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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
13#define STACK_FRAME_SIZE_PTREGS (STACK_FRAME_OVERHEAD + __PT_SIZE)
14#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
15#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
16#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
17
18#define STACK_FRAME_SIZE_FREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_SIZE)
19#define STACK_FREGS (STACK_FRAME_OVERHEAD)
20#define STACK_FREGS_PTREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_PT_REGS)
21#define STACK_FREGS_PTREGS_GPRS (STACK_FREGS_PTREGS + __PT_GPRS)
22#define STACK_FREGS_PTREGS_PSW (STACK_FREGS_PTREGS + __PT_PSW)
23#define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK_FREGS_PTREGS + __PT_ORIG_GPR2)
24#define STACK_FREGS_PTREGS_FLAGS (STACK_FREGS_PTREGS + __PT_FLAGS)
25
26/* packed stack: allocate just enough for r14, r15 and backchain */
27#define TRACED_FUNC_FRAME_SIZE 24
28
29#ifdef CONFIG_FUNCTION_TRACER
30
31 GEN_BR_THUNK %r1
32 GEN_BR_THUNK %r14
33
34 .section .kprobes.text, "ax"
35
36SYM_FUNC_START(ftrace_stub)
37 BR_EX %r14
38SYM_FUNC_END(ftrace_stub)
39
40SYM_CODE_START(ftrace_stub_direct_tramp)
41 lgr %r1, %r0
42 BR_EX %r1
43SYM_CODE_END(ftrace_stub_direct_tramp)
44
45 .macro ftrace_regs_entry, allregs=0
46 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
47
48 .if \allregs == 1
49 # save psw mask
50 # don't put any instructions clobbering CC before this point
51 epsw %r1,%r14
52 risbg %r14,%r1,0,31,32
53 .endif
54
55 lgr %r1,%r15
56 # allocate stack frame for ftrace_caller to contain traced function
57 aghi %r15,-TRACED_FUNC_FRAME_SIZE
58 stg %r1,__SF_BACKCHAIN(%r15)
59 stg %r0,(__SF_GPRS+8*8)(%r15)
60 stg %r15,(__SF_GPRS+9*8)(%r15)
61 # allocate ftrace_regs and stack frame for ftrace_trace_function
62 aghi %r15,-STACK_FRAME_SIZE_FREGS
63 stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15)
64 xc STACK_FREGS_PTREGS_ORIG_GPR2(8,%r15),STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
65
66 .if \allregs == 1
67 stg %r14,(STACK_FREGS_PTREGS_PSW)(%r15)
68 mvghi STACK_FREGS_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
69 .else
70 xc STACK_FREGS_PTREGS_FLAGS(8,%r15),STACK_FREGS_PTREGS_FLAGS(%r15)
71 .endif
72
73 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
74 aghi %r1,-TRACED_FUNC_FRAME_SIZE
75 stg %r1,__SF_BACKCHAIN(%r15)
76 stg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15)
77 stmg %r2,%r14,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15)
78 .endm
79
80SYM_CODE_START(ftrace_regs_caller)
81 ftrace_regs_entry 1
82 j ftrace_common
83SYM_CODE_END(ftrace_regs_caller)
84
85SYM_CODE_START(ftrace_caller)
86 ftrace_regs_entry 0
87 j ftrace_common
88SYM_CODE_END(ftrace_caller)
89
90SYM_CODE_START(ftrace_common)
91#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
92 aghik %r2,%r0,-MCOUNT_INSN_SIZE
93 lgrl %r4,function_trace_op
94 lgrl %r1,ftrace_func
95#else
96 lgr %r2,%r0
97 aghi %r2,-MCOUNT_INSN_SIZE
98 larl %r4,function_trace_op
99 lg %r4,0(%r4)
100 larl %r1,ftrace_func
101 lg %r1,0(%r1)
102#endif
103 lgr %r3,%r14
104 la %r5,STACK_FREGS(%r15)
105 BASR_EX %r14,%r1
106#ifdef CONFIG_FUNCTION_GRAPH_TRACER
107# The j instruction gets runtime patched to a nop instruction.
108# See ftrace_enable_ftrace_graph_caller.
109SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
110 j .Lftrace_graph_caller_end
111 lmg %r2,%r3,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15)
112 lg %r4,(STACK_FREGS_PTREGS_PSW+8)(%r15)
113 brasl %r14,prepare_ftrace_return
114 stg %r2,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15)
115.Lftrace_graph_caller_end:
116#endif
117 lg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15)
118#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
119 ltg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
120 locgrz %r1,%r0
121#else
122 lg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
123 ltgr %r1,%r1
124 jnz 0f
125 lgr %r1,%r0
126#endif
1270: lmg %r2,%r15,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15)
128 BR_EX %r1
129SYM_CODE_END(ftrace_common)
130
131#ifdef CONFIG_FUNCTION_GRAPH_TRACER
132
133SYM_FUNC_START(return_to_handler)
134 stmg %r2,%r5,32(%r15)
135 lgr %r1,%r15
136 aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE)
137 stg %r1,__SF_BACKCHAIN(%r15)
138 la %r3,STACK_FRAME_OVERHEAD(%r15)
139 stg %r1,__FGRAPH_RET_FP(%r3)
140 stg %r2,__FGRAPH_RET_GPR2(%r3)
141 lgr %r2,%r3
142 brasl %r14,ftrace_return_to_handler
143 aghi %r15,STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE
144 lgr %r14,%r2
145 lmg %r2,%r5,32(%r15)
146 BR_EX %r14
147SYM_FUNC_END(return_to_handler)
148
149#endif
150#endif /* CONFIG_FUNCTION_TRACER */
151
152SYM_CODE_START(ftrace_shared_hotpatch_trampoline_br)
153 lmg %r0,%r1,2(%r1)
154 br %r1
155SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_br_end, SYM_L_GLOBAL)
156SYM_CODE_END(ftrace_shared_hotpatch_trampoline_br)
157
158#ifdef CONFIG_EXPOLINE
159SYM_CODE_START(ftrace_shared_hotpatch_trampoline_exrl)
160 lmg %r0,%r1,2(%r1)
161 exrl %r0,0f
162 j .
1630: br %r1
164SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_exrl_end, SYM_L_GLOBAL)
165SYM_CODE_END(ftrace_shared_hotpatch_trampoline_exrl)
166#endif /* CONFIG_EXPOLINE */
167
168#ifdef CONFIG_RETHOOK
169
170SYM_CODE_START(arch_rethook_trampoline)
171 stg %r14,(__SF_GPRS+8*8)(%r15)
172 lay %r15,-STACK_FRAME_SIZE_PTREGS(%r15)
173 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
174
175 # store original stack pointer in backchain and pt_regs
176 lay %r7,STACK_FRAME_SIZE_PTREGS(%r15)
177 stg %r7,__SF_BACKCHAIN(%r15)
178 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
179
180 # store full psw
181 epsw %r2,%r3
182 risbg %r3,%r2,0,31,32
183 stg %r3,STACK_PTREGS_PSW(%r15)
184 larl %r1,arch_rethook_trampoline
185 stg %r1,STACK_PTREGS_PSW+8(%r15)
186
187 lay %r2,STACK_PTREGS(%r15)
188 brasl %r14,arch_rethook_trampoline_callback
189
190 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
191 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
192 lpswe __SF_EMPTY(%r15)
193SYM_CODE_END(arch_rethook_trampoline)
194
195#endif /* CONFIG_RETHOOK */
1/*
2 * Copyright IBM Corp. 2008, 2009
3 *
4 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
5 *
6 */
7
8#include <linux/linkage.h>
9#include <asm/asm-offsets.h>
10#include <asm/ftrace.h>
11
12 .section .kprobes.text, "ax"
13
14ENTRY(ftrace_stub)
15 br %r14
16
17ENTRY(_mcount)
18#ifdef CONFIG_DYNAMIC_FTRACE
19 br %r14
20
21ENTRY(ftrace_caller)
22#endif
23 stm %r2,%r5,16(%r15)
24 bras %r1,2f
250: .long ftrace_trace_function
261: .long function_trace_stop
272: l %r2,1b-0b(%r1)
28 icm %r2,0xf,0(%r2)
29 jnz 3f
30 st %r14,56(%r15)
31 lr %r0,%r15
32 ahi %r15,-96
33 l %r3,100(%r15)
34 la %r2,0(%r14)
35 st %r0,__SF_BACKCHAIN(%r15)
36 la %r3,0(%r3)
37 ahi %r2,-MCOUNT_INSN_SIZE
38 l %r14,0b-0b(%r1)
39 l %r14,0(%r14)
40 basr %r14,%r14
41#ifdef CONFIG_FUNCTION_GRAPH_TRACER
42 l %r2,100(%r15)
43 l %r3,152(%r15)
44ENTRY(ftrace_graph_caller)
45# The bras instruction gets runtime patched to call prepare_ftrace_return.
46# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
47# bras %r14,prepare_ftrace_return
48 bras %r14,0f
490: st %r2,100(%r15)
50#endif
51 ahi %r15,96
52 l %r14,56(%r15)
533: lm %r2,%r5,16(%r15)
54 br %r14
55
56#ifdef CONFIG_FUNCTION_GRAPH_TRACER
57
58ENTRY(return_to_handler)
59 stm %r2,%r5,16(%r15)
60 st %r14,56(%r15)
61 lr %r0,%r15
62 ahi %r15,-96
63 st %r0,__SF_BACKCHAIN(%r15)
64 bras %r1,0f
65 .long ftrace_return_to_handler
660: l %r2,0b-0b(%r1)
67 basr %r14,%r2
68 lr %r14,%r2
69 ahi %r15,96
70 lm %r2,%r5,16(%r15)
71 br %r14
72
73#endif