xref: /OK3568_Linux_fs/kernel/arch/s390/lib/probes.c (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  *    Common helper functions for kprobes and uprobes
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  *    Copyright IBM Corp. 2014
6*4882a593Smuzhiyun  */
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun #include <linux/errno.h>
9*4882a593Smuzhiyun #include <asm/kprobes.h>
10*4882a593Smuzhiyun #include <asm/dis.h>
11*4882a593Smuzhiyun 
probe_is_prohibited_opcode(u16 * insn)12*4882a593Smuzhiyun int probe_is_prohibited_opcode(u16 *insn)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun 	if (!is_known_insn((unsigned char *)insn))
15*4882a593Smuzhiyun 		return -EINVAL;
16*4882a593Smuzhiyun 	switch (insn[0] >> 8) {
17*4882a593Smuzhiyun 	case 0x0c:	/* bassm */
18*4882a593Smuzhiyun 	case 0x0b:	/* bsm	 */
19*4882a593Smuzhiyun 	case 0x83:	/* diag  */
20*4882a593Smuzhiyun 	case 0x44:	/* ex	 */
21*4882a593Smuzhiyun 	case 0xac:	/* stnsm */
22*4882a593Smuzhiyun 	case 0xad:	/* stosm */
23*4882a593Smuzhiyun 		return -EINVAL;
24*4882a593Smuzhiyun 	case 0xc6:
25*4882a593Smuzhiyun 		switch (insn[0] & 0x0f) {
26*4882a593Smuzhiyun 		case 0x00: /* exrl   */
27*4882a593Smuzhiyun 			return -EINVAL;
28*4882a593Smuzhiyun 		}
29*4882a593Smuzhiyun 	}
30*4882a593Smuzhiyun 	switch (insn[0]) {
31*4882a593Smuzhiyun 	case 0x0101:	/* pr	 */
32*4882a593Smuzhiyun 	case 0xb25a:	/* bsa	 */
33*4882a593Smuzhiyun 	case 0xb240:	/* bakr  */
34*4882a593Smuzhiyun 	case 0xb258:	/* bsg	 */
35*4882a593Smuzhiyun 	case 0xb218:	/* pc	 */
36*4882a593Smuzhiyun 	case 0xb228:	/* pt	 */
37*4882a593Smuzhiyun 	case 0xb98d:	/* epsw	 */
38*4882a593Smuzhiyun 	case 0xe560:	/* tbegin */
39*4882a593Smuzhiyun 	case 0xe561:	/* tbeginc */
40*4882a593Smuzhiyun 	case 0xb2f8:	/* tend	 */
41*4882a593Smuzhiyun 		return -EINVAL;
42*4882a593Smuzhiyun 	}
43*4882a593Smuzhiyun 	return 0;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun 
probe_get_fixup_type(u16 * insn)46*4882a593Smuzhiyun int probe_get_fixup_type(u16 *insn)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun 	/* default fixup method */
49*4882a593Smuzhiyun 	int fixup = FIXUP_PSW_NORMAL;
50*4882a593Smuzhiyun 
51*4882a593Smuzhiyun 	switch (insn[0] >> 8) {
52*4882a593Smuzhiyun 	case 0x05:	/* balr	*/
53*4882a593Smuzhiyun 	case 0x0d:	/* basr */
54*4882a593Smuzhiyun 		fixup = FIXUP_RETURN_REGISTER;
55*4882a593Smuzhiyun 		/* if r2 = 0, no branch will be taken */
56*4882a593Smuzhiyun 		if ((insn[0] & 0x0f) == 0)
57*4882a593Smuzhiyun 			fixup |= FIXUP_BRANCH_NOT_TAKEN;
58*4882a593Smuzhiyun 		break;
59*4882a593Smuzhiyun 	case 0x06:	/* bctr	*/
60*4882a593Smuzhiyun 	case 0x07:	/* bcr	*/
61*4882a593Smuzhiyun 		fixup = FIXUP_BRANCH_NOT_TAKEN;
62*4882a593Smuzhiyun 		break;
63*4882a593Smuzhiyun 	case 0x45:	/* bal	*/
64*4882a593Smuzhiyun 	case 0x4d:	/* bas	*/
65*4882a593Smuzhiyun 		fixup = FIXUP_RETURN_REGISTER;
66*4882a593Smuzhiyun 		break;
67*4882a593Smuzhiyun 	case 0x47:	/* bc	*/
68*4882a593Smuzhiyun 	case 0x46:	/* bct	*/
69*4882a593Smuzhiyun 	case 0x86:	/* bxh	*/
70*4882a593Smuzhiyun 	case 0x87:	/* bxle	*/
71*4882a593Smuzhiyun 		fixup = FIXUP_BRANCH_NOT_TAKEN;
72*4882a593Smuzhiyun 		break;
73*4882a593Smuzhiyun 	case 0x82:	/* lpsw	*/
74*4882a593Smuzhiyun 		fixup = FIXUP_NOT_REQUIRED;
75*4882a593Smuzhiyun 		break;
76*4882a593Smuzhiyun 	case 0xb2:	/* lpswe */
77*4882a593Smuzhiyun 		if ((insn[0] & 0xff) == 0xb2)
78*4882a593Smuzhiyun 			fixup = FIXUP_NOT_REQUIRED;
79*4882a593Smuzhiyun 		break;
80*4882a593Smuzhiyun 	case 0xa7:	/* bras	*/
