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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "asm_support_arm.S"
#define MANAGED_ARGS_R4_LR_SAVE_SIZE /*s0-s15*/ 16 * 4 + /*r0-r3*/ 4 * 4 + /*r4*/ 4 + /*lr*/ 4
// Note: R4 is saved for stack alignment.
.macro SAVE_MANAGED_ARGS_R4_LR_INCREASE_FRAME
// Save GPR args r0-r3 and return address. Also save r4 for stack alignment.
push {r0-r4, lr}
.cfi_adjust_cfa_offset 24
.cfi_rel_offset lr, 20
// Save FPR args.
vpush {s0-s15}
.cfi_adjust_cfa_offset 64
.endm
.macro RESTORE_MANAGED_ARGS_R4_AND_RETURN restore_cfa
// Restore FPR args.
vpop {s0-s15}
.cfi_adjust_cfa_offset -64
// Restore GPR args and r4 and return.
pop {r0-r4, pc}
.if \restore_cfa
.cfi_adjust_cfa_offset 64
.endif
.endm
.macro JNI_SAVE_MANAGED_ARGS_TRAMPOLINE name, cxx_name, arg1 = "none"
.extern \cxx_name
ENTRY \name
// Note: Managed callee-save registers have been saved by the JNI stub.
// Save managed args, r4 (for stack alignment) and LR.
SAVE_MANAGED_ARGS_R4_LR_INCREASE_FRAME
// Call `cxx_name()`.
.ifnc \arg1, none
mov r0, \arg1 @ Pass arg1.
.endif
bl \cxx_name @ Call cxx_name(...).
// Restore args and R4 and return.
RESTORE_MANAGED_ARGS_R4_AND_RETURN /*restore_cfa*/ 0
END \name
.endm
.macro JNI_SAVE_RETURN_VALUE_TRAMPOLINE name, cxx_name, arg1, arg2 = "none", label = "none"
.extern \cxx_name
ENTRY \name
.ifnc \label, none
\label:
.endif
// Save GPR return registers and return address. Also save r4 for stack alignment.
push {r0-r1, r4, lr}
.cfi_adjust_cfa_offset 16
.cfi_rel_offset lr, 12
// Save FPR return registers.
vpush {s0-s1}
.cfi_adjust_cfa_offset 8
// Call `cxx_name()`.
mov r0, \arg1 @ Pass arg1.
.ifnc \arg2, none
mov r1, \arg2 @ Pass arg2.
.endif
bl \cxx_name @ Call cxx_name(...).
// Restore FPR return registers.
vpop {s0-s1}
.cfi_adjust_cfa_offset -8
// Restore GPR return registers and r4 and return.
pop {r0-r1, r4, pc}
END \name
.endm
/*
* Jni dlsym lookup stub.
*/
.extern artFindNativeMethod
.extern artFindNativeMethodRunnable
ENTRY art_jni_dlsym_lookup_stub
push {r0, r1, r2, r3, lr} @ spill regs
.cfi_adjust_cfa_offset 20
.cfi_rel_offset lr, 16
sub sp, #12 @ pad stack pointer to align frame
.cfi_adjust_cfa_offset 12
mov r0, rSELF @ pass Thread::Current()
// Call artFindNativeMethod() for normal native and artFindNativeMethodRunnable()
// for @FastNative or @CriticalNative.
ldr ip, [r0, #THREAD_TOP_QUICK_FRAME_OFFSET] // uintptr_t tagged_quick_frame
bic ip, #TAGGED_JNI_SP_MASK // ArtMethod** sp
ldr ip, [ip] // ArtMethod* method
ldr ip, [ip, #ART_METHOD_ACCESS_FLAGS_OFFSET] // uint32_t access_flags
tst ip, #(ACCESS_FLAGS_METHOD_IS_FAST_NATIVE | ACCESS_FLAGS_METHOD_IS_CRITICAL_NATIVE)
bne .Llookup_stub_fast_or_critical_native
blx artFindNativeMethod
b .Llookup_stub_continue
.Llookup_stub_fast_or_critical_native:
blx artFindNativeMethodRunnable
.Llookup_stub_continue:
mov r12, r0 @ save result in r12
add sp, #12 @ restore stack pointer
.cfi_adjust_cfa_offset -12
CFI_REMEMBER_STATE
cbz r0, 1f @ is method code null?
