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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Common code for probe-based Dynamic events.
- *
- * This code was copied from kernel/trace/trace_kprobe.c written by
- * Masami Hiramatsu <[email protected]>
- *
- * Updates to make this generic:
- * Copyright (C) IBM Corporation, 2010-2011
- * Author: Srikar Dronamraju
- */
- #define pr_fmt(fmt) "trace_probe: " fmt
- #include "trace_probe.h"
- #undef C
- #define C(a, b) b
- static const char *trace_probe_err_text[] = { ERRORS };
- static const char *reserved_field_names[] = {
- "common_type",
- "common_flags",
- "common_preempt_count",
- "common_pid",
- "common_tgid",
- FIELD_STRING_IP,
- FIELD_STRING_RETIP,
- FIELD_STRING_FUNC,
- };
- /* Printing in basic type function template */
- #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
- int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
- { \
- trace_seq_printf(s, fmt, *(type *)data); \
- return !trace_seq_has_overflowed(s); \
- } \
- const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
- DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
- DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
- DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
- DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
- DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
- DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
- DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
- DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
- DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
- DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
- DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
- DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
- int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
- {
- trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
- return !trace_seq_has_overflowed(s);
- }
- const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
- /* Print type function for string type */
- int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
- {
- int len = *(u32 *)data >> 16;
- if (!len)
- trace_seq_puts(s, FAULT_STRING);
- else
- trace_seq_printf(s, "\"%s\"",
- (const char *)get_loc_data(data, ent));
- return !trace_seq_has_overflowed(s);
- }
- const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
- /* Fetch type information table */
- static const struct fetch_type probe_fetch_types[] = {
- /* Special types */
- __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1,
- "__data_loc char[]"),
- __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1,
- "__data_loc char[]"),
- __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
- "__data_loc char[]"),
- /* Basic types */
- ASSIGN_FETCH_TYPE(u8, u8, 0),
- ASSIGN_FETCH_TYPE(u16, u16, 0),
- ASSIGN_FETCH_TYPE(u32, u32, 0),
- ASSIGN_FETCH_TYPE(u64, u64, 0),
- ASSIGN_FETCH_TYPE(s8, u8, 1),
- ASSIGN_FETCH_TYPE(s16, u16, 1),
- ASSIGN_FETCH_TYPE(s32, u32, 1),
- ASSIGN_FETCH_TYPE(s64, u64, 1),
- ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
- ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
- ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
- ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
- ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
- ASSIGN_FETCH_TYPE_END
- };
- static const struct fetch_type *find_fetch_type(const char *type)
- {
- int i;
- if (!type)
- type = DEFAULT_FETCH_TYPE_STR;
- /* Special case: bitfield */
- if (*type == 'b') {
- unsigned long bs;
- type = strchr(type, '/');
- if (!type)
- goto fail;
- type++;
- if (kstrtoul(type, 0, &bs))
- goto fail;
- switch (bs) {
- case 8:
- return find_fetch_type("u8");
- case 16:
- return find_fetch_type("u16");
- case 32:
- return find_fetch_type("u32");
- case 64:
- return find_fetch_type("u64");
- default:
- goto fail;
- }
- }
- for (i = 0; probe_fetch_types[i].name; i++) {
- if (strcmp(type, probe_fetch_types[i].name) == 0)
- return &probe_fetch_types[i];
- }
- fail:
- return NULL;
- }
- static struct trace_probe_log trace_probe_log;
- void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
- {
- trace_probe_log.subsystem = subsystem;
- trace_probe_log.argc = argc;
- trace_probe_log.argv = argv;
- trace_probe_log.index = 0;
- }
- void trace_probe_log_clear(void)
- {
- memset(&trace_probe_log, 0, sizeof(trace_probe_log));
- }
- void trace_probe_log_set_index(int index)
- {
- trace_probe_log.index = index;
- }
- void __trace_probe_log_err(int offset, int err_type)
- {
- char *command, *p;
- int i, len = 0, pos = 0;
- if (!trace_probe_log.argv)
- return;
- /* Recalculate the length and allocate buffer */
- for (i = 0; i < trace_probe_log.argc; i++) {
- if (i == trace_probe_log.index)
- pos = len;
- len += strlen(trace_probe_log.argv[i]) + 1;
- }
- command = kzalloc(len, GFP_KERNEL);
- if (!command)
- return;
- if (trace_probe_log.index >= trace_probe_log.argc) {
- /**
- * Set the error position is next to the last arg + space.
