t** ret_sp, intptr_t** ret_fp);
 
   static bool get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr);
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/linux/vm/os_linux.cpp
--- a/hotspot/src/os/linux/vm/os_linux.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/linux/vm/os_linux.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -1341,7 +1341,7 @@
 // Note: os::abort() might be called very early during initialization, or
 // called from signal handler. Before adding something to os::abort(), make
 // sure it is async-safe and can handle partially initialized VM.
-void os::abort(bool dump_core, void* siginfo, void* context) {
+void os::abort(bool dump_core, void* siginfo, const void* context) {
   os::shutdown();
   if (dump_core) {
 #ifndef PRODUCT
@@ -4853,7 +4853,7 @@
   Thread* thread = context.thread();
   OSThread* osthread = thread->osthread();
   if (osthread->ucontext() != NULL) {
-    _epc = os::Linux::ucontext_get_pc((ucontext_t *) context.ucontext());
+    _epc = os::Linux::ucontext_get_pc((const ucontext_t *) context.ucontext());
   } else {
     // NULL context is unexpected, double-check this is the VMThread
     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/linux/vm/os_linux.hpp
--- a/hotspot/src/os/linux/vm/os_linux.hpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/linux/vm/os_linux.hpp	Mon Dec 14 02:29:11 2015 -0500
@@ -123,17 +123,17 @@
 
   static int vm_default_page_size(void)                             { return _vm_default_page_size; }
 
-  static address   ucontext_get_pc(ucontext_t* uc);
+  static address   ucontext_get_pc(const ucontext_t* uc);
   static void ucontext_set_pc(ucontext_t* uc, address pc);
-  static intptr_t* ucontext_get_sp(ucontext_t* uc);
-  static intptr_t* ucontext_get_fp(ucontext_t* uc);
+  static intptr_t* ucontext_get_sp(const ucontext_t* uc);
+  static intptr_t* ucontext_get_fp(const ucontext_t* uc);
 
   // For Analyzer Forte AsyncGetCallTrace profiling support:
   //
   // This interface should be declared in os_linux_i486.hpp, but
   // that file provides extensions to the os class and not the
   // Linux class.
-  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
+  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, const ucontext_t* uc,
                                               intptr_t** ret_sp, intptr_t** ret_fp);
 
   static bool get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr);
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/posix/vm/os_posix.cpp
--- a/hotspot/src/os/posix/vm/os_posix.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/posix/vm/os_posix.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -1031,7 +1031,7 @@
   return pthread_sigmask(SIG_UNBLOCK, set, NULL);
 }
 
-address os::Posix::ucontext_get_pc(ucontext_t* ctx) {
+address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
 #ifdef TARGET_OS_FAMILY_linux
    return Linux::ucontext_get_pc(ctx);
 #elif defined(TARGET_OS_FAMILY_solaris)
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/posix/vm/os_posix.hpp
--- a/hotspot/src/os/posix/vm/os_posix.hpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/posix/vm/os_posix.hpp	Mon Dec 14 02:29:11 2015 -0500
@@ -76,7 +76,7 @@
   // A POSIX conform, platform-independend siginfo print routine.
   static void print_siginfo_brief(outputStream* os, const siginfo_t* si);
 
-  static address ucontext_get_pc(ucontext_t* ctx);
+  static address ucontext_get_pc(const ucontext_t* ctx);
   // Set PC into context. Needed for continuation after signal.
   static void ucontext_set_pc(ucontext_t* ctx, address pc);
 };
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/solaris/vm/os_solaris.cpp
--- a/hotspot/src/os/solaris/vm/os_solaris.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/solaris/vm/os_solaris.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -1380,7 +1380,7 @@
 // Note: os::abort() might be called very early during initialization, or
 // called from signal handler. Before adding something to os::abort(), make
 // sure it is async-safe and can handle partially initialized VM.
-void os::abort(bool dump_core, void* siginfo, void* context) {
+void os::abort(bool dump_core, void* siginfo, const void* context) {
   os::shutdown();
   if (dump_core) {
 #ifndef PRODUCT
@@ -3736,7 +3736,7 @@
   Thread* thread = context.thread();
   OSThread* osthread = thread->osthread();
   if (osthread->ucontext() != NULL) {
-    _epc = os::Solaris::ucontext_get_pc((ucontext_t *) context.ucontext());
+    _epc = os::Solaris::ucontext_get_pc((const ucontext_t *) context.ucontext());
   } else {
     // NULL context is unexpected, double-check this is the VMThread
     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/solaris/vm/os_solaris.hpp
--- a/hotspot/src/os/solaris/vm/os_solaris.hpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/solaris/vm/os_solaris.hpp	Mon Dec 14 02:29:11 2015 -0500
@@ -130,15 +130,15 @@
   static address handler_start, handler_end; // start and end pc of thr_sighndlrinfo
 
