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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /kernel/trace/trace_probe.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'kernel/trace/trace_probe.c')
-rw-r--r--kernel/trace/trace_probe.c1162
1 files changed, 1162 insertions, 0 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
new file mode 100644
index 000000000..073abbe38
--- /dev/null
+++ b/kernel/trace/trace_probe.c
@@ -0,0 +1,1162 @@
+// 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 <masami.hiramatsu.pt@hitachi.com>
+ *
+ * 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)");
+ 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,
+ "__data_loc char[]"),
+ __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 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;
+
+ /* Recalcurate 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
+ * appaers 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) {
+ 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_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) {
+ 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 (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, &param);
+ 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, &param);
+ 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);
+ 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 */
+ 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, &param);
+ 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(char *arg, ssize_t *size,
+ struct probe_arg *parg, unsigned int flags, int offset)
+{
+ struct fetch_insn *code, *scode, *tmp = NULL;
+ char *t, *t2, *t3;
+ int ret, len;
+
+ len = strlen(arg);
+ if (len > MAX_ARGSTR_LEN) {
+ trace_probe_log_err(offset, ARG_TOO_LONG);
+ return -EINVAL;
+ } else if (len == 0) {
+ trace_probe_log_err(offset, NO_ARG_BODY);
+ return -EINVAL;
+ }
+
+ parg->comm = kstrdup(arg, GFP_KERNEL);
+ if (!parg->comm)
+ return -ENOMEM;
+
+ 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);
+ return -EINVAL;
+ } else if (t3[1] != '\0') {
+ trace_probe_log_err(offset + t3 + 1 - arg,
+ BAD_ARRAY_SUFFIX);
+ return -EINVAL;
+ }
+ *t3 = '\0';
+ if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
+ trace_probe_log_err(offset + t2 - arg,
+ BAD_ARRAY_NUM);
+ return -EINVAL;
+ }
+ if (parg->count > MAX_ARRAY_LEN) {
+ trace_probe_log_err(offset + t2 - arg,
+ ARRAY_TOO_BIG);
+ return -EINVAL;
+ }
+ }
+ }
+
+ /*
+ * Since $comm and immediate string can not be dereferred,
+ * we can find those by strcmp.
+ */
+ if (strcmp(arg, "$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")))
+ return -EINVAL;
+ 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);
+ return -EINVAL;
+ }
+ parg->offset = *size;
+ *size += parg->type->size * (parg->count ?: 1);
+
+ if (parg->count) {
+ len = strlen(parg->type->fmttype) + 6;
+ parg->fmt = kmalloc(len, GFP_KERNEL);
+ if (!parg->fmt)
+ return -ENOMEM;
+ snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
+ parg->count);
+ }
+
+ code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
+ if (!code)
+ return -ENOMEM;
+ 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;
+
+ /* Store operation */
+ if (!strcmp(parg->type->name, "string") ||
+ !strcmp(parg->type->name, "ustring")) {
+ 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) {
+ trace_probe_log_err(offset + (t ? (t - arg) : 0),
+ BAD_STRING);
+ ret = -EINVAL;
+ goto fail;
+ }
+ if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
+ code->op == FETCH_OP_DATA) || 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.
+ */
+ code++;
+ if (code->op != FETCH_OP_NOP) {
+ trace_probe_log_err(offset, TOO_MANY_OPS);
+ ret = -EINVAL;
+ 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
+ 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);
+ ret = -EINVAL;
+ 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;
+ }
+ }
+ /* 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);
+ ret = -EINVAL;
+ goto fail;
+ }
+ code++;
+ if (code->op != FETCH_OP_NOP) {
+ trace_probe_log_err(offset, TOO_MANY_OPS);
+ ret = -EINVAL;
+ goto fail;
+ }
+ code->op = FETCH_OP_LP_ARRAY;
+ code->param = parg->count;
+ }
+ code++;
+ code->op = FETCH_OP_END;
+
+ /* 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);
+
+ 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, char *arg,
+ unsigned int flags)
+{
+ struct probe_arg *parg = &tp->args[i];
+ 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,
+ bool is_return)
+{
+ struct probe_arg *parg;
+ int i, j;
+ int pos = 0;
+ const char *fmt, *arg;
+
+ if (!is_return) {
+ fmt = "(%lx)";
+ arg = "REC->" FIELD_STRING_IP;
+ } else {
+ fmt = "(%lx <- %lx)";
+ arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
+ }
+
+ 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 ((strcmp(parg->type->name, "string") == 0) ||
+ (strcmp(parg->type->name, "ustring") == 0))
+ 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 ((strcmp(parg->type->name, "string") == 0) ||
+ (strcmp(parg->type->name, "ustring") == 0))
+ 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, bool is_return)
+{
+ 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, is_return);
+ 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, is_return);
+ 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);
+ synchronize_rcu();
+ kfree(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;
+}