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1// SPDX-License-Identifier: GPL-2.02#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_regs.h"9#include "../../../perf-sys.h"10#include "../../../util/perf_regs.h"11#include "../../../util/debug.h"12#include "../../../util/event.h"13#include "../../../util/pmu.h"14#include "../../../util/pmus.h"15 16static const struct sample_reg sample_reg_masks[] = {17	SMPL_REG(AX, PERF_REG_X86_AX),18	SMPL_REG(BX, PERF_REG_X86_BX),19	SMPL_REG(CX, PERF_REG_X86_CX),20	SMPL_REG(DX, PERF_REG_X86_DX),21	SMPL_REG(SI, PERF_REG_X86_SI),22	SMPL_REG(DI, PERF_REG_X86_DI),23	SMPL_REG(BP, PERF_REG_X86_BP),24	SMPL_REG(SP, PERF_REG_X86_SP),25	SMPL_REG(IP, PERF_REG_X86_IP),26	SMPL_REG(FLAGS, PERF_REG_X86_FLAGS),27	SMPL_REG(CS, PERF_REG_X86_CS),28	SMPL_REG(SS, PERF_REG_X86_SS),29#ifdef HAVE_ARCH_X86_64_SUPPORT30	SMPL_REG(R8, PERF_REG_X86_R8),31	SMPL_REG(R9, PERF_REG_X86_R9),32	SMPL_REG(R10, PERF_REG_X86_R10),33	SMPL_REG(R11, PERF_REG_X86_R11),34	SMPL_REG(R12, PERF_REG_X86_R12),35	SMPL_REG(R13, PERF_REG_X86_R13),36	SMPL_REG(R14, PERF_REG_X86_R14),37	SMPL_REG(R15, PERF_REG_X86_R15),38#endif39	SMPL_REG2(XMM0, PERF_REG_X86_XMM0),40	SMPL_REG2(XMM1, PERF_REG_X86_XMM1),41	SMPL_REG2(XMM2, PERF_REG_X86_XMM2),42	SMPL_REG2(XMM3, PERF_REG_X86_XMM3),43	SMPL_REG2(XMM4, PERF_REG_X86_XMM4),44	SMPL_REG2(XMM5, PERF_REG_X86_XMM5),45	SMPL_REG2(XMM6, PERF_REG_X86_XMM6),46	SMPL_REG2(XMM7, PERF_REG_X86_XMM7),47	SMPL_REG2(XMM8, PERF_REG_X86_XMM8),48	SMPL_REG2(XMM9, PERF_REG_X86_XMM9),49	SMPL_REG2(XMM10, PERF_REG_X86_XMM10),50	SMPL_REG2(XMM11, PERF_REG_X86_XMM11),51	SMPL_REG2(XMM12, PERF_REG_X86_XMM12),52	SMPL_REG2(XMM13, PERF_REG_X86_XMM13),53	SMPL_REG2(XMM14, PERF_REG_X86_XMM14),54	SMPL_REG2(XMM15, PERF_REG_X86_XMM15),55	SMPL_REG_END56};57 58struct sdt_name_reg {59	const char *sdt_name;60	const char *uprobe_name;61};62#define SDT_NAME_REG(n, m) {.sdt_name = "%" #n, .uprobe_name = "%" #m}63#define SDT_NAME_REG_END {.sdt_name = NULL, .uprobe_name = NULL}64 65static const struct sdt_name_reg sdt_reg_tbl[] = {66	SDT_NAME_REG(eax, ax),67	SDT_NAME_REG(rax, ax),68	SDT_NAME_REG(al,  ax),69	SDT_NAME_REG(ah,  ax),70	SDT_NAME_REG(ebx, bx),71	SDT_NAME_REG(rbx, bx),72	SDT_NAME_REG(bl,  bx),73	SDT_NAME_REG(bh,  bx),74	SDT_NAME_REG(ecx, cx),75	SDT_NAME_REG(rcx, cx),76	SDT_NAME_REG(cl,  cx),77	SDT_NAME_REG(ch,  cx),78	SDT_NAME_REG(edx, dx),79	SDT_NAME_REG(rdx, dx),80	SDT_NAME_REG(dl,  dx),81	SDT_NAME_REG(dh,  dx),82	SDT_NAME_REG(esi, si),83	SDT_NAME_REG(rsi, si),84	SDT_NAME_REG(sil, si),85	SDT_NAME_REG(edi, di),86	SDT_NAME_REG(rdi, di),87	SDT_NAME_REG(dil, di),88	SDT_NAME_REG(ebp, bp),89	SDT_NAME_REG(rbp, bp),90	SDT_NAME_REG(bpl, bp),91	SDT_NAME_REG(rsp, sp),92	SDT_NAME_REG(esp, sp),93	SDT_NAME_REG(spl, sp),94 95	/* rNN registers */96	SDT_NAME_REG(r8b,  r8),97	SDT_NAME_REG(r8w,  r8),98	SDT_NAME_REG(r8d,  r8),99	SDT_NAME_REG(r9b,  r9),100	SDT_NAME_REG(r9w,  r9),101	SDT_NAME_REG(r9d,  r9),102	SDT_NAME_REG(r10b, r10),103	SDT_NAME_REG(r10w, r10),104	SDT_NAME_REG(r10d, r10),105	