   static bool valid_stack_address(Thread* thread, address sp);
-  static bool valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect);
-  static ucontext_t* get_valid_uc_in_signal_handler(Thread* thread,
-                                                    ucontext_t* uc);
+  static bool valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect);
+  static const ucontext_t* get_valid_uc_in_signal_handler(Thread* thread,
+                                                    const ucontext_t* uc);
 
-  static ExtendedPC  ucontext_get_ExtendedPC(ucontext_t* uc);
-  static intptr_t*   ucontext_get_sp(ucontext_t* uc);
+  static ExtendedPC  ucontext_get_ExtendedPC(const ucontext_t* uc);
+  static intptr_t*   ucontext_get_sp(const ucontext_t* uc);
   // ucontext_get_fp() is only used by Solaris X86 (see note below)
-  static intptr_t*   ucontext_get_fp(ucontext_t* uc);
-  static address    ucontext_get_pc(ucontext_t* uc);
+  static intptr_t*   ucontext_get_fp(const ucontext_t* uc);
+  static address    ucontext_get_pc(const ucontext_t* uc);
   static void ucontext_set_pc(ucontext_t* uc, address pc);
 
   // For Analyzer Forte AsyncGetCallTrace profiling support:
@@ -147,7 +147,7 @@
   // We should have different declarations of this interface in
   // os_solaris_i486.hpp and os_solaris_sparc.hpp, but that file
   // provides extensions to the os class and not the Solaris class.
-  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
+  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, const ucontext_t* uc,
                                               intptr_t** ret_sp, intptr_t** ret_fp);
 
   static bool get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr);
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os/windows/vm/os_windows.cpp
--- a/hotspot/src/os/windows/vm/os_windows.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os/windows/vm/os_windows.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -1028,7 +1028,7 @@
   VMError::record_coredump_status(buffer, status);
 }
 
-void os::abort(bool dump_core, void* siginfo, void* context) {
+void os::abort(bool dump_core, void* siginfo, const void* context) {
   HINSTANCE dbghelp;
   EXCEPTION_POINTERS ep;
   MINIDUMP_EXCEPTION_INFORMATION mei;
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp
--- a/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -98,12 +98,12 @@
   return (address)uc->uc_mcontext.jmp_context.iar;
 }
 
-intptr_t* os::Aix::ucontext_get_sp(ucontext_t * uc) {
+intptr_t* os::Aix::ucontext_get_sp(const ucontext_t * uc) {
   // gpr1 holds the stack pointer on aix
   return (intptr_t*)uc->uc_mcontext.jmp_context.gpr[1/*REG_SP*/];
 }
 
-intptr_t* os::Aix::ucontext_get_fp(ucontext_t * uc) {
+intptr_t* os::Aix::ucontext_get_fp(const ucontext_t * uc) {
   return NULL;
 }
 
@@ -111,11 +111,11 @@
   uc->uc_mcontext.jmp_context.iar = (uint64_t) new_pc;
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                                         intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
-  ucontext_t* uc = (ucontext_t*)ucVoid;
+  const ucontext_t* uc = (const ucontext_t*)ucVoid;
 
   if (uc != NULL) {
     epc = ExtendedPC(os::Aix::ucontext_get_pc(uc));
@@ -131,7 +131,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -507,10 +507,10 @@
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t* uc = (ucontext_t*)context;
+  const ucontext_t* uc = (const ucontext_t*)context;
 
   st->print_cr("Registers:");
   st->print("pc =" INTPTR_FORMAT "  ", uc->uc_mcontext.jmp_context.iar);
@@ -544,7 +544,7 @@
   st->cr();
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
   ucontext_t *uc = (ucontext_t*)context;
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp
--- a/hotspot/src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -304,7 +304,7 @@
 // Nothing to do.
 }
 
