提交 2fe5714c 编写于 作者: G goetz

8016697: Use stubs to implement safefetch

Summary: Implement Safefetch as stub routines. This reduces compiler and os dependencies.
Reviewed-by: twisti, kvn
上级 77e58731
......@@ -410,6 +410,51 @@ class StubGenerator: public StubCodeGenerator {
return start;
}
// Safefetch stubs.
void generate_safefetch(const char* name, int size, address* entry,
address* fault_pc, address* continuation_pc) {
// safefetch signatures:
// int SafeFetch32(int* adr, int errValue);
// intptr_t SafeFetchN (intptr_t* adr, intptr_t errValue);
//
// arguments:
// o0 = adr
// o1 = errValue
//
// result:
// o0 = *adr or errValue
StubCodeMark mark(this, "StubRoutines", name);
// Entry point, pc or function descriptor.
__ align(CodeEntryAlignment);
*entry = __ pc();
__ mov(O0, G1); // g1 = o0
__ mov(O1, O0); // o0 = o1
// Load *adr into c_rarg1, may fault.
*fault_pc = __ pc();
switch (size) {
case 4:
// int32_t
__ ldsw(G1, 0, O0); // o0 = [g1]
break;
case 8:
// int64_t
__ ldx(G1, 0, O0); // o0 = [g1]
break;
default:
ShouldNotReachHere();
}
// return errValue or *adr
*continuation_pc = __ pc();
// By convention with the trap handler we ensure there is a non-CTI
// instruction in the trap shadow.
__ nop();
__ retl();
__ delayed()->nop();
}
//------------------------------------------------------------------------------------------------------------------------
// Continuation point for throwing of implicit exceptions that are not handled in
......@@ -3315,6 +3360,14 @@ class StubGenerator: public StubCodeGenerator {
// Don't initialize the platform math functions since sparc
// doesn't have intrinsics for these operations.
// Safefetch stubs.
generate_safefetch("SafeFetch32", sizeof(int), &StubRoutines::_safefetch32_entry,
&StubRoutines::_safefetch32_fault_pc,
&StubRoutines::_safefetch32_continuation_pc);
generate_safefetch("SafeFetchN", sizeof(intptr_t), &StubRoutines::_safefetchN_entry,
&StubRoutines::_safefetchN_fault_pc,
&StubRoutines::_safefetchN_continuation_pc);
}
......
......@@ -2766,6 +2766,39 @@ class StubGenerator: public StubCodeGenerator {
return start;
}
// Safefetch stubs.
void generate_safefetch(const char* name, int size, address* entry,
address* fault_pc, address* continuation_pc) {
// safefetch signatures:
// int SafeFetch32(int* adr, int errValue);
// intptr_t SafeFetchN (intptr_t* adr, intptr_t errValue);
StubCodeMark mark(this, "StubRoutines", name);
// Entry point, pc or function descriptor.
*entry = __ pc();
__ movl(rax, Address(rsp, 0x8));
__ movl(rcx, Address(rsp, 0x4));
// Load *adr into eax, may fault.
*fault_pc = __ pc();
switch (size) {
case 4:
// int32_t
__ movl(rax, Address(rcx, 0));
break;
case 8:
// int64_t
Unimplemented();
break;
default:
ShouldNotReachHere();
}
// Return errValue or *adr.
*continuation_pc = __ pc();
__ ret(0);
}
public:
// Information about frame layout at time of blocking runtime call.
......@@ -2978,6 +3011,14 @@ class StubGenerator: public StubCodeGenerator {
StubRoutines::_cipherBlockChaining_encryptAESCrypt = generate_cipherBlockChaining_encryptAESCrypt();
StubRoutines::_cipherBlockChaining_decryptAESCrypt = generate_cipherBlockChaining_decryptAESCrypt();
}
// Safefetch stubs.
generate_safefetch("SafeFetch32", sizeof(int), &StubRoutines::_safefetch32_entry,
&StubRoutines::_safefetch32_fault_pc,
&StubRoutines::_safefetch32_continuation_pc);
StubRoutines::_safefetchN_entry = StubRoutines::_safefetch32_entry;
StubRoutines::_safefetchN_fault_pc = StubRoutines::_safefetch32_fault_pc;
StubRoutines::_safefetchN_continuation_pc = StubRoutines::_safefetch32_continuation_pc;
}
......
