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gerrit-public.fairphone.software / kernel / msm-4.9 / f660f6066716b700148f60dba3461e65efff3123 / . / arch / s390 / lib / probes.c
blob: ae90e1ae3607052c6ac4403f815d33061fcaf604 [file] [log] [blame]
Jan Willeke975fab12014-09-22 16:37:27 +0200[diff] [blame]1/*
2 * Common helper functions for kprobes and uprobes
3 *
4 * Copyright IBM Corp. 2014
5 */
6
Jan Willeked6fe5be2014-10-08 10:16:08 +0200[diff] [blame]7#include <asm/kprobes.h>
Jan Willeke975fab12014-09-22 16:37:27 +0200[diff] [blame]8#include <asm/dis.h>
9
10int probe_is_prohibited_opcode(u16 *insn)
11{
12 if (!is_known_insn((unsigned char *)insn))
13 return -EINVAL;
14 switch (insn[0] >> 8) {
15 case 0x0c: /* bassm */
16 case 0x0b: /* bsm */
17 case 0x83: /* diag */
18 case 0x44: /* ex */
19 case 0xac: /* stnsm */
20 case 0xad: /* stosm */
21 return -EINVAL;
22 case 0xc6:
23 switch (insn[0] & 0x0f) {
24 case 0x00: /* exrl */
25 return -EINVAL;
26 }
27 }
28 switch (insn[0]) {
29 case 0x0101: /* pr */
30 case 0xb25a: /* bsa */
31 case 0xb240: /* bakr */
32 case 0xb258: /* bsg */
33 case 0xb218: /* pc */
34 case 0xb228: /* pt */
35 case 0xb98d: /* epsw */
36 case 0xe560: /* tbegin */
37 case 0xe561: /* tbeginc */
38 case 0xb2f8: /* tend */
39 return -EINVAL;
40 }
41 return 0;
42}
43
44int probe_get_fixup_type(u16 *insn)
45{
46 /* default fixup method */
47 int fixup = FIXUP_PSW_NORMAL;
48
49 switch (insn[0] >> 8) {
50 case 0x05: /* balr */
51 case 0x0d: /* basr */
52 fixup = FIXUP_RETURN_REGISTER;
53 /* if r2 = 0, no branch will be taken */
54 if ((insn[0] & 0x0f) == 0)
55 fixup |= FIXUP_BRANCH_NOT_TAKEN;
56 break;
57 case 0x06: /* bctr */
58 case 0x07: /* bcr */
59 fixup = FIXUP_BRANCH_NOT_TAKEN;
60 break;
61 case 0x45: /* bal */
62 case 0x4d: /* bas */
63 fixup = FIXUP_RETURN_REGISTER;
64 break;
65 case 0x47: /* bc */
66 case 0x46: /* bct */
67 case 0x86: /* bxh */
68 case 0x87: /* bxle */
69 fixup = FIXUP_BRANCH_NOT_TAKEN;
70 break;
71 case 0x82: /* lpsw */
72 fixup = FIXUP_NOT_REQUIRED;
73 break;
74 case 0xb2: /* lpswe */
75 if ((insn[0] & 0xff) == 0xb2)
76 fixup = FIXUP_NOT_REQUIRED;
77 break;
78 case 0xa7: /* bras */
79 if ((insn[0] & 0x0f) == 0x05)
80 fixup |= FIXUP_RETURN_REGISTER;
81 break;
82 case 0xc0:
83 if ((insn[0] & 0x0f) == 0x05) /* brasl */
84 fixup |= FIXUP_RETURN_REGISTER;
85 break;
86 case 0xeb:
87 switch (insn[2] & 0xff) {
88 case 0x44: /* bxhg */
89 case 0x45: /* bxleg */
90 fixup = FIXUP_BRANCH_NOT_TAKEN;
91 break;
92 }
93 break;
94 case 0xe3: /* bctg */
95 if ((insn[2] & 0xff) == 0x46)
96 fixup = FIXUP_BRANCH_NOT_TAKEN;
97 break;
98 case 0xec:
99 switch (insn[2] & 0xff) {
100 case 0xe5: /* clgrb */
101 case 0xe6: /* cgrb */
102 case 0xf6: /* crb */
103 case 0xf7: /* clrb */
104 case 0xfc: /* cgib */
105 case 0xfd: /* cglib */
106 case 0xfe: /* cib */
107 case 0xff: /* clib */
108 fixup = FIXUP_BRANCH_NOT_TAKEN;
109 break;
110 }
111 break;
112 }
113 return fixup;
114}
115
116int probe_is_insn_relative_long(u16 *insn)
117{
118 /* Check if we have a RIL-b or RIL-c format instruction which
119 * we need to modify in order to avoid instruction emulation. */
120 switch (insn[0] >> 8) {
121 case 0xc0:
122 if ((insn[0] & 0x0f) == 0x00) /* larl */
123 return true;
124 break;
125 case 0xc4:
126 switch (insn[0] & 0x0f) {
127 case 0x02: /* llhrl */
128 case 0x04: /* lghrl */
129 case 0x05: /* lhrl */
130 case 0x06: /* llghrl */
131 case 0x07: /* sthrl */
132 case 0x08: /* lgrl */
133 case 0x0b: /* stgrl */
134 case 0x0c: /* lgfrl */
135 case 0x0d: /* lrl */
136 case 0x0e: /* llgfrl */
137 case 0x0f: /* strl */
138 return true;
139 }
140 break;
141 case 0xc6:
142 switch (insn[0] & 0x0f) {
143 case 0x02: /* pfdrl */
144 case 0x04: /* cghrl */
145 case 0x05: /* chrl */
146 case 0x06: /* clghrl */
147 case 0x07: /* clhrl */
148 case 0x08: /* cgrl */
149 case 0x0a: /* clgrl */
150 case 0x0c: /* cgfrl */
151 case 0x0d: /* crl */
152 case 0x0e: /* clgfrl */
153 case 0x0f: /* clrl */
154 return true;
155 }
156 break;
157 }
158 return false;
159}