- * Note that len includes the terminal null and the cursor
- * appears at pos + 1.
- */
- pos = len;
- offset = 0;
- }
- /* And make a command string from argv array */
- p = command;
- for (i = 0; i < trace_probe_log.argc; i++) {
- len = strlen(trace_probe_log.argv[i]);
- strcpy(p, trace_probe_log.argv[i]);
- p[len] = ' ';
- p += len + 1;
- }
- *(p - 1) = '\0';
- tracing_log_err(NULL, trace_probe_log.subsystem, command,
- trace_probe_err_text, err_type, pos + offset);
- kfree(command);
- }
- /* Split symbol and offset. */
- int traceprobe_split_symbol_offset(char *symbol, long *offset)
- {
- char *tmp;
- int ret;
- if (!offset)
- return -EINVAL;
- tmp = strpbrk(symbol, "+-");
- if (tmp) {
- ret = kstrtol(tmp, 0, offset);
- if (ret)
- return ret;
- *tmp = '\0';
- } else
- *offset = 0;
- return 0;
- }
- /* @buf must has MAX_EVENT_NAME_LEN size */
- int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
- char *buf, int offset)
- {
- const char *slash, *event = *pevent;
- int len;
- slash = strchr(event, '/');
- if (!slash)
- slash = strchr(event, '.');
- if (slash) {
- if (slash == event) {
- trace_probe_log_err(offset, NO_GROUP_NAME);
- return -EINVAL;
- }
- if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
- trace_probe_log_err(offset, GROUP_TOO_LONG);
- return -EINVAL;
- }
- strlcpy(buf, event, slash - event + 1);
- if (!is_good_system_name(buf)) {
- trace_probe_log_err(offset, BAD_GROUP_NAME);
- return -EINVAL;
- }
- *pgroup = buf;
- *pevent = slash + 1;
- offset += slash - event + 1;
- event = *pevent;
- }
- len = strlen(event);
- if (len == 0) {
- if (slash) {
- *pevent = NULL;
- return 0;
- }
- trace_probe_log_err(offset, NO_EVENT_NAME);
- return -EINVAL;
- } else if (len > MAX_EVENT_NAME_LEN) {
- trace_probe_log_err(offset, EVENT_TOO_LONG);
- return -EINVAL;
- }
- if (!is_good_name(event)) {
- trace_probe_log_err(offset, BAD_EVENT_NAME);
- return -EINVAL;
- }
- return 0;
- }
- #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
- static int parse_probe_vars(char *arg, const struct fetch_type *t,
- struct fetch_insn *code, unsigned int flags, int offs)
- {
- unsigned long param;
- int ret = 0;
- int len;
- if (flags & TPARG_FL_TPOINT) {
- if (code->data)
- return -EFAULT;
- code->data = kstrdup(arg, GFP_KERNEL);
- if (!code->data)
- return -ENOMEM;
- code->op = FETCH_OP_TP_ARG;
- } else if (strcmp(arg, "retval") == 0) {
- if (flags & TPARG_FL_RETURN) {
- code->op = FETCH_OP_RETVAL;
- } else {
- trace_probe_log_err(offs, RETVAL_ON_PROBE);
- ret = -EINVAL;
- }
- } else if ((len = str_has_prefix(arg, "stack"))) {
- if (arg[len] == '\0') {
- code->op = FETCH_OP_STACKP;
- } else if (isdigit(arg[len])) {
- ret = kstrtoul(arg + len, 10, ¶m);
- if (ret) {
- goto inval_var;
- } else if ((flags & TPARG_FL_KERNEL) &&
- param > PARAM_MAX_STACK) {
