runtime/arch/arm/jni_entrypoints_arm.S - platform/art - Git at Google

 /*
  * 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"

     /*
      * 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 r0, 0
     .cfi_rel_offset r1, 4
     .cfi_rel_offset r2, 8
     .cfi_rel_offset r3, 12
     .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, #1                                     // 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_native
     blx    artFindNativeMethod
     b      .Llookup_stub_continue
 .Llookup_stub_fast_native:
     blx    artFindNativeMethodRunnable
 .Llookup_stub_continue:
     mov    r12, r0                        @ save result in r12

     add    sp, #12                        @ restore stack pointer
     .cfi_adjust_cfa_offset -12
     cbz    r0, 1f                         @ is method code null?
     pop    {r0, r1, r2, r3, lr}           @ restore regs
     .cfi_adjust_cfa_offset -20
     .cfi_restore r0
     .cfi_restore r1
     .cfi_restore r2
     .cfi_restore r3
     .cfi_restore lr
     bx     r12                            @ if non-null, tail call to method's code
 1:
     pop    {r0, r1, r2, r3, pc}           @ restore regs and return to caller to handle exception
 END art_jni_dlsym_lookup_stub

 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

     // We need to create a GenericJNI managed frame above the stack args.

     // GenericJNI frame is similar to SaveRegsAndArgs frame with the native method
     // instead of runtime method saved at the bottom. 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.
     SETUP_SAVE_REFS_AND_ARGS_FRAME_REGISTERS_ONLY
     // Save the hidden arg as method pointer, r0 in the padding.
     // (x0 is an arg in native ABI but not considered an arg in managed ABI.)
     strd   r4, r0, [sp]

     // Call artCriticalNativeOutArgsSize(method)
     mov    r0, r4  // r0 := method (from hidden arg)
     bl     artCriticalNativeOutArgsSize

     // Check if we have any stack args.
     cbnz   r0, .Lcritical_has_stack_args

     // Without stack args, the frame is fully constructed.
     // Place tagged managed sp in Thread::Current()->top_quick_frame.
     mov    ip, sp
     orr    ip, #1  // Tag as GenericJNI frame.
     str    ip, [rSELF, #THREAD_TOP_QUICK_FRAME_OFFSET]

     // Call artFindNativeMethodRunnable()
     mov    r0, rSELF   // pass Thread::Current()
     bl     artFindNativeMethodRunnable

     // Store result in scratch reg.
     mov    ip, r0

     // Restore frame.
     .cfi_remember_state
     ldrd   r4, r0, [sp]
     RESTORE_SAVE_REFS_AND_ARGS_FRAME
     REFRESH_MARKING_REGISTER

     // Check for exception.
     cmp    ip, #0
     beq    .Lcritical_deliver_exception

     // Do the tail call.
     bx     ip
     .cfi_restore_state
     .cfi_def_cfa_offset FRAME_SIZE_SAVE_REFS_AND_ARGS

 .Lcritical_has_stack_args:
     // Move the out args size to a scratch register.
     mov    ip, r0

     // Restore register args as we're about to move stack args.
     ldrd   r4, r0, [sp]
     RESTORE_SAVE_REFS_AND_ARGS_FRAME

     // Reserve space for SaveRefsAndArgs frame.
     sub sp, #FRAME_SIZE_SAVE_REFS_AND_ARGS
     .cfi_adjust_cfa_offset FRAME_SIZE_SAVE_REFS_AND_ARGS

     // Save arg regs so that we can use them as temporaries.
     push   {r0-r3}
     .cfi_adjust_cfa_offset 16

     // Move out args. For simplicity include the return address at the end.
     add    r0, sp, #16   // Destination.
     add    ip, r0, ip    // Destination end.
 1:
     ldrd   r2, r3, [r0, #FRAME_SIZE_SAVE_REFS_AND_ARGS]
     strd   r2, r3, [r0], #8
     cmp    r0, ip
     bne    1b

     // Save our LR, load caller's LR and redefine CFI to take ownership of the JNI stub frame.
     str    lr, [ip, #-__SIZEOF_POINTER__]
     mov    lr, r3  // The last moved value from the loop above.
     .cfi_def_cfa ip, FRAME_SIZE_SAVE_REFS_AND_ARGS

     // Restore arg regs.
     pop    {r0-r3}  // No `.cfi_adjust_cfa_offset`, CFA register is currently ip, not sp.

