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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/export.h>
13
14
15#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE)
16#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
17#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
18#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
19#define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2)
20#define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS)
21/* packed stack: allocate just enough for r14, r15 and backchain */
22#define TRACED_FUNC_FRAME_SIZE 24
23
24#ifdef CONFIG_FUNCTION_TRACER
25
26 GEN_BR_THUNK %r1
27 GEN_BR_THUNK %r14
28
29 .section .kprobes.text, "ax"
30
31ENTRY(ftrace_stub)
32 BR_EX %r14
33ENDPROC(ftrace_stub)
34
35 .macro ftrace_regs_entry, allregs=0
36 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
37
38 .if \allregs == 1
39 # save psw mask
40 # don't put any instructions clobbering CC before this point
41 epsw %r1,%r14
42 risbg %r14,%r1,0,31,32
43 .endif
44
45 lgr %r1,%r15
46 # allocate stack frame for ftrace_caller to contain traced function
47 aghi %r15,-TRACED_FUNC_FRAME_SIZE
48 stg %r1,__SF_BACKCHAIN(%r15)
49 stg %r0,(__SF_GPRS+8*8)(%r15)
50 stg %r15,(__SF_GPRS+9*8)(%r15)
51 # allocate pt_regs and stack frame for ftrace_trace_function
52 aghi %r15,-STACK_FRAME_SIZE
53 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
54 xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15)
55
56 .if \allregs == 1
57 stg %r14,(STACK_PTREGS_PSW)(%r15)
58 mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
59 .else
60 xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15)
61 .endif
62
63 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
64 aghi %r1,-TRACED_FUNC_FRAME_SIZE
65 stg %r1,__SF_BACKCHAIN(%r15)
66 stg %r0,(STACK_PTREGS_PSW+8)(%r15)
67 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
68 .endm
69
70SYM_CODE_START(ftrace_regs_caller)
71 ftrace_regs_entry 1
72 j ftrace_common
73SYM_CODE_END(ftrace_regs_caller)
74
75SYM_CODE_START(ftrace_caller)
76 ftrace_regs_entry 0
77 j ftrace_common
78SYM_CODE_END(ftrace_caller)
79
80SYM_CODE_START(ftrace_common)
81#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
82 aghik %r2,%r0,-MCOUNT_INSN_SIZE
83 lgrl %r4,function_trace_op
84 lgrl %r1,ftrace_func
85#else
86 lgr %r2,%r0
87 aghi %r2,-MCOUNT_INSN_SIZE
88 larl %r4,function_trace_op
89 lg %r4,0(%r4)
90 larl %r1,ftrace_func
91 lg %r1,0(%r1)
92#endif
93 lgr %r3,%r14
94 la %r5,STACK_PTREGS(%r15)
95 BASR_EX %r14,%r1
96#ifdef CONFIG_FUNCTION_GRAPH_TRACER
97# The j instruction gets runtime patched to a nop instruction.
98# See ftrace_enable_ftrace_graph_caller.
99SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
100 j .Lftrace_graph_caller_end
101 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
102 lg %r4,(STACK_PTREGS_PSW+8)(%r15)
103 brasl %r14,prepare_ftrace_return
104 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
105.Lftrace_graph_caller_end:
106#endif
107 lg %r0,(STACK_PTREGS_PSW+8)(%r15)
108#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
109 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
110 locgrz %r1,%r0
111#else
112 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
113 ltgr %r1,%r1
114 jnz 0f
115 lgr %r1,%r0
116#endif
1170: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
118 BR_EX %r1
119SYM_CODE_END(ftrace_common)
120
121#ifdef CONFIG_FUNCTION_GRAPH_TRACER
122
123SYM_FUNC_START(return_to_handler)
124 stmg %r2,%r5,32(%r15)
125 lgr %r1,%r15
126 aghi %r15,-STACK_FRAME_OVERHEAD
127 stg %r1,__SF_BACKCHAIN(%r15)
128 brasl %r14,ftrace_return_to_handler
129 aghi %r15,STACK_FRAME_OVERHEAD
130 lgr %r14,%r2
131 lmg %r2,%r5,32(%r15)
132 BR_EX %r14
133SYM_FUNC_END(return_to_handler)
134
135#endif
136#endif /* CONFIG_FUNCTION_TRACER */
137
138#ifdef CONFIG_KPROBES
139
140SYM_FUNC_START(__kretprobe_trampoline)
141
142 stg %r14,(__SF_GPRS+8*8)(%r15)
143 lay %r15,-STACK_FRAME_SIZE(%r15)
144 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
145
146 # store original stack pointer in backchain and pt_regs
147 lay %r7,STACK_FRAME_SIZE(%r15)
148 stg %r7,__SF_BACKCHAIN(%r15)
149 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
150
151 # store full psw
152 epsw %r2,%r3
153 risbg %r3,%r2,0,31,32
154 stg %r3,STACK_PTREGS_PSW(%r15)
155 larl %r1,__kretprobe_trampoline
156 stg %r1,STACK_PTREGS_PSW+8(%r15)
157
158 lay %r2,STACK_PTREGS(%r15)
159 brasl %r14,trampoline_probe_handler
160
161 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
162 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
163 lpswe __SF_EMPTY(%r15)
164
165SYM_FUNC_END(__kretprobe_trampoline)
166
167#endif /* CONFIG_KPROBES */
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
11 .section .kprobes.text, "ax"
12
13ENTRY(ftrace_stub)
14 br %r14
15
16ENTRY(_mcount)
17#ifdef CONFIG_DYNAMIC_FTRACE
18 br %r14
19
20ENTRY(ftrace_caller)
21#endif
22 stm %r2,%r5,16(%r15)
23 bras %r1,2f
240: .long ftrace_trace_function
251: .long function_trace_stop
262: l %r2,1b-0b(%r1)
27 icm %r2,0xf,0(%r2)
28 jnz 3f
29 st %r14,56(%r15)
30 lr %r0,%r15
31 ahi %r15,-96
32 l %r3,100(%r15)
33 la %r2,0(%r14)
34 st %r0,__SF_BACKCHAIN(%r15)
35 la %r3,0(%r3)
36 l %r14,0b-0b(%r1)
37 l %r14,0(%r14)
38 basr %r14,%r14
39#ifdef CONFIG_FUNCTION_GRAPH_TRACER
40 l %r2,100(%r15)
41 l %r3,152(%r15)
42ENTRY(ftrace_graph_caller)
43# The bras instruction gets runtime patched to call prepare_ftrace_return.
44# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
45# bras %r14,prepare_ftrace_return
46 bras %r14,0f
470: st %r2,100(%r15)
48#endif
49 ahi %r15,96
50 l %r14,56(%r15)
513: lm %r2,%r5,16(%r15)
52 br %r14
53
54#ifdef CONFIG_FUNCTION_GRAPH_TRACER
55
56ENTRY(return_to_handler)
57 stm %r2,%r5,16(%r15)
58 st %r14,56(%r15)
59 lr %r0,%r15
60 ahi %r15,-96
61 st %r0,__SF_BACKCHAIN(%r15)
62 bras %r1,0f
63 .long ftrace_return_to_handler
640: l %r2,0b-0b(%r1)
65 basr %r14,%r2
66 lr %r14,%r2
67 ahi %r15,96
68 lm %r2,%r5,16(%r15)
69 br %r14
70
71#endif