- trace_probe_log_err(offs, BAD_STACK_NUM);
- ret = -EINVAL;
- } else {
- code->op = FETCH_OP_STACK;
- code->param = (unsigned int)param;
- }
- } else
- goto inval_var;
- } else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
- code->op = FETCH_OP_COMM;
- #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
- } else if (((flags & TPARG_FL_MASK) ==
- (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
- (len = str_has_prefix(arg, "arg"))) {
- ret = kstrtoul(arg + len, 10, ¶m);
- if (ret) {
- goto inval_var;
- } else if (!param || param > PARAM_MAX_STACK) {
- trace_probe_log_err(offs, BAD_ARG_NUM);
- return -EINVAL;
- }
- code->op = FETCH_OP_ARG;
- code->param = (unsigned int)param - 1;
- #endif
- } else
- goto inval_var;
- return ret;
- inval_var:
- trace_probe_log_err(offs, BAD_VAR);
- return -EINVAL;
- }
- static int str_to_immediate(char *str, unsigned long *imm)
- {
- if (isdigit(str[0]))
- return kstrtoul(str, 0, imm);
- else if (str[0] == '-')
- return kstrtol(str, 0, (long *)imm);
- else if (str[0] == '+')
- return kstrtol(str + 1, 0, (long *)imm);
- return -EINVAL;
- }
- static int __parse_imm_string(char *str, char **pbuf, int offs)
- {
- size_t len = strlen(str);
- if (str[len - 1] != '"') {
- trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
- return -EINVAL;
- }
- *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
- if (!*pbuf)
- return -ENOMEM;
- return 0;
- }
- /* Recursive argument parser */
- static int
- parse_probe_arg(char *arg, const struct fetch_type *type,
- struct fetch_insn **pcode, struct fetch_insn *end,
- unsigned int flags, int offs)
- {
- struct fetch_insn *code = *pcode;
- unsigned long param;
- int deref = FETCH_OP_DEREF;
- long offset = 0;
- char *tmp;
- int ret = 0;
- switch (arg[0]) {
- case '$':
- ret = parse_probe_vars(arg + 1, type, code, flags, offs);
- break;
- case '%': /* named register */
- if (flags & TPARG_FL_TPOINT) {
- /* eprobes do not handle registers */
- trace_probe_log_err(offs, BAD_VAR);
- break;
- }
- ret = regs_query_register_offset(arg + 1);
- if (ret >= 0) {
- code->op = FETCH_OP_REG;
- code->param = (unsigned int)ret;
- ret = 0;
- } else
- trace_probe_log_err(offs, BAD_REG_NAME);
- break;
- case '@': /* memory, file-offset or symbol */
- if (isdigit(arg[1])) {
- ret = kstrtoul(arg + 1, 0, ¶m);
- if (ret) {
- trace_probe_log_err(offs, BAD_MEM_ADDR);
- break;
- }
- /* load address */
- code->op = FETCH_OP_IMM;
- code->immediate = param;
- } else if (arg[1] == '+') {
- /* kprobes don't support file offsets */
- if (flags & TPARG_FL_KERNEL) {
- trace_probe_log_err(offs, FILE_ON_KPROBE);
- return -EINVAL;
- }
- ret = kstrtol(arg + 2, 0, &offset);
- if (ret) {
- trace_probe_log_err(offs, BAD_FILE_OFFS);
- break;
- }
- code->op = FETCH_OP_FOFFS;
- code->immediate = (unsigned long)offset; // imm64?