pop {r0, r1, r2, r3, lr} @ restore regs
.cfi_adjust_cfa_offset -20
.cfi_restore lr
bx r12 @ if non-null, tail call to method's code
1:
CFI_RESTORE_STATE_AND_DEF_CFA sp, 20
pop {r0, r1, r2, r3, pc} @ restore regs and return to caller to handle exception
END art_jni_dlsym_lookup_stub
/*
* Jni dlsym lookup stub for @CriticalNative.
*/
ENTRY art_jni_dlsym_lookup_critical_stub
// The hidden arg holding the tagged method (bit 0 set means GenericJNI) is r4.
// For Generic JNI we already have a managed frame, so we reuse the art_jni_dlsym_lookup_stub.
tst r4, #1
bne art_jni_dlsym_lookup_stub
// Reserve space for a SaveRefsAndArgs managed frame, either for the actual runtime
// method or for a GenericJNI frame which is similar but has a native method and a tag.
// Do this eagerly, so that we can use these registers as temps without the need to
// save and restore them multiple times.
INCREASE_FRAME FRAME_SIZE_SAVE_REFS_AND_ARGS
// Save args, the hidden arg and caller PC. No CFI needed for args and the hidden arg.
push {r0, r1, r2, r3, r4, lr}
.cfi_adjust_cfa_offset 24
.cfi_rel_offset lr, 20
// Call artCriticalNativeFrameSize(method, caller_pc)
mov r0, r4 // r0 := method (from hidden arg)
mov r1, lr // r1 := caller_pc
bl artCriticalNativeFrameSize
// Prepare the return address for managed stack walk of the SaveRefsAndArgs frame.
// If we're coming from JNI stub with tail call, it is LR. If we're coming from
// JNI stub that saved the return address, it will be the last value we copy below.
// If we're coming directly from compiled code, it is LR, set further down.
ldr lr, [sp, #20]
// Move the stack args if any.
add r4, sp, #24
cbz r0, .Lcritical_skip_copy_args
.Lcritical_copy_args_loop:
ldrd ip, lr, [r4, #FRAME_SIZE_SAVE_REFS_AND_ARGS]
subs r0, r0, #8
strd ip, lr, [r4], #8
bne .Lcritical_copy_args_loop
.Lcritical_skip_copy_args:
// The managed frame address is now in R4. This is conveniently a callee-save in native ABI.
// Restore args.
pop {r0, r1, r2, r3}
.cfi_adjust_cfa_offset -16
// Spill registers for the SaveRefsAndArgs frame above the stack args.
// Note that the runtime shall not examine the args here, otherwise we would have to
// move them in registers and stack to account for the difference between managed and
// native ABIs.
add ip, r4, #FRAME_SIZE_SAVE_REFS_AND_ARGS - 40
stmia ip, {r1-r3, r5-r8, r10-r11, lr} // LR: Save return address for tail call from JNI stub.
// (If there were any stack args, we're storing the value that's already there.
// For direct calls from compiled managed code, we shall overwrite this below.)
// Skip args r1-r3.
CFI_EXPRESSION_BREG 5, 4, FRAME_SIZE_SAVE_REFS_AND_ARGS - 28
CFI_EXPRESSION_BREG 6, 4, FRAME_SIZE_SAVE_REFS_AND_ARGS - 24
CFI_EXPRESSION_BREG 7, 4, FRAME_SIZE_SAVE_REFS_AND_ARGS - 20
CFI_EXPRESSION_BREG 8, 4, FRAME_SIZE_SAVE_REFS_AND_ARGS - 16
CFI_EXPRESSION_BREG 10, 4, FRAME_SIZE_SAVE_REFS_AND_ARGS - 12
CFI_EXPRESSION_BREG 11, 4, FRAME_SIZE_SAVE_REFS_AND_ARGS - 8
// The saved return PC for managed stack walk is not necessarily our LR.
