linux_dsm_epyc7002/kernel/trace/trace_probe.c

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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 <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;
tracing/probe: Fix to check the difference of nr_args before adding probe Steven reported that a test triggered: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_kprobe_create+0xa9e/0xe40 Read of size 8 at addr ffff8880c4f25a48 by task ftracetest/4798 CPU: 2 PID: 4798 Comm: ftracetest Not tainted 5.3.0-rc6-test+ #30 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 Call Trace: dump_stack+0x7c/0xc0 ? trace_kprobe_create+0xa9e/0xe40 print_address_description+0x6c/0x332 ? trace_kprobe_create+0xa9e/0xe40 ? trace_kprobe_create+0xa9e/0xe40 __kasan_report.cold.6+0x1a/0x3b ? trace_kprobe_create+0xa9e/0xe40 kasan_report+0xe/0x12 trace_kprobe_create+0xa9e/0xe40 ? print_kprobe_event+0x280/0x280 ? match_held_lock+0x1b/0x240 ? find_held_lock+0xac/0xd0 ? fs_reclaim_release.part.112+0x5/0x20 ? lock_downgrade+0x350/0x350 ? kasan_unpoison_shadow+0x30/0x40 ? __kasan_kmalloc.constprop.6+0xc1/0xd0 ? trace_kprobe_create+0xe40/0xe40 ? trace_kprobe_create+0xe40/0xe40 create_or_delete_trace_kprobe+0x2e/0x60 trace_run_command+0xc3/0xe0 ? trace_panic_handler+0x20/0x20 ? kasan_unpoison_shadow+0x30/0x40 trace_parse_run_command+0xdc/0x163 vfs_write+0xe1/0x240 ksys_write+0xba/0x150 ? __ia32_sys_read+0x50/0x50 ? tracer_hardirqs_on+0x61/0x180 ? trace_hardirqs_off_caller+0x43/0x110 ? mark_held_locks+0x29/0xa0 ? do_syscall_64+0x14/0x260 do_syscall_64+0x68/0x260 Fix to check the difference of nr_args before adding probe on existing probes. This also may set the error log index bigger than the number of command parameters. In that case it sets the error position is next to the last parameter. Link: http://lkml.kernel.org/r/156966474783.3478.13217501608215769150.stgit@devnote2 Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support") Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-28 16:53:29 +07:00
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) {
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 || 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) ||
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) {
tracing/kprobes: Have uname use __get_str() in print_fmt Thomas Richter reported: > Test case 66 'Use vfs_getname probe to get syscall args filenames' > is broken on s390, but works on x86. The test case fails with: > > [root@m35lp76 perf]# perf test -F 66 > 66: Use vfs_getname probe to get syscall args filenames > :Recording open file: > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.004 MB /tmp/__perf_test.perf.data.TCdYj\ > (20 samples) ] > Looking at perf.data file for vfs_getname records for the file we touched: > FAILED! > [root@m35lp76 perf]# The root cause was the print_fmt of the kprobe event that referenced the "ustring" > Setting up the kprobe event using perf command: > > # ./perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring" > > generates this format file: > [root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/probe/\ > vfs_getname/format > name: vfs_getname > ID: 1172 > format: > field:unsigned short common_type; offset:0; size:2; signed:0; > field:unsigned char common_flags; offset:2; size:1; signed:0; > field:unsigned char common_preempt_count; offset:3; size:1; signed:0; > field:int common_pid; offset:4; size:4; signed:1; > > field:unsigned long __probe_ip; offset:8; size:8; signed:0; > field:__data_loc char[] pathname; offset:16; size:4; signed:1; > > print fmt: "(%lx) pathname=\"%s\"", REC->__probe_ip, REC->pathname Instead of using "__get_str(pathname)" it referenced it directly. Link: http://lkml.kernel.org/r/20200124100742.4050c15e@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 88903c464321 ("tracing/probe: Add ustring type for user-space string") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reported-by: Thomas Richter <tmricht@linux.ibm.com> Tested-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 22:07:42 +07:00
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 {