- } else {
- /* uprobes don't support symbols */
- if (!(flags & TPARG_FL_KERNEL)) {
- trace_probe_log_err(offs, SYM_ON_UPROBE);
- return -EINVAL;
- }
- /* Preserve symbol for updating */
- code->op = FETCH_NOP_SYMBOL;
- code->data = kstrdup(arg + 1, GFP_KERNEL);
- if (!code->data)
- return -ENOMEM;
- if (++code == end) {
- trace_probe_log_err(offs, TOO_MANY_OPS);
- return -EINVAL;
- }
- code->op = FETCH_OP_IMM;
- code->immediate = 0;
- }
- /* These are fetching from memory */
- if (++code == end) {
- trace_probe_log_err(offs, TOO_MANY_OPS);
- return -EINVAL;
- }
- *pcode = code;
- code->op = FETCH_OP_DEREF;
- code->offset = offset;
- break;
- case '+': /* deref memory */
- case '-':
- if (arg[1] == 'u') {
- deref = FETCH_OP_UDEREF;
- arg[1] = arg[0];
- arg++;
- }
- if (arg[0] == '+')
- arg++; /* Skip '+', because kstrtol() rejects it. */
- tmp = strchr(arg, '(');
- if (!tmp) {
- trace_probe_log_err(offs, DEREF_NEED_BRACE);
- return -EINVAL;
- }
- *tmp = '\0';
- ret = kstrtol(arg, 0, &offset);
- if (ret) {
- trace_probe_log_err(offs, BAD_DEREF_OFFS);
- break;
- }
- offs += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
- arg = tmp + 1;
- tmp = strrchr(arg, ')');
- if (!tmp) {
- trace_probe_log_err(offs + strlen(arg),
- DEREF_OPEN_BRACE);
- return -EINVAL;
- } else {
- const struct fetch_type *t2 = find_fetch_type(NULL);
- *tmp = '\0';
- ret = parse_probe_arg(arg, t2, &code, end, flags, offs);
- if (ret)
- break;
- if (code->op == FETCH_OP_COMM ||
- code->op == FETCH_OP_DATA) {
- trace_probe_log_err(offs, COMM_CANT_DEREF);
- return -EINVAL;
- }
- if (++code == end) {
- trace_probe_log_err(offs, TOO_MANY_OPS);
- return -EINVAL;
- }
- *pcode = code;
- code->op = deref;
- code->offset = offset;
- }
- break;
- case '\\': /* Immediate value */
- if (arg[1] == '"') { /* Immediate string */
- ret = __parse_imm_string(arg + 2, &tmp, offs + 2);
- if (ret)
- break;
- code->op = FETCH_OP_DATA;
- code->data = tmp;
- } else {
- ret = str_to_immediate(arg + 1, &code->immediate);
- if (ret)
- trace_probe_log_err(offs + 1, BAD_IMM);
- else
- code->op = FETCH_OP_IMM;
- }
- break;
- }
- if (!ret && code->op == FETCH_OP_NOP) {
- /* Parsed, but do not find fetch method */
- trace_probe_log_err(offs, BAD_FETCH_ARG);
- ret = -EINVAL;
- }
- return ret;
- }
- #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
- /* Bitfield type needs to be parsed into a fetch function */
- static int __parse_bitfield_probe_arg(const char *bf,
- const struct fetch_type *t,
- struct fetch_insn **pcode)
- {
- struct fetch_insn *code = *pcode;
- unsigned long bw, bo;
- char *tail;
- if (*bf != 'b')
- return 0;
- bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
- if (bw == 0 || *tail != '@')
- return -EINVAL;
- bf = tail + 1;
- bo = simple_strtoul(bf, &tail, 0);
- if (tail == bf || *tail != '/')
- return -EINVAL;
- code++;
- if (code->op != FETCH_OP_NOP)
- return -EINVAL;
- *pcode = code;
- code->op = FETCH_OP_MOD_BF;
- code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
- code->rshift = BYTES_TO_BITS(t->size) - bw;
- code->basesize = t->size;
- return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
- }
- /* String length checking wrapper */
- static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
- struct probe_arg *parg, unsigned int flags, int offset)
- {
- struct fetch_insn *code, *scode, *tmp = NULL;
- char *t, *t2, *t3;
- char *arg;
- int ret, len;
- arg = kstrdup(argv, GFP_KERNEL);
- if (!arg)
- return -ENOMEM;
- ret = -EINVAL;
- len = strlen(arg);
- if (len > MAX_ARGSTR_LEN) {
- trace_probe_log_err(offset, ARG_TOO_LONG);
- goto out;
- } else if (len == 0) {
- trace_probe_log_err(offset, NO_ARG_BODY);
- goto out;
- }
- ret = -ENOMEM;
- parg->comm = kstrdup(arg, GFP_KERNEL);
- if (!parg->comm)
- goto out;
- ret = -EINVAL;
- t = strchr(arg, ':');
- if (t) {
- *t = '\0';
- t2 = strchr(++t, '[');
- if (t2) {
- *t2++ = '\0';
- t3 = strchr(t2, ']');
- if (!t3) {
- offset += t2 + strlen(t2) - arg;
- trace_probe_log_err(offset,
- ARRAY_NO_CLOSE);
- goto out;
- } else if (t3[1] != '\0') {
- trace_probe_log_err(offset + t3 + 1 - arg,
- BAD_ARRAY_SUFFIX);
- goto out;
- }
- *t3 = '\0';
- if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
- trace_probe_log_err(offset + t2 - arg,
- BAD_ARRAY_NUM);
- goto out;
- }
- if (parg->count > MAX_ARRAY_LEN) {
- trace_probe_log_err(offset + t2 - arg,
- ARRAY_TOO_BIG);
- goto out;
- }
- }
- }
- /*
- * Since $comm and immediate string can not be dereferenced,
- * we can find those by strcmp. But ignore for eprobes.