// Skip managed FP args as these are native ABI caller-saves and not args.
// Restore the hidden arg to r1 and caller PC.
pop {r1, lr}
.cfi_adjust_cfa_offset -8
.cfi_restore lr
// Save our return PC in the padding.
str lr, [r4, #__SIZEOF_POINTER__]
CFI_EXPRESSION_BREG 14, 4, __SIZEOF_POINTER__
ldr ip, [r1, #ART_METHOD_ACCESS_FLAGS_OFFSET] // Load access flags.
add r2, r4, #1 // Prepare managed SP tagged for a GenericJNI frame.
tst ip, #ACCESS_FLAGS_METHOD_IS_NATIVE
bne .Lcritical_skip_prepare_runtime_method
// When coming from a compiled method, the return PC for managed stack walk is LR.
// (When coming from a compiled stub, the correct return PC is already stored above.)
str lr, [r4, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - __SIZEOF_POINTER__)]
// Replace the target method with the SaveRefsAndArgs runtime method.
LOAD_RUNTIME_INSTANCE r1
ldr r1, [r1, #RUNTIME_SAVE_REFS_AND_ARGS_METHOD_OFFSET]
mov r2, r4 // Prepare untagged managed SP for the runtime method.
.Lcritical_skip_prepare_runtime_method:
// Store the method on the bottom of the managed frame.
str r1, [r4]
// Place (maybe tagged) managed SP in Thread::Current()->top_quick_frame.
str r2, [rSELF, #THREAD_TOP_QUICK_FRAME_OFFSET]
// Preserve the native arg register r0 in callee-save register r10 which was saved above.
mov r10, r0
// Call artFindNativeMethodRunnable()
mov r0, rSELF // pass Thread::Current()
bl artFindNativeMethodRunnable
// Store result in scratch reg.
mov ip, r0
// Restore the native arg register r0.
mov r0, r10
// Restore the frame. We shall not need the method anymore.
add r1, r4, #FRAME_SIZE_SAVE_REFS_AND_ARGS - 40
ldmia r1, {r1-r3, r5-r8, r10-r11}
.cfi_restore r5
.cfi_restore r6
.cfi_restore r7
.cfi_restore r8
.cfi_restore r10
.cfi_restore r11
REFRESH_MARKING_REGISTER
// Check for exception before moving args back to keep the return PC for managed stack walk.
cmp ip, #0
CFI_REMEMBER_STATE
beq .Lcritical_deliver_exception
// Restore our return PC.
ldr lr, [r4, #__SIZEOF_POINTER__]
.cfi_restore lr
// Move stack args to their original place.
cmp sp, r4
beq .Lcritical_skip_copy_args_back
push {r0, r1, r2, r3}
.cfi_adjust_cfa_offset 16
add r0, sp, #16
sub r0, r4, r0
.Lcritical_copy_args_loop_back:
ldrd r2, r3, [r4, #-8]!
subs r0, r0, #8
strd r2, r3, [r4, #FRAME_SIZE_SAVE_REFS_AND_ARGS]
bne .Lcritical_copy_args_loop_back
pop {r0, r1, r2, r3}
.cfi_adjust_cfa_offset -16
.Lcritical_skip_copy_args_back:
// Remove the frame reservation.
DECREASE_FRAME FRAME_SIZE_SAVE_REFS_AND_ARGS
// Do the tail call.
bx ip
.Lcritical_deliver_exception:
CFI_RESTORE_STATE_AND_DEF_CFA sp, FRAME_SIZE_SAVE_REFS_AND_ARGS
// The exception delivery checks that rSELF was saved but the SaveRefsAndArgs
// frame does not save it, so we cannot use the existing SaveRefsAndArgs frame.
