/* * Copyright (C) 2014 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_arm64.S" /* * Jni dlsym lookup stub. */ .extern artFindNativeMethod .extern artFindNativeMethodRunnable ENTRY art_jni_dlsym_lookup_stub // spill regs. stp x29, x30, [sp, #-16]! .cfi_adjust_cfa_offset 16 .cfi_rel_offset x29, 0 .cfi_rel_offset x30, 8 mov x29, sp stp d6, d7, [sp, #-16]! .cfi_adjust_cfa_offset 16 stp d4, d5, [sp, #-16]! .cfi_adjust_cfa_offset 16 stp d2, d3, [sp, #-16]! .cfi_adjust_cfa_offset 16 stp d0, d1, [sp, #-16]! .cfi_adjust_cfa_offset 16 stp x6, x7, [sp, #-16]! .cfi_adjust_cfa_offset 16 stp x4, x5, [sp, #-16]! .cfi_adjust_cfa_offset 16 stp x2, x3, [sp, #-16]! .cfi_adjust_cfa_offset 16 stp x0, x1, [sp, #-16]! .cfi_adjust_cfa_offset 16 mov x0, xSELF // pass Thread::Current() // Call artFindNativeMethod() for normal native and artFindNativeMethodRunnable() // for @FastNative or @CriticalNative. ldr xIP0, [x0, #THREAD_TOP_QUICK_FRAME_OFFSET] // uintptr_t tagged_quick_frame bic xIP0, xIP0, #1 // ArtMethod** sp ldr xIP0, [xIP0] // ArtMethod* method ldr xIP0, [xIP0, #ART_METHOD_ACCESS_FLAGS_OFFSET] // uint32_t access_flags mov xIP1, #(ACCESS_FLAGS_METHOD_IS_FAST_NATIVE | ACCESS_FLAGS_METHOD_IS_CRITICAL_NATIVE) tst xIP0, xIP1 b.ne .Llookup_stub_fast_or_critical_native bl artFindNativeMethod b .Llookup_stub_continue .Llookup_stub_fast_or_critical_native: bl artFindNativeMethodRunnable .Llookup_stub_continue: mov x17, x0 // store result in scratch reg. // load spill regs. ldp x0, x1, [sp], #16 .cfi_adjust_cfa_offset -16 ldp x2, x3, [sp], #16 .cfi_adjust_cfa_offset -16 ldp x4, x5, [sp], #16 .cfi_adjust_cfa_offset -16 ldp x6, x7, [sp], #16 .cfi_adjust_cfa_offset -16 ldp d0, d1, [sp], #16 .cfi_adjust_cfa_offset -16 ldp d2, d3, [sp], #16 .cfi_adjust_cfa_offset -16 ldp d4, d5, [sp], #16 .cfi_adjust_cfa_offset -16 ldp d6, d7, [sp], #16 .cfi_adjust_cfa_offset -16 ldp x29, x30, [sp], #16 .cfi_adjust_cfa_offset -16 .cfi_restore x29 .cfi_restore x30 cbz x17, 1f // is method code null ? br x17 // if non-null, tail call to method's code. 1: ret // 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 x15. // For Generic JNI we already have a managed frame, so we reuse the art_jni_dlsym_lookup_stub. tbnz x15, #0, art_jni_dlsym_lookup_stub // Save args, the hidden arg and caller PC. No CFI needed for args and the hidden arg. stp x0, x1, [sp, #-(8 * 8 + 8 * 8 + 2 * 8)]! .cfi_adjust_cfa_offset (8 * 8 + 8 * 8 + 2 * 8) stp x2, x3, [sp, #16] stp x4, x5, [sp, #32] stp x6, x7, [sp, #48] stp d0, d1, [sp, #64] stp d2, d3, [sp, #80] stp d4, d5, [sp, #96] stp d6, d7, [sp, #112] stp x15, lr, [sp, #128] .cfi_rel_offset lr, 136 // Call artCriticalNativeFrameSize(method, caller_pc) mov x0, x15 // x0 := method (from hidden arg) mov x1, lr // x1 := caller_pc bl artCriticalNativeFrameSize // Move frame size to x14. mov x14, x0 // Restore args, the hidden arg and caller PC. ldp x2, x3, [sp, #16] ldp x4, x5, [sp, #32] ldp x6, x7, [sp, #48] ldp d0, d1, [sp, #64] ldp d2, d3, [sp, #80] ldp