1 /* SPDX-License-Identifier: GPL-2.0 */ !! 1 /*
2 /* Copyright (C) 2017 Andes Technology Corpora !! 2 * MIPS specific _mcount support
>> 3 *
>> 4 * This file is subject to the terms and conditions of the GNU General Public
>> 5 * License. See the file "COPYING" in the main directory of this archive for
>> 6 * more details.
>> 7 *
>> 8 * Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
>> 9 * Copyright (C) 2010 DSLab, Lanzhou University, China
>> 10 * Author: Wu Zhangjin <wuzhangjin@gmail.com>
>> 11 */
3 12
4 #include <linux/init.h> !! 13 #include <asm/regdef.h>
5 #include <linux/linkage.h> !! 14 #include <asm/stackframe.h>
6 #include <linux/cfi_types.h> <<
7 #include <linux/export.h> <<
8 #include <asm/asm.h> <<
9 #include <asm/csr.h> <<
10 #include <asm/unistd.h> <<
11 #include <asm/thread_info.h> <<
12 #include <asm/asm-offsets.h> <<
13 #include <asm/ftrace.h> 15 #include <asm/ftrace.h>
14 16
15 .text 17 .text
>> 18 .set noreorder
>> 19 .set noat
16 20
17 .macro SAVE_ABI_STATE !! 21 .macro MCOUNT_SAVE_REGS
18 addi sp, sp, -16 !! 22 PTR_SUBU sp, PT_SIZE
19 REG_S s0, 0*SZREG(sp) !! 23 PTR_S ra, PT_R31(sp)
20 REG_S ra, 1*SZREG(sp) !! 24 PTR_S AT, PT_R1(sp)
21 addi s0, sp, 16 !! 25 PTR_S a0, PT_R4(sp)
>> 26 PTR_S a1, PT_R5(sp)
>> 27 PTR_S a2, PT_R6(sp)
>> 28 PTR_S a3, PT_R7(sp)
>> 29 #ifdef CONFIG_64BIT
>> 30 PTR_S a4, PT_R8(sp)
>> 31 PTR_S a5, PT_R9(sp)
>> 32 PTR_S a6, PT_R10(sp)
>> 33 PTR_S a7, PT_R11(sp)
>> 34 #endif
22 .endm 35 .endm
23 36
24 /* !! 37 .macro MCOUNT_RESTORE_REGS
25 * The call to ftrace_return_to_handle !! 38 PTR_L ra, PT_R31(sp)
26 * register if a0 was not saved. !! 39 PTR_L AT, PT_R1(sp)
27 */ !! 40 PTR_L a0, PT_R4(sp)
28 .macro SAVE_RET_ABI_STATE !! 41 PTR_L a1, PT_R5(sp)
29 addi sp, sp, -4*SZREG !! 42 PTR_L a2, PT_R6(sp)
30 REG_S s0, 2*SZREG(sp) !! 43 PTR_L a3, PT_R7(sp)
31 REG_S ra, 3*SZREG(sp) !! 44 #ifdef CONFIG_64BIT
32 REG_S a0, 1*SZREG(sp) !! 45 PTR_L a4, PT_R8(sp)
33 REG_S a1, 0*SZREG(sp) !! 46 PTR_L a5, PT_R9(sp)
34 addi s0, sp, 4*SZREG !! 47 PTR_L a6, PT_R10(sp)
>> 48 PTR_L a7, PT_R11(sp)