// That's why we checked for exception after restoring registers from it.
// We need to build a SaveAllCalleeSaves frame instead. Args are irrelevant at this
// point but keep the area allocated for stack args to keep CFA definition simple.
#if FRAME_SIZE_SAVE_REFS_AND_ARGS != FRAME_SIZE_SAVE_ALL_CALLEE_SAVES
# error "Expected FRAME_SIZE_SAVE_REFS_AND_ARGS == FRAME_SIZE_SAVE_ALL_CALLEE_SAVES"
// Otherwise we would need to adjust SP and R4 and move our return PC which is at [R4, #4].
// (Luckily, both SaveRefsAndArgs and SaveAllCalleeSaves frames have padding there.)
#endif
// Spill registers for the SaveAllCalleeSaves frame above the stack args area.
add ip, r4, #FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 32
stmia ip, {r5-r11} // Keep the caller PC for managed stack walk.
CFI_EXPRESSION_BREG 5, 4, FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 32
CFI_EXPRESSION_BREG 6, 4, FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 28
CFI_EXPRESSION_BREG 7, 4, FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 24
CFI_EXPRESSION_BREG 8, 4, FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 20
CFI_EXPRESSION_BREG 9, 4, FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 16
CFI_EXPRESSION_BREG 10, 4, FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 12
CFI_EXPRESSION_BREG 11, 4, FRAME_SIZE_SAVE_ALL_CALLEE_SAVES - 8
// Skip R4, it is callee-save in managed ABI.
add ip, r4, #12
vstmia ip, {s16-s31}
// Store ArtMethod* Runtime::callee_save_methods_[kSaveAllCalleeSaves] to the managed frame.
LOAD_RUNTIME_INSTANCE ip
ldr ip, [ip, #RUNTIME_SAVE_ALL_CALLEE_SAVES_METHOD_OFFSET]
str ip, [r4]
// Place the managed frame SP in Thread::Current()->top_quick_frame.
str r4, [rSELF, #THREAD_TOP_QUICK_FRAME_OFFSET]
DELIVER_PENDING_EXCEPTION_FRAME_READY
END art_jni_dlsym_lookup_critical_stub
/*
* Read barrier for the method's declaring class needed by JNI stub for static methods.
* (We're using a pointer to the declaring class in `ArtMethod` as `jclass`.)
*/
// The method argument is already in r0 for call to `artJniReadBarrier(ArtMethod*)`.
JNI_SAVE_MANAGED_ARGS_TRAMPOLINE art_jni_read_barrier, artJniReadBarrier
/*
* Trampoline to `artJniMethodStart()` that preserves all managed arguments.
*/
JNI_SAVE_MANAGED_ARGS_TRAMPOLINE art_jni_method_start, artJniMethodStart, rSELF
/*
* Trampoline to `artJniMethodEntryHook()` that preserves all managed arguments.
*/
JNI_SAVE_MANAGED_ARGS_TRAMPOLINE art_jni_method_entry_hook, artJniMethodEntryHook, rSELF
/*
* Trampoline to `artJniMonitoredMethodStart()` that preserves all managed arguments.
*/
JNI_SAVE_MANAGED_ARGS_TRAMPOLINE art_jni_monitored_method_start, artJniMonitoredMethodStart, rSELF
/*
* Trampoline to `artJniMethodEnd()` that preserves all return registers.
*/
JNI_SAVE_RETURN_VALUE_TRAMPOLINE art_jni_method_end, artJniMethodEnd, rSELF
/*
* Trampoline to `artJniMonitoredMethodEnd()` that preserves all return registers.
*/
JNI_SAVE_RETURN_VALUE_TRAMPOLINE art_jni_monitored_method_end, artJniMonitoredMethodEnd, rSELF
/*
* Entry from JNI stub that tries to lock the object in a fast path and
* calls `artLockObjectFromCode()` (the same as for managed code) for the
* difficult cases, may block for GC.
