1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <string.h>
4 #include <regex.h>
5 #include <linux/zalloc.h>
6 
7 #include "../../util/perf_regs.h"
8 #include "../../util/debug.h"
9 
10 #include <linux/kernel.h>
11 
12 const struct sample_reg sample_reg_masks[] = {
13 	SMPL_REG(r0, PERF_REG_POWERPC_R0),
14 	SMPL_REG(r1, PERF_REG_POWERPC_R1),
15 	SMPL_REG(r2, PERF_REG_POWERPC_R2),
16 	SMPL_REG(r3, PERF_REG_POWERPC_R3),
17 	SMPL_REG(r4, PERF_REG_POWERPC_R4),
18 	SMPL_REG(r5, PERF_REG_POWERPC_R5),
19 	SMPL_REG(r6, PERF_REG_POWERPC_R6),
20 	SMPL_REG(r7, PERF_REG_POWERPC_R7),
21 	SMPL_REG(r8, PERF_REG_POWERPC_R8),
22 	SMPL_REG(r9, PERF_REG_POWERPC_R9),
23 	SMPL_REG(r10, PERF_REG_POWERPC_R10),
24 	SMPL_REG(r11, PERF_REG_POWERPC_R11),
25 	SMPL_REG(r12, PERF_REG_POWERPC_R12),
26 	SMPL_REG(r13, PERF_REG_POWERPC_R13),
27 	SMPL_REG(r14, PERF_REG_POWERPC_R14),
28 	SMPL_REG(r15, PERF_REG_POWERPC_R15),
29 	SMPL_REG(r16, PERF_REG_POWERPC_R16),
30 	SMPL_REG(r17, PERF_REG_POWERPC_R17),
31 	SMPL_REG(r18, PERF_REG_POWERPC_R18),
32 	SMPL_REG(r19, PERF_REG_POWERPC_R19),
33 	SMPL_REG(r20, PERF_REG_POWERPC_R20),
34 	SMPL_REG(r21, PERF_REG_POWERPC_R21),
35 	SMPL_REG(r22, PERF_REG_POWERPC_R22),
36 	SMPL_REG(r23, PERF_REG_POWERPC_R23),
37 	SMPL_REG(r24, PERF_REG_POWERPC_R24),
38 	SMPL_REG(r25, PERF_REG_POWERPC_R25),
39 	SMPL_REG(r26, PERF_REG_POWERPC_R26),
40 	SMPL_REG(r27, PERF_REG_POWERPC_R27),
41 	SMPL_REG(r28, PERF_REG_POWERPC_R28),
42 	SMPL_REG(r29, PERF_REG_POWERPC_R29),
43 	SMPL_REG(r30, PERF_REG_POWERPC_R30),
44 	SMPL_REG(r31, PERF_REG_POWERPC_R31),
45 	SMPL_REG(nip, PERF_REG_POWERPC_NIP),
46 	SMPL_REG(msr, PERF_REG_POWERPC_MSR),
47 	SMPL_REG(orig_r3, PERF_REG_POWERPC_ORIG_R3),
48 	SMPL_REG(ctr, PERF_REG_POWERPC_CTR),
49 	SMPL_REG(link, PERF_REG_POWERPC_LINK),
50 	SMPL_REG(xer, PERF_REG_POWERPC_XER),
51 	SMPL_REG(ccr, PERF_REG_POWERPC_CCR),
52 	SMPL_REG(softe, PERF_REG_POWERPC_SOFTE),
53 	SMPL_REG(trap, PERF_REG_POWERPC_TRAP),
54 	SMPL_REG(dar, PERF_REG_POWERPC_DAR),
55 	SMPL_REG(dsisr, PERF_REG_POWERPC_DSISR),
56 	SMPL_REG(sier, PERF_REG_POWERPC_SIER),
57 	SMPL_REG(mmcra, PERF_REG_POWERPC_MMCRA),
58 	SMPL_REG_END
59 };
60 
61 /* REG or %rREG */
62 #define SDT_OP_REGEX1  "^(%r)?([1-2]?[0-9]|3[0-1])$"
63 
64 /* -NUM(REG) or NUM(REG) or -NUM(%rREG) or NUM(%rREG) */
65 #define SDT_OP_REGEX2  "^(\\-)?([0-9]+)\\((%r)?([1-2]?[0-9]|3[0-1])\\)$"
66 
67 static regex_t sdt_op_regex1, sdt_op_regex2;
68 
69 static int sdt_init_op_regex(void)
70 {
71 	static int initialized;
72 	int ret = 0;
73 