......@@ -3357,7 +3357,45 @@ class StubGenerator: public StubCodeGenerator {
return start;
}
// Safefetch stubs.
void generate_safefetch(const char* name, int size, address* entry,
address* fault_pc, address* continuation_pc) {
// safefetch signatures:
// int SafeFetch32(int* adr, int errValue);
// intptr_t SafeFetchN (intptr_t* adr, intptr_t errValue);
//
// arguments:
// c_rarg0 = adr
// c_rarg1 = errValue
//
// result:
// PPC_RET = *adr or errValue
StubCodeMark mark(this, "StubRoutines", name);
// Entry point, pc or function descriptor.
*entry = __ pc();
// Load *adr into c_rarg1, may fault.
*fault_pc = __ pc();
switch (size) {
case 4:
// int32_t
__ movl(c_rarg1, Address(c_rarg0, 0));
break;
case 8:
// int64_t
__ movq(c_rarg1, Address(c_rarg0, 0));
break;
default:
ShouldNotReachHere();
}
// return errValue or *adr
*continuation_pc = __ pc();
__ movq(rax, c_rarg1);
__ ret(0);
}
// This is a version of CBC/AES Decrypt which does 4 blocks in a loop at a time
// to hide instruction latency
......@@ -3833,6 +3871,14 @@ class StubGenerator: public StubCodeGenerator {
StubRoutines::_cipherBlockChaining_encryptAESCrypt = generate_cipherBlockChaining_encryptAESCrypt();
StubRoutines::_cipherBlockChaining_decryptAESCrypt = generate_cipherBlockChaining_decryptAESCrypt_Parallel();
}
// Safefetch stubs.
generate_safefetch("SafeFetch32", sizeof(int), &StubRoutines::_safefetch32_entry,
&StubRoutines::_safefetch32_fault_pc,
&StubRoutines::_safefetch32_continuation_pc);
generate_safefetch("SafeFetchN", sizeof(intptr_t), &StubRoutines::_safefetchN_entry,
&StubRoutines::_safefetchN_fault_pc,
&StubRoutines::_safefetchN_continuation_pc);
}
public:
......
......@@ -2317,6 +2317,11 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
#endif
Thread* t = ThreadLocalStorage::get_thread_slow(); // slow & steady
// Handle SafeFetch32 and SafeFetchN exceptions.
if (StubRoutines::is_safefetch_fault(pc)) {
return Handle_Exception(exceptionInfo, StubRoutines::continuation_for_safefetch_fault(pc));
}
#ifndef _WIN64
// Execution protection violation - win32 running on AMD64 only
// Handled first to avoid misdiagnosis as a "normal" access violation;
......
......@@ -63,24 +63,6 @@ SYMBOL(fixcw):
popl %eax
ret
.globl SYMBOL(SafeFetch32), SYMBOL(Fetch32PFI), SYMBOL(Fetch32Resume)
.globl SYMBOL(SafeFetchN)
## TODO: avoid exposing Fetch32PFI and Fetch32Resume.
## Instead, the signal handler would call a new SafeFetchTriage(FaultingEIP)
## routine to vet the address. If the address is the faulting LD then
## SafeFetchTriage() would return the resume-at EIP, otherwise null.
ELF_TYPE(SafeFetch32,@function)
.p2align 4,,15
SYMBOL(SafeFetch32):
SYMBOL(SafeFetchN):
movl 0x8(%esp), %eax
movl 0x4(%esp), %ecx
SYMBOL(Fetch32PFI):
movl (%ecx), %eax
SYMBOL(Fetch32Resume):
ret
.globl SYMBOL(SpinPause)
ELF_TYPE(SpinPause,@function)
.p2align 4,,15
......
......@@ -46,28 +46,6 @@
.text
.globl SYMBOL(SafeFetch32), SYMBOL(Fetch32PFI), SYMBOL(Fetch32Resume)
.p2align 4,,15
ELF_TYPE(SafeFetch32,@function)
// Prototype: int SafeFetch32 (int * Adr, int ErrValue)
SYMBOL(SafeFetch32):
movl %esi, %eax
SYMBOL(Fetch32PFI):
movl (%rdi), %eax
SYMBOL(Fetch32Resume):
ret
.globl SYMBOL(SafeFetchN), SYMBOL(FetchNPFI), SYMBOL(FetchNResume)
.p2align 4,,15
ELF_TYPE(SafeFetchN,@function)
// Prototype: intptr_t SafeFetchN (intptr_t * Adr, intptr_t ErrValue)
SYMBOL(SafeFetchN):
movq %rsi, %rax
SYMBOL(FetchNPFI):
movq (%rdi), %rax
SYMBOL(FetchNResume):
ret
.globl SYMBOL(SpinPause)
.p2align 4,,15
ELF_TYPE(SpinPause,@function)
......