* Custom calling convention:
* r4 holds the non-null object to lock.
* Callee-save registers have been saved and can be used as temporaries.
* All argument registers need to be preserved.
*/
ENTRY art_jni_lock_object
// Note: the slow path is actually the art_jni_lock_object_no_inline (tail call).
LOCK_OBJECT_FAST_PATH r4, r5, r6, r7, .Llock_object_jni_slow, /*can_be_null*/ 0
END art_jni_lock_object
/*
* Entry from JNI stub that calls `artLockObjectFromCode()`
* (the same as for managed code), may block for GC.
* Custom calling convention:
* r4 holds the non-null object to lock.
* Callee-save registers have been saved and can be used as temporaries.
* All argument registers need to be preserved.
*/
.extern artLockObjectFromCode
ENTRY art_jni_lock_object_no_inline
// This is also the slow path for art_jni_lock_object.
// Note that we need a local label as the assembler emits bad instructions
// for CBZ/CBNZ if we try to jump to `art_jni_lock_object_no_inline`.
.Llock_object_jni_slow:
// Save managed args, r4 (for stack alignment) and LR.
SAVE_MANAGED_ARGS_R4_LR_INCREASE_FRAME
// Call `artLockObjectFromCode()`
mov r0, r4 @ Pass the object to lock.
mov r1, rSELF @ Pass Thread::Current().
bl artLockObjectFromCode @ (Object* obj, Thread*)
// Check result.
cbnz r0, 1f
// Restore args and r4 and return.
RESTORE_MANAGED_ARGS_R4_AND_RETURN /*restore_cfa*/ 1
1:
// All args are irrelevant when throwing an exception and R4 is preserved
// by the `artLockObjectFromCode()` call. Load LR and drop saved args and R4.
ldr lr, [sp, #(MANAGED_ARGS_R4_LR_SAVE_SIZE - 4)]
.cfi_restore lr
DECREASE_FRAME MANAGED_ARGS_R4_LR_SAVE_SIZE
// Make a tail call to `artDeliverPendingExceptionFromCode()`.
// Rely on the JNI transition frame constructed in the JNI stub.
mov r0, rSELF @ Pass Thread::Current().
b artDeliverPendingExceptionFromCode @ (Thread*)
END art_jni_lock_object_no_inline
/*
* Entry from JNI stub that tries to unlock the object in a fast path and calls
* `artJniUnlockObject()` for the difficult cases. Note that failure to unlock
* is fatal, so we do not need to check for exceptions in the slow path.
* Custom calling convention:
* r4 holds the non-null object to unlock.
* Callee-save registers have been saved and can be used as temporaries.
* Return registers r0-r1 and s0-s1 need to be preserved.
*/
ENTRY art_jni_unlock_object
// Note: the slow path is actually the art_jni_unlock_object_no_inline (tail call).
UNLOCK_OBJECT_FAST_PATH r4, r5, r6, r7, .Lunlock_object_jni_slow, /*can_be_null*/ 0
END art_jni_unlock_object
/*
* Entry from JNI stub that calls `artJniUnlockObject()`. Note that failure to
* unlock is fatal, so we do not need to check for exceptions.
* Custom calling convention:
* r4 holds the non-null object to unlock.
* Callee-save registers have been saved and can be used as temporaries.
* Return registers r0-r1 and s0-s1 need to be preserved.
*/
// This is also the slow path for art_jni_unlock_object.
JNI_SAVE_RETURN_VALUE_TRAMPOLINE art_jni_unlock_object_no_inline, artJniUnlockObject, r4, rSELF, \
/* Note that we need a local label as the assembler emits bad instructions */ \
/* for CBZ/CBNZ if we try to jump to `art_jni_unlock_object_no_inline`. */ \
.Lunlock_object_jni_slow