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 <linux/export.h>
8 #include <asm/asm-offsets.h> !! 14 #include <asm/regdef.h>
>> 15 #include <asm/stackframe.h>
9 #include <asm/ftrace.h> 16 #include <asm/ftrace.h>
10 #include <asm/nospec-insn.h> !! 17
11 #include <asm/ptrace.h> !! 18 .text
12 #include <asm/march.h> !! 19 .set noreorder
13 !! 20 .set noat
14 #define STACK_FRAME_SIZE_PTREGS (STACK !! 21
15 #define STACK_PTREGS (STACK !! 22 .macro MCOUNT_SAVE_REGS
16 #define STACK_PTREGS_GPRS (STACK !! 23 PTR_SUBU sp, PT_SIZE
17 #define STACK_PTREGS_PSW (STACK !! 24 PTR_S ra, PT_R31(sp)
18 !! 25 PTR_S AT, PT_R1(sp)
19 #define STACK_FRAME_SIZE_FREGS (STACK !! 26 PTR_S a0, PT_R4(sp)
20 #define STACK_FREGS (STACK !! 27 PTR_S a1, PT_R5(sp)
21 #define STACK_FREGS_PTREGS (STACK !! 28 PTR_S a2, PT_R6(sp)
22 #define STACK_FREGS_PTREGS_GPRS (STACK !! 29 PTR_S a3, PT_R7(sp)
23 #define STACK_FREGS_PTREGS_PSW (STACK !! 30 #ifdef CONFIG_64BIT
24 #define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK !! 31 PTR_S a4, PT_R8(sp)
25 #define STACK_FREGS_PTREGS_FLAGS (STACK !! 32 PTR_S a5, PT_R9(sp)
26 !! 33 PTR_S a6, PT_R10(sp)
27 /* packed stack: allocate just enough for r14, !! 34 PTR_S a7, PT_R11(sp)
28 #define TRACED_FUNC_FRAME_SIZE 24 !! 35 #endif
29 !! 36 .endm
30 #ifdef CONFIG_FUNCTION_TRACER !! 37
31 !! 38 .macro MCOUNT_RESTORE_REGS
32 GEN_BR_THUNK %r1 !! 39 PTR_L ra, PT_R31(sp)
33 GEN_BR_THUNK %r14 !! 40 PTR_L AT, PT_R1(sp)
34 !! 41 PTR_L a0, PT_R4(sp)
35 .section .kprobes.text, "ax" !! 42 PTR_L a1, PT_R5(sp)
36 !! 43 PTR_L a2, PT_R6(sp)
37 SYM_FUNC_START(ftrace_stub) !! 44 PTR_L a3, PT_R7(sp)
38 BR_EX %r14 !! 45 #ifdef CONFIG_64BIT
39 SYM_FUNC_END(ftrace_stub) !! 46 PTR_L a4, PT_R8(sp)
40 !! 47 PTR_L a5, PT_R9(sp)
41 SYM_CODE_START(ftrace_stub_direct_tramp) !! 48 PTR_L a6, PT_R10(sp)
42 lgr %r1, %r0 !! 49 PTR_L a7, PT_R11(sp)
43 BR_EX %r1 !! 50 #endif
44 SYM_CODE_END(ftrace_stub_direct_tramp) !! 51 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 52 .endm
80 53
81 SYM_CODE_START(ftrace_regs_caller) !! 54 .macro RETURN_BACK
82 ftrace_regs_entry 1 !! 55 jr ra
83 j ftrace_common !! 56 move ra, AT
84 SYM_CODE_END(ftrace_regs_caller) !! 57 .endm
85 !! 58
86 SYM_CODE_START(ftrace_caller) !! 59 /*
87 ftrace_regs_entry 0 !! 60 * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
88 j ftrace_common !! 61 * the location of the parent's return address.