- */
- if (!(flags & TPARG_FL_TPOINT) &&
- (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
- strncmp(arg, "\\\"", 2) == 0)) {
- /* The type of $comm must be "string", and not an array. */
- if (parg->count || (t && strcmp(t, "string")))
- goto out;
- parg->type = find_fetch_type("string");
- } else
- parg->type = find_fetch_type(t);
- if (!parg->type) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE);
- goto out;
- }
- parg->offset = *size;
- *size += parg->type->size * (parg->count ?: 1);
- ret = -ENOMEM;
- if (parg->count) {
- len = strlen(parg->type->fmttype) + 6;
- parg->fmt = kmalloc(len, GFP_KERNEL);
- if (!parg->fmt)
- goto out;
- snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
- parg->count);
- }
- code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
- if (!code)
- goto out;
- code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
- ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
- flags, offset);
- if (ret)
- goto fail;
- ret = -EINVAL;
- /* Store operation */
- if (parg->type->is_string) {
- if (!strcmp(parg->type->name, "symstr")) {
- if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
- code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
- code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0),
- BAD_SYMSTRING);
- goto fail;
- }
- } else {
- if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
- code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
- code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0),
- BAD_STRING);
- goto fail;
- }
- }
- if (!strcmp(parg->type->name, "symstr") ||
- (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
- code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
- parg->count) {
- /*
- * IMM, DATA and COMM is pointing actual address, those
- * must be kept, and if parg->count != 0, this is an
- * array of string pointers instead of string address
- * itself.
- * For the symstr, it doesn't need to dereference, thus
- * it just get the value.
- */
- code++;
- if (code->op != FETCH_OP_NOP) {
- trace_probe_log_err(offset, TOO_MANY_OPS);
- goto fail;
- }
- }
- /* If op == DEREF, replace it with STRING */
- if (!strcmp(parg->type->name, "ustring") ||
- code->op == FETCH_OP_UDEREF)
- code->op = FETCH_OP_ST_USTRING;
- else if (!strcmp(parg->type->name, "symstr"))
- code->op = FETCH_OP_ST_SYMSTR;
- else
- code->op = FETCH_OP_ST_STRING;
- code->size = parg->type->size;
- parg->dynamic = true;
- } else if (code->op == FETCH_OP_DEREF) {
- code->op = FETCH_OP_ST_MEM;
- code->size = parg->type->size;
- } else if (code->op == FETCH_OP_UDEREF) {
- code->op = FETCH_OP_ST_UMEM;
- code->size = parg->type->size;
- } else {
- code++;
- if (code->op != FETCH_OP_NOP) {
- trace_probe_log_err(offset, TOO_MANY_OPS);
- goto fail;
- }
- code->op = FETCH_OP_ST_RAW;
- code->size = parg->type->size;
- }
- scode = code;
- /* Modify operation */
- if (t != NULL) {
- ret = __parse_bitfield_probe_arg(t, parg->type, &code);
- if (ret) {
- trace_probe_log_err(offset + t - arg, BAD_BITFIELD);
- goto fail;
- }
- }
- ret = -EINVAL;
- /* Loop(Array) operation */
- if (parg->count) {
- if (scode->op != FETCH_OP_ST_MEM &&
- scode->op != FETCH_OP_ST_STRING &&
- scode->op != FETCH_OP_ST_USTRING) {
- trace_probe_log_err(offset + (t ? (t - arg) : 0),
- BAD_STRING);
- goto fail;
- }
- code++;
- if (code->op != FETCH_OP_NOP) {
- trace_probe_log_err(offset, TOO_MANY_OPS);
- goto fail;
- }
- code->op = FETCH_OP_LP_ARRAY;
- code->param = parg->count;
- }
- code++;