     // Re-create the SaveRefsAndArgs frame above the args.
     strd   r4, r0, [ip]  // r0 in the padding as before.
     add    r4, ip, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40
     stmia  r4, {r1-r3, r5-r8, r10-r11, lr}   @ 10 words of callee saves and args.
     .cfi_rel_offset r1, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 0
     .cfi_rel_offset r2, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 4
     .cfi_rel_offset r3, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 8
     .cfi_rel_offset r5, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 12
     .cfi_rel_offset r6, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 16
     .cfi_rel_offset r7, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 20
     .cfi_rel_offset r8, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 24
     .cfi_rel_offset r10, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 28
     .cfi_rel_offset r11, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 32
     .cfi_rel_offset lr, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 36
     vstmdb r4!, {s0-s15}                     @ 16 words of float args.

     // Move the frame register to a callee-save register.
     mov    r11, ip
     .cfi_def_cfa_register r11

     // Place tagged managed sp in Thread::Current()->top_quick_frame.
     orr    ip, r11, #1  // Tag as GenericJNI frame.
     str    ip, [rSELF, #THREAD_TOP_QUICK_FRAME_OFFSET]

     // Call artFindNativeMethodRunnable()
     mov    r0, rSELF   // pass Thread::Current()
     bl     artFindNativeMethodRunnable

     // Store result in scratch reg.
     mov    ip, r0

     // Restore the frame. We shall not need the method anymore, so use r4 as scratch register.
     mov    r4, r11
     .cfi_def_cfa_register r4
     ldr    r0, [r4, #4]
     add    r11, r4, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 - 64)
     vldmia r11!, {s0-s15}                    @ 16 words of float args.
     ldmia  r11, {r1-r3, r5-r8, r10-r11, lr}  @ 10 words of callee saves and args.
     .cfi_restore r1
     .cfi_restore r2
     .cfi_restore r3
     .cfi_restore r5
     .cfi_restore r6
     .cfi_restore r7
     .cfi_restore r8
     .cfi_restore r10
     .cfi_restore r11
     .cfi_restore lr
     REFRESH_MARKING_REGISTER

     // Check for exception.
     cmp    ip, #0
     beq    3f

     // Save arg regs so that we can use them as temporaries.
     push   {r0-r3}  // No `.cfi_adjust_cfa_offset`, CFA register is currently r4, not sp.

     // Move stack args to their original place.
     mov    r0, r4
     add    r1, sp, #16
 2:
     ldrd   r2, r3, [r0, #-8]!
     strd   r2, r3, [r0, #FRAME_SIZE_SAVE_REFS_AND_ARGS]
     cmp    r1, r0
     bne    2b

     // Replace original return address with caller's return address.
     ldr    r1, [r4, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - __SIZEOF_POINTER__)]
     str    lr, [r4, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - __SIZEOF_POINTER__)]

     // Restore LR and redefine CFI to release ownership of the JNI stub frame.
     .cfi_remember_state
     mov    lr, r1
     .cfi_def_cfa sp, FRAME_SIZE_SAVE_REFS_AND_ARGS + 16

     // Restore args
     pop    {r0-r3}
     .cfi_adjust_cfa_offset -16

     // Remove the frame reservation.
     add    sp, #FRAME_SIZE_SAVE_REFS_AND_ARGS
     .cfi_adjust_cfa_offset -FRAME_SIZE_SAVE_REFS_AND_ARGS

     // Do the tail call.
     bx     ip
     .cfi_restore_state
     .cfi_def_cfa x4, FRAME_SIZE_SAVE_REFS_AND_ARGS

 3:
     // Drop stack args and the SaveRefsAndArgs reservation.
     mov    sp, r4
     add    sp, #FRAME_SIZE_SAVE_REFS_AND_ARGS
     .cfi_def_cfa sp, 0

 .Lcritical_deliver_exception:
     // When delivering exception, we check that rSELF was saved but the SaveRefsAndArgs frame does
     // not save it, so we cannot use DELIVER_PENDING_EXCEPTION_FRAME_READY with the above frames.
     DELIVER_PENDING_EXCEPTION
 END art_jni_dlsym_lookup_critical_stub
	/*
	* 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"