d4, d5, [sp, #96] ldp d6, d7, [sp, #112] ldp x15, lr, [sp, #128] .cfi_restore lr ldp x0, x1, [sp], #(8 * 8 + 8 * 8 + 2 * 8) .cfi_adjust_cfa_offset -(8 * 8 + 8 * 8 + 2 * 8) // 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. INCREASE_FRAME FRAME_SIZE_SAVE_REFS_AND_ARGS // Calculate the base address of the managed frame. add x13, sp, x14 // 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. mov xIP1, lr // Move the stack args if any. cbz x14, .Lcritical_skip_copy_args mov x12, sp .Lcritical_copy_args_loop: ldp xIP0, xIP1, [x12, #FRAME_SIZE_SAVE_REFS_AND_ARGS] subs x14, x14, #16 stp xIP0, xIP1, [x12], #16 bne .Lcritical_copy_args_loop .Lcritical_skip_copy_args: // 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. Do not update CFI while we hold the frame address in x13 and the values // in registers are unchanged. stp d0, d1, [x13, #16] stp d2, d3, [x13, #32] stp d4, d5, [x13, #48] stp d6, d7, [x13, #64] stp x1, x2, [x13, #80] stp x3, x4, [x13, #96] stp x5, x6, [x13, #112] stp x7, x20, [x13, #128] stp x21, x22, [x13, #144] stp x23, x24, [x13, #160] stp x25, x26, [x13, #176] stp x27, x28, [x13, #192] stp x29, xIP1, [x13, #208] // xIP1: 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.) // Move the managed frame address to native callee-save register x29 and update CFI. mov x29, x13 // Skip args d0-d7, x1-x7 CFI_EXPRESSION_BREG 20, 29, 136 CFI_EXPRESSION_BREG 21, 29, 144 CFI_EXPRESSION_BREG 22, 29, 152 CFI_EXPRESSION_BREG 23, 29, 160 CFI_EXPRESSION_BREG 24, 29, 168 CFI_EXPRESSION_BREG 25, 29, 176 CFI_EXPRESSION_BREG 26, 29, 184 CFI_EXPRESSION_BREG 27, 29, 192 CFI_EXPRESSION_BREG 28, 29, 200 CFI_EXPRESSION_BREG 29, 29, 208 // The saved return PC for managed stack walk is not necessarily our LR. // Save our return PC in the padding. str lr, [x29, #__SIZEOF_POINTER__] CFI_EXPRESSION_BREG 30, 29, __SIZEOF_POINTER__ ldr wIP0, [x15, #ART_METHOD_ACCESS_FLAGS_OFFSET] // Load access flags. add x14, x29, #1 // Prepare managed SP tagged for a GenericJNI frame. tbnz wIP0, #ACCESS_FLAGS_METHOD_IS_NATIVE_BIT, .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, [x29, #(FRAME_SIZE_SAVE_REFS_AND_ARGS - __SIZEOF_POINTER__)] // Replace the target method with the SaveRefsAndArgs runtime method. LOAD_RUNTIME_INSTANCE x15 ldr x15, [x15, #RUNTIME_SAVE_REFS_AND_ARGS_METHOD_OFFSET] mov x14, x29 // Prepare untagged managed SP for the runtime method. .Lcritical_skip_prepare_runtime_method: // Store the method on the bottom of the managed frame. str x15, [x29] // Place (maybe tagged) managed SP in Thread::Current()->top_quick_frame. str x14, [xSELF, #THREAD_TOP_QUICK_FRAME_OFFSET] // Preserve the native arg register x0 in callee-save register x28 which was saved above. mov x28, x0 // Call artFindNativeMethodRunnable() mov x0, xSELF // pass Thread::Current() bl artFindNativeMethodRunnable // Store result in scratch reg. mov x13, x0 // Restore the native arg register x0. mov x0, x28 // Restore our return PC. RESTORE_REG_BASE x29, lr, __SIZEOF_POINTER__ // Remember