1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <string.h>
4 #include <regex.h>
5 
6 #include "../../perf.h"
7 #include "../../util/util.h"
8 #include "../../util/perf_regs.h"
9 #include "../../util/debug.h"
10 
11 const struct sample_reg sample_reg_masks[] = {
12 	SMPL_REG(r0, PERF_REG_POWERPC_R0),
13 	SMPL_REG(r1, PERF_REG_POWERPC_R1),
14 	SMPL_REG(r2, PERF_REG_POWERPC_R2),
15 	SMPL_REG(r3, PERF_REG_POWERPC_R3),
16 	SMPL_REG(r4, PERF_REG_POWERPC_R4),
17 	SMPL_REG(r5, PERF_REG_POWERPC_R5),
18 	SMPL_REG(r6, PERF_REG_POWERPC_R6),
19 	SMPL_REG(r7, PERF_REG_POWERPC_R7),
20 	SMPL_REG(r8, PERF_REG_POWERPC_R8),
21 	SMPL_REG(r9, PERF_REG_POWERPC_R9),
22 	SMPL_REG(r10, PERF_REG_POWERPC_R10),
23 	SMPL_REG(r11, PERF_REG_POWERPC_R11),
24 	SMPL_REG(r12, PERF_REG_POWERPC_R12),
25 	SMPL_REG(r13, PERF_REG_POWERPC_R13),
26 	SMPL_REG(r14, PERF_REG_POWERPC_R14),
27 	SMPL_REG(r15, PERF_REG_POWERPC_R15),
28 	SMPL_REG(r16, PERF_REG_POWERPC_R16),
29 	SMPL_REG(r17, PERF_REG_POWERPC_R17),
30 	SMPL_REG(r18, PERF_REG_POWERPC_R18),
31 	SMPL_REG(r19, PERF_REG_POWERPC_R19),
32 	SMPL_REG(r20, PERF_REG_POWERPC_R20),
33 	SMPL_REG(r21, PERF_REG_POWERPC_R21),
34 	SMPL_REG(r22, PERF_REG_POWERPC_R22),
35 	SMPL_REG(r23, PERF_REG_POWERPC_R23),
36 	SMPL_REG(r24, PERF_REG_POWERPC_R24),
37 	SMPL_REG(r25, PERF_REG_POWERPC_R25),
38 	SMPL_REG(r26, PERF_REG_POWERPC_R26),
39 	SMPL_REG(r27, PERF_REG_POWERPC_R27),
40 	SMPL_REG(r28, PERF_REG_POWERPC_R28),
41 	SMPL_REG(r29, PERF_REG_POWERPC_R29),
42 	SMPL_REG(r30, PERF_REG_POWERPC_R30),
43 	SMPL_REG(r31, PERF_REG_POWERPC_R31),
44 	SMPL_REG(nip, PERF_REG_POWERPC_NIP),
45 	SMPL_REG(msr, PERF_REG_POWERPC_MSR),
46 	SMPL_REG(orig_r3, PERF_REG_POWERPC_ORIG_R3),
47 	SMPL_REG(ctr, PERF_REG_POWERPC_CTR),
48 	SMPL_REG(link, PERF_REG_POWERPC_LINK),
49 	SMPL_REG(xer, PERF_REG_POWERPC_XER),
50 	SMPL_REG(ccr, PERF_REG_POWERPC_CCR),
51 	SMPL_REG(softe, PERF_REG_POWERPC_SOFTE),
52 	SMPL_REG(trap, PERF_REG_POWERPC_TRAP),
53 	SMPL_REG(dar, PERF_REG_POWERPC_DAR),
54 	SMPL_REG(dsisr, PERF_REG_POWERPC_DSISR),
55 	SMPL_REG(sier, PERF_REG_POWERPC_SIER),
56 	SMPL_REG_END
57 };
58 
59 /* REG or %rREG */
60 #define SDT_OP_REGEX1  "^(%r)?([1-2]?[0-9]|3[0-1])$"
61 
62 /* -NUM(REG) or NUM(REG) or -NUM(%rREG) or NUM(%rREG) */
63 #define SDT_OP_REGEX2  "^(\\-)?([0-9]+)\\((%r)?([1-2]?[0-9]|3[0-1])\\)$"
64 
65 static regex_t sdt_op_regex1, sdt_op_regex2;
66 
67 static int sdt_init_op_regex(void)
68 {
69 	static int initialized;
70 	int ret = 0;
71 
72 	if (initialized)
73 		return 0;
