1 /* SPDX-License-Identifier: GPL-2.0 */ <<
2 /* 1 /*
3 * Copyright IBM Corp. 2008, 2009 !! 2 * MIPS specific _mcount support
4 * 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>
5 */ 11 */
6 12
7 #include <linux/linkage.h> !! 13 #include <asm/regdef.h>
8 #include <asm/asm-offsets.h> !! 14 #include <asm/stackframe.h>
9 #include <asm/ftrace.h> 15 #include <asm/ftrace.h>
10 #include <asm/nospec-insn.h> !! 16
11 #include <asm/ptrace.h> !! 17 .text
12 #include <asm/march.h> !! 18 .set noreorder
13 !! 19 .set noat
14 #define STACK_FRAME_SIZE_PTREGS (STACK !! 20
15 #define STACK_PTREGS (STACK !! 21 .macro MCOUNT_SAVE_REGS
16 #define STACK_PTREGS_GPRS (STACK !! 22 PTR_SUBU sp, PT_SIZE
17 #define STACK_PTREGS_PSW (STACK !! 23 PTR_S ra, PT_R31(sp)
18 !! 24 PTR_S AT, PT_R1(sp)
19 #define STACK_FRAME_SIZE_FREGS (STACK !! 25 PTR_S a0, PT_R4(sp)
20 #define STACK_FREGS (STACK !! 26 PTR_S a1, PT_R5(sp)
21 #define STACK_FREGS_PTREGS (STACK !! 27 PTR_S a2, PT_R6(sp)
22 #define STACK_FREGS_PTREGS_GPRS (STACK !! 28 PTR_S a3, PT_R7(sp)
23 #define STACK_FREGS_PTREGS_PSW (STACK !! 29 #ifdef CONFIG_64BIT
24 #define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK !! 30 PTR_S a4, PT_R8(sp)
25 #define STACK_FREGS_PTREGS_FLAGS (STACK !! 31 PTR_S a5, PT_R9(sp)
26 !! 32 PTR_S a6, PT_R10(sp)
27 /* packed stack: allocate just enough for r14, !! 33 PTR_S a7, PT_R11(sp)
28 #define TRACED_FUNC_FRAME_SIZE 24 !! 34 #endif
29 !! 35 .endm
30 #ifdef CONFIG_FUNCTION_TRACER !! 36
31 !! 37 .macro MCOUNT_RESTORE_REGS
32 GEN_BR_THUNK %r1 !! 38 PTR_L ra, PT_R31(sp)
33 GEN_BR_THUNK %r14 !! 39 PTR_L AT, PT_R1(sp)
34 !! 40 PTR_L a0, PT_R4(sp)
35 .section .kprobes.text, "ax" !! 41 PTR_L a1, PT_R5(sp)
36 !! 42 PTR_L a2, PT_R6(sp)
37 SYM_FUNC_START(ftrace_stub) !! 43 PTR_L a3, PT_R7(sp)
38 BR_EX %r14 !! 44 #ifdef CONFIG_64BIT
39 SYM_FUNC_END(ftrace_stub) !! 45 PTR_L a4, PT_R8(sp)
40 !! 46 PTR_L a5, PT_R9(sp)
41 SYM_CODE_START(ftrace_stub_direct_tramp) !! 47 PTR_L a6, PT_R10(sp)
42 lgr %r1, %r0 !! 48 PTR_L a7, PT_R11(sp)
43 BR_EX %r1 !! 49 #endif
44 SYM_CODE_END(ftrace_stub_direct_tramp) !! 50 PTR_ADDIU sp, PT_SIZE
45 <<
46 .macro ftrace_regs_entry, allregs=0 <<
47 stg %r14,(__SF_GPRS+8*8)(%r15) <<
48 <<
49 .if \allregs == 1 <<
50 # save psw mask <<
51 # don't put any instructions clobberin <<
52 epsw %r1,%r14 <<
53 risbg %r14,%r1,0,31,32 <<
54 .endif <<
55 <<
56 lgr %r1,%r15 <<
57 # allocate stack frame for ftrace_call <<
58 aghi %r15,-TRACED_FUNC_FRAME_SIZE <<
59 stg %r1,__SF_BACKCHAIN(%r15) <<
60 stg %r0,(__SF_GPRS+8*8)(%r15) <<
61 stg %r15,(__SF_GPRS+9*8)(%r15) <<
62 # allocate ftrace_regs and stack frame <<
63 aghi %r15,-STACK_FRAME_SIZE_FREGS <<