-address os::Bsd::ucontext_get_pc(ucontext_t * uc) {
+address os::Bsd::ucontext_get_pc(const ucontext_t * uc) {
   return (address)uc->context_pc;
 }
 
@@ -312,11 +312,11 @@
   uc->context_pc = (intptr_t)pc ;
 }
 
-intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) {
+intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) {
   return (intptr_t*)uc->context_sp;
 }
 
-intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) {
+intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) {
   return (intptr_t*)uc->context_fp;
 }
 
@@ -327,7 +327,7 @@
 // os::fetch_frame_from_context().
 // This method is also used for stack overflow signal handling.
 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread,
-  ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
+  const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 
   assert(thread != NULL, "just checking");
   assert(ret_sp != NULL, "just checking");
@@ -336,11 +336,11 @@
   return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                     intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
-  ucontext_t* uc = (ucontext_t*)ucVoid;
+  const ucontext_t* uc = (const ucontext_t*)ucVoid;
 
   if (uc != NULL) {
     epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc));
@@ -356,7 +356,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -971,10 +971,10 @@
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
   st->print_cr("Registers:");
 #ifdef AMD64
   st->print(  "RAX=" INTPTR_FORMAT, uc->context_rax);
@@ -1032,10 +1032,10 @@
   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
 
   st->print_cr("Register to memory mapping:");
   st->cr();
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/bsd_zero/vm/os_bsd_zero.cpp
--- a/hotspot/src/os_cpu/bsd_zero/vm/os_bsd_zero.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/bsd_zero/vm/os_bsd_zero.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -106,7 +106,7 @@
   // Nothing to do.
 }
 
-address os::Bsd::ucontext_get_pc(ucontext_t* uc) {
+address os::Bsd::ucontext_get_pc(const ucontext_t* uc) {
   ShouldNotCallThis();
   return NULL;
 }
@@ -115,14 +115,14 @@
   ShouldNotCallThis();
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                                         intptr_t** ret_sp,
                                         intptr_t** ret_fp) {
   ShouldNotCallThis();
   return ExtendedPC();
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   ShouldNotCallThis();
   return frame();
 }
@@ -374,11 +374,11 @@
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler
 
-void os::print_context(outputStream* st, void* context) {
+void os::print_context(outputStream* st, const void* context) {
   ShouldNotCallThis();
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   ShouldNotCallThis();
 }
 
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp
--- a/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -109,7 +109,7 @@
 void os::initialize_thread(Thread *thr) {
 }
 
-address os::Linux::ucontext_get_pc(ucontext_t * uc) {
+address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
 #ifdef BUILTIN_SIM
   return (address)uc->uc_mcontext.gregs[REG_PC];
 #else
@@ -125,7 +125,7 @@
 #endif
 }
 
-intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
+intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
 #ifdef BUILTIN_SIM
   return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
 #else
@@ -133,7 +133,7 @@
 #endif
 }
 
-intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
+intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
 #ifdef BUILTIN_SIM
   return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
 #else
@@ -147,7 +147,7 @@
 // frames. Currently we don't do that on Linux, so it's the same as
 // os::fetch_frame_from_context().
 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
-  ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
+  const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 
   assert(thread != NULL, "just checking");
   assert(ret_sp != NULL, "just checking");
@@ -156,11 +156,11 @@
   return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                     intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
-  ucontext_t* uc = (ucontext_t*)ucVoid;
+  const ucontext_t* uc = (const ucontext_t*)ucVoid;
 
   if (uc != NULL) {
     epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
@@ -176,7 +176,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -591,10 +591,10 @@
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
   st->print_cr("Registers:");
 #ifdef BUILTIN_SIM
   st->print(  "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
@@ -643,10 +643,10 @@
   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
 