SDT_NAME_REG(r11b, r11),106	SDT_NAME_REG(r11w, r11),107	SDT_NAME_REG(r11d, r11),108	SDT_NAME_REG(r12b, r12),109	SDT_NAME_REG(r12w, r12),110	SDT_NAME_REG(r12d, r12),111	SDT_NAME_REG(r13b, r13),112	SDT_NAME_REG(r13w, r13),113	SDT_NAME_REG(r13d, r13),114	SDT_NAME_REG(r14b, r14),115	SDT_NAME_REG(r14w, r14),116	SDT_NAME_REG(r14d, r14),117	SDT_NAME_REG(r15b, r15),118	SDT_NAME_REG(r15w, r15),119	SDT_NAME_REG(r15d, r15),120	SDT_NAME_REG_END,121};122 123/*124 * Perf only supports OP which is in  +/-NUM(REG)  form.125 * Here plus-minus sign, NUM and parenthesis are optional,126 * only REG is mandatory.127 *128 * SDT events also supports indirect addressing mode with a129 * symbol as offset, scaled mode and constants in OP. But130 * perf does not support them yet. Below are few examples.131 *132 * OP with scaled mode:133 *     (%rax,%rsi,8)134 *     10(%ras,%rsi,8)135 *136 * OP with indirect addressing mode:137 *     check_action(%rip)138 *     mp_+52(%rip)139 *     44+mp_(%rip)140 *141 * OP with constant values:142 *     $0143 *     $123144 *     $-1145 */146#define SDT_OP_REGEX  "^([+\\-]?)([0-9]*)(\\(?)(%[a-z][a-z0-9]+)(\\)?)$"147 148static regex_t sdt_op_regex;149 150static int sdt_init_op_regex(void)151{152	static int initialized;153	int ret = 0;154 155	if (initialized)156		return 0;157 158	ret = regcomp(&sdt_op_regex, SDT_OP_REGEX, REG_EXTENDED);159	if (ret < 0) {160		pr_debug4("Regex compilation error.\n");161		return ret;162	}163 164	initialized = 1;165	return 0;166}167 168/*169 * Max x86 register name length is 5(ex: %r15d). So, 6th char170 * should always contain NULL. This helps to find register name171 * length using strlen, instead of maintaining one more variable.172 */173#define SDT_REG_NAME_SIZE  6174 175/*176 * The uprobe parser does not support all gas register names;177 * so, we have to replace them (ex. for x86_64: %rax -> %ax).178 * Note: If register does not require renaming, just copy179 * paste as it is, but don't leave it empty.180 */181static void sdt_rename_register(char *sdt_reg, int sdt_len, char *uprobe_reg)182{183	int i = 0;184 185	for (i = 0; sdt_reg_tbl[i].sdt_name != NULL; i++) {186		if (!strncmp(sdt_reg_tbl[i].sdt_name, sdt_reg, sdt_len)) {187			strcpy(uprobe_reg, sdt_reg_tbl[i].uprobe_name);188			return;189		}190	}191 192	strncpy(uprobe_reg, sdt_reg, sdt_len);193}194 195int arch_sdt_arg_parse_op(char *old_op, char **new_op)196{197	char new_reg[SDT_REG_NAME_SIZE] = {0};198	int new_len = 0, ret;199	/*200	 * rm[0]:  +/-NUM(REG)201	 * rm[1]:  +/-202	 * rm[2]:  NUM203	 * rm[3]:  (204	 * rm[4]:  REG205	 * rm[5]:  )206	 */207	regmatch_t rm[6];208	/*209	 * Max prefix length is 2 as it may contains sign(+/-)210	 * and displacement 0 (Both sign and displacement 0 are211	 * optional so it may be empty). Use one more character212	 * to hold last NULL so that strlen can be used to find213	 * prefix length, instead of maintaining one more variable.214	 */215	char prefix[3] = {0};216 217	ret = sdt_init_op_regex();218	if (ret < 0)219		return ret;220 221	