1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright IBM Corp. 2008, 2009
4 *
5 */
6
7 #include <linux/linkage.h>
8 #include <asm/asm-offsets.h>
9 #include <asm/ftrace.h>
10 #include <asm/nospec-insn.h>
11 #include <asm/ptrace.h>
12 #include <asm/march.h>
13
14 #define STACK_FRAME_SIZE_PTREGS (STACK
15 #define STACK_PTREGS (STACK
16 #define STACK_PTREGS_GPRS (STACK
17 #define STACK_PTREGS_PSW (STACK
18
19 #define STACK_FRAME_SIZE_FREGS (STACK
20 #define STACK_FREGS (STACK
21 #define STACK_FREGS_PTREGS (STACK
22 #define STACK_FREGS_PTREGS_GPRS (STACK
23 #define STACK_FREGS_PTREGS_PSW (STACK
24 #define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK
25 #define STACK_FREGS_PTREGS_FLAGS (STACK
26
27 /* packed stack: allocate just enough for r14,
28 #define TRACED_FUNC_FRAME_SIZE 24
29
30 #ifdef CONFIG_FUNCTION_TRACER
31
32 GEN_BR_THUNK %r1
33 GEN_BR_THUNK %r14
34
35 .section .kprobes.text, "ax"
36
37 SYM_FUNC_START(ftrace_stub)
38 BR_EX %r14
39 SYM_FUNC_END(ftrace_stub)
40
41 SYM_CODE_START(ftrace_stub_direct_tramp)
42 lgr %r1, %r0
43 BR_EX %r1
44 SYM_CODE_END(ftrace_stub_direct_tramp)
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
80
81 SYM_CODE_START(ftrace_regs_caller)
82 ftrace_regs_entry 1
83 j ftrace_common
84 SYM_CODE_END(ftrace_regs_caller)
85
86 SYM_CODE_START(ftrace_caller)
87 ftrace_regs_entry 0
88 j ftrace_common
89 SYM_CODE_END(ftrace_caller)
90
91 SYM_CODE_START(ftrace_common)
92 #ifdef MARCH_HAS_Z196_FEATURES
93 aghik %r2,%r0,-MCOUNT_INSN_SIZE
94 lgrl %r4,function_trace_op
95 lgrl %r1,ftrace_func
96 #else
97 lgr %r2,%r0
98 aghi %r2,-MCOUNT_INSN_SIZE
99 larl %r4,function_trace_op
100 lg %r4,0(%r4)
101 larl %r1,ftrace_func
102 lg %r1,0(%r1)
103 #endif
104 lgr %r3,%r14
105 la %r5,STACK_FREGS(%r15)
106 BASR_EX %r14,%r1
107 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
108 # The j instruction gets runtime patched to a
109 # See ftrace_enable_ftrace_graph_caller.
110 SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLO
111 j .Lftrace_graph_caller_end
112 lmg %r2,%r3,(STACK_FREGS_PTREGS_GP
113 lg %r4,(STACK_FREGS_PTREGS_PSW+8)
114 brasl %r14,prepare_ftrace_return
115 stg %r2,(STACK_FREGS_PTREGS_GPRS+1
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
123 lg %r1,STACK_FREGS_PTREGS_ORIG_GP
124 ltgr %r1,%r1
125 jnz 0f
126 lgr %r1,%r0
127 #endif
128 0: lmg %r2,%r15,(STACK_FREGS_PTREGS_G
129 BR_EX %r1
130 SYM_CODE_END(ftrace_common)
131
132 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
133
134 SYM_FUNC_START(return_to_handler)
135 stmg %r2,%r5,32(%r15)
136 lgr %r1,%r15
137 aghi %r15,-(STACK_FRAME_OVERHEAD+__
138 stg %r1,__SF_BACKCHAIN(%r15)
139 la %r3,STACK_FRAME_OVERHEAD(%r15)
140 stg %r1,__FGRAPH_RET_FP(%r3)
141 stg %r2,__FGRAPH_RET_GPR2(%r3)
142 lgr %r2,%r3
143 brasl %r14,ftrace_return_to_handler
144 aghi %r15,STACK_FRAME_OVERHEAD+__FG
145 lgr %r14,%r2
146 lmg %r2,%r5,32(%r15)
147 BR_EX %r14
148 SYM_FUNC_END(return_to_handler)
149
150 #endif
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
196 #endif /* CONFIG_RETHOOK */
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