64 stg %r1,(STACK_FREGS_PTREGS_GPRS+1 <<
65 xc STACK_FREGS_PTREGS_ORIG_GPR2(8 <<
66 <<
67 .if \allregs == 1 <<
68 stg %r14,(STACK_FREGS_PTREGS_PSW)( <<
69 mvghi STACK_FREGS_PTREGS_FLAGS(%r15) <<
70 .else <<
71 xc STACK_FREGS_PTREGS_FLAGS(8,%r1 <<
72 .endif <<
73 <<
74 lg %r14,(__SF_GPRS+8*8)(%r1) <<
75 aghi %r1,-TRACED_FUNC_FRAME_SIZE <<
76 stg %r1,__SF_BACKCHAIN(%r15) <<
77 stg %r0,(STACK_FREGS_PTREGS_PSW+8) <<
78 stmg %r2,%r14,(STACK_FREGS_PTREGS_G <<
79 .endm 51 .endm
80 52
81 SYM_CODE_START(ftrace_regs_caller) !! 53 .macro RETURN_BACK
82 ftrace_regs_entry 1 !! 54 jr ra
83 j ftrace_common !! 55 move ra, AT
84 SYM_CODE_END(ftrace_regs_caller) !! 56 .endm
85 !! 57
86 SYM_CODE_START(ftrace_caller) !! 58 /*
87 ftrace_regs_entry 0 !! 59 * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
88 j ftrace_common !! 60 * the location of the parent's return address.
89 SYM_CODE_END(ftrace_caller) !! 61 */
90 !! 62 #define MCOUNT_RA_ADDRESS_REG $12
91 SYM_CODE_START(ftrace_common) !! 63
92 #ifdef MARCH_HAS_Z196_FEATURES !! 64 #ifdef CONFIG_DYNAMIC_FTRACE
93 aghik %r2,%r0,-MCOUNT_INSN_SIZE !! 65
94 lgrl %r4,function_trace_op !! 66 NESTED(ftrace_caller, PT_SIZE, ra)
95 lgrl %r1,ftrace_func !! 67 .globl _mcount
>> 68 _mcount:
>> 69 b ftrace_stub
>> 70 #ifdef CONFIG_32BIT
>> 71 addiu sp,sp,8
96 #else 72 #else
97 lgr %r2,%r0 !! 73 nop
98 aghi %r2,-MCOUNT_INSN_SIZE !! 74 #endif
99 larl %r4,function_trace_op !! 75
100 lg %r4,0(%r4) !! 76 /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
101 larl %r1,ftrace_func !! 77 lw t1, function_trace_stop
102 lg %r1,0(%r1) !! 78 bnez t1, ftrace_stub
103 #endif !! 79 nop
104 lgr %r3,%r14 !! 80
105 la %r5,STACK_FREGS(%r15) !! 81 MCOUNT_SAVE_REGS
106 BASR_EX %r14,%r1 !! 82 #ifdef KBUILD_MCOUNT_RA_ADDRESS
>> 83 PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
>> 84 #endif
>> 85
>> 86 move a0, ra /* arg1: self return address */
>> 87 .globl ftrace_call
>> 88 ftrace_call:
>> 89 nop /* a placeholder for the call to a real tracing function */
>> 90 move a1, AT /* arg2: parent's return address */
>> 91
107 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 92 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
108 # The j instruction gets runtime patched to a !! 93 .globl ftrace_graph_call
109 # See ftrace_enable_ftrace_graph_caller. !! 94 ftrace_graph_call:
110 SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLO !! 95 nop
111 j .Lftrace_graph_caller_end !! 96 nop
112 lmg %r2,%r3,(STACK_FREGS_PTREGS_GP !! 97 #endif
113 lg %r4,(STACK_FREGS_PTREGS_PSW+8) !! 98
114 brasl %r14,prepare_ftrace_return !! 99 MCOUNT_RESTORE_REGS