81*4882a593Smuzhiyun 		if ((insn[0] & 0x0f) == 0x05)
82*4882a593Smuzhiyun 			fixup |= FIXUP_RETURN_REGISTER;
83*4882a593Smuzhiyun 		break;
84*4882a593Smuzhiyun 	case 0xc0:
85*4882a593Smuzhiyun 		if ((insn[0] & 0x0f) == 0x05)	/* brasl */
86*4882a593Smuzhiyun 			fixup |= FIXUP_RETURN_REGISTER;
87*4882a593Smuzhiyun 		break;
88*4882a593Smuzhiyun 	case 0xeb:
89*4882a593Smuzhiyun 		switch (insn[2] & 0xff) {
90*4882a593Smuzhiyun 		case 0x44: /* bxhg  */
91*4882a593Smuzhiyun 		case 0x45: /* bxleg */
92*4882a593Smuzhiyun 			fixup = FIXUP_BRANCH_NOT_TAKEN;
93*4882a593Smuzhiyun 			break;
94*4882a593Smuzhiyun 		}
95*4882a593Smuzhiyun 		break;
96*4882a593Smuzhiyun 	case 0xe3:	/* bctg	*/
97*4882a593Smuzhiyun 		if ((insn[2] & 0xff) == 0x46)
98*4882a593Smuzhiyun 			fixup = FIXUP_BRANCH_NOT_TAKEN;
99*4882a593Smuzhiyun 		break;
100*4882a593Smuzhiyun 	case 0xec:
101*4882a593Smuzhiyun 		switch (insn[2] & 0xff) {
102*4882a593Smuzhiyun 		case 0xe5: /* clgrb */
103*4882a593Smuzhiyun 		case 0xe6: /* cgrb  */
104*4882a593Smuzhiyun 		case 0xf6: /* crb   */
105*4882a593Smuzhiyun 		case 0xf7: /* clrb  */
106*4882a593Smuzhiyun 		case 0xfc: /* cgib  */
107*4882a593Smuzhiyun 		case 0xfd: /* cglib */
108*4882a593Smuzhiyun 		case 0xfe: /* cib   */
109*4882a593Smuzhiyun 		case 0xff: /* clib  */
110*4882a593Smuzhiyun 			fixup = FIXUP_BRANCH_NOT_TAKEN;
111*4882a593Smuzhiyun 			break;
112*4882a593Smuzhiyun 		}
113*4882a593Smuzhiyun 		break;
114*4882a593Smuzhiyun 	}
115*4882a593Smuzhiyun 	return fixup;
116*4882a593Smuzhiyun }
117*4882a593Smuzhiyun 
probe_is_insn_relative_long(u16 * insn)118*4882a593Smuzhiyun int probe_is_insn_relative_long(u16 *insn)
119*4882a593Smuzhiyun {
120*4882a593Smuzhiyun 	/* Check if we have a RIL-b or RIL-c format instruction which
121*4882a593Smuzhiyun 	 * we need to modify in order to avoid instruction emulation. */
122*4882a593Smuzhiyun 	switch (insn[0] >> 8) {
123*4882a593Smuzhiyun 	case 0xc0:
124*4882a593Smuzhiyun 		if ((insn[0] & 0x0f) == 0x00) /* larl */
125*4882a593Smuzhiyun 			return true;
126*4882a593Smuzhiyun 		break;
127*4882a593Smuzhiyun 	case 0xc4:
128*4882a593Smuzhiyun 		switch (insn[0] & 0x0f) {
129*4882a593Smuzhiyun 		case 0x02: /* llhrl  */
130*4882a593Smuzhiyun 		case 0x04: /* lghrl  */
131*4882a593Smuzhiyun 		case 0x05: /* lhrl   */
132*4882a593Smuzhiyun 		case 0x06: /* llghrl */
133*4882a593Smuzhiyun 		case 0x07: /* sthrl  */
134*4882a593Smuzhiyun 		case 0x08: /* lgrl   */
135*4882a593Smuzhiyun 		case 0x0b: /* stgrl  */
136*4882a593Smuzhiyun 		case 0x0c: /* lgfrl  */
137*4882a593Smuzhiyun 		case 0x0d: /* lrl    */
138*4882a593Smuzhiyun 		case 0x0e: /* llgfrl */
139*4882a593Smuzhiyun 		case 0x0f: /* strl   */
140*4882a593Smuzhiyun 			return true;
141*4882a593Smuzhiyun 		}
142*4882a593Smuzhiyun 		break;
143*4882a593Smuzhiyun 	case 0xc6:
144*4882a593Smuzhiyun 		switch (insn[0] & 0x0f) {
145*4882a593Smuzhiyun 		case 0x02: /* pfdrl  */
146*4882a593Smuzhiyun 		case 0x04: /* cghrl  */
147*4882a593Smuzhiyun 		case 0x05: /* chrl   */
148*4882a593Smuzhiyun 		case 0x06: /* clghrl */
149*4882a593Smuzhiyun 		case 0x07: /* clhrl  */
150*4882a593Smuzhiyun 		case 0x08: /* cgrl   */
151*4882a593Smuzhiyun 		case 0x0a: /* clgrl  */
152*4882a593Smuzhiyun 		case 0x0c: /* cgfrl  */
153*4882a593Smuzhiyun 		case 0x0d: /* crl    */
154*4882a593Smuzhiyun 		case 0x0e: /* clgfrl */
155*4882a593Smuzhiyun 		case 0x0f: /* clrl   */
156*4882a593Smuzhiyun 			return true;
157*4882a593Smuzhiyun 		}
158*4882a593Smuzhiyun 		break;
159*4882a593Smuzhiyun 	}
160*4882a593Smuzhiyun 	return false;
161*4882a593Smuzhiyun }
162