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