115 stg %r2,(STACK_FREGS_PTREGS_GPRS+1 !! 100 .globl ftrace_stub
116 .Lftrace_graph_caller_end: !! 101 ftrace_stub:
117 #endif !! 102 RETURN_BACK
118 lg %r0,(STACK_FREGS_PTREGS_PSW+8) !! 103 END(ftrace_caller)
119 #ifdef MARCH_HAS_Z196_FEATURES !! 104
120 ltg %r1,STACK_FREGS_PTREGS_ORIG_GP !! 105 #else /* ! CONFIG_DYNAMIC_FTRACE */
121 locgrz %r1,%r0 !! 106
>> 107 NESTED(_mcount, PT_SIZE, ra)
>> 108 lw t1, function_trace_stop
>> 109 bnez t1, ftrace_stub
>> 110 nop
>> 111 PTR_LA t1, ftrace_stub
>> 112 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
>> 113 bne t1, t2, static_trace
>> 114 nop
>> 115
>> 116 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 117 PTR_L t3, ftrace_graph_return
>> 118 bne t1, t3, ftrace_graph_caller
>> 119 nop
>> 120 PTR_LA t1, ftrace_graph_entry_stub
>> 121 PTR_L t3, ftrace_graph_entry
>> 122 bne t1, t3, ftrace_graph_caller
>> 123 nop
>> 124 #endif
>> 125 b ftrace_stub
>> 126 #ifdef CONFIG_32BIT
>> 127 addiu sp, sp, 8
122 #else 128 #else
123 lg %r1,STACK_FREGS_PTREGS_ORIG_GP !! 129 nop
124 ltgr %r1,%r1 !! 130 #endif
125 jnz 0f !! 131
126 lgr %r1,%r0 !! 132 static_trace:
127 #endif !! 133 MCOUNT_SAVE_REGS
128 0: lmg %r2,%r15,(STACK_FREGS_PTREGS_G !! 134
129 BR_EX %r1 !! 135 move a0, ra /* arg1: self return address */
130 SYM_CODE_END(ftrace_common) !! 136 jalr t2 /* (1) call *ftrace_trace_function */
>> 137 move a1, AT /* arg2: parent's return address */
>> 138
>> 139 MCOUNT_RESTORE_REGS
>> 140 #ifdef CONFIG_32BIT
>> 141 addiu sp, sp, 8
>> 142 #endif
>> 143 .globl ftrace_stub
>> 144 ftrace_stub:
>> 145 RETURN_BACK
>> 146 END(_mcount)
>> 147
>> 148 #endif /* ! CONFIG_DYNAMIC_FTRACE */
131 149
132 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 150 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
133 151
134 SYM_FUNC_START(return_to_handler) !! 152 NESTED(ftrace_graph_caller, PT_SIZE, ra)
135 stmg %r2,%r5,32(%r15) !! 153 #ifndef CONFIG_DYNAMIC_FTRACE
136 lgr %r1,%r15 !! 154 MCOUNT_SAVE_REGS
137 aghi %r15,-(STACK_FRAME_OVERHEAD+__ !! 155 #endif
138 stg %r1,__SF_BACKCHAIN(%r15) !! 156
139 la %r3,STACK_FRAME_OVERHEAD(%r15) !! 157 /* arg1: Get the location of the parent's return address */
140 stg %r1,__FGRAPH_RET_FP(%r3) !! 158 #ifdef KBUILD_MCOUNT_RA_ADDRESS
141 stg %r2,__FGRAPH_RET_GPR2(%r3) !! 159 #ifdef CONFIG_DYNAMIC_FTRACE
142 lgr %r2,%r3 !! 160 PTR_L a0, PT_R12(sp)
143 brasl %r14,ftrace_return_to_handler !! 161 #else
144 aghi %r15,STACK_FRAME_OVERHEAD+__FG !! 162 move a0, MCOUNT_RA_ADDRESS_REG
145 lgr %r14,%r2 !! 163 #endif
146 lmg %r2,%r5,32(%r15) !! 164 bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
147 BR_EX %r14 !! 165 nop
148 SYM_FUNC_END(return_to_handler) !! 166 #endif