	/*
	* 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 r0, 0
	.cfi_rel_offset r1, 4
	.cfi_rel_offset r2, 8
	.cfi_rel_offset r3, 12
	.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, #1 // 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_native
	blx artFindNativeMethod
	b .Llookup_stub_continue
	.Llookup_stub_fast_native:
	blx artFindNativeMethodRunnable
	.Llookup_stub_continue:
	mov r12, r0 @ save result in r12

	add sp, #12 @ restore stack pointer
	.cfi_adjust_cfa_offset -12
	cbz r0, 1f @ is method code null?
	pop {r0, r1, r2, r3, lr} @ restore regs
	.cfi_adjust_cfa_offset -20
	.cfi_restore r0
	.cfi_restore r1
	.cfi_restore r2
	.cfi_restore r3
	.cfi_restore lr
	bx r12 @ if non-null, tail call to method's code
	1:
	pop {r0, r1, r2, r3, pc} @ restore regs and return to caller to handle exception
	END art_jni_dlsym_lookup_stub

	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

	// We need to create a GenericJNI managed frame above the stack args.

	// GenericJNI frame is similar to SaveRegsAndArgs frame with the native method
	// instead of runtime method saved at the bottom. 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.
	SETUP_SAVE_REFS_AND_ARGS_FRAME_REGISTERS_ONLY
	// Save the hidden arg as method pointer, r0 in the padding.
	// (x0 is an arg in native ABI but not considered an arg in managed ABI.)
	strd r4, r0, [sp]

	// Call artCriticalNativeOutArgsSize(method)
	mov r0, r4 // r0 := method (from hidden arg)
	bl artCriticalNativeOutArgsSize

	// Check if we have any stack args.
	cbnz r0, .Lcritical_has_stack_args

	// Without stack args, the frame is fully constructed.
	// Place tagged managed sp in Thread::Current()->top_quick_frame.
	mov ip, sp
	orr ip, #1 // Tag as GenericJNI frame.
	str ip, [rSELF, #THREAD_TOP_QUICK_FRAME_OFFSET]

	// Call artFindNativeMethodRunnable()
	mov r0, rSELF // pass Thread::Current()
	bl artFindNativeMethodRunnable

	// Store result in scratch reg.
	mov ip, r0

	// Restore frame.
	.cfi_remember_state
	ldrd r4, r0, [sp]
	RESTORE_SAVE_REFS_AND_ARGS_FRAME
	REFRESH_MARKING_REGISTER

	// Check for exception.
	cmp ip, #0
	beq .Lcritical_deliver_exception

	// Do the tail call.
	bx ip
	.cfi_restore_state
	.cfi_def_cfa_offset FRAME_SIZE_SAVE_REFS_AND_ARGS

	.Lcritical_has_stack_args:
	// Move the out args size to a scratch register.
	mov ip, r0

	// Restore register args as we're about to move stack args.
	ldrd r4, r0, [sp]
	RESTORE_SAVE_REFS_AND_ARGS_FRAME

	// Reserve space for SaveRefsAndArgs frame.
	sub sp, #FRAME_SIZE_SAVE_REFS_AND_ARGS
	.cfi_adjust_cfa_offset FRAME_SIZE_SAVE_REFS_AND_ARGS

	// Save arg regs so that we can use them as temporaries.
	push {r0-r3}
	.cfi_adjust_cfa_offset 16

	// Move out args. For simplicity include the return address at the end.
	add r0, sp, #16 // Destination.
	add ip, r0, ip // Destination end.
	1:
	ldrd r2, r3, [r0, #FRAME_SIZE_SAVE_REFS_AND_ARGS]
	strd r2, r3, [r0], #8
	cmp r0, ip
	bne 1b

	// Save our LR, load caller's LR and redefine CFI to take ownership of the JNI stub frame.
	str lr, [ip, #-__SIZEOF_POINTER__]
	mov lr, r3 // The last moved value from the loop above.
	.cfi_def_cfa ip, FRAME_SIZE_SAVE_REFS_AND_ARGS

	// Restore arg regs.
	pop {r0-r3} // No `.cfi_adjust_cfa_offset`, CFA register is currently ip, not sp.

