1#include "../builtins/assembly.h"
2
3    .syntax unified
4    .arch armv6t2
5    .fpu vfpv2
6    .code 32
7    .global _ZN6__xray19XRayPatchedFunctionE
8
9    @ Word-aligned function entry point
10    .p2align 2
11    @ Let C/C++ see the symbol
12    .global __xray_FunctionEntry
13    @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc)
14    @ Assume that "q" part of the floating-point registers is not used
15    @   for passing parameters to C/C++ functions.
16    .type __xray_FunctionEntry, %function
17    @ In C++ it is void extern "C" __xray_FunctionEntry(uint32_t FuncId) with
18    @   FuncId passed in r0 register.
19__xray_FunctionEntry:
20    PUSH {r1-r3,lr}
21    @ Save floating-point parameters of the instrumented function
22    VPUSH {d0-d7}
23    MOVW r1,#:lower16:_ZN6__xray19XRayPatchedFunctionE
24    MOVT r1,#:upper16:_ZN6__xray19XRayPatchedFunctionE
25    LDR r2, [r1]
26    @ Handler address is nullptr if handler is not set
27    CMP r2, #0
28    BEQ FunctionEntry_restore
29    @ Function ID is already in r0 (the first parameter).
30    @ r1=0 means that we are tracing an entry event
31    MOV r1, #0
32    @ Call the handler with 2 parameters in r0 and r1
33    BLX r2
34FunctionEntry_restore:
35    @ Restore floating-point parameters of the instrumented function
36    VPOP {d0-d7}
37    POP {r1-r3,pc}
38
39    @ Word-aligned function entry point
40    .p2align 2
41    @ Let C/C++ see the symbol
42	.global __xray_FunctionExit
43	@ Assume that d1-d7 are not used for the return value.
44    @ Assume that "q" part of the floating-point registers is not used for the
45    @   return value in C/C++.
46	.type __xray_FunctionExit, %function
47	@ In C++ it is extern "C" void __xray_FunctionExit(uint32_t FuncId) with
48    @   FuncId passed in r0 register.
49__xray_FunctionExit:
50    PUSH {r1-r3,lr}
51    @ Save the floating-point return value of the instrumented function
52    VPUSH {d0}
53    @ Load the handler address
54    MOVW r1,#:lower16:_ZN6__xray19XRayPatchedFunctionE
55    MOVT r1,#:upper16:_ZN6__xray19XRayPatchedFunctionE
56    LDR r2, [r1]
57    @ Handler address is nullptr if handler is not set
58    CMP r2, #0
59    BEQ FunctionExit_restore
60    @ Function ID is already in r0 (the first parameter).
61    @ 1 means that we are tracing an exit event
62    MOV r1, #1
63    @ Call the handler with 2 parameters in r0 and r1
64    BLX r2
65FunctionExit_restore:
66    @ Restore the floating-point return value of the instrumented function
67    VPOP {d0}
68    POP {r1-r3,pc}
69
70    @ Word-aligned function entry point
71    .p2align 2
72    @ Let C/C++ see the symbol
73    .global __xray_FunctionTailExit
74    @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc)
75    @ Assume that "q" part of the floating-point registers is not used
76    @   for passing parameters to C/C++ functions.
77    .type __xray_FunctionTailExit, %function
78    @ In C++ it is void extern "C" __xray_FunctionTailExit(uint32_t FuncId)
79    @   with FuncId passed in r0 register.
80__xray_FunctionTailExit:
81    PUSH {r1-r3,lr}
82    @ Save floating-point parameters of the instrumented function
83    VPUSH {d0-d7}
84    MOVW r1,#:lower16:_ZN6__xray19XRayPatchedFunctionE
85    MOVT r1,#:upper16:_ZN6__xray19XRayPatchedFunctionE
86    LDR r2, [r1]
87    @ Handler address is nullptr if handler is not set
88    CMP r2, #0
89    BEQ FunctionTailExit_restore
90    @ Function ID is already in r0 (the first parameter).
91    @ r1=2 means that we are tracing a tail exit event
92    @ But before the logging part of XRay is ready, we pretend that here a
93    @   normal function exit happens, so we give the handler code 1
94    MOV r1, #1
95    @ Call the handler with 2 parameters in r0 and r1
96    BLX r2
97FunctionTailExit_restore:
98    @ Restore floating-point parameters of the instrumented function
99    VPOP {d0-d7}
100    POP {r1-r3,pc}
101
102NO_EXEC_STACK_DIRECTIVE
103