149 !! 167 PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
150 #endif !! 168 1:
151 #endif /* CONFIG_FUNCTION_TRACER */ !! 169
152 !! 170 /* arg2: Get self return address */
153 SYM_CODE_START(ftrace_shared_hotpatch_trampoli !! 171 #ifdef CONFIG_DYNAMIC_FTRACE
154 lmg %r0,%r1,2(%r1) !! 172 PTR_L a1, PT_R31(sp)
155 br %r1 !! 173 #else
156 SYM_INNER_LABEL(ftrace_shared_hotpatch_trampol !! 174 move a1, ra
157 SYM_CODE_END(ftrace_shared_hotpatch_trampoline !! 175 #endif
158 !! 176
159 #ifdef CONFIG_EXPOLINE !! 177 /* arg3: Get frame pointer of current stack */
160 SYM_CODE_START(ftrace_shared_hotpatch_trampoli !! 178 #ifdef CONFIG_FRAME_POINTER
161 lmg %r0,%r1,2(%r1) !! 179 move a2, fp
162 exrl %r0,0f !! 180 #else /* ! CONFIG_FRAME_POINTER */
163 j . !! 181 #ifdef CONFIG_64BIT
164 0: br %r1 !! 182 PTR_LA a2, PT_SIZE(sp)
165 SYM_INNER_LABEL(ftrace_shared_hotpatch_trampol !! 183 #else
166 SYM_CODE_END(ftrace_shared_hotpatch_trampoline !! 184 PTR_LA a2, (PT_SIZE+8)(sp)
167 #endif /* CONFIG_EXPOLINE */ !! 185 #endif
168 !! 186 #endif
169 #ifdef CONFIG_RETHOOK !! 187
170 !! 188 jal prepare_ftrace_return
171 SYM_CODE_START(arch_rethook_trampoline) !! 189 nop
172 stg %r14,(__SF_GPRS+8*8)(%r15) !! 190 MCOUNT_RESTORE_REGS
173 lay %r15,-STACK_FRAME_SIZE_PTREGS( !! 191 #ifndef CONFIG_DYNAMIC_FTRACE
174 stmg %r0,%r14,STACK_PTREGS_GPRS(%r1 !! 192 #ifdef CONFIG_32BIT
175 !! 193 addiu sp, sp, 8
176 # store original stack pointer in back !! 194 #endif
177 lay %r7,STACK_FRAME_SIZE_PTREGS(%r !! 195 #endif
178 stg %r7,__SF_BACKCHAIN(%r15) !! 196 RETURN_BACK
179 stg %r7,STACK_PTREGS_GPRS+(15*8)(% !! 197 END(ftrace_graph_caller)
180 !! 198
181 # store full psw !! 199 .align 2
182 epsw %r2,%r3 !! 200 .globl return_to_handler
183 risbg %r3,%r2,0,31,32 !! 201 return_to_handler:
184 stg %r3,STACK_PTREGS_PSW(%r15) !! 202 PTR_SUBU sp, PT_SIZE
185 larl %r1,arch_rethook_trampoline !! 203 PTR_S v0, PT_R2(sp)
186 stg %r1,STACK_PTREGS_PSW+8(%r15) !! 204
187 !! 205 jal ftrace_return_to_handler
188 lay %r2,STACK_PTREGS(%r15) !! 206 PTR_S v1, PT_R3(sp)
189 brasl %r14,arch_rethook_trampoline_c !! 207
190 !! 208 /* restore the real parent address: v0 -> ra */
191 mvc __SF_EMPTY(16,%r7),STACK_PTREG !! 209 move ra, v0
192 lmg %r0,%r15,STACK_PTREGS_GPRS(%r1 !! 210
193 lpswe __SF_EMPTY(%r15) !! 211 PTR_L v0, PT_R2(sp)
194 SYM_CODE_END(arch_rethook_trampoline) !! 212 PTR_L v1, PT_R3(sp)
>> 213 jr ra
>> 214 PTR_ADDIU sp, PT_SIZE
>> 215 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
195 216
196 #endif /* CONFIG_RETHOOK */ !! 217 .set at
>> 218 .set reorder
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