the stack args size, negated because SP cannot be on the right-hand side in SUB. sub x14, sp, x29 // Restore the frame. We shall not need the method anymore. ldp d0, d1, [x29, #16] ldp d2, d3, [x29, #32] ldp d4, d5, [x29, #48] ldp d6, d7, [x29, #64] ldp x1, x2, [x29, #80] ldp x3, x4, [x29, #96] ldp x5, x6, [x29, #112] ldp x7, x20, [x29, #128] .cfi_restore x20 RESTORE_TWO_REGS_BASE x29, x21, x22, 144 RESTORE_TWO_REGS_BASE x29, x23, x24, 160 RESTORE_TWO_REGS_BASE x29, x25, x26, 176 RESTORE_TWO_REGS_BASE x29, x27, x28, 192 RESTORE_REG_BASE x29, x29, 208 REFRESH_MARKING_REGISTER // Check for exception before moving args back to keep the return PC for managed stack walk. cbz x13, .Lcritical_deliver_exception .cfi_remember_state // Move stack args to their original place. cbz x14, .Lcritical_skip_copy_args_back sub x12, sp, x14 .Lcritical_copy_args_back_loop: ldp xIP0, xIP1, [x12, #-16]! adds x14, x14, #16 stp xIP0, xIP1, [x12, #FRAME_SIZE_SAVE_REFS_AND_ARGS] bne .Lcritical_copy_args_back_loop .Lcritical_skip_copy_args_back: // Remove the frame reservation. DECREASE_FRAME FRAME_SIZE_SAVE_REFS_AND_ARGS // Do the tail call. br x13 .cfi_restore_state .cfi_def_cfa sp, FRAME_SIZE_SAVE_REFS_AND_ARGS .Lcritical_deliver_exception: // The exception delivery checks that xSELF 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. DECREASE_FRAME FRAME_SIZE_SAVE_REFS_AND_ARGS - FRAME_SIZE_SAVE_ALL_CALLEE_SAVES // Calculate the base address of the managed frame. sub x13, sp, x14 // Spill registers for the SaveAllCalleeSaves frame above the stack args area. Do not update // CFI while we hold the frame address in x13 and the values in registers are unchanged. stp d8, d9, [x13, #16] stp d10, d11, [x13, #32] stp d12, d13, [x13, #48] stp d14, d15, [x13, #64] stp x19, x20, [x13, #80] stp x21, x22, [x13, #96] stp x23, x24, [x13, #112] stp x25, x26, [x13, #128] stp x27, x28, [x13, #144] str x29, [x13, #160] // Keep the caller PC for managed stack walk. // Move the managed frame address to native callee-save register x29 and update CFI. mov x29, x13 CFI_EXPRESSION_BREG 19, 29, 80 CFI_EXPRESSION_BREG 20, 29, 88 CFI_EXPRESSION_BREG 21, 29, 96 CFI_EXPRESSION_BREG 22, 29, 104 CFI_EXPRESSION_BREG 23, 29, 112 CFI_EXPRESSION_BREG 24, 29, 120 CFI_EXPRESSION_BREG 25, 29, 128 CFI_EXPRESSION_BREG 26, 29, 136 CFI_EXPRESSION_BREG 27, 29, 144 CFI_EXPRESSION_BREG 28, 29, 152 CFI_EXPRESSION_BREG 29, 29, 160 // The saved return PC for managed stack walk is not necessarily our LR. // Save our return PC in the padding. str lr, [x29, #__SIZEOF_POINTER__] CFI_EXPRESSION_BREG 30, 29, __SIZEOF_POINTER__ // Store ArtMethod* Runtime::callee_save_methods_[kSaveAllCalleeSaves] to the managed frame. LOAD_RUNTIME_INSTANCE xIP0 ldr xIP0, [xIP0, #RUNTIME_SAVE_ALL_CALLEE_SAVES_METHOD_OFFSET] str xIP0, [x29] // Place the managed frame SP in Thread::Current()->top_quick_frame. str x29, [xSELF, #THREAD_TOP_QUICK_FRAME_OFFSET] DELIVER_PENDING_EXCEPTION_FRAME_READY END art_jni_dlsym_lookup_critical_stub