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14#include <linux/uaccess.h>
15#include <linux/ftrace.h>
16
17#include <asm/cacheflush.h>
18#include <asm/patch.h>
19
20
21static unsigned char __attribute__((aligned(8)))
22ftrace_orig_code[MCOUNT_INSN_SIZE] = {
23 0x02, 0x40, 0x31, 0x10, 0x80, 0x05,
24 0xb0, 0x02, 0x00, 0x00, 0x42, 0x40,
25 0x05, 0x00, 0xc4, 0x00,
26 0x11, 0x48, 0x01, 0x02, 0x00, 0x21,
27 0x00, 0x00, 0x00, 0x02, 0x00, 0x00,
28 0x08, 0x00, 0x00, 0x50
29};
30
31struct ftrace_orig_insn {
32 u64 dummy1, dummy2, dummy3;
33 u64 dummy4:64-41+13;
34 u64 imm20:20;
35 u64 dummy5:3;
36 u64 sign:1;
37 u64 dummy6:4;
38};
39
40
41static unsigned char ftrace_nop_code[MCOUNT_INSN_SIZE] = {
42 0x00, 0x00, 0x00, 0x00, 0x01, 0x00,
43 0x30, 0x00, 0x00, 0x60, 0x00, 0x00,
44 0x00, 0x00, 0x04, 0x00,
45 0x05, 0x00, 0x00, 0x00, 0x01, 0x00,
46 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
47 0x00, 0x00, 0x04, 0x00
48};
49
50static unsigned char *ftrace_nop_replace(void)
51{
52 return ftrace_nop_code;
53}
54
55
56
57
58
59static unsigned char __attribute__((aligned(8)))
60ftrace_call_code[MCOUNT_INSN_SIZE] = {
61 0x00, 0x00, 0x00, 0x00, 0x01, 0x00,
62 0x30, 0x00, 0x00, 0x60, 0x00, 0x00,
63 0x00, 0x00, 0x04, 0x00,
64 0x05, 0x00, 0x00, 0x00, 0x01, 0x00,
65 0xff, 0xff, 0xff, 0xff, 0x7f, 0x00,
66 0xf8, 0xff, 0xff, 0xc8
67};
68
69struct ftrace_call_insn {
70 u64 dummy1, dummy2;
71 u64 dummy3:48;
72 u64 imm39_l:16;
73 u64 imm39_h:23;
74 u64 dummy4:13;
75 u64 imm20:20;
76 u64 dummy5:3;
77 u64 i:1;
78 u64 dummy6:4;
79};
80
81static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
82{
83 struct ftrace_call_insn *code = (void *)ftrace_call_code;
84 unsigned long offset = addr - (ip + 0x10);
85
86 code->imm39_l = offset >> 24;
87 code->imm39_h = offset >> 40;
88 code->imm20 = offset >> 4;
89 code->i = offset >> 63;
90 return ftrace_call_code;
91}
92
93static int
94ftrace_modify_code(unsigned long ip, unsigned char *old_code,
95 unsigned char *new_code, int do_check)
96{
97 unsigned char replaced[MCOUNT_INSN_SIZE];
98
99
100
101
102
103
104
105
106
107
108
109 if (!do_check)
110 goto skip_check;
111
112
113 if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
114 return -EFAULT;
115
116
117 if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0)
118 return -EINVAL;
119
120skip_check:
121
122 if (probe_kernel_write(((void *)ip), new_code, MCOUNT_INSN_SIZE))
123 return -EPERM;
124 flush_icache_range(ip, ip + MCOUNT_INSN_SIZE);
125
126 return 0;
127}
128
129static int ftrace_make_nop_check(struct dyn_ftrace *rec, unsigned long addr)
130{
131 unsigned char __attribute__((aligned(8))) replaced[MCOUNT_INSN_SIZE];
132 unsigned long ip = rec->ip;
133
134 if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
135 return -EFAULT;
136 if (rec->flags & FTRACE_FL_CONVERTED) {
137 struct ftrace_call_insn *call_insn, *tmp_call;
138
139 call_insn = (void *)ftrace_call_code;
140 tmp_call = (void *)replaced;
141 call_insn->imm39_l = tmp_call->imm39_l;
142 call_insn->imm39_h = tmp_call->imm39_h;
143 call_insn->imm20 = tmp_call->imm20;
144 call_insn->i = tmp_call->i;
145 if (memcmp(replaced, ftrace_call_code, MCOUNT_INSN_SIZE) != 0)
146 return -EINVAL;
147 return 0;
148 } else {
149 struct ftrace_orig_insn *call_insn, *tmp_call;
150
151 call_insn = (void *)ftrace_orig_code;
152 tmp_call = (void *)replaced;
153 call_insn->sign = tmp_call->sign;
154 call_insn->imm20 = tmp_call->imm20;
155 if (memcmp(replaced, ftrace_orig_code, MCOUNT_INSN_SIZE) != 0)
156 return -EINVAL;
157 return 0;
158 }
159}
160
161int ftrace_make_nop(struct module *mod,
162 struct dyn_ftrace *rec, unsigned long addr)
163{
164 int ret;
165 char *new;
166
167 ret = ftrace_make_nop_check(rec, addr);
168 if (ret)
169 return ret;
170 new = ftrace_nop_replace();
171 return ftrace_modify_code(rec->ip, NULL, new, 0);
172}
173
174int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
175{
176 unsigned long ip = rec->ip;
177 unsigned char *old, *new;
178
179 old= ftrace_nop_replace();
180 new = ftrace_call_replace(ip, addr);
181 return ftrace_modify_code(ip, old, new, 1);
182}
183
184
185int ftrace_update_ftrace_func(ftrace_func_t func)
186{
187 unsigned long ip;
188 unsigned long addr = ((struct fnptr *)ftrace_call)->ip;
189
190 if (func == ftrace_stub)
191 return 0;
192 ip = ((struct fnptr *)func)->ip;
193
194 ia64_patch_imm64(addr + 2, ip);
195
196 flush_icache_range(addr, addr + 16);
197 return 0;
198}
199
200
201int __init ftrace_dyn_arch_init(void *data)
202{
203 *(unsigned long *)data = 0;
204
205 return 0;
206}
207