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