1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <regex.h>
4 #include <string.h>
5 #include <linux/kernel.h>
6 #include <linux/zalloc.h>
7 
8 #include "../../../util/debug.h"
9 #include "../../../util/event.h"
10 #include "../../../util/perf_regs.h"
11 
12 const struct sample_reg sample_reg_masks[] = {
13 	SMPL_REG(x0, PERF_REG_ARM64_X0),
14 	SMPL_REG(x1, PERF_REG_ARM64_X1),
15 	SMPL_REG(x2, PERF_REG_ARM64_X2),
16 	SMPL_REG(x3, PERF_REG_ARM64_X3),
17 	SMPL_REG(x4, PERF_REG_ARM64_X4),
18 	SMPL_REG(x5, PERF_REG_ARM64_X5),
19 	SMPL_REG(x6, PERF_REG_ARM64_X6),
20 	SMPL_REG(x7, PERF_REG_ARM64_X7),
21 	SMPL_REG(x8, PERF_REG_ARM64_X8),
22 	SMPL_REG(x9, PERF_REG_ARM64_X9),
23 	SMPL_REG(x10, PERF_REG_ARM64_X10),
24 	SMPL_REG(x11, PERF_REG_ARM64_X11),
25 	SMPL_REG(x12, PERF_REG_ARM64_X12),
26 	SMPL_REG(x13, PERF_REG_ARM64_X13),
27 	SMPL_REG(x14, PERF_REG_ARM64_X14),
28 	SMPL_REG(x15, PERF_REG_ARM64_X15),
29 	SMPL_REG(x16, PERF_REG_ARM64_X16),
30 	SMPL_REG(x17, PERF_REG_ARM64_X17),
31 	SMPL_REG(x18, PERF_REG_ARM64_X18),
32 	SMPL_REG(x19, PERF_REG_ARM64_X19),
33 	SMPL_REG(x20, PERF_REG_ARM64_X20),
34 	SMPL_REG(x21, PERF_REG_ARM64_X21),
35 	SMPL_REG(x22, PERF_REG_ARM64_X22),
36 	SMPL_REG(x23, PERF_REG_ARM64_X23),
37 	SMPL_REG(x24, PERF_REG_ARM64_X24),
38 	SMPL_REG(x25, PERF_REG_ARM64_X25),
39 	SMPL_REG(x26, PERF_REG_ARM64_X26),
40 	SMPL_REG(x27, PERF_REG_ARM64_X27),
41 	SMPL_REG(x28, PERF_REG_ARM64_X28),
42 	SMPL_REG(x29, PERF_REG_ARM64_X29),
43 	SMPL_REG(lr, PERF_REG_ARM64_LR),
44 	SMPL_REG(sp, PERF_REG_ARM64_SP),
45 	SMPL_REG(pc, PERF_REG_ARM64_PC),
46 	SMPL_REG_END
47 };
48 
49 /* %xNUM */
50 #define SDT_OP_REGEX1  "^(x[1-2]?[0-9]|3[0-1])$"
51 
52 /* [sp], [sp, NUM] */
53 #define SDT_OP_REGEX2  "^\\[sp(, )?([0-9]+)?\\]$"
54 
55 static regex_t sdt_op_regex1, sdt_op_regex2;
56 
57 static int sdt_init_op_regex(void)
58 {
59 	static int initialized;
60 	int ret = 0;
61 
62 	if (initialized)
63 		return 0;
64 
65 	ret = regcomp(&sdt_op_regex1, SDT_OP_REGEX1, REG_EXTENDED);
66 	if (ret)
67 		goto error;
68 
69 	ret = regcomp(&sdt_op_regex2, SDT_OP_REGEX2, REG_EXTENDED);
70 	if (ret)
71 		goto free_regex1;
72 
73 	initialized = 1;
74 	return 0;
75 
76 free_regex1:
77 	regfree(&sdt_op_regex1);
78 error:
79 	pr_debug4("Regex compilation error.\n");
80 	return ret;
81 }
82 
83 /*
84  * SDT marker arguments on Arm64 uses %xREG or [sp, NUM], currently
85  * support these two formats.
86  */
87 int arch_sdt_arg_parse_op(char *old_op, char **new_op)
88 {
89 	int ret, new_len;
90 	regmatch_t rm[5];
91 
92 	ret = sdt_init_op_regex();
93 	if (ret < 0)
94 		return ret;
95 
96 	if (!regexec(&sdt_op_regex1, old_op, 3, rm, 0)) {
97 		/* Extract xNUM */
98 		new_len = 2;	/* % NULL */
99 		new_len += (int)(rm[1].rm_eo - rm[1].rm_so);
100 
101 		*new_op = zalloc(new_len);
102 		if (!*new_op)
103 			return -ENOMEM;
104 
105 		scnprintf(*new_op, new_len, "%%%.*s",
106 			(int)(rm[1].rm_eo - rm[1].rm_so), old_op + rm[1].rm_so);
107 	} else if (!regexec(&sdt_op_regex2, old_op, 5, rm, 0)) {
108 		/* [sp], [sp, NUM] or [sp,NUM] */
109 		new_len = 7;	/* + ( % s p ) NULL */
110 
111 		/* If the arugment is [sp], need to fill offset '0' */
112 		if (rm[2].rm_so == -1)
113 			new_len += 1;
114 		else
115 			new_len += (int)(rm[2].rm_eo - rm[2].rm_so);
116 
117 		*new_op = zalloc(new_len);
118 		if (!*new_op)
119 			return -ENOMEM;
120 
121 		if (rm[2].rm_so == -1)
122 			scnprintf(*new_op, new_len, "+0(%%sp)");
123 		else
124 			scnprintf(*new_op, new_len, "+%.*s(%%sp)",
125 				  (int)(rm[2].rm_eo - rm[2].rm_so),
126 				  old_op + rm[2].rm_so);
127 	} else {
128 		pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
129 		return SDT_ARG_SKIP;
130 	}
131 
132 	return SDT_ARG_VALID;
133 }
134