1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 2008, 2009
*
*/
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/ftrace.h>
#include <asm/nospec-insn.h>
#include <asm/ptrace.h>
#include <asm/export.h>
#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE)
#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
#define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2)
#define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS)
/* packed stack: allocate just enough for r14, r15 and backchain */
#define TRACED_FUNC_FRAME_SIZE 24
#ifdef CONFIG_FUNCTION_TRACER
GEN_BR_THUNK %r1
GEN_BR_THUNK %r14
.section .kprobes.text, "ax"
ENTRY(ftrace_stub)
BR_EX %r14
ENDPROC(ftrace_stub)
.macro ftrace_regs_entry, allregs=0
stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
.if \allregs == 1
# save psw mask
# don't put any instructions clobbering CC before this point
epsw %r1,%r14
risbg %r14,%r1,0,31,32
.endif
lgr %r1,%r15
# allocate stack frame for ftrace_caller to contain traced function
aghi %r15,-TRACED_FUNC_FRAME_SIZE
stg %r1,__SF_BACKCHAIN(%r15)
stg %r0,(__SF_GPRS+8*8)(%r15)
stg %r15,(__SF_GPRS+9*8)(%r15)
# allocate pt_regs and stack frame for ftrace_trace_function
aghi %r15,-STACK_FRAME_SIZE
stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15)
.if \allregs == 1
stg %r14,(STACK_PTREGS_PSW)(%r15)
mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
.else
xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15)
.endif
lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
aghi %r1,-TRACED_FUNC_FRAME_SIZE
stg %r1,__SF_BACKCHAIN(%r15)
stg %r0,(STACK_PTREGS_PSW+8)(%r15)
stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
.endm
SYM_CODE_START(ftrace_regs_caller)
ftrace_regs_entry 1
j ftrace_common
SYM_CODE_END(ftrace_regs_caller)
SYM_CODE_START(ftrace_caller)
ftrace_regs_entry 0
j ftrace_common
SYM_CODE_END(ftrace_caller)
SYM_CODE_START(ftrace_common)
#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
aghik %r2,%r0,-MCOUNT_INSN_SIZE
lgrl %r4,function_trace_op
lgrl %r1,ftrace_func
#else
lgr %r2,%r0
aghi %r2,-MCOUNT_INSN_SIZE
larl %r4,function_trace_op
lg %r4,0(%r4)
larl %r1,ftrace_func
lg %r1,0(%r1)
#endif
lgr %r3,%r14
la %r5,STACK_PTREGS(%r15)
BASR_EX %r14,%r1
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
# The j instruction gets runtime patched to a nop instruction.
# See ftrace_enable_ftrace_graph_caller.
SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
j .Lftrace_graph_caller_end
lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
lg %r4,(STACK_PTREGS_PSW+8)(%r15)
brasl %r14,prepare_ftrace_return
stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
.Lftrace_graph_caller_end:
#endif
lg %r0,(STACK_PTREGS_PSW+8)(%r15)
#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
locgrz %r1,%r0
#else
lg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
ltgr %r1,%r1
jnz 0f
lgr %r1,%r0
#endif
0: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
BR_EX %r1
SYM_CODE_END(ftrace_common)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
SYM_FUNC_START(return_to_handler)
stmg %r2,%r5,32(%r15)
lgr %r1,%r15
aghi %r15,-STACK_FRAME_OVERHEAD
stg %r1,__SF_BACKCHAIN(%r15)
brasl %r14,ftrace_return_to_handler
aghi %r15,STACK_FRAME_OVERHEAD
lgr %r14,%r2
lmg %r2,%r5,32(%r15)
BR_EX %r14
SYM_FUNC_END(return_to_handler)
#endif
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_RETHOOK
SYM_FUNC_START(arch_rethook_trampoline)
stg %r14,(__SF_GPRS+8*8)(%r15)
lay %r15,-STACK_FRAME_SIZE(%r15)
stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
# store original stack pointer in backchain and pt_regs
lay %r7,STACK_FRAME_SIZE(%r15)
stg %r7,__SF_BACKCHAIN(%r15)
stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
# store full psw
epsw %r2,%r3
risbg %r3,%r2,0,31,32
stg %r3,STACK_PTREGS_PSW(%r15)
larl %r1,arch_rethook_trampoline
stg %r1,STACK_PTREGS_PSW+8(%r15)
lay %r2,STACK_PTREGS(%r15)
brasl %r14,arch_rethook_trampoline_callback
mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
lpswe __SF_EMPTY(%r15)
SYM_FUNC_END(arch_rethook_trampoline)
#endif /* CONFIG_RETHOOK */
|