89 SYM_CODE_END(ftrace_caller) !! 62 */
90 !! 63 #define MCOUNT_RA_ADDRESS_REG $12
91 SYM_CODE_START(ftrace_common) !! 64
92 #ifdef MARCH_HAS_Z196_FEATURES !! 65 #ifdef CONFIG_DYNAMIC_FTRACE
93 aghik %r2,%r0,-MCOUNT_INSN_SIZE !! 66
94 lgrl %r4,function_trace_op !! 67 NESTED(ftrace_caller, PT_SIZE, ra)
95 lgrl %r1,ftrace_func !! 68 .globl _mcount
>> 69 _mcount:
>> 70 EXPORT_SYMBOL(_mcount)
>> 71 b ftrace_stub
>> 72 #ifdef CONFIG_32BIT
>> 73 addiu sp,sp,8
96 #else 74 #else
97 lgr %r2,%r0 !! 75 nop
98 aghi %r2,-MCOUNT_INSN_SIZE !! 76 #endif
99 larl %r4,function_trace_op !! 77
100 lg %r4,0(%r4) !! 78 /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
101 larl %r1,ftrace_func !! 79 MCOUNT_SAVE_REGS
102 lg %r1,0(%r1) !! 80 #ifdef KBUILD_MCOUNT_RA_ADDRESS
103 #endif !! 81 PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
104 lgr %r3,%r14 !! 82 #endif
105 la %r5,STACK_FREGS(%r15) !! 83
106 BASR_EX %r14,%r1 !! 84 PTR_SUBU a0, ra, 8 /* arg1: self address */
107 #ifdef CONFIG_FUNCTION_GRAPH_TRACER !! 85 PTR_LA t1, _stext
108 # The j instruction gets runtime patched to a !! 86 sltu t2, a0, t1 /* t2 = (a0 < _stext) */
109 # See ftrace_enable_ftrace_graph_caller. !! 87 PTR_LA t1, _etext
110 SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLO !! 88 sltu t3, t1, a0 /* t3 = (a0 > _etext) */
111 j .Lftrace_graph_caller_end !! 89 or t1, t2, t3
112 lmg %r2,%r3,(STACK_FREGS_PTREGS_GP !! 90 beqz t1, ftrace_call
113 lg %r4,(STACK_FREGS_PTREGS_PSW+8) !! 91 nop
114 brasl %r14,prepare_ftrace_return !! 92 #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
115 stg %r2,(STACK_FREGS_PTREGS_GPRS+1 !! 93 PTR_SUBU a0, a0, 16 /* arg1: adjust to module's recorded callsite */
116 .Lftrace_graph_caller_end: <<
117 #endif <<
118 lg %r0,(STACK_FREGS_PTREGS_PSW+8) <<
119 #ifdef MARCH_HAS_Z196_FEATURES <<
120 ltg %r1,STACK_FREGS_PTREGS_ORIG_GP <<
121 locgrz %r1,%r0 <<
122 #else 94 #else
123 lg %r1,STACK_FREGS_PTREGS_ORIG_GP !! 95 PTR_SUBU a0, a0, 12
124 ltgr %r1,%r1 !! 96 #endif
125 jnz 0f !! 97
126 lgr %r1,%r0 !! 98 .globl ftrace_call
127 #endif !! 99 ftrace_call:
128 0: lmg %r2,%r15,(STACK_FREGS_PTREGS_G !! 100 nop /* a placeholder for the call to a real tracing function */
129 BR_EX %r1 !! 101 move a1, AT /* arg2: parent's return address */
130 SYM_CODE_END(ftrace_common) <<
131 102
132 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 103 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 104 .globl ftrace_graph_call
>> 105 ftrace_graph_call:
>> 106 nop
>> 107 nop
>> 108 #endif
>> 109
>> 110 MCOUNT_RESTORE_REGS
>> 111 .globl ftrace_stub
>> 112 ftrace_stub:
>> 113 RETURN_BACK
>> 114 END(ftrace_caller)
>> 115
>> 116 #else /* ! CONFIG_DYNAMIC_FTRACE */
>> 117
>> 118 NESTED(_mcount, PT_SIZE, ra)
>> 119 EXPORT_SYMBOL(_mcount)
>> 120 PTR_LA t1, ftrace_stub
>> 121 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
>> 122 beq t1, t2, fgraph_trace
>> 123 nop
>> 124
>> 125 MCOUNT_SAVE_REGS
>> 126
>> 127 move a0, ra /* arg1: self return address */
>> 128 jalr t2 /* (1) call *ftrace_trace_function */
>> 129 move a1, AT /* arg2: parent's return address */
>> 130
>> 131 MCOUNT_RESTORE_REGS
>> 132
>> 133 fgraph_trace:
>> 134 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 135 PTR_LA t1, ftrace_stub
>> 136 PTR_L t3, ftrace_graph_return
>> 137 bne t1, t3, ftrace_graph_caller
>> 138 nop
>> 139 PTR_LA t1, ftrace_graph_entry_stub
>> 140 PTR_L t3, ftrace_graph_entry
>> 141 bne t1, t3, ftrace_graph_caller
>> 142 nop
>> 143 #endif
>> 144
>> 145 #ifdef CONFIG_32BIT
>> 146 addiu sp, sp, 8
>> 147 #endif
>> 148
>> 149 .globl ftrace_stub
>> 150 ftrace_stub:
>> 151 RETURN_BACK
>> 152 END(_mcount)
>> 153
