/* * 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 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_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 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: 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 // 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. RUNTIME_CURRENT1 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 beq .Lcritical_deliver_exception .cfi_remember_state // 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 .cfi_restore_state .cfi_def_cfa sp, FRAME_SIZE_SAVE_REFS_AND_ARGS .Lcritical_deliver_exception: // 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. RUNTIME_CURRENT2 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