1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <string.h>
4 #include <regex.h>
5 #include <linux/kernel.h>
6 #include <linux/zalloc.h>
7
8 #include "../../../perf-sys.h"
9 #include "../../../util/perf_regs.h"
10 #include "../../../util/debug.h"
11 #include "../../../util/event.h"
12 #include "../../../util/pmu.h"
13 #include "../../../util/pmu-hybrid.h"
14
15 const struct sample_reg sample_reg_masks[] = {
16 SMPL_REG(AX, PERF_REG_X86_AX),
17 SMPL_REG(BX, PERF_REG_X86_BX),
18 SMPL_REG(CX, PERF_REG_X86_CX),
19 SMPL_REG(DX, PERF_REG_X86_DX),
20 SMPL_REG(SI, PERF_REG_X86_SI),
21 SMPL_REG(DI, PERF_REG_X86_DI),
22 SMPL_REG(BP, PERF_REG_X86_BP),
23 SMPL_REG(SP, PERF_REG_X86_SP),
24 SMPL_REG(IP, PERF_REG_X86_IP),
25 SMPL_REG(FLAGS, PERF_REG_X86_FLAGS),
26 SMPL_REG(CS, PERF_REG_X86_CS),
27 SMPL_REG(SS, PERF_REG_X86_SS),
28 #ifdef HAVE_ARCH_X86_64_SUPPORT
29 SMPL_REG(R8, PERF_REG_X86_R8),
30 SMPL_REG(R9, PERF_REG_X86_R9),
31 SMPL_REG(R10, PERF_REG_X86_R10),
32 SMPL_REG(R11, PERF_REG_X86_R11),
33 SMPL_REG(R12, PERF_REG_X86_R12),
34 SMPL_REG(R13, PERF_REG_X86_R13),
35 SMPL_REG(R14, PERF_REG_X86_R14),
36 SMPL_REG(R15, PERF_REG_X86_R15),
37 #endif
38 SMPL_REG2(XMM0, PERF_REG_X86_XMM0),
39 SMPL_REG2(XMM1, PERF_REG_X86_XMM1),
40 SMPL_REG2(XMM2, PERF_REG_X86_XMM2),
41 SMPL_REG2(XMM3, PERF_REG_X86_XMM3),
42 SMPL_REG2(XMM4, PERF_REG_X86_XMM4),
43 SMPL_REG2(XMM5, PERF_REG_X86_XMM5),
44 SMPL_REG2(XMM6, PERF_REG_X86_XMM6),
45 SMPL_REG2(XMM7, PERF_REG_X86_XMM7),
46 SMPL_REG2(XMM8, PERF_REG_X86_XMM8),
47 SMPL_REG2(XMM9, PERF_REG_X86_XMM9),
48 SMPL_REG2(XMM10, PERF_REG_X86_XMM10),
49 SMPL_REG2(XMM11, PERF_REG_X86_XMM11),
50 SMPL_REG2(XMM12, PERF_REG_X86_XMM12),
51 SMPL_REG2(XMM13, PERF_REG_X86_XMM13),
52 SMPL_REG2(XMM14, PERF_REG_X86_XMM14),
53 SMPL_REG2(XMM15, PERF_REG_X86_XMM15),
54 SMPL_REG_END
55 };
56
57 struct sdt_name_reg {
58 const char *sdt_name;
59 const char *uprobe_name;
60 };
61 #define SDT_NAME_REG(n, m) {.sdt_name = "%" #n, .uprobe_name = "%" #m}
62 #define SDT_NAME_REG_END {.sdt_name = NULL, .uprobe_name = NULL}
63
64 static const struct sdt_name_reg sdt_reg_tbl[] = {
65 SDT_NAME_REG(eax, ax),
66 SDT_NAME_REG(rax, ax),
67 SDT_NAME_REG(al, ax),
68 SDT_NAME_REG(ah, ax),
69 SDT_NAME_REG(ebx, bx),
70 SDT_NAME_REG(rbx, bx),
71 SDT_NAME_REG(bl, bx),
72 SDT_NAME_REG(bh, bx),
73 SDT_NAME_REG(ecx, cx),
74 SDT_NAME_REG(rcx, cx),
75 SDT_NAME_REG(cl, cx),
76 SDT_NAME_REG(ch, cx),
77 SDT_NAME_REG(edx, dx),
78 SDT_NAME_REG(rdx, dx),
79 SDT_NAME_REG(dl, dx),
80 SDT_NAME_REG(dh, dx),
81 SDT_NAME_REG(esi, si),
82 SDT_NAME_REG(rsi, si),
83 SDT_NAME_REG(sil, si),
84 SDT_NAME_REG(edi, di),
85 SDT_NAME_REG(rdi, di),
86 SDT_NAME_REG(dil, di),
87 SDT_NAME_REG(ebp, bp),
88 SDT_NAME_REG(rbp, bp),
89 SDT_NAME_REG(bpl, bp),
90 SDT_NAME_REG(rsp, sp),
91 SDT_NAME_REG(esp, sp),
92 SDT_NAME_REG(spl, sp),
93
94 /* rNN registers */
95 SDT_NAME_REG(r8b, r8),
96 SDT_NAME_REG(r8w, r8),
97 SDT_NAME_REG(r8d, r8),
98 SDT_NAME_REG(r9b, r9),
99 SDT_NAME_REG(r9w, r9),
100 SDT_NAME_REG(r9d, r9),
101 SDT_NAME_REG(r10b, r10),
102 SDT_NAME_REG(r10w, r10),
103 SDT_NAME_REG(r10d, r10),