>> 49 #endif
>> 50 PTR_ADDIU sp, PT_SIZE
35 .endm 51 .endm
36 52
37 .macro RESTORE_ABI_STATE !! 53 .macro RETURN_BACK
38 REG_L ra, 1*SZREG(sp) !! 54 jr ra
39 REG_L s0, 0*SZREG(sp) !! 55 move ra, AT
40 addi sp, sp, 16 <<
41 .endm 56 .endm
42 57
43 .macro RESTORE_RET_ABI_STATE !! 58 /*
44 REG_L ra, 3*SZREG(sp) !! 59 * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
45 REG_L s0, 2*SZREG(sp) !! 60 * the location of the parent's return address.
46 REG_L a0, 1*SZREG(sp) !! 61 */
47 REG_L a1, 0*SZREG(sp) !! 62 #define MCOUNT_RA_ADDRESS_REG $12
48 addi sp, sp, 4*SZREG <<
49 .endm <<
50 63
51 SYM_TYPED_FUNC_START(ftrace_stub) <<
52 #ifdef CONFIG_DYNAMIC_FTRACE 64 #ifdef CONFIG_DYNAMIC_FTRACE
53 .global _mcount !! 65
54 .set _mcount, ftrace_stub !! 66 NESTED(ftrace_caller, PT_SIZE, ra)
55 #endif !! 67 .globl _mcount
56 ret !! 68 _mcount:
57 SYM_FUNC_END(ftrace_stub) !! 69 b ftrace_stub
>> 70 #ifdef CONFIG_32BIT
>> 71 addiu sp,sp,8
>> 72 #else
>> 73 nop
>> 74 #endif
>> 75
>> 76 /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
>> 77 MCOUNT_SAVE_REGS
>> 78 #ifdef KBUILD_MCOUNT_RA_ADDRESS
>> 79 PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
>> 80 #endif
>> 81
>> 82 PTR_SUBU a0, ra, 8 /* arg1: self address */
>> 83 PTR_LA t1, _stext
>> 84 sltu t2, a0, t1 /* t2 = (a0 < _stext) */
>> 85 PTR_LA t1, _etext
>> 86 sltu t3, t1, a0 /* t3 = (a0 > _etext) */
>> 87 or t1, t2, t3
>> 88 beqz t1, ftrace_call
>> 89 nop
>> 90 #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
>> 91 PTR_SUBU a0, a0, 16 /* arg1: adjust to module's recorded callsite */
>> 92 #else
>> 93 PTR_SUBU a0, a0, 12
>> 94 #endif
>> 95
>> 96 .globl ftrace_call
>> 97 ftrace_call:
>> 98 nop /* a placeholder for the call to a real tracing function */
>> 99 move a1, AT /* arg2: parent's return address */
58 100
59 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 101 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
60 SYM_TYPED_FUNC_START(ftrace_stub_graph) !! 102 .globl ftrace_graph_call
61 ret !! 103 ftrace_graph_call:
62 SYM_FUNC_END(ftrace_stub_graph) !! 104 nop
>> 105 nop
>> 106 #endif
63 107
64 SYM_FUNC_START(return_to_handler) !! 108 MCOUNT_RESTORE_REGS
65 /* !! 109 .globl ftrace_stub
66 * On implementing the frame point test, the i !! 110 ftrace_stub:
67 * s0 (frame pointer, if enabled) on entry and !! 111 RETURN_BACK
68 * However, the psABI of variable-length-argum !! 112 END(ftrace_caller)
69 * !! 113
70 * So alternatively we check the *old* frame p !! 114 #else /* ! CONFIG_DYNAMIC_FTRACE */
71 * value stored in -16(s0) on entry, and the s !! 115
72 */ !! 116 NESTED(_mcount, PT_SIZE, ra)
73 SAVE_RET_ABI_STATE !! 117 PTR_LA t1, ftrace_stub
74 mv a0, sp !! 118 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
75 call ftrace_return_to_handler !! 119 beq t1, t2, fgraph_trace
76 mv a2, a0 !! 120 nop
77 RESTORE_RET_ABI_STATE !! 121
78 jalr a2 !! 122 MCOUNT_SAVE_REGS
79 SYM_FUNC_END(return_to_handler) !! 123
>> 124 move a0, ra /* arg1: self return address */
>> 125 jalr t2 /* (1) call *ftrace_trace_function */
>> 126 move a1, AT /* arg2: parent's return address */
>> 127
>> 128 MCOUNT_RESTORE_REGS
>> 129
>> 130 fgraph_trace:
>> 131 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 132 PTR_LA t1, ftrace_stub
>> 133 PTR_L t3, ftrace_graph_return
>> 134 bne t1, t3, ftrace_graph_caller
