106 lines · plain
1#include "../builtins/assembly.h"2 3 .syntax unified4 .arch armv6t25 .fpu vfpv26 .code 327 .global _ZN6__xray19XRayPatchedFunctionE8 9 @ Word-aligned function entry point10 .p2align 211 @ Let C/C++ see the symbol12 .global __xray_FunctionEntry13 .hidden __xray_FunctionEntry14 @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc)15 @ Assume that "q" part of the floating-point registers is not used16 @ for passing parameters to C/C++ functions.17 .type __xray_FunctionEntry, %function18 @ In C++ it is void extern "C" __xray_FunctionEntry(uint32_t FuncId) with19 @ FuncId passed in r0 register.20__xray_FunctionEntry:21 PUSH {r1-r3,lr}22 @ Save floating-point parameters of the instrumented function23 VPUSH {d0-d7}24 MOVW r1, #:lower16:_ZN6__xray19XRayPatchedFunctionE - (. + 16)25 MOVT r1, #:upper16:_ZN6__xray19XRayPatchedFunctionE - (. + 12)26 LDR r2, [pc, r1]27 @ Handler address is nullptr if handler is not set28 CMP r2, #029 BEQ FunctionEntry_restore30 @ Function ID is already in r0 (the first parameter).31 @ r1=0 means that we are tracing an entry event32 MOV r1, #033 @ Call the handler with 2 parameters in r0 and r134 BLX r235FunctionEntry_restore:36 @ Restore floating-point parameters of the instrumented function37 VPOP {d0-d7}38 POP {r1-r3,pc}39 40 @ Word-aligned function entry point41 .p2align 242 @ Let C/C++ see the symbol43 .global __xray_FunctionExit44 .hidden __xray_FunctionExit45 @ Assume that d1-d7 are not used for the return value.46 @ Assume that "q" part of the floating-point registers is not used for the47 @ return value in C/C++.48 .type __xray_FunctionExit, %function49 @ In C++ it is extern "C" void __xray_FunctionExit(uint32_t FuncId) with50 @ FuncId passed in r0 register.51__xray_FunctionExit:52 PUSH {r1-r3,lr}53 @ Save the floating-point return value of the instrumented function54 VPUSH {d0}55 @ Load the handler address56 MOVW r1, #:lower16:_ZN6__xray19XRayPatchedFunctionE - (. + 16)57 MOVT r1, #:upper16:_ZN6__xray19XRayPatchedFunctionE - (. + 12)58 LDR r2, [pc, r1]59 @ Handler address is nullptr if handler is not set60 CMP r2, #061 BEQ FunctionExit_restore62 @ Function ID is already in r0 (the first parameter).63 @ 1 means that we are tracing an exit event64 MOV r1, #165 @ Call the handler with 2 parameters in r0 and r166 BLX r267FunctionExit_restore:68 @ Restore the floating-point return value of the instrumented function69 VPOP {d0}70 POP {r1-r3,pc}71 72 @ Word-aligned function entry point73 .p2align 274 @ Let C/C++ see the symbol75 .global __xray_FunctionTailExit76 .hidden __xray_FunctionTailExit77 @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc)78 @ Assume that "q" part of the floating-point registers is not used79 @ for passing parameters to C/C++ functions.80 .type __xray_FunctionTailExit, %function81 @ In C++ it is void extern "C" __xray_FunctionTailExit(uint32_t FuncId)82 @ with FuncId passed in r0 register.83__xray_FunctionTailExit:84 PUSH {r1-r3,lr}85 @ Save floating-point parameters of the instrumented function86 VPUSH {d0-d7}87 MOVW r1, #:lower16:_ZN6__xray19XRayPatchedFunctionE - (. + 16)88 MOVT r1, #:upper16:_ZN6__xray19XRayPatchedFunctionE - (. + 12)89 LDR r2, [pc, r1]90 @ Handler address is nullptr if handler is not set91 CMP r2, #092 BEQ FunctionTailExit_restore93 @ Function ID is already in r0 (the first parameter).94 @ r1=2 means that we are tracing a tail exit event95 @ But before the logging part of XRay is ready, we pretend that here a96 @ normal function exit happens, so we give the handler code 197 MOV r1, #198 @ Call the handler with 2 parameters in r0 and r199 BLX r2100FunctionTailExit_restore:101 @ Restore floating-point parameters of the instrumented function102 VPOP {d0-d7}103 POP {r1-r3,pc}104 105NO_EXEC_STACK_DIRECTIVE106