......@@ -385,13 +385,6 @@ enum {
trap_page_fault = 0xE
};
extern "C" void Fetch32PFI () ;
extern "C" void Fetch32Resume () ;
#ifdef AMD64
extern "C" void FetchNPFI () ;
extern "C" void FetchNResume () ;
#endif // AMD64
extern "C" JNIEXPORT int
JVM_handle_bsd_signal(int sig,
siginfo_t* info,
......@@ -454,16 +447,10 @@ JVM_handle_bsd_signal(int sig,
if (info != NULL && uc != NULL && thread != NULL) {
pc = (address) os::Bsd::ucontext_get_pc(uc);
if (pc == (address) Fetch32PFI) {
uc->context_pc = intptr_t(Fetch32Resume) ;
return 1 ;
if (StubRoutines::is_safefetch_fault(pc)) {
uc->context_pc = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
return 1;
}
#ifdef AMD64
if (pc == (address) FetchNPFI) {
uc->context_pc = intptr_t (FetchNResume) ;
return 1 ;
}
#endif // AMD64
// Handle ALL stack overflow variations here
if (sig == SIGSEGV || sig == SIGBUS) {
......
......@@ -21,42 +21,6 @@
# questions.
#
# Prototype: int SafeFetch32 (int * adr, int ErrValue)
# The "ld" at Fetch32 is potentially faulting instruction.
# If the instruction traps the trap handler will arrange
# for control to resume at Fetch32Resume.
# By convention with the trap handler we ensure there is a non-CTI
# instruction in the trap shadow.
.globl SafeFetch32, Fetch32PFI, Fetch32Resume
.globl SafeFetchN
.align 32
.type SafeFetch32,@function
SafeFetch32:
mov %o0, %g1
mov %o1, %o0
Fetch32PFI:
# <-- Potentially faulting instruction
ld [%g1], %o0
Fetch32Resume:
nop
retl
nop
.globl SafeFetchN, FetchNPFI, FetchNResume
.type SafeFetchN,@function
.align 32
SafeFetchN:
mov %o0, %g1
mov %o1, %o0
FetchNPFI:
ldn [%g1], %o0
FetchNResume:
nop
retl
nop
# Possibilities:
# -- membar
# -- CAS (SP + BIAS, G0, G0)
......
......@@ -366,18 +366,9 @@ intptr_t* os::Linux::ucontext_get_fp(ucontext_t *uc) {
// Utility functions
extern "C" void Fetch32PFI();
extern "C" void Fetch32Resume();
extern "C" void FetchNPFI();
extern "C" void FetchNResume();
inline static bool checkPrefetch(sigcontext* uc, address pc) {
if (pc == (address) Fetch32PFI) {
set_cont_address(uc, address(Fetch32Resume));
return true;
}
if (pc == (address) FetchNPFI) {
set_cont_address(uc, address(FetchNResume));
if (StubRoutines::is_safefetch_fault(pc)) {
set_cont_address(uc, address(StubRoutines::continuation_for_safefetch_fault(pc)));
return true;
}
return false;
......
......@@ -42,24 +42,6 @@
.text
.globl SafeFetch32, Fetch32PFI, Fetch32Resume
.globl SafeFetchN
## TODO: avoid exposing Fetch32PFI and Fetch32Resume.
## Instead, the signal handler would call a new SafeFetchTriage(FaultingEIP)
## routine to vet the address. If the address is the faulting LD then
## SafeFetchTriage() would return the resume-at EIP, otherwise null.
.type SafeFetch32,@function
.p2align 4,,15
SafeFetch32:
SafeFetchN:
movl 0x8(%esp), %eax
movl 0x4(%esp), %ecx
Fetch32PFI:
movl (%ecx), %eax
Fetch32Resume:
ret
.globl SpinPause
.type SpinPause,@function
.p2align 4,,15
......