104 SDT_NAME_REG(r11b, r11),
105 SDT_NAME_REG(r11w, r11),
106 SDT_NAME_REG(r11d, r11),
107 SDT_NAME_REG(r12b, r12),
108 SDT_NAME_REG(r12w, r12),
109 SDT_NAME_REG(r12d, r12),
110 SDT_NAME_REG(r13b, r13),
111 SDT_NAME_REG(r13w, r13),
112 SDT_NAME_REG(r13d, r13),
113 SDT_NAME_REG(r14b, r14),
114 SDT_NAME_REG(r14w, r14),
115 SDT_NAME_REG(r14d, r14),
116 SDT_NAME_REG(r15b, r15),
117 SDT_NAME_REG(r15w, r15),
118 SDT_NAME_REG(r15d, r15),
119 SDT_NAME_REG_END,
120 };
121
122 /*
123 * Perf only supports OP which is in +/-NUM(REG) form.
124 * Here plus-minus sign, NUM and parenthesis are optional,
125 * only REG is mandatory.
126 *
127 * SDT events also supports indirect addressing mode with a
128 * symbol as offset, scaled mode and constants in OP. But
129 * perf does not support them yet. Below are few examples.
130 *
131 * OP with scaled mode:
132 * (%rax,%rsi,8)
133 * 10(%ras,%rsi,8)
134 *
135 * OP with indirect addressing mode:
136 * check_action(%rip)
137 * mp_+52(%rip)
138 * 44+mp_(%rip)
139 *
140 * OP with constant values:
141 * $0
142 * $123
143 * $-1
144 */
145 #define SDT_OP_REGEX "^([+\\-]?)([0-9]*)(\\(?)(%[a-z][a-z0-9]+)(\\)?)$"
146
147 static regex_t sdt_op_regex;
148
sdt_init_op_regex(void)149 static int sdt_init_op_regex(void)
150 {
151 static int initialized;
152 int ret = 0;
153
154 if (initialized)
155 return 0;
156
157 ret = regcomp(&sdt_op_regex, SDT_OP_REGEX, REG_EXTENDED);
158 if (ret < 0) {
159 pr_debug4("Regex compilation error.\n");
160 return ret;
161 }
162
163 initialized = 1;
164 return 0;
165 }
166
167 /*
168 * Max x86 register name length is 5(ex: %r15d). So, 6th char
169 * should always contain NULL. This helps to find register name
170 * length using strlen, instead of maintaining one more variable.
171 */
172 #define SDT_REG_NAME_SIZE 6
173
174 /*
175 * The uprobe parser does not support all gas register names;
176 * so, we have to replace them (ex. for x86_64: %rax -> %ax).
177 * Note: If register does not require renaming, just copy
178 * paste as it is, but don't leave it empty.
179 */
sdt_rename_register(char * sdt_reg,int sdt_len,char * uprobe_reg)180 static void sdt_rename_register(char *sdt_reg, int sdt_len, char *uprobe_reg)
181 {
182 int i = 0;
183
184 for (i = 0; sdt_reg_tbl[i].sdt_name != NULL; i++) {
185 if (!strncmp(sdt_reg_tbl[i].sdt_name, sdt_reg, sdt_len)) {
186 strcpy(uprobe_reg, sdt_reg_tbl[i].uprobe_name);
187 return;
188 }
189 }
190
191 strncpy(uprobe_reg, sdt_reg, sdt_len);
192 }
193
arch_sdt_arg_parse_op(char * old_op,char ** new_op)194 int arch_sdt_arg_parse_op(char *old_op, char **new_op)
195 {
196 char new_reg[SDT_REG_NAME_SIZE] = {0};
197 int new_len = 0, ret;
198 /*
199 * rm[0]: +/-NUM(REG)
200 * rm[1]: +/-
201 * rm[2]: NUM
202 * rm[3]: (
203 * rm[4]: REG
204 * rm[5]: )
205 */
206 regmatch_t rm[6];
207 /*
208 * Max prefix length is 2 as it may contains sign(+/-)
209 * and displacement 0 (Both sign and displacement 0 are
210 * optional so it may be empty). Use one more character
211 * to hold last NULL so that strlen can be used to find
212 * prefix length, instead of maintaining one more variable.
