Merge branch 'upstream-master'

src/hotspot/cpu/riscv/macroAssembler_riscv.cpp

@@ -3313,14 +3313,11 @@ void MacroAssembler::store_conditional(Register dst,
 }
 
 
-void MacroAssembler::cmpxchg_narrow_value_helper(Register addr, Register expected,
-                                                 Register new_val,
+void MacroAssembler::cmpxchg_narrow_value_helper(Register addr, Register expected, Register new_val,
                                                  enum operand_size size,
-                                                 Register tmp1, Register tmp2, Register tmp3) {
+                                                 Register shift, Register mask, Register aligned_addr) {
   assert(size == int8 || size == int16, "unsupported operand size");
 
-  Register aligned_addr = t1, shift = tmp1, mask = tmp2, not_mask = tmp3;
-
   andi(shift, addr, 3);
   slli(shift, shift, 3);
 
@@ -3335,8 +3332,6 @@ void MacroAssembler::cmpxchg_narrow_value_helper(Register addr, Register expecte
   }
   sll(mask, mask, shift);
 
-  notr(not_mask, mask);
-
   sll(expected, expected, shift);
   andr(expected, expected, mask);
 
@@ -3353,35 +3348,46 @@ void MacroAssembler::cmpxchg_narrow_value(Register addr, Register expected,
                                           Assembler::Aqrl acquire, Assembler::Aqrl release,
                                           Register result, bool result_as_bool,
                                           Register tmp1, Register tmp2, Register tmp3) {
-  Register aligned_addr = t1, shift = tmp1, mask = tmp2, not_mask = tmp3, old = result, tmp = t0;
-  assert_different_registers(addr, old, mask, not_mask, new_val, expected, shift, tmp);
-  cmpxchg_narrow_value_helper(addr, expected, new_val, size, tmp1, tmp2, tmp3);
+  assert_different_registers(addr, expected, new_val, result, tmp1, tmp2, tmp3, t0, t1);
 
-  Label retry, fail, done;
+  Register scratch0 = t0, aligned_addr = t1;
+  Register shift = tmp1, mask = tmp2, scratch1 = tmp3;
+
+  cmpxchg_narrow_value_helper(addr, expected, new_val, size, shift, mask, aligned_addr);
 
-  bind(retry);
+  Label retry, fail, done;
 
   if (UseZacas) {
-    lw(old, aligned_addr);
+    lw(result, aligned_addr);
+
+    bind(retry); // amocas loads the current value into result
+    notr(scratch1, mask);
 
-    // if old & mask != expected
-    andr(tmp, old, mask);
-    bne(tmp, expected, fail);
+    andr(scratch0, result, scratch1);  // scratch0 = word - cas bits
+    orr(scratch1, expected, scratch0); // scratch1 = non-cas bits + cas bits
+    bne(result, scratch1, fail);       // cas bits differ, cas failed
 
-    andr(tmp, old, not_mask);
-    orr(tmp, tmp, new_val);
+    // result is the same as expected, use as expected value.
 
-    atomic_cas(old, tmp, aligned_addr, operand_size::int32, acquire, release);
-    bne(tmp, old, retry);
+    // scratch0 is still = word - cas bits
+    // Or in the new value to create complete new value.
+    orr(scratch0, scratch0, new_val);
+
+    mv(scratch1, result); // save our expected value
+    atomic_cas(result, scratch0, aligned_addr, operand_size::int32, acquire, release);
+    bne(scratch1, result, retry);
   } else {
-    lr_w(old, aligned_addr, acquire);
-    andr(tmp, old, mask);
-    bne(tmp, expected, fail);
+    notr(scratch1, mask);
+    bind(retry);
+
+    lr_w(result, aligned_addr, acquire);
+    andr(scratch0, result, mask);
+    bne(scratch0, expected, fail);
 