......@@ -38,28 +38,6 @@
.text
.globl SafeFetch32, Fetch32PFI, Fetch32Resume
.align 16
.type SafeFetch32,@function
// Prototype: int SafeFetch32 (int * Adr, int ErrValue)
SafeFetch32:
movl %esi, %eax
Fetch32PFI:
movl (%rdi), %eax
Fetch32Resume:
ret
.globl SafeFetchN, FetchNPFI, FetchNResume
.align 16
.type SafeFetchN,@function
// Prototype: intptr_t SafeFetchN (intptr_t * Adr, intptr_t ErrValue)
SafeFetchN:
movq %rsi, %rax
FetchNPFI:
movq (%rdi), %rax
FetchNResume:
ret
.globl SpinPause
.align 16
.type SpinPause,@function
......
......@@ -209,13 +209,6 @@ enum {
trap_page_fault = 0xE
};
extern "C" void Fetch32PFI () ;
extern "C" void Fetch32Resume () ;
#ifdef AMD64
extern "C" void FetchNPFI () ;
extern "C" void FetchNResume () ;
#endif // AMD64
extern "C" JNIEXPORT int
JVM_handle_linux_signal(int sig,
siginfo_t* info,
......@@ -278,16 +271,10 @@ JVM_handle_linux_signal(int sig,
if (info != NULL && uc != NULL && thread != NULL) {
pc = (address) os::Linux::ucontext_get_pc(uc);
if (pc == (address) Fetch32PFI) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
return 1 ;
if (StubRoutines::is_safefetch_fault(pc)) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
return 1;
}
#ifdef AMD64
if (pc == (address) FetchNPFI) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
return 1 ;
}
#endif // AMD64
#ifndef AMD64
// Halt if SI_KERNEL before more crashes get misdiagnosed as Java bugs
......
......@@ -303,11 +303,6 @@ bool os::is_allocatable(size_t bytes) {
#endif
}
extern "C" void Fetch32PFI () ;
extern "C" void Fetch32Resume () ;
extern "C" void FetchNPFI () ;
extern "C" void FetchNResume () ;
extern "C" JNIEXPORT int
JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
int abort_if_unrecognized) {
......@@ -379,17 +374,10 @@ JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
npc = (address) uc->uc_mcontext.gregs[REG_nPC];
// SafeFetch() support
// Implemented with either a fixed set of addresses such
// as Fetch32*, or with Thread._OnTrap.
if (uc->uc_mcontext.gregs[REG_PC] == intptr_t(Fetch32PFI)) {
uc->uc_mcontext.gregs [REG_PC] = intptr_t(Fetch32Resume) ;
uc->uc_mcontext.gregs [REG_nPC] = intptr_t(Fetch32Resume) + 4 ;
return true ;
}
if (uc->uc_mcontext.gregs[REG_PC] == intptr_t(FetchNPFI)) {
uc->uc_mcontext.gregs [REG_PC] = intptr_t(FetchNResume) ;
uc->uc_mcontext.gregs [REG_nPC] = intptr_t(FetchNResume) + 4 ;
return true ;
if (StubRoutines::is_safefetch_fault(pc)) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
uc->uc_mcontext.gregs[REG_nPC] = uc->uc_mcontext.gregs[REG_PC] + 4;
return 1;
}
// Handle ALL stack overflow variations here
......
......@@ -21,47 +21,6 @@
!! questions.
!!
!! Prototype: int SafeFetch32 (int * adr, int ErrValue)
!! The "ld" at Fetch32 is potentially faulting instruction.
!! If the instruction traps the trap handler will arrange
!! for control to resume at Fetch32Resume.
!! By convention with the trap handler we ensure there is a non-CTI
!! instruction in the trap shadow.
!!
!! The reader might be tempted to move this service to .il.
!! Don't. Sun's CC back-end reads and optimize code emitted
!! by the .il "call", in some cases optimizing the code, completely eliding it,
!! or by moving the code from the "call site".
!! ASM better know we may use G6 for our own purposes
.register %g6, #ignore
.globl SafeFetch32
.align 32
.global Fetch32PFI, Fetch32Resume
SafeFetch32:
mov %o0, %g1
mov %o1, %o0
Fetch32PFI:
ld [%g1], %o0 !! <-- Potentially faulting instruction
Fetch32Resume:
nop
retl
nop
.globl SafeFetchN
.align 32
.globl FetchNPFI, FetchNResume
SafeFetchN:
mov %o0, %g1
mov %o1, %o0
FetchNPFI:
ldn [%g1], %o0
FetchNResume:
nop
retl
nop
!! Possibilities:
!! -- membar
!! -- CAS (SP + BIAS, G0, G0)
......
