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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#include <asm/march.h>
13
14#define STACK_FRAME_SIZE_PTREGS (STACK_FRAME_OVERHEAD + __PT_SIZE)
15#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
16#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
17#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
18
19#define STACK_FRAME_SIZE_FREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_SIZE)
20#define STACK_FREGS (STACK_FRAME_OVERHEAD)
21#define STACK_FREGS_PTREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_PT_REGS)
22#define STACK_FREGS_PTREGS_GPRS (STACK_FREGS_PTREGS + __PT_GPRS)
23#define STACK_FREGS_PTREGS_PSW (STACK_FREGS_PTREGS + __PT_PSW)
24#define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK_FREGS_PTREGS + __PT_ORIG_GPR2)
25#define STACK_FREGS_PTREGS_FLAGS (STACK_FREGS_PTREGS + __PT_FLAGS)
26
27/* packed stack: allocate just enough for r14, r15 and backchain */
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
37SYM_FUNC_START(ftrace_stub)
38 BR_EX %r14
39SYM_FUNC_END(ftrace_stub)
40
41SYM_CODE_START(ftrace_stub_direct_tramp)
42 lgr %r1, %r0
43 BR_EX %r1
44SYM_CODE_END(ftrace_stub_direct_tramp)
45
46 .macro ftrace_regs_entry, allregs=0
47 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
48
49 .if \allregs == 1
50 # save psw mask
51 # don't put any instructions clobbering CC before this point
52 epsw %r1,%r14
53 risbg %r14,%r1,0,31,32
54 .endif
55
56 lgr %r1,%r15
57 # allocate stack frame for ftrace_caller to contain traced function
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 for ftrace_trace_function
63 aghi %r15,-STACK_FRAME_SIZE_FREGS
64 stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15)
65 xc STACK_FREGS_PTREGS_ORIG_GPR2(8,%r15),STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
66
67 .if \allregs == 1
68 stg %r14,(STACK_FREGS_PTREGS_PSW)(%r15)
69 mvghi STACK_FREGS_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
70 .else
71 xc STACK_FREGS_PTREGS_FLAGS(8,%r15),STACK_FREGS_PTREGS_FLAGS(%r15)
72 .endif
73
74 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
75 aghi %r1,-TRACED_FUNC_FRAME_SIZE
76 stg %r1,__SF_BACKCHAIN(%r15)
77 stg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15)
78 stmg %r2,%r14,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15)
79 .endm
80
81SYM_CODE_START(ftrace_regs_caller)
82 ftrace_regs_entry 1
83 j ftrace_common
84SYM_CODE_END(ftrace_regs_caller)
85
86SYM_CODE_START(ftrace_caller)
87 ftrace_regs_entry 0
88 j ftrace_common
89SYM_CODE_END(ftrace_caller)
90
91SYM_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 nop instruction.
109# See ftrace_enable_ftrace_graph_caller.
110SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
111 j .Lftrace_graph_caller_end
112 lmg %r2,%r3,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15)
113 lg %r4,(STACK_FREGS_PTREGS_PSW+8)(%r15)
114 brasl %r14,prepare_ftrace_return
115 stg %r2,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15)
116.Lftrace_graph_caller_end:
117#endif
118 lg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15)
119#ifdef MARCH_HAS_Z196_FEATURES
120 ltg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
121 locgrz %r1,%r0
122#else
123 lg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
124 ltgr %r1,%r1
125 jnz 0f
126 lgr %r1,%r0
127#endif
1280: lmg %r2,%r15,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15)
129 BR_EX %r1
130SYM_CODE_END(ftrace_common)
131
132#ifdef CONFIG_FUNCTION_GRAPH_TRACER
133
134SYM_FUNC_START(return_to_handler)
135 stmg %r2,%r5,32(%r15)
136 lgr %r1,%r15
137 aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE)
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+__FGRAPH_RET_SIZE
145 lgr %r14,%r2
146 lmg %r2,%r5,32(%r15)
147 BR_EX %r14
148SYM_FUNC_END(return_to_handler)
149
150#endif
151#endif /* CONFIG_FUNCTION_TRACER */
152
153SYM_CODE_START(ftrace_shared_hotpatch_trampoline_br)
154 lmg %r0,%r1,2(%r1)
155 br %r1
156SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_br_end, SYM_L_GLOBAL)
157SYM_CODE_END(ftrace_shared_hotpatch_trampoline_br)
158
159#ifdef CONFIG_EXPOLINE
160SYM_CODE_START(ftrace_shared_hotpatch_trampoline_exrl)
161 lmg %r0,%r1,2(%r1)
162 exrl %r0,0f
163 j .