/*222	 * If unsupported OR does not match with regex OR223	 * register name too long, skip it.224	 */225	if (strchr(old_op, ',') || strchr(old_op, '$') ||226	    regexec(&sdt_op_regex, old_op, 6, rm, 0)   ||227	    rm[4].rm_eo - rm[4].rm_so > SDT_REG_NAME_SIZE) {228		pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);229		return SDT_ARG_SKIP;230	}231 232	/*233	 * Prepare prefix.234	 * If SDT OP has parenthesis but does not provide235	 * displacement, add 0 for displacement.236	 *     SDT         Uprobe     Prefix237	 *     -----------------------------238	 *     +24(%rdi)   +24(%di)   +239	 *     24(%rdi)    +24(%di)   +240	 *     %rdi        %di241	 *     (%rdi)      +0(%di)    +0242	 *     -80(%rbx)   -80(%bx)   -243	 */244	if (rm[3].rm_so != rm[3].rm_eo) {245		if (rm[1].rm_so != rm[1].rm_eo)246			prefix[0] = *(old_op + rm[1].rm_so);247		else if (rm[2].rm_so != rm[2].rm_eo)248			prefix[0] = '+';249		else250			scnprintf(prefix, sizeof(prefix), "+0");251	}252 253	/* Rename register */254	sdt_rename_register(old_op + rm[4].rm_so, rm[4].rm_eo - rm[4].rm_so,255			    new_reg);256 257	/* Prepare final OP which should be valid for uprobe_events */258	new_len = strlen(prefix)              +259		  (rm[2].rm_eo - rm[2].rm_so) +260		  (rm[3].rm_eo - rm[3].rm_so) +261		  strlen(new_reg)             +262		  (rm[5].rm_eo - rm[5].rm_so) +263		  1;					/* NULL */264 265	*new_op = zalloc(new_len);266	if (!*new_op)267		return -ENOMEM;268 269	scnprintf(*new_op, new_len, "%.*s%.*s%.*s%.*s%.*s",270		  strlen(prefix), prefix,271		  (int)(rm[2].rm_eo - rm[2].rm_so), old_op + rm[2].rm_so,272		  (int)(rm[3].rm_eo - rm[3].rm_so), old_op + rm[3].rm_so,273		  strlen(new_reg), new_reg,274		  (int)(rm[5].rm_eo - rm[5].rm_so), old_op + rm[5].rm_so);275 276	return SDT_ARG_VALID;277}278 279const struct sample_reg *arch__sample_reg_masks(void)280{281	return sample_reg_masks;282}283 284uint64_t arch__intr_reg_mask(void)285{286	struct perf_event_attr attr = {287		.type			= PERF_TYPE_HARDWARE,288		.config			= PERF_COUNT_HW_CPU_CYCLES,289		.sample_type		= PERF_SAMPLE_REGS_INTR,290		.sample_regs_intr	= PERF_REG_EXTENDED_MASK,291		.precise_ip		= 1,292		.disabled 		= 1,293		.exclude_kernel		= 1,294	};295	int fd;296	/*297	 * In an unnamed union, init it here to build on older gcc versions298	 */299	attr.sample_period = 1;300 301	if (perf_pmus__num_core_pmus() > 1) {302		struct perf_pmu *pmu = NULL;303		__u64 type = PERF_TYPE_RAW;304 305		/*306		 * The same register set is supported among different hybrid PMUs.307		 * Only check the first available one.308		 */309		while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {310			type = pmu->type;311			break;312		}313		attr.config |= type << PERF_PMU_TYPE_SHIFT;314	}315 316	event_attr_init(&attr);317 318	fd = sys_perf_event_open(&attr, 0, -1, -1, 0);319	if (fd != -1) {320		close(fd);321		return (PERF_REG_EXTENDED_MASK | PERF_REGS_MASK);322	}323 324	return PERF_REGS_MASK;325}326 327uint64_t arch__user_reg_mask(void)328{329	return PERF_REGS_MASK;330}331