   st->print_cr("Register to memory mapping:");
   st->cr();
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
--- a/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -99,7 +99,7 @@
 // Frame information (pc, sp, fp) retrieved via ucontext
 // always looks like a C-frame according to the frame
 // conventions in frame_ppc64.hpp.
-address os::Linux::ucontext_get_pc(ucontext_t * uc) {
+address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
   // On powerpc64, ucontext_t is not selfcontained but contains
   // a pointer to an optional substructure (mcontext_t.regs) containing the volatile
   // registers - NIP, among others.
@@ -122,19 +122,19 @@
   uc->uc_mcontext.regs->nip = (unsigned long)pc;
 }
 
-intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
+intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
   return (intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/];
 }
 
-intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
+intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
   return NULL;
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                     intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
-  ucontext_t* uc = (ucontext_t*)ucVoid;
+  const ucontext_t* uc = (const ucontext_t*)ucVoid;
 
   if (uc != NULL) {
     epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
@@ -150,7 +150,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -564,10 +564,10 @@
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t* uc = (ucontext_t*)context;
+  const ucontext_t* uc = (const ucontext_t*)context;
 
   st->print_cr("Registers:");
   st->print("pc =" INTPTR_FORMAT "  ", uc->uc_mcontext.regs->nip);
@@ -595,10 +595,10 @@
   st->cr();
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
 
   st->print_cr("Register to memory mapping:");
   st->cr();
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp
--- a/hotspot/src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -92,7 +92,7 @@
 // signal frames. Currently we don't do that on Linux, so it's the
 // same as os::fetch_frame_from_context().
 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
-                                                ucontext_t* uc,
+                                                const ucontext_t* uc,
                                                 intptr_t** ret_sp,
                                                 intptr_t** ret_fp) {
   assert(thread != NULL, "just checking");
@@ -102,10 +102,10 @@
   return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                                         intptr_t** ret_sp,
                                         intptr_t** ret_fp) {
-  ucontext_t* uc = (ucontext_t*) ucVoid;
+  const ucontext_t* uc = (const ucontext_t*) ucVoid;
   ExtendedPC  epc;
 
   if (uc != NULL) {
@@ -130,7 +130,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, NULL);
   return frame(sp, frame::unpatchable, epc.pc());
@@ -213,10 +213,10 @@
 
 void os::initialize_thread(Thread* thr) {}
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t* uc = (ucontext_t*)context;
+  const ucontext_t* uc = (const ucontext_t*)context;
   sigcontext* sc = (sigcontext*)context;
   st->print_cr("Registers:");
 
@@ -291,11 +291,11 @@
 }
 
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
-  sigcontext* sc = (sigcontext*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
+  const sigcontext* sc = (const sigcontext*)context;
   intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
 
   st->print_cr("Register to memory mapping:");
@@ -343,7 +343,7 @@
 }
 
 
-address os::Linux::ucontext_get_pc(ucontext_t* uc) {
+address os::Linux::ucontext_get_pc(const ucontext_t* uc) {
   return (address) SIG_PC((sigcontext*)uc);
 }
 
@@ -353,13 +353,13 @@
   SIG_NPC(ctx) = (intptr_t)(pc+4);
 }
 
-intptr_t* os::Linux::ucontext_get_sp(ucontext_t *uc) {
+intptr_t* os::Linux::ucontext_get_sp(const ucontext_t *uc) {
   return (intptr_t*)
     ((intptr_t)SIG_REGS((sigcontext*)uc).u_regs[CON_O6] + STACK_BIAS);
 }
 
 // not used on Sparc
-intptr_t* os::Linux::ucontext_get_fp(ucontext_t *uc) {
+intptr_t* os::Linux::ucontext_get_fp(const ucontext_t *uc) {
   ShouldNotReachHere();
   return NULL;
 }
@@ -684,7 +684,7 @@
   }
 
   if (pc == NULL && uc != NULL) {
-    pc = os::Linux::ucontext_get_pc((ucontext_t*)uc);
+    pc = os::Linux::ucontext_get_pc((const ucontext_t*)uc);
   }
 