>> 154 #endif /* ! CONFIG_DYNAMIC_FTRACE */
>> 155
>> 156 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 157
>> 158 NESTED(ftrace_graph_caller, PT_SIZE, ra)
>> 159 #ifndef CONFIG_DYNAMIC_FTRACE
>> 160 MCOUNT_SAVE_REGS
>> 161 #endif
>> 162
>> 163 /* arg1: Get the location of the parent's return address */
>> 164 #ifdef KBUILD_MCOUNT_RA_ADDRESS
>> 165 #ifdef CONFIG_DYNAMIC_FTRACE
>> 166 PTR_L a0, PT_R12(sp)
>> 167 #else
>> 168 move a0, MCOUNT_RA_ADDRESS_REG
>> 169 #endif
>> 170 bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
>> 171 nop
>> 172 #endif
>> 173 PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
>> 174 1:
>> 175
>> 176 /* arg2: Get self return address */
>> 177 #ifdef CONFIG_DYNAMIC_FTRACE
>> 178 PTR_L a1, PT_R31(sp)
>> 179 #else
>> 180 move a1, ra
>> 181 #endif
>> 182
>> 183 /* arg3: Get frame pointer of current stack */
>> 184 #ifdef CONFIG_64BIT
>> 185 PTR_LA a2, PT_SIZE(sp)
>> 186 #else
>> 187 PTR_LA a2, (PT_SIZE+8)(sp)
>> 188 #endif
>> 189
>> 190 jal prepare_ftrace_return
>> 191 nop
>> 192 MCOUNT_RESTORE_REGS
>> 193 #ifndef CONFIG_DYNAMIC_FTRACE
>> 194 #ifdef CONFIG_32BIT
>> 195 addiu sp, sp, 8
>> 196 #endif
>> 197 #endif
>> 198 RETURN_BACK
>> 199 END(ftrace_graph_caller)
133 200
134 SYM_FUNC_START(return_to_handler) !! 201 .align 2
135 stmg %r2,%r5,32(%r15) !! 202 .globl return_to_handler
136 lgr %r1,%r15 !! 203 return_to_handler:
137 aghi %r15,-(STACK_FRAME_OVERHEAD+__ !! 204 PTR_SUBU sp, PT_SIZE
138 stg %r1,__SF_BACKCHAIN(%r15) !! 205 PTR_S v0, PT_R2(sp)
139 la %r3,STACK_FRAME_OVERHEAD(%r15) !! 206
140 stg %r1,__FGRAPH_RET_FP(%r3) !! 207 jal ftrace_return_to_handler
141 stg %r2,__FGRAPH_RET_GPR2(%r3) !! 208 PTR_S v1, PT_R3(sp)
142 lgr %r2,%r3 !! 209
143 brasl %r14,ftrace_return_to_handler !! 210 /* restore the real parent address: v0 -> ra */
144 aghi %r15,STACK_FRAME_OVERHEAD+__FG !! 211 move ra, v0
145 lgr %r14,%r2 !! 212
146 lmg %r2,%r5,32(%r15) !! 213 PTR_L v0, PT_R2(sp)
147 BR_EX %r14 !! 214 PTR_L v1, PT_R3(sp)
148 SYM_FUNC_END(return_to_handler) !! 215 jr ra
149 !! 216 PTR_ADDIU sp, PT_SIZE
150 #endif !! 217 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
151 #endif /* CONFIG_FUNCTION_TRACER */ <<
152 <<
153 SYM_CODE_START(ftrace_shared_hotpatch_trampoli <<
154 lmg %r0,%r1,2(%r1) <<
155 br %r1 <<
156 SYM_INNER_LABEL(ftrace_shared_hotpatch_trampol <<
157 SYM_CODE_END(ftrace_shared_hotpatch_trampoline <<
158 <<
159 #ifdef CONFIG_EXPOLINE <<
160 SYM_CODE_START(ftrace_shared_hotpatch_trampoli <<
161 lmg %r0,%r1,2(%r1) <<
162 exrl %r0,0f <<
163 j . <<
164 0: br %r1 <<
165 SYM_INNER_LABEL(ftrace_shared_hotpatch_trampol <<
166 SYM_CODE_END(ftrace_shared_hotpatch_trampoline <<
167 #endif /* CONFIG_EXPOLINE */ <<
168 <<
169 #ifdef CONFIG_RETHOOK <<
170 <<
171 SYM_CODE_START(arch_rethook_trampoline) <<
172 stg %r14,(__SF_GPRS+8*8)(%r15) <<
173 lay %r15,-STACK_FRAME_SIZE_PTREGS( <<
174 stmg %r0,%r14,STACK_PTREGS_GPRS(%r1 <<
175 <<
176 # store original stack pointer in back <<
177 lay %r7,STACK_FRAME_SIZE_PTREGS(%r <<
178 stg %r7,__SF_BACKCHAIN(%r15) <<
179 stg %r7,STACK_PTREGS_GPRS+(15*8)(% <<
180 <<
181 # store full psw <<
182 epsw %r2,%r3 <<
183 risbg %r3,%r2,0,31,32 <<
184 stg %r3,STACK_PTREGS_PSW(%r15) <<
185 larl %r1,arch_rethook_trampoline <<
186 stg %r1,STACK_PTREGS_PSW+8(%r15) <<
187 <<
188 lay %r2,STACK_PTREGS(%r15) <<
189 brasl %r14,arch_rethook_trampoline_c <<
190 <<
191 mvc __SF_EMPTY(16,%r7),STACK_PTREG <<
192 lmg %r0,%r15,STACK_PTREGS_GPRS(%r1 <<
193 lpswe __SF_EMPTY(%r15) <<
194 SYM_CODE_END(arch_rethook_trampoline) <<
195 218
196 #endif /* CONFIG_RETHOOK */ !! 219 .set at
>> 220 .set reorder
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