-    andr(tmp, old, not_mask);
-    orr(tmp, tmp, new_val);
-    sc_w(tmp, tmp, aligned_addr, release);
-    bnez(tmp, retry);
+    andr(scratch0, result, scratch1); // scratch1 is ~mask
+    orr(scratch0, scratch0, new_val);
+    sc_w(scratch0, scratch0, aligned_addr, release);
+    bnez(scratch0, retry);
   }
 
   if (result_as_bool) {
@@ -3393,10 +3399,10 @@ void MacroAssembler::cmpxchg_narrow_value(Register addr, Register expected,
 
     bind(done);
   } else {
-    andr(tmp, old, mask);
-
     bind(fail);
-    srl(result, tmp, shift);
+
+    andr(scratch0, result, mask);
+    srl(result, scratch0, shift);
 
     if (size == int8) {
       sign_extend(result, result, 8);
@@ -3416,33 +3422,44 @@ void MacroAssembler::weak_cmpxchg_narrow_value(Register addr, Register expected,
                                                Assembler::Aqrl acquire, Assembler::Aqrl release,
                                                Register result,
                                                Register tmp1, Register tmp2, Register tmp3) {
-  Register aligned_addr = t1, shift = tmp1, mask = tmp2, not_mask = tmp3, old = result, tmp = t0;
-  assert_different_registers(addr, old, mask, not_mask, new_val, expected, shift, tmp);
-  cmpxchg_narrow_value_helper(addr, expected, new_val, size, tmp1, tmp2, tmp3);
+  assert_different_registers(addr, expected, new_val, result, tmp1, tmp2, tmp3, t0, t1);
+
+  Register scratch0 = t0, aligned_addr = t1;
+  Register shift = tmp1, mask = tmp2, scratch1 = tmp3;
+
+  cmpxchg_narrow_value_helper(addr, expected, new_val, size, shift, mask, aligned_addr);
 
   Label fail, done;
 
   if (UseZacas) {
-    lw(old, aligned_addr);
+    lw(result, aligned_addr);
 
-    // if old & mask != expected
-    andr(tmp, old, mask);
-    bne(tmp, expected, fail);
+    notr(scratch1, mask);
 
-    andr(tmp, old, not_mask);
-    orr(tmp, tmp, new_val);
+    andr(scratch0, result, scratch1);  // scratch0 = word - cas bits
+    orr(scratch1, expected, scratch0); // scratch1 = non-cas bits + cas bits
+    bne(result, scratch1, fail);       // cas bits differ, cas failed
 
-    atomic_cas(tmp, new_val, addr, operand_size::int32, acquire, release);
-    bne(tmp, old, fail);
+    // result is the same as expected, use as expected value.
+
+    // scratch0 is still = word - cas bits
+    // Or in the new value to create complete new value.
+    orr(scratch0, scratch0, new_val);
+
+    mv(scratch1, result); // save our expected value
+    atomic_cas(result, scratch0, aligned_addr, operand_size::int32, acquire, release);
+    bne(scratch1, result, fail); // This weak, so just bail-out.
   } else {
-    lr_w(old, aligned_addr, acquire);
-    andr(tmp, old, mask);
-    bne(tmp, expected, fail);
-
-    andr(tmp, old, not_mask);
-    orr(tmp, tmp, new_val);
-    sc_w(tmp, tmp, aligned_addr, release);
-    bnez(tmp, fail);
+    notr(scratch1, mask);
+
+    lr_w(result, aligned_addr, acquire);
+    andr(scratch0, result, mask);
+    bne(scratch0, expected, fail);
+
+    andr(scratch0, result, scratch1); // scratch1 is ~mask
+    orr(scratch0, scratch0, new_val);
+    sc_w(scratch0, scratch0, aligned_addr, release);
+    bnez(scratch0, fail);
   }
 
   // Success

src/hotspot/cpu/riscv/macroAssembler_riscv.hpp

@@ -1146,10 +1146,9 @@ class MacroAssembler: public Assembler {
                     enum operand_size size,
                     Assembler::Aqrl acquire, Assembler::Aqrl release,
                     Register result);
-  void cmpxchg_narrow_value_helper(Register addr, Register expected,
-                                   Register new_val,
+  void cmpxchg_narrow_value_helper(Register addr, Register expected, Register new_val,
                                    enum operand_size size,
-                                   Register tmp1, Register tmp2, Register tmp3);
+                                   Register shift, Register mask, Register aligned_addr);
   void cmpxchg_narrow_value(Register addr, Register expected,
                             Register new_val,
                             enum operand_size size,