213 */
214 char prefix[3] = {0};
215
216 ret = sdt_init_op_regex();
217 if (ret < 0)
218 return ret;
219
220 /*
221 * If unsupported OR does not match with regex OR
222 * register name too long, skip it.
223 */
224 if (strchr(old_op, ',') || strchr(old_op, '$') ||
225 regexec(&sdt_op_regex, old_op, 6, rm, 0) ||
226 rm[4].rm_eo - rm[4].rm_so > SDT_REG_NAME_SIZE) {
227 pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
228 return SDT_ARG_SKIP;
229 }
230
231 /*
232 * Prepare prefix.
233 * If SDT OP has parenthesis but does not provide
234 * displacement, add 0 for displacement.
235 * SDT Uprobe Prefix
236 * -----------------------------
237 * +24(%rdi) +24(%di) +
238 * 24(%rdi) +24(%di) +
239 * %rdi %di
240 * (%rdi) +0(%di) +0
241 * -80(%rbx) -80(%bx) -
242 */
243 if (rm[3].rm_so != rm[3].rm_eo) {
244 if (rm[1].rm_so != rm[1].rm_eo)
245 prefix[0] = *(old_op + rm[1].rm_so);
246 else if (rm[2].rm_so != rm[2].rm_eo)
247 prefix[0] = '+';
248 else
249 scnprintf(prefix, sizeof(prefix), "+0");
250 }
251
252 /* Rename register */
253 sdt_rename_register(old_op + rm[4].rm_so, rm[4].rm_eo - rm[4].rm_so,
254 new_reg);
255
256 /* Prepare final OP which should be valid for uprobe_events */
257 new_len = strlen(prefix) +
258 (rm[2].rm_eo - rm[2].rm_so) +
259 (rm[3].rm_eo - rm[3].rm_so) +
260 strlen(new_reg) +
261 (rm[5].rm_eo - rm[5].rm_so) +
262 1; /* NULL */
263
264 *new_op = zalloc(new_len);
265 if (!*new_op)
266 return -ENOMEM;
267
268 scnprintf(*new_op, new_len, "%.*s%.*s%.*s%.*s%.*s",
269 strlen(prefix), prefix,
270 (int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so,
271 (int)(rm[3].rm_eo - rm[3].rm_so), old_op + rm[3].rm_so,
272 strlen(new_reg), new_reg,
273 (int)(rm[5].rm_eo - rm[5].rm_so), old_op + rm[5].rm_so);
274
275 return SDT_ARG_VALID;
276 }
277
arch__intr_reg_mask(void)278 uint64_t arch__intr_reg_mask(void)
279 {
280 struct perf_event_attr attr = {
281 .type = PERF_TYPE_HARDWARE,
282 .config = PERF_COUNT_HW_CPU_CYCLES,
283 .sample_type = PERF_SAMPLE_REGS_INTR,
284 .sample_regs_intr = PERF_REG_EXTENDED_MASK,
285 .precise_ip = 1,
286 .disabled = 1,
287 .exclude_kernel = 1,
288 };
289 struct perf_pmu *pmu;
290 int fd;
291 /*
292 * In an unnamed union, init it here to build on older gcc versions
293 */
294 attr.sample_period = 1;
295
296 if (perf_pmu__has_hybrid()) {
297 /*
298 * The same register set is supported among different hybrid PMUs.
299 * Only check the first available one.
300 */
301 pmu = list_first_entry(&perf_pmu__hybrid_pmus, typeof(*pmu), hybrid_list);
302 attr.config |= (__u64)pmu->type << PERF_PMU_TYPE_SHIFT;
303 }
304
305 event_attr_init(&attr);
306
307 fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
308 if (fd != -1) {
309 close(fd);
310 return (PERF_REG_EXTENDED_MASK | PERF_REGS_MASK);
311 }
312
313 return PERF_REGS_MASK;
314 }
315