- code->op = FETCH_OP_END;
- ret = 0;
- /* Shrink down the code buffer */
- parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
- if (!parg->code)
- ret = -ENOMEM;
- else
- memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
- fail:
- if (ret) {
- for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
- if (code->op == FETCH_NOP_SYMBOL ||
- code->op == FETCH_OP_DATA)
- kfree(code->data);
- }
- kfree(tmp);
- out:
- kfree(arg);
- return ret;
- }
- /* Return 1 if name is reserved or already used by another argument */
- static int traceprobe_conflict_field_name(const char *name,
- struct probe_arg *args, int narg)
- {
- int i;
- for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
- if (strcmp(reserved_field_names[i], name) == 0)
- return 1;
- for (i = 0; i < narg; i++)
- if (strcmp(args[i].name, name) == 0)
- return 1;
- return 0;
- }
- int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
- unsigned int flags)
- {
- struct probe_arg *parg = &tp->args[i];
- const char *body;
- /* Increment count for freeing args in error case */
- tp->nr_args++;
- body = strchr(arg, '=');
- if (body) {
- if (body - arg > MAX_ARG_NAME_LEN) {
- trace_probe_log_err(0, ARG_NAME_TOO_LONG);
- return -EINVAL;
- } else if (body == arg) {
- trace_probe_log_err(0, NO_ARG_NAME);
- return -EINVAL;
- }
- parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
- body++;
- } else {
- /* If argument name is omitted, set "argN" */
- parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
- body = arg;
- }
- if (!parg->name)
- return -ENOMEM;
- if (!is_good_name(parg->name)) {
- trace_probe_log_err(0, BAD_ARG_NAME);
- return -EINVAL;
- }
- if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
- trace_probe_log_err(0, USED_ARG_NAME);
- return -EINVAL;
- }
- /* Parse fetch argument */
- return traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags,
- body - arg);
- }
- void traceprobe_free_probe_arg(struct probe_arg *arg)
- {
- struct fetch_insn *code = arg->code;
- while (code && code->op != FETCH_OP_END) {
- if (code->op == FETCH_NOP_SYMBOL ||
- code->op == FETCH_OP_DATA)
- kfree(code->data);
- code++;
- }
- kfree(arg->code);
- kfree(arg->name);
- kfree(arg->comm);
- kfree(arg->fmt);
- }
- int traceprobe_update_arg(struct probe_arg *arg)
- {
- struct fetch_insn *code = arg->code;
- long offset;
- char *tmp;
- char c;
- int ret = 0;
- while (code && code->op != FETCH_OP_END) {
- if (code->op == FETCH_NOP_SYMBOL) {
- if (code[1].op != FETCH_OP_IMM)
- return -EINVAL;
- tmp = strpbrk(code->data, "+-");
- if (tmp)
- c = *tmp;
- ret = traceprobe_split_symbol_offset(code->data,
- &offset);
- if (ret)
- return ret;
- code[1].immediate =
- (unsigned long)kallsyms_lookup_name(code->data);
- if (tmp)
- *tmp = c;
- if (!code[1].immediate)
- return -ENOENT;
- code[1].immediate += offset;
- }
- code++;
- }
- return 0;
- }
- /* When len=0, we just calculate the needed length */
- #define LEN_OR_ZERO (len ? len - pos : 0)
- static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
- enum probe_print_type ptype)
- {
- struct probe_arg *parg;
- int i, j;
- int pos = 0;
- const char *fmt, *arg;
- switch (ptype) {
- case PROBE_PRINT_NORMAL:
- fmt = "(%lx)";
- arg = ", REC->" FIELD_STRING_IP;
- break;
- case PROBE_PRINT_RETURN:
- fmt = "(%lx <- %lx)";
- arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
- break;
- case PROBE_PRINT_EVENT:
- fmt = "";
- arg = "";
- break;
- default:
- WARN_ON_ONCE(1);
- return 0;
- }
- pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