src/hotspot/cpu/riscv/stubGenerator_riscv.cpp

@@ -2112,7 +2112,7 @@ class StubGenerator: public StubCodeGenerator {
 
     // Remaining count is less than 8 bytes. Fill it by a single store.
     // Note that the total length is no less than 8 bytes.
-    if (t == T_BYTE || t == T_SHORT) {
+    if (!AvoidUnalignedAccesses && (t == T_BYTE || t == T_SHORT)) {
       __ beqz(count, L_exit1);
       __ shadd(to, count, to, tmp_reg, shift); // points to the end
       __ sd(value, Address(to, -8)); // overwrite some elements

src/hotspot/os/posix/os_posix.cpp

@@ -2111,7 +2111,7 @@ void os::shutdown() {
 // easily trigger secondary faults in those threads. To reduce the likelihood
 // of that we use _exit rather than exit, so that no atexit hooks get run.
 // But note that os::shutdown() could also trigger secondary faults.
-void os::abort(bool dump_core, void* siginfo, const void* context) {
+void os::abort(bool dump_core, const void* siginfo, const void* context) {
   os::shutdown();
   if (dump_core) {
     LINUX_ONLY(if (DumpPrivateMappingsInCore) ClassLoader::close_jrt_image();)
@@ -2186,3 +2186,43 @@ char* os::pd_map_memory(int fd, const char* unused,
 bool os::pd_unmap_memory(char* addr, size_t bytes) {
   return munmap(addr, bytes) == 0;
 }
+
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+static ucontext_t _saved_assert_context;
+static bool _has_saved_context = false;
+#endif // CAN_SHOW_REGISTERS_ON_ASSERT
+
+void os::save_assert_context(const void* ucVoid) {
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+  assert(ucVoid != nullptr, "invariant");
+  assert(!_has_saved_context, "invariant");
+  memcpy(&_saved_assert_context, ucVoid, sizeof(ucontext_t));
+  // on Linux ppc64, ucontext_t contains pointers into itself which have to be patched up
+  //  after copying the context (see comment in sys/ucontext.h):
+#if defined(PPC64)
+  *((void**)&_saved_assert_context.uc_mcontext.regs) = &(_saved_assert_context.uc_mcontext.gp_regs);
+#elif defined(AMD64)
+  // In the copied version, fpregs should point to the copied contents.
+  // Sanity check: fpregs should point into the context.
+  if ((address)((const ucontext_t*)ucVoid)->uc_mcontext.fpregs > (address)ucVoid) {
+    size_t fpregs_offset = pointer_delta(((const ucontext_t*)ucVoid)->uc_mcontext.fpregs, ucVoid, 1);
+    if (fpregs_offset < sizeof(ucontext_t)) {
+      // Preserve the offset.
+      *((void**)&_saved_assert_context.uc_mcontext.fpregs) = (void*)((address)(void*)&_saved_assert_context + fpregs_offset);
+    }
+  }
+#endif
+  _has_saved_context = true;
+#endif // CAN_SHOW_REGISTERS_ON_ASSERT
+}
+
+const void* os::get_saved_assert_context(const void** sigInfo) {
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+  assert(sigInfo != nullptr, "invariant");
+  *sigInfo = nullptr;
+  return _has_saved_context ? &_saved_assert_context : nullptr;
+#endif
+  *sigInfo = nullptr;
+  return nullptr;
+}
+

src/hotspot/os/posix/signals_posix.cpp

@@ -578,9 +578,8 @@ int JVM_HANDLE_XXX_SIGNAL(int sig, siginfo_t* info,
 
   // Handle assertion poison page accesses.
 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
-  if (!signal_was_handled &&
-      ((sig == SIGSEGV || sig == SIGBUS) && info != nullptr && info->si_addr == g_assert_poison)) {
-    signal_was_handled = handle_assert_poison_fault(ucVoid, info->si_addr);
+  if (VMError::was_assert_poison_crash(info)) {
+    signal_was_handled = handle_assert_poison_fault(ucVoid);
   }
 #endif
 
@@ -1136,8 +1135,16 @@ static const char* get_signal_name(int sig, char* out, size_t outlen) {
 }
 
 void os::print_siginfo(outputStream* os, const void* si0) {
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+  // If we are here because of an assert/guarantee, we suppress
+  // printing the siginfo, because it is only an implementation
+  // detail capturing the context for said assert/guarantee.
+  if (VMError::was_assert_poison_crash(si0)) {
+    return;
+  }
+#endif
 