74 	if (initialized)
75 		return 0;
76 
77 	ret = regcomp(&sdt_op_regex1, SDT_OP_REGEX1, REG_EXTENDED);
78 	if (ret)
79 		goto error;
80 
81 	ret = regcomp(&sdt_op_regex2, SDT_OP_REGEX2, REG_EXTENDED);
82 	if (ret)
83 		goto free_regex1;
84 
85 	initialized = 1;
86 	return 0;
87 
88 free_regex1:
89 	regfree(&sdt_op_regex1);
90 error:
91 	pr_debug4("Regex compilation error.\n");
92 	return ret;
93 }
94 
95 /*
96  * Parse OP and convert it into uprobe format, which is, +/-NUM(%gprREG).
97  * Possible variants of OP are:
98  *	Format		Example
99  *	-------------------------
100  *	NUM(REG)	48(18)
101  *	-NUM(REG)	-48(18)
102  *	NUM(%rREG)	48(%r18)
103  *	-NUM(%rREG)	-48(%r18)
104  *	REG		18
105  *	%rREG		%r18
106  *	iNUM		i0
107  *	i-NUM		i-1
108  *
109  * SDT marker arguments on Powerpc uses %rREG form with -mregnames flag
110  * and REG form with -mno-regnames. Here REG is general purpose register,
111  * which is in 0 to 31 range.
112  */
113 int arch_sdt_arg_parse_op(char *old_op, char **new_op)
114 {
115 	int ret, new_len;
116 	regmatch_t rm[5];
117 	char prefix;
118 
119 	/* Constant argument. Uprobe does not support it */
120 	if (old_op[0] == 'i') {
121 		pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
122 		return SDT_ARG_SKIP;
123 	}
124 
125 	ret = sdt_init_op_regex();
126 	if (ret < 0)
127 		return ret;
128 
129 	if (!regexec(&sdt_op_regex1, old_op, 3, rm, 0)) {
130 		/* REG or %rREG --> %gprREG */
131 
132 		new_len = 5;	/* % g p r NULL */
133 		new_len += (int)(rm[2].rm_eo - rm[2].rm_so);
134 
135 		*new_op = zalloc(new_len);
136 		if (!*new_op)
137 			return -ENOMEM;
138 
139 		scnprintf(*new_op, new_len, "%%gpr%.*s",
140 			(int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so);
141 	} else if (!regexec(&sdt_op_regex2, old_op, 5, rm, 0)) {
142 		/*
143 		 * -NUM(REG) or NUM(REG) or -NUM(%rREG) or NUM(%rREG) -->
144 		 *	+/-NUM(%gprREG)
145 		 */
146 		prefix = (rm[1].rm_so == -1) ? '+' : '-';
147 
148 		new_len = 8;	/* +/- ( % g p r ) NULL */
149 		new_len += (int)(rm[2].rm_eo - rm[2].rm_so);
150 		new_len += (int)(rm[4].rm_eo - rm[4].rm_so);
151 
152 		*new_op = zalloc(new_len);
153 		if (!*new_op)
154 			return -ENOMEM;
155 
156 		scnprintf(*new_op, new_len, "%c%.*s(%%gpr%.*s)", prefix,
157 			(int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so,
158 			(int)(rm[4].rm_eo - rm[4].rm_so), old_op + rm[4].rm_so);
159 	} else {
160 		pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
161 		return SDT_ARG_SKIP;
162 	}
163 
164 	return SDT_ARG_VALID;
165 }
166