	// Re-create the SaveRefsAndArgs frame above the args.
	strd r4, r0, [ip] // r0 in the padding as before.
	add r4, ip, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40
	stmia r4, {r1-r3, r5-r8, r10-r11, lr} @ 10 words of callee saves and args.
	.cfi_rel_offset r1, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 0
	.cfi_rel_offset r2, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 4
	.cfi_rel_offset r3, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 8
	.cfi_rel_offset r5, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 12
	.cfi_rel_offset r6, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 16
	.cfi_rel_offset r7, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 20
	.cfi_rel_offset r8, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 24
	.cfi_rel_offset r10, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 28
	.cfi_rel_offset r11, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 32
	.cfi_rel_offset lr, FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 + 36
	vstmdb r4!, {s0-s15} @ 16 words of float args.

	// Move the frame register to a callee-save register.
	mov r11, ip
	.cfi_def_cfa_register r11

	// Place tagged managed sp in Thread::Current()->top_quick_frame.
	orr ip, r11, #1 // Tag as GenericJNI frame.
	str ip, [rSELF, #THREAD_TOP_QUICK_FRAME_OFFSET]

	// Call artFindNativeMethodRunnable()
	mov r0, rSELF // pass Thread::Current()
	bl artFindNativeMethodRunnable

	// Store result in scratch reg.
	mov ip, r0

	// Restore the frame. We shall not need the method anymore, so use r4 as scratch register.
	mov r4, r11
	.cfi_def_cfa_register r4
	ldr r0, [r4, #4]
	add r11, r4, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - 40 - 64)
	vldmia r11!, {s0-s15} @ 16 words of float args.
	ldmia r11, {r1-r3, r5-r8, r10-r11, lr} @ 10 words of callee saves and args.
	.cfi_restore r1
	.cfi_restore r2
	.cfi_restore r3
	.cfi_restore r5
	.cfi_restore r6
	.cfi_restore r7
	.cfi_restore r8
	.cfi_restore r10
	.cfi_restore r11
	.cfi_restore lr
	REFRESH_MARKING_REGISTER

	// Check for exception.
	cmp ip, #0
	beq 3f

	// Save arg regs so that we can use them as temporaries.
	push {r0-r3} // No `.cfi_adjust_cfa_offset`, CFA register is currently r4, not sp.

	// Move stack args to their original place.
	mov r0, r4
	add r1, sp, #16
	2:
	ldrd r2, r3, [r0, #-8]!
	strd r2, r3, [r0, #FRAME_SIZE_SAVE_REFS_AND_ARGS]
	cmp r1, r0
	bne 2b

	// Replace original return address with caller's return address.
	ldr r1, [r4, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - __SIZEOF_POINTER__)]
	str lr, [r4, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - __SIZEOF_POINTER__)]

	// Restore LR and redefine CFI to release ownership of the JNI stub frame.
	.cfi_remember_state
	mov lr, r1
	.cfi_def_cfa sp, FRAME_SIZE_SAVE_REFS_AND_ARGS + 16

	// Restore args
	pop {r0-r3}
	.cfi_adjust_cfa_offset -16

	// Remove the frame reservation.
	add sp, #FRAME_SIZE_SAVE_REFS_AND_ARGS
	.cfi_adjust_cfa_offset -FRAME_SIZE_SAVE_REFS_AND_ARGS

	// Do the tail call.
	bx ip
	.cfi_restore_state
	.cfi_def_cfa x4, FRAME_SIZE_SAVE_REFS_AND_ARGS

	3:
	// Drop stack args and the SaveRefsAndArgs reservation.
	mov sp, r4
	add sp, #FRAME_SIZE_SAVE_REFS_AND_ARGS
	.cfi_def_cfa sp, 0

	.Lcritical_deliver_exception:
	// When delivering exception, we check that rSELF was saved but the SaveRefsAndArgs frame does
	// not save it, so we cannot use DELIVER_PENDING_EXCEPTION_FRAME_READY with the above frames.
	DELIVER_PENDING_EXCEPTION
	END art_jni_dlsym_lookup_critical_stub