   // unmask current signal
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp
--- a/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -117,7 +117,7 @@
 // Nothing to do.
 }
 
-address os::Linux::ucontext_get_pc(ucontext_t * uc) {
+address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
   return (address)uc->uc_mcontext.gregs[REG_PC];
 }
 
@@ -125,11 +125,11 @@
   uc->uc_mcontext.gregs[REG_PC] = (intptr_t)pc;
 }
 
-intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
+intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
   return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
 }
 
-intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
+intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
   return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
 }
 
@@ -140,7 +140,7 @@
 // os::fetch_frame_from_context().
 // This method is also used for stack overflow signal handling.
 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
-  ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
+  const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 
   assert(thread != NULL, "just checking");
   assert(ret_sp != NULL, "just checking");
@@ -149,11 +149,11 @@
   return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                     intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
-  ucontext_t* uc = (ucontext_t*)ucVoid;
+  const ucontext_t* uc = (const ucontext_t*)ucVoid;
 
   if (uc != NULL) {
     epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
@@ -169,7 +169,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -784,10 +784,10 @@
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
   st->print_cr("Registers:");
 #ifdef AMD64
   st->print(  "RAX=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RAX]);
@@ -847,10 +847,10 @@
   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
 
   st->print_cr("Register to memory mapping:");
   st->cr();
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.cpp
--- a/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -100,7 +100,7 @@
   // Nothing to do.
 }
 
-address os::Linux::ucontext_get_pc(ucontext_t* uc) {
+address os::Linux::ucontext_get_pc(const ucontext_t* uc) {
   ShouldNotCallThis();
 }
 
@@ -108,13 +108,13 @@
   ShouldNotCallThis();
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                                         intptr_t** ret_sp,
                                         intptr_t** ret_fp) {
   ShouldNotCallThis();
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   ShouldNotCallThis();
 }
 
@@ -406,11 +406,11 @@
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler
 
-void os::print_context(outputStream* st, void* context) {
+void os::print_context(outputStream* st, const void* context) {
   ShouldNotCallThis();
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   ShouldNotCallThis();
 }
 
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp
--- a/hotspot/src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -121,7 +121,7 @@
 // There are issues with libthread giving out uc_links for different threads
 // on the same uc_link chain and bad or circular links.
 //
-bool os::Solaris::valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect) {
+bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) {
   if (valid >= suspect ||
       valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
       valid->uc_stack.ss_sp    != suspect->uc_stack.ss_sp    ||
@@ -148,10 +148,10 @@
 // We will only follow one level of uc_link since there are libthread
 // issues with ucontext linking and it is better to be safe and just
 // let caller retry later.
-ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
-  ucontext_t *uc) {
+const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
+  const ucontext_t *uc) {
 
-  ucontext_t *retuc = NULL;
+  const ucontext_t *retuc = NULL;
 
   // Sometimes the topmost register windows are not properly flushed.
   // i.e., if the kernel would have needed to take a page fault
@@ -179,7 +179,7 @@
 }
 
 // Assumes ucontext is valid
-ExtendedPC os::Solaris::ucontext_get_ExtendedPC(ucontext_t *uc) {
+ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) {
   address pc = (address)uc->uc_mcontext.gregs[REG_PC];
   // set npc to zero to avoid using it for safepoint, good for profiling only
   return ExtendedPC(pc);
@@ -191,17 +191,17 @@
 }
 
 // Assumes ucontext is valid
-intptr_t* os::Solaris::ucontext_get_sp(ucontext_t *uc) {
+intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {
   return (intptr_t*)((intptr_t)uc->uc_mcontext.gregs[REG_SP] + STACK_BIAS);
 }
 
 // Solaris X86 only
-intptr_t* os::Solaris::ucontext_get_fp(ucontext_t *uc) {
+intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {
   ShouldNotReachHere();
   return NULL;
 }
 
-address os::Solaris::ucontext_get_pc(ucontext_t *uc) {
+address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {
   return (address) uc->uc_mcontext.gregs[REG_PC];
 }
 