-  const siginfo_t* const si = (const siginfo_t*) si0;
+  const siginfo_t* const si = (const siginfo_t*)si0;
 
   char buf[20];
   os->print("siginfo:");

src/hotspot/os/posix/vmError_posix.cpp

@@ -84,8 +84,8 @@ static void crash_handler(int sig, siginfo_t* info, void* context) {
 
   // Needed because asserts may happen in error handling too.
 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
-  if ((sig == SIGSEGV || sig == SIGBUS) && info != nullptr && info->si_addr == g_assert_poison) {
-    if (handle_assert_poison_fault(context, info->si_addr)) {
+  if (VMError::was_assert_poison_crash(info)) {
+    if (handle_assert_poison_fault(context)) {
       return;
     }
   }
@@ -127,3 +127,14 @@ void VMError::check_failing_cds_access(outputStream* st, const void* siginfo) {
   }
 #endif
 }
+
+bool VMError::was_assert_poison_crash(const void* siginfo) {
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+  if (siginfo == nullptr) {
+    return false;
+  }
+  const siginfo_t* const si = (siginfo_t*)siginfo;
+  return (si->si_signo == SIGSEGV || si->si_signo == SIGBUS) && si->si_addr == g_assert_poison_read_only;
+#endif
+  return false;
+}

src/hotspot/os/windows/os_windows.cpp

@@ -72,6 +72,7 @@
 #include "services/runtimeService.hpp"
 #include "symbolengine.hpp"
 #include "utilities/align.hpp"
+#include "utilities/debug.hpp"
 #include "utilities/decoder.hpp"
 #include "utilities/defaultStream.hpp"
 #include "utilities/events.hpp"
@@ -1317,7 +1318,7 @@ void os::check_core_dump_prerequisites(char* buffer, size_t bufferSize, bool che
   }
 }
 
-void os::abort(bool dump_core, void* siginfo, const void* context) {
+void os::abort(bool dump_core, const void* siginfo, const void* context) {
   EXCEPTION_POINTERS ep;
   MINIDUMP_EXCEPTION_INFORMATION mei;
   MINIDUMP_EXCEPTION_INFORMATION* pmei;
@@ -2112,7 +2113,17 @@ bool os::signal_sent_by_kill(const void* siginfo) {
 }
 
 void os::print_siginfo(outputStream *st, const void* siginfo) {
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+  // If we are here because of an assert/guarantee, we suppress
+  // printing the siginfo, because it is only an implementation
+  // detail capturing the context for said assert/guarantee.
+  if (VMError::was_assert_poison_crash(siginfo)) {
+    return;
+  }
+#endif
+
   const EXCEPTION_RECORD* const er = (EXCEPTION_RECORD*)siginfo;
+
   st->print("siginfo:");
 
   char tmp[64];
@@ -2625,6 +2636,14 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
 #endif
 #endif
 
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+  if (VMError::was_assert_poison_crash(exception_record)) {
+    if (handle_assert_poison_fault(exceptionInfo)) {
+      return EXCEPTION_CONTINUE_EXECUTION;
+    }
+  }
+#endif
+
   if (t != nullptr && t->is_Java_thread()) {
     JavaThread* thread = JavaThread::cast(t);
     bool in_java = thread->thread_state() == _thread_in_Java;
@@ -6165,3 +6184,26 @@ void os::print_user_info(outputStream* st) {
 void os::print_active_locale(outputStream* st) {
   // not implemented yet
 }
+
+static CONTEXT _saved_assert_context;
+static EXCEPTION_RECORD _saved_exception_record;
+static bool _has_saved_context = false;
+
+void os::save_assert_context(const void* ucVoid) {
+  assert(ucVoid != nullptr, "invariant");
+  assert(!_has_saved_context, "invariant");
+  const EXCEPTION_POINTERS* ep = static_cast<const EXCEPTION_POINTERS*>(ucVoid);
+  memcpy(&_saved_assert_context, ep->ContextRecord, sizeof(CONTEXT));
+  memcpy(&_saved_exception_record, ep->ExceptionRecord, sizeof(EXCEPTION_RECORD));
+  _has_saved_context = true;
+}
+
+const void* os::get_saved_assert_context(const void** sigInfo) {
+  assert(sigInfo != nullptr, "invariant");
+  if (_has_saved_context) {
+    *sigInfo = &_saved_exception_record;
+    return &_saved_assert_context;
+  }
+  *sigInfo = nullptr;
+  return nullptr;
+}