74 
75 	ret = regcomp(&sdt_op_regex1, SDT_OP_REGEX1, REG_EXTENDED);
76 	if (ret)
77 		goto error;
78 
79 	ret = regcomp(&sdt_op_regex2, SDT_OP_REGEX2, REG_EXTENDED);
80 	if (ret)
81 		goto free_regex1;
82 
83 	initialized = 1;
84 	return 0;
85 
86 free_regex1:
87 	regfree(&sdt_op_regex1);
88 error:
89 	pr_debug4("Regex compilation error.\n");
90 	return ret;
91 }
92 
93 /*
94  * Parse OP and convert it into uprobe format, which is, +/-NUM(%gprREG).
95  * Possible variants of OP are:
96  *	Format		Example
97  *	-------------------------
98  *	NUM(REG)	48(18)
99  *	-NUM(REG)	-48(18)
100  *	NUM(%rREG)	48(%r18)
101  *	-NUM(%rREG)	-48(%r18)
102  *	REG		18
103  *	%rREG		%r18
104  *	iNUM		i0
105  *	i-NUM		i-1
106  *
107  * SDT marker arguments on Powerpc uses %rREG form with -mregnames flag
108  * and REG form with -mno-regnames. Here REG is general purpose register,
109  * which is in 0 to 31 range.
110  */
111 int arch_sdt_arg_parse_op(char *old_op, char **new_op)
112 {
113 	int ret, new_len;
114 	regmatch_t rm[5];
115 	char prefix;
116 
117 	/* Constant argument. Uprobe does not support it */
118 	if (old_op[0] == 'i') {
119 		pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
120 		return SDT_ARG_SKIP;
121 	}
122 
123 	ret = sdt_init_op_regex();
124 	if (ret < 0)
125 		return ret;
126 
127 	if (!regexec(&sdt_op_regex1, old_op, 3, rm, 0)) {
128 		/* REG or %rREG --> %gprREG */
129 
130 		new_len = 5;	/* % g p r NULL */
131 		new_len += (int)(rm[2].rm_eo - rm[2].rm_so);
132 
133 		*new_op = zalloc(new_len);
134 		if (!*new_op)
135 			return -ENOMEM;
136 
137 		scnprintf(*new_op, new_len, "%%gpr%.*s",
138 			(int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so);
139 	} else if (!regexec(&sdt_op_regex2, old_op, 5, rm, 0)) {
140 		/*
141 		 * -NUM(REG) or NUM(REG) or -NUM(%rREG) or NUM(%rREG) -->
142 		 *	+/-NUM(%gprREG)
143 		 */
144 		prefix = (rm[1].rm_so == -1) ? '+' : '-';
145 
146 		new_len = 8;	/* +/- ( % g p r ) NULL */
147 		new_len += (int)(rm[2].rm_eo - rm[2].rm_so);
148 		new_len += (int)(rm[4].rm_eo - rm[4].rm_so);
149 
150 		*new_op = zalloc(new_len);
151 		if (!*new_op)
152 			return -ENOMEM;
153 
154 		scnprintf(*new_op, new_len, "%c%.*s(%%gpr%.*s)", prefix,
155 			(int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so,
156 			(int)(rm[4].rm_eo - rm[4].rm_so), old_op + rm[4].rm_so);
157 	} else {
158 		pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
159 		return SDT_ARG_SKIP;
160 	}
161 
162 	return SDT_ARG_VALID;
163 }
164