@@ -215,24 +215,24 @@
 // here we try to skip nested signal frames.
 // This method is also used for stack overflow signal handling.
 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
-  ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
+  const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 
   assert(thread != NULL, "just checking");
   assert(ret_sp != NULL, "just checking");
   assert(ret_fp == NULL, "just checking");
 
-  ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
+  const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
 
   return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
 }
 
 
 // ret_fp parameter is only used by Solaris X86.
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                     intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
-  ucontext_t *uc = (ucontext_t*)ucVoid;
+  const ucontext_t *uc = (const ucontext_t*)ucVoid;
 
   if (uc != NULL) {
     epc = os::Solaris::ucontext_get_ExtendedPC(uc);
@@ -246,7 +246,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -605,10 +605,10 @@
   return false;
 }
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
   st->print_cr("Registers:");
 
   st->print_cr(" G1=" INTPTR_FORMAT " G2=" INTPTR_FORMAT
@@ -682,10 +682,10 @@
   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
   intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
 
   st->print_cr("Register to memory mapping:");
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp
--- a/hotspot/src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -121,7 +121,7 @@
 // There are issues with libthread giving out uc_links for different threads
 // on the same uc_link chain and bad or circular links.
 //
-bool os::Solaris::valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect) {
+bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) {
   if (valid >= suspect ||
       valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
       valid->uc_stack.ss_sp    != suspect->uc_stack.ss_sp    ||
@@ -146,10 +146,10 @@
 // We will only follow one level of uc_link since there are libthread
 // issues with ucontext linking and it is better to be safe and just
 // let caller retry later.
-ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
-  ucontext_t *uc) {
+const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
+  const ucontext_t *uc) {
 
-  ucontext_t *retuc = NULL;
+  const ucontext_t *retuc = NULL;
 
   if (uc != NULL) {
     if (uc->uc_link == NULL) {
@@ -171,7 +171,7 @@
 }
 
 // Assumes ucontext is valid
-ExtendedPC os::Solaris::ucontext_get_ExtendedPC(ucontext_t *uc) {
+ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) {
   return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]);
 }
 
@@ -180,16 +180,16 @@
 }
 
 // Assumes ucontext is valid
-intptr_t* os::Solaris::ucontext_get_sp(ucontext_t *uc) {
+intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {
   return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
 }
 
 // Assumes ucontext is valid
-intptr_t* os::Solaris::ucontext_get_fp(ucontext_t *uc) {
+intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {
   return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
 }
 
-address os::Solaris::ucontext_get_pc(ucontext_t *uc) {
+address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {
   return (address) uc->uc_mcontext.gregs[REG_PC];
 }
 
@@ -200,21 +200,21 @@
 // here we try to skip nested signal frames.
 // This method is also used for stack overflow signal handling.
 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
-  ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
+  const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 
   assert(thread != NULL, "just checking");
   assert(ret_sp != NULL, "just checking");
   assert(ret_fp != NULL, "just checking");
 
-  ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
+  const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
   return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
 }
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                     intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
-  ucontext_t *uc = (ucontext_t*)ucVoid;
+  const ucontext_t *uc = (const ucontext_t*)ucVoid;
 
   if (uc != NULL) {
     epc = os::Solaris::ucontext_get_ExtendedPC(uc);
@@ -230,7 +230,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -774,10 +774,10 @@
   return false;
 }
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
   st->print_cr("Registers:");
 #ifdef AMD64
   st->print(  "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
@@ -833,10 +833,10 @@
   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 }
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  ucontext_t *uc = (ucontext_t*)context;
+  const ucontext_t *uc = (const ucontext_t*)context;
 
   st->print_cr("Register to memory mapping:");
   st->cr();
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/windows_x86/vm/os_windows_x86.cpp
--- a/hotspot/src/os_cpu/windows_x86/vm/os_windows_x86.cpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/windows_x86/vm/os_windows_x86.cpp	Mon Dec 14 02:29:11 2015 -0500
@@ -359,7 +359,7 @@
  *     while (...) {...  fr = os::get_sender_for_C_frame(&fr); }
  * loop in vmError.cpp. We need to roll our own loop.
  */
-bool os::platform_print_native_stack(outputStream* st, void* context,
+bool os::platform_print_native_stack(outputStream* st, const void* context,
                                      char *buf, int buf_size)
 {
   CONTEXT ctx;
@@ -435,7 +435,7 @@
 }
 #endif // AMD64
 