>> 135 nop
>> 136 PTR_LA t1, ftrace_graph_entry_stub
>> 137 PTR_L t3, ftrace_graph_entry
>> 138 bne t1, t3, ftrace_graph_caller
>> 139 nop
80 #endif 140 #endif
81 141
82 #ifndef CONFIG_DYNAMIC_FTRACE !! 142 #ifdef CONFIG_32BIT
83 SYM_FUNC_START(_mcount) !! 143 addiu sp, sp, 8
84 la t4, ftrace_stub !! 144 #endif
85 #ifdef CONFIG_FUNCTION_GRAPH_TRACER !! 145
86 la t0, ftrace_graph_return !! 146 .globl ftrace_stub
87 REG_L t1, 0(t0) !! 147 ftrace_stub:
88 bne t1, t4, .Ldo_ftrace_graph_call !! 148 RETURN_BACK
89 !! 149 END(_mcount)
90 la t3, ftrace_graph_entry !! 150
91 REG_L t2, 0(t3) !! 151 #endif /* ! CONFIG_DYNAMIC_FTRACE */
92 la t6, ftrace_graph_entry_stub <<
93 bne t2, t6, .Ldo_ftrace_graph_call <<
94 #endif <<
95 la t3, ftrace_trace_function <<
96 REG_L t5, 0(t3) <<
97 bne t5, t4, .Ldo_trace <<
98 ret <<
99 152
100 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 153 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
101 /* !! 154
102 * A pseudo representation for the function gr !! 155 NESTED(ftrace_graph_caller, PT_SIZE, ra)
103 * prepare_to_return(&ra_to_caller_of_caller, !! 156 #ifndef CONFIG_DYNAMIC_FTRACE
104 */ !! 157 MCOUNT_SAVE_REGS
105 .Ldo_ftrace_graph_caller: <<
106 addi a0, s0, -SZREG <<
107 mv a1, ra <<
108 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST <<
109 REG_L a2, -2*SZREG(s0) <<
110 #endif <<
111 SAVE_ABI_STATE <<
112 call prepare_ftrace_return <<
113 RESTORE_ABI_STATE <<
114 ret <<
115 #endif 158 #endif
116 159
117 /* !! 160 /* arg1: Get the location of the parent's return address */
118 * A pseudo representation for the function tr !! 161 #ifdef KBUILD_MCOUNT_RA_ADDRESS
119 * (*ftrace_trace_function)(ra_to_caller, ra_t !! 162 #ifdef CONFIG_DYNAMIC_FTRACE
120 */ !! 163 PTR_L a0, PT_R12(sp)
121 .Ldo_trace: !! 164 #else
122 REG_L a1, -SZREG(s0) !! 165 move a0, MCOUNT_RA_ADDRESS_REG
123 mv a0, ra !! 166 #endif
124 !! 167 bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
125 SAVE_ABI_STATE !! 168 nop
126 jalr t5 !! 169 #endif
127 RESTORE_ABI_STATE !! 170 PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
128 ret !! 171 1:
129 SYM_FUNC_END(_mcount) !! 172
>> 173 /* arg2: Get self return address */
>> 174 #ifdef CONFIG_DYNAMIC_FTRACE
>> 175 PTR_L a1, PT_R31(sp)
>> 176 #else
>> 177 move a1, ra
>> 178 #endif
>> 179
>> 180 /* arg3: Get frame pointer of current stack */
>> 181 #ifdef CONFIG_64BIT
>> 182 PTR_LA a2, PT_SIZE(sp)
>> 183 #else
>> 184 PTR_LA a2, (PT_SIZE+8)(sp)
>> 185 #endif
>> 186
>> 187 jal prepare_ftrace_return
>> 188 nop
>> 189 MCOUNT_RESTORE_REGS
>> 190 #ifndef CONFIG_DYNAMIC_FTRACE
>> 191 #ifdef CONFIG_32BIT
>> 192 addiu sp, sp, 8
130 #endif 193 #endif
131 EXPORT_SYMBOL(_mcount) !! 194 #endif
>> 195 RETURN_BACK
>> 196 END(ftrace_graph_caller)
>> 197
>> 198 .align 2
>> 199 .globl return_to_handler
>> 200 return_to_handler:
>> 201 PTR_SUBU sp, PT_SIZE
>> 202 PTR_S v0, PT_R2(sp)
>> 203
>> 204 jal ftrace_return_to_handler
>> 205 PTR_S v1, PT_R3(sp)
>> 206
>> 207 /* restore the real parent address: v0 -> ra */
>> 208 move ra, v0
>> 209
>> 210 PTR_L v0, PT_R2(sp)
>> 211 PTR_L v1, PT_R3(sp)
>> 212 jr ra
>> 213 PTR_ADDIU sp, PT_SIZE
>> 214 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
>> 215
>> 216 .set at
>> 217 .set reorder
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.