......@@ -352,13 +352,6 @@ bool os::is_allocatable(size_t bytes) {
}
extern "C" void Fetch32PFI () ;
extern "C" void Fetch32Resume () ;
#ifdef AMD64
extern "C" void FetchNPFI () ;
extern "C" void FetchNResume () ;
#endif // AMD64
extern "C" JNIEXPORT int
JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
int abort_if_unrecognized) {
......@@ -436,17 +429,10 @@ JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
// factor me: getPCfromContext
pc = (address) uc->uc_mcontext.gregs[REG_PC];
// SafeFetch32() support
if (pc == (address) Fetch32PFI) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
return true ;
}
#ifdef AMD64
if (pc == (address) FetchNPFI) {
uc->uc_mcontext.gregs [REG_PC] = intptr_t(FetchNResume) ;
return true ;
if (StubRoutines::is_safefetch_fault(pc)) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
return true;
}
#endif // AMD64
// Handle ALL stack overflow variations here
if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
......
......@@ -54,20 +54,6 @@ fixcw:
popl %eax
ret
.align 16
.globl SafeFetch32
.globl SafeFetchN
.globl Fetch32PFI, Fetch32Resume
SafeFetch32:
SafeFetchN:
movl 0x8(%esp), %eax
movl 0x4(%esp), %ecx
Fetch32PFI:
movl (%ecx), %eax
Fetch32Resume:
ret
.align 16
.globl SpinPause
SpinPause:
......
......@@ -21,54 +21,34 @@
/ questions.
/
.globl fs_load
.globl fs_thread
.globl fs_load
.globl fs_thread
// NOTE WELL! The _Copy functions are called directly
// from server-compiler-generated code via CallLeafNoFP,
// which means that they *must* either not use floating
// point or use it in the same manner as does the server
// compiler.
// from server-compiler-generated code via CallLeafNoFP,
// which means that they *must* either not use floating
// point or use it in the same manner as does the server
// compiler.
.globl _Copy_arrayof_conjoint_bytes
.globl _Copy_conjoint_jshorts_atomic
.globl _Copy_arrayof_conjoint_jshorts
.globl _Copy_arrayof_conjoint_jshorts
.globl _Copy_conjoint_jints_atomic
.globl _Copy_arrayof_conjoint_jints
.globl _Copy_conjoint_jlongs_atomic
.globl _Copy_conjoint_jlongs_atomic
.globl _Copy_arrayof_conjoint_jlongs
.section .text,"ax"
.section .text,"ax"
/ Fast thread accessors, used by threadLS_solaris_amd64.cpp
.align 16
.align 16
fs_load:
movq %fs:(%rdi),%rax
ret
.align 16
fs_thread:
movq %fs:0x0,%rax
ret
.globl SafeFetch32, Fetch32PFI, Fetch32Resume
.align 16
// Prototype: int SafeFetch32 (int * Adr, int ErrValue)
SafeFetch32:
movl %esi, %eax
Fetch32PFI:
movl (%rdi), %eax
Fetch32Resume:
movq %fs:(%rdi),%rax
ret
.globl SafeFetchN, FetchNPFI, FetchNResume
.align 16
// Prototype: intptr_t SafeFetchN (intptr_t * Adr, intptr_t ErrValue)
SafeFetchN:
movq %rsi, %rax
FetchNPFI:
movq (%rdi), %rax
FetchNResume:
.align 16
fs_thread:
movq %fs:0x0,%rax
ret
.globl SpinPause
......@@ -78,7 +58,7 @@ SpinPause:
nop
movq $1, %rax
ret
/ Support for void Copy::arrayof_conjoint_bytes(void* from,
/ void* to,
......@@ -340,7 +320,7 @@ aci_CopyLeft:
addq $4,%rdx
jg 1b
ret
/ Support for void Copy::arrayof_conjoint_jlongs(jlong* from,
/ jlong* to,
/ size_t count)
......