-ExtendedPC os::fetch_frame_from_context(void* ucVoid,
+ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
                     intptr_t** ret_sp, intptr_t** ret_fp) {
 
   ExtendedPC  epc;
@@ -455,7 +455,7 @@
   return epc;
 }
 
-frame os::fetch_frame_from_context(void* ucVoid) {
+frame os::fetch_frame_from_context(const void* ucVoid) {
   intptr_t* sp;
   intptr_t* fp;
   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
@@ -527,10 +527,10 @@
   }
 }
 
-void os::print_context(outputStream *st, void *context) {
+void os::print_context(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  CONTEXT* uc = (CONTEXT*)context;
+  const CONTEXT* uc = (const CONTEXT*)context;
 
   st->print_cr("Registers:");
 #ifdef AMD64
@@ -588,10 +588,10 @@
 }
 
 
-void os::print_register_info(outputStream *st, void *context) {
+void os::print_register_info(outputStream *st, const void *context) {
   if (context == NULL) return;
 
-  CONTEXT* uc = (CONTEXT*)context;
+  const CONTEXT* uc = (const CONTEXT*)context;
 
   st->print_cr("Register to memory mapping:");
   st->cr();
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/os_cpu/windows_x86/vm/os_windows_x86.hpp
--- a/hotspot/src/os_cpu/windows_x86/vm/os_windows_x86.hpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/os_cpu/windows_x86/vm/os_windows_x86.hpp	Mon Dec 14 02:29:11 2015 -0500
@@ -66,7 +66,7 @@
 
 #ifdef AMD64
 #define PLATFORM_PRINT_NATIVE_STACK 1
-static bool platform_print_native_stack(outputStream* st, void* context,
+static bool platform_print_native_stack(outputStream* st, const void* context,
                                         char *buf, int buf_size);
 #endif
 
diff -r 14858721b3b3 -r 8b86440d3bf1 hotspot/src/share/vm/runtime/os.hpp
--- a/hotspot/src/share/vm/runtime/os.hpp	Thu Dec 10 14:22:00 2015 +0100
+++ b/hotspot/src/share/vm/runtime/os.hpp	Mon Dec 14 02:29:11 2015 -0500
@@ -471,8 +471,8 @@
 
   static int pd_self_suspend_thread(Thread* thread);
 
-  static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
-  static frame      fetch_frame_from_context(void* ucVoid);
+  static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
+  static frame      fetch_frame_from_context(const void* ucVoid);
   static frame      fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
 
   static ExtendedPC get_thread_pc(Thread *thread);
@@ -499,7 +499,7 @@
 
   // Terminate with an error.  Default is to generate a core file on platforms
   // that support such things.  This calls shutdown() and then aborts.
-  static void abort(bool dump_core, void *siginfo, void *context);
+  static void abort(bool dump_core, void *siginfo, const void *context);
   static void abort(bool dump_core = true);
 
   // Die immediately, no exit hook, no abort hook, no cleanup.
@@ -604,8 +604,8 @@
   static void print_memory_info(outputStream* st);
   static void print_dll_info(outputStream* st);
   static void print_environment_variables(outputStream* st, const char** env_list);
-  static void print_context(outputStream* st, void* context);
-  static void print_register_info(outputStream* st, void* context);
+  static void print_context(outputStream* st, const void* context);
+  static void print_register_info(outputStream* st, const void* context);
   static void print_siginfo(outputStream* st, void* siginfo);
   static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
   static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
@@ -848,7 +848,7 @@
  public:
 #ifndef PLATFORM_PRINT_NATIVE_STACK
   // No platform-specific code for printing the native stack.
-  static bool platform_print_native_stack(outputStream* st, void* context,
+  static bool platform_print_native_stack(outputStream* st, const void* context,
                                           char *buf, int buf_size) {
     return false;
   }