- for (i = 0; i < tp->nr_args; i++) {
- parg = tp->args + i;
- pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
- if (parg->count) {
- pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
- parg->type->fmt);
- for (j = 1; j < parg->count; j++)
- pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
- parg->type->fmt);
- pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
- } else
- pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
- parg->type->fmt);
- }
- pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg);
- for (i = 0; i < tp->nr_args; i++) {
- parg = tp->args + i;
- if (parg->count) {
- if (parg->type->is_string)
- fmt = ", __get_str(%s[%d])";
- else
- fmt = ", REC->%s[%d]";
- for (j = 0; j < parg->count; j++)
- pos += snprintf(buf + pos, LEN_OR_ZERO,
- fmt, parg->name, j);
- } else {
- if (parg->type->is_string)
- fmt = ", __get_str(%s)";
- else
- fmt = ", REC->%s";
- pos += snprintf(buf + pos, LEN_OR_ZERO,
- fmt, parg->name);
- }
- }
- /* return the length of print_fmt */
- return pos;
- }
- #undef LEN_OR_ZERO
- int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
- {
- struct trace_event_call *call = trace_probe_event_call(tp);
- int len;
- char *print_fmt;
- /* First: called with 0 length to calculate the needed length */
- len = __set_print_fmt(tp, NULL, 0, ptype);
- print_fmt = kmalloc(len + 1, GFP_KERNEL);
- if (!print_fmt)
- return -ENOMEM;
- /* Second: actually write the @print_fmt */
- __set_print_fmt(tp, print_fmt, len + 1, ptype);
- call->print_fmt = print_fmt;
- return 0;
- }
- int traceprobe_define_arg_fields(struct trace_event_call *event_call,
- size_t offset, struct trace_probe *tp)
- {
- int ret, i;
- /* Set argument names as fields */
- for (i = 0; i < tp->nr_args; i++) {
- struct probe_arg *parg = &tp->args[i];
- const char *fmt = parg->type->fmttype;
- int size = parg->type->size;
- if (parg->fmt)
- fmt = parg->fmt;
- if (parg->count)
- size *= parg->count;
- ret = trace_define_field(event_call, fmt, parg->name,
- offset + parg->offset, size,
- parg->type->is_signed,
- FILTER_OTHER);
- if (ret)
- return ret;
- }
- return 0;
- }
- static void trace_probe_event_free(struct trace_probe_event *tpe)
- {
- kfree(tpe->class.system);
- kfree(tpe->call.name);
- kfree(tpe->call.print_fmt);
- kfree(tpe);
- }
- int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
- {
- if (trace_probe_has_sibling(tp))
- return -EBUSY;
- list_del_init(&tp->list);
- trace_probe_event_free(tp->event);
- tp->event = to->event;
- list_add_tail(&tp->list, trace_probe_probe_list(to));
- return 0;
- }
- void trace_probe_unlink(struct trace_probe *tp)
- {
- list_del_init(&tp->list);
- if (list_empty(trace_probe_probe_list(tp)))
- trace_probe_event_free(tp->event);
- tp->event = NULL;
- }
- void trace_probe_cleanup(struct trace_probe *tp)
- {
- int i;
- for (i = 0; i < tp->nr_args; i++)
- traceprobe_free_probe_arg(&tp->args[i]);
- if (tp->event)
- trace_probe_unlink(tp);
- }
- int trace_probe_init(struct trace_probe *tp, const char *event,
- const char *group, bool alloc_filter)
- {
- struct trace_event_call *call;
- size_t size = sizeof(struct trace_probe_event);
- int ret = 0;
- if (!event || !group)
- return -EINVAL;
- if (alloc_filter)
- size += sizeof(struct trace_uprobe_filter);
- tp->event = kzalloc(size, GFP_KERNEL);
- if (!tp->event)
- return -ENOMEM;
- INIT_LIST_HEAD(&tp->event->files);
- INIT_LIST_HEAD(&tp->event->class.fields);
- INIT_LIST_HEAD(&tp->event->probes);
- INIT_LIST_HEAD(&tp->list);