......@@ -518,24 +518,6 @@ void os::print_register_info(outputStream *st, void *context) {
st->cr();
}
extern "C" int SafeFetch32 (int * adr, int Err) {
int rv = Err ;
_try {
rv = *((volatile int *) adr) ;
} __except(EXCEPTION_EXECUTE_HANDLER) {
}
return rv ;
}
extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t Err) {
intptr_t rv = Err ;
_try {
rv = *((volatile intptr_t *) adr) ;
} __except(EXCEPTION_EXECUTE_HANDLER) {
}
return rv ;
}
extern "C" int SpinPause () {
#ifdef AMD64
return 0 ;
......
......@@ -915,8 +915,6 @@ class os: AllStatic {
// of the global SpinPause() with C linkage.
// It'd also be eligible for inlining on many platforms.
extern "C" int SpinPause () ;
extern "C" int SafeFetch32 (int * adr, int errValue) ;
extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t errValue) ;
extern "C" int SpinPause();
#endif // SHARE_VM_RUNTIME_OS_HPP
......@@ -136,6 +136,13 @@ double (* StubRoutines::_intrinsic_sin )(double) = NULL;
double (* StubRoutines::_intrinsic_cos )(double) = NULL;
double (* StubRoutines::_intrinsic_tan )(double) = NULL;
address StubRoutines::_safefetch32_entry = NULL;
address StubRoutines::_safefetch32_fault_pc = NULL;
address StubRoutines::_safefetch32_continuation_pc = NULL;
address StubRoutines::_safefetchN_entry = NULL;
address StubRoutines::_safefetchN_fault_pc = NULL;
address StubRoutines::_safefetchN_continuation_pc = NULL;
// Initialization
//
// Note: to break cycle with universe initialization, stubs are generated in two phases.
......
......@@ -221,6 +221,14 @@ class StubRoutines: AllStatic {
static double (*_intrinsic_cos)(double);
static double (*_intrinsic_tan)(double);
// Safefetch stubs.
static address _safefetch32_entry;
static address _safefetch32_fault_pc;
static address _safefetch32_continuation_pc;
static address _safefetchN_entry;
static address _safefetchN_fault_pc;
static address _safefetchN_continuation_pc;
public:
// Initialization/Testing
static void initialize1(); // must happen before universe::genesis
......@@ -381,6 +389,34 @@ class StubRoutines: AllStatic {
return _intrinsic_tan(d);
}
//
// Safefetch stub support
//
typedef int (*SafeFetch32Stub)(int* adr, int errValue);
typedef intptr_t (*SafeFetchNStub) (intptr_t* adr, intptr_t errValue);
static SafeFetch32Stub SafeFetch32_stub() { return CAST_TO_FN_PTR(SafeFetch32Stub, _safefetch32_entry); }
static SafeFetchNStub SafeFetchN_stub() { return CAST_TO_FN_PTR(SafeFetchNStub, _safefetchN_entry); }
static bool is_safefetch_fault(address pc) {
return pc != NULL &&
(pc == _safefetch32_fault_pc ||
pc == _safefetchN_fault_pc);
}
static address continuation_for_safefetch_fault(address pc) {
assert(_safefetch32_continuation_pc != NULL &&
_safefetchN_continuation_pc != NULL,
"not initialized");
if (pc == _safefetch32_fault_pc) return _safefetch32_continuation_pc;
if (pc == _safefetchN_fault_pc) return _safefetchN_continuation_pc;
ShouldNotReachHere();
return NULL;
}
//
// Default versions of the above arraycopy functions for platforms which do
// not have specialized versions
......@@ -400,4 +436,15 @@ class StubRoutines: AllStatic {
static void arrayof_oop_copy_uninit(HeapWord* src, HeapWord* dest, size_t count);
};
// Safefetch allows to load a value from a location that's not known
// to be valid. If the load causes a fault, the error value is returned.
inline int SafeFetch32(int* adr, int errValue) {
assert(StubRoutines::SafeFetch32_stub(), "stub not yet generated");
return StubRoutines::SafeFetch32_stub()(adr, errValue);
}
inline intptr_t SafeFetchN(intptr_t* adr, intptr_t errValue) {
assert(StubRoutines::SafeFetchN_stub(), "stub not yet generated");
return StubRoutines::SafeFetchN_stub()(adr, errValue);
}
#endif // SHARE_VM_RUNTIME_STUBROUTINES_HPP
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