1640: br %r1
165SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_exrl_end, SYM_L_GLOBAL)
166SYM_CODE_END(ftrace_shared_hotpatch_trampoline_exrl)
167#endif /* CONFIG_EXPOLINE */
168
169#ifdef CONFIG_RETHOOK
170
171SYM_CODE_START(arch_rethook_trampoline)
172 stg %r14,(__SF_GPRS+8*8)(%r15)
173 lay %r15,-STACK_FRAME_SIZE_PTREGS(%r15)
174 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
175
176 # store original stack pointer in backchain and pt_regs
177 lay %r7,STACK_FRAME_SIZE_PTREGS(%r15)
178 stg %r7,__SF_BACKCHAIN(%r15)
179 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
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_callback
190
191 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
192 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
193 lpswe __SF_EMPTY(%r15)
194SYM_CODE_END(arch_rethook_trampoline)
195
196#endif /* CONFIG_RETHOOK */
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright IBM Corp. 2008, 2009
4 *
5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
6 *
7 */
8
9#include <linux/linkage.h>
10#include <asm/asm-offsets.h>
11#include <asm/ftrace.h>
12#include <asm/nospec-insn.h>
13#include <asm/ptrace.h>
14#include <asm/export.h>
15
16 GEN_BR_THUNK %r1
17 GEN_BR_THUNK %r14
18
19 .section .kprobes.text, "ax"
20
21ENTRY(ftrace_stub)
22 BR_EX %r14
23ENDPROC(ftrace_stub)
24
25#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE)
26#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
27#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
28#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
29#ifdef __PACK_STACK
30/* allocate just enough for r14, r15 and backchain */
31#define TRACED_FUNC_FRAME_SIZE 24
32#else
33#define TRACED_FUNC_FRAME_SIZE STACK_FRAME_OVERHEAD
34#endif
35
36ENTRY(ftrace_caller)
37 .globl ftrace_regs_caller
38 .set ftrace_regs_caller,ftrace_caller
39 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
40 lghi %r14,0 # save condition code
41 ipm %r14 # don't put any instructions
42 sllg %r14,%r14,16 # clobbering CC before this point
43 lgr %r1,%r15
44 # allocate stack frame for ftrace_caller to contain traced function
45 aghi %r15,-TRACED_FUNC_FRAME_SIZE
46 stg %r1,__SF_BACKCHAIN(%r15)
47 stg %r0,(__SF_GPRS+8*8)(%r15)
48 stg %r15,(__SF_GPRS+9*8)(%r15)
49 # allocate pt_regs and stack frame for ftrace_trace_function
50 aghi %r15,-STACK_FRAME_SIZE
51 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
52 stg %r14,(STACK_PTREGS_PSW)(%r15)
53 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
54 stosm (STACK_PTREGS_PSW)(%r15),0
55 aghi %r1,-TRACED_FUNC_FRAME_SIZE
56 stg %r1,__SF_BACKCHAIN(%r15)
57 stg %r0,(STACK_PTREGS_PSW+8)(%r15)
58 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
59#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
60 aghik %r2,%r0,-MCOUNT_INSN_SIZE
61 lgrl %r4,function_trace_op
62 lgrl %r1,ftrace_func
63#else
64 lgr %r2,%r0
65 aghi %r2,-MCOUNT_INSN_SIZE
66 larl %r4,function_trace_op
67 lg %r4,0(%r4)
68 larl %r1,ftrace_func
69 lg %r1,0(%r1)
70#endif
71 lgr %r3,%r14
72 la %r5,STACK_PTREGS(%r15)
73 BASR_EX %r14,%r1
74#ifdef CONFIG_FUNCTION_GRAPH_TRACER
75# The j instruction gets runtime patched to a nop instruction.
76# See ftrace_enable_ftrace_graph_caller.
77 .globl ftrace_graph_caller
78ftrace_graph_caller:
79 j ftrace_graph_caller_end
80 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
81 lg %r4,(STACK_PTREGS_PSW+8)(%r15)
82 brasl %r14,prepare_ftrace_return
83 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
84ftrace_graph_caller_end:
85 .globl ftrace_graph_caller_end
86#endif
87 lg %r1,(STACK_PTREGS_PSW+8)(%r15)
88 lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
89 BR_EX %r1
90ENDPROC(ftrace_caller)
91
92#ifdef CONFIG_FUNCTION_GRAPH_TRACER
93
94ENTRY(return_to_handler)
95 stmg %r2,%r5,32(%r15)
96 lgr %r1,%r15
97 aghi %r15,-STACK_FRAME_OVERHEAD
98 stg %r1,__SF_BACKCHAIN(%r15)
99 brasl %r14,ftrace_return_to_handler
100 aghi %r15,STACK_FRAME_OVERHEAD
101 lgr %r14,%r2
102 lmg %r2,%r5,32(%r15)
103 BR_EX %r14
104ENDPROC(return_to_handler)
105
106#endif