- list_add(&tp->list, &tp->event->probes);
- call = trace_probe_event_call(tp);
- call->class = &tp->event->class;
- call->name = kstrdup(event, GFP_KERNEL);
- if (!call->name) {
- ret = -ENOMEM;
- goto error;
- }
- tp->event->class.system = kstrdup(group, GFP_KERNEL);
- if (!tp->event->class.system) {
- ret = -ENOMEM;
- goto error;
- }
- return 0;
- error:
- trace_probe_cleanup(tp);
- return ret;
- }
- static struct trace_event_call *
- find_trace_event_call(const char *system, const char *event_name)
- {
- struct trace_event_call *tp_event;
- const char *name;
- list_for_each_entry(tp_event, &ftrace_events, list) {
- if (!tp_event->class->system ||
- strcmp(system, tp_event->class->system))
- continue;
- name = trace_event_name(tp_event);
- if (!name || strcmp(event_name, name))
- continue;
- return tp_event;
- }
- return NULL;
- }
- int trace_probe_register_event_call(struct trace_probe *tp)
- {
- struct trace_event_call *call = trace_probe_event_call(tp);
- int ret;
- lockdep_assert_held(&event_mutex);
- if (find_trace_event_call(trace_probe_group_name(tp),
- trace_probe_name(tp)))
- return -EEXIST;
- ret = register_trace_event(&call->event);
- if (!ret)
- return -ENODEV;
- ret = trace_add_event_call(call);
- if (ret)
- unregister_trace_event(&call->event);
- return ret;
- }
- int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
- {
- struct event_file_link *link;
- link = kmalloc(sizeof(*link), GFP_KERNEL);
- if (!link)
- return -ENOMEM;
- link->file = file;
- INIT_LIST_HEAD(&link->list);
- list_add_tail_rcu(&link->list, &tp->event->files);
- trace_probe_set_flag(tp, TP_FLAG_TRACE);
- return 0;
- }
- struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
- struct trace_event_file *file)
- {
- struct event_file_link *link;
- trace_probe_for_each_link(link, tp) {
- if (link->file == file)
- return link;
- }
- return NULL;
- }
- int trace_probe_remove_file(struct trace_probe *tp,
- struct trace_event_file *file)
- {
- struct event_file_link *link;
- link = trace_probe_get_file_link(tp, file);
- if (!link)
- return -ENOENT;
- list_del_rcu(&link->list);
- kvfree_rcu(link);
- if (list_empty(&tp->event->files))
- trace_probe_clear_flag(tp, TP_FLAG_TRACE);
- return 0;
- }
- /*
- * Return the smallest index of different type argument (start from 1).
- * If all argument types and name are same, return 0.
- */
- int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
- {
- int i;
- /* In case of more arguments */
- if (a->nr_args < b->nr_args)
- return a->nr_args + 1;
- if (a->nr_args > b->nr_args)
- return b->nr_args + 1;
- for (i = 0; i < a->nr_args; i++) {
- if ((b->nr_args <= i) ||
- ((a->args[i].type != b->args[i].type) ||
- (a->args[i].count != b->args[i].count) ||
- strcmp(a->args[i].name, b->args[i].name)))
- return i + 1;
- }
- return 0;
- }
- bool trace_probe_match_command_args(struct trace_probe *tp,
- int argc, const char **argv)
- {
- char buf[MAX_ARGSTR_LEN + 1];
- int i;
- if (tp->nr_args < argc)
- return false;
- for (i = 0; i < argc; i++) {
- snprintf(buf, sizeof(buf), "%s=%s",
- tp->args[i].name, tp->args[i].comm);
- if (strcmp(buf, argv[i]))
- return false;
- }
- return true;
- }
- int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
- {
- int argc = 0, ret = 0;
- char **argv;
- argv = argv_split(GFP_KERNEL, raw_command, &argc);
- if (!argv)
- return -ENOMEM;
- if (argc)
- ret = createfn(argc, (const char **)argv);
- argv_free(argv);
- return ret;
- }
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