tracing/kprobes: Have uname use __get_str() in print_fmt Thomas Richter reported: > Test case 66 'Use vfs_getname probe to get syscall args filenames' > is broken on s390, but works on x86. The test case fails with: > > [root@m35lp76 perf]# perf test -F 66 > 66: Use vfs_getname probe to get syscall args filenames > :Recording open file: > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.004 MB /tmp/__perf_test.perf.data.TCdYj\ > (20 samples) ] > Looking at perf.data file for vfs_getname records for the file we touched: > FAILED! > [root@m35lp76 perf]# The root cause was the print_fmt of the kprobe event that referenced the "ustring" > Setting up the kprobe event using perf command: > > # ./perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring" > > generates this format file: > [root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/probe/\ > vfs_getname/format > name: vfs_getname > ID: 1172 > format: > field:unsigned short common_type; offset:0; size:2; signed:0; > field:unsigned char common_flags; offset:2; size:1; signed:0; > field:unsigned char common_preempt_count; offset:3; size:1; signed:0; > field:int common_pid; offset:4; size:4; signed:1; > > field:unsigned long __probe_ip; offset:8; size:8; signed:0; > field:__data_loc char[] pathname; offset:16; size:4; signed:1; > > print fmt: "(%lx) pathname=\"%s\"", REC->__probe_ip, REC->pathname Instead of using "__get_str(pathname)" it referenced it directly. Link: http://lkml.kernel.org/r/20200124100742.4050c15e@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 88903c464321 ("tracing/probe: Add ustring type for user-space string") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reported-by: Thomas Richter <tmricht@linux.ibm.com> Tested-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 22:07:42 +07:00
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;
tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink() Fix NULL pointer access in trace_probe_unlink() by initializing trace_probe.list correctly in trace_probe_init(). In the error case of trace_probe_init(), it can call trace_probe_unlink() before initializing trace_probe.list member. This causes NULL pointer dereference at list_del_init() in trace_probe_unlink(). Syzbot reported : kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8633 Comm: syz-executor797 Not tainted 5.3.0-rc8-next-20190915 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__list_del_entry_valid+0x85/0xf5 lib/list_debug.c:51 Code: 0f 84 e1 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 e2 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 53 49 8b 14 24 4c 39 f2 0f 85 99 00 00 00 49 8d 7d RSP: 0018:ffff888090a7f9d8 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88809b6f90c0 RCX: ffffffff817c0ca9 RDX: 0000000000000000 RSI: ffffffff817c0a73 RDI: ffff88809b6f90c8 RBP: ffff888090a7f9f0 R08: ffff88809a04e600 R09: ffffed1015d26aed R10: ffffed1015d26aec R11: ffff8880ae935763 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88809b6f90c0 R15: ffff88809b6f90d0 FS: 0000555556f99880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006cc090 CR3: 00000000962b2000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry include/linux/list.h:131 [inline] list_del_init include/linux/list.h:190 [inline] trace_probe_unlink+0x1f/0x200 kernel/trace/trace_probe.c:959 trace_probe_cleanup+0xd3/0x110 kernel/trace/trace_probe.c:973 trace_probe_init+0x3f2/0x510 kernel/trace/trace_probe.c:1011 alloc_trace_uprobe+0x5e/0x250 kernel/trace/trace_uprobe.c:353 create_local_trace_uprobe+0x109/0x4a0 kernel/trace/trace_uprobe.c:1508 perf_uprobe_init+0x131/0x210 kernel/trace/trace_event_perf.c:314 perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:8898 perf_try_init_event+0x135/0x590 kernel/events/core.c:10184 perf_init_event kernel/events/core.c:10228 [inline] perf_event_alloc.part.0+0x1b89/0x33d0 kernel/events/core.c:10505 perf_event_alloc kernel/events/core.c:10887 [inline] __do_sys_perf_event_open+0xa2d/0x2d00 kernel/events/core.c:10989 __se_sys_perf_event_open kernel/events/core.c:10871 [inline] __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10871 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Link: http://lkml.kernel.org/r/156869709721.22406.5153754822203046939.stgit@devnote2 Reported-by: syzbot+2f807f4d3a2a4e87f18f@syzkaller.appspotmail.com Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-17 12:11:37 +07:00
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->event->probes, &tp->list);
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;
}
int trace_probe_register_event_call(struct trace_probe *tp)
{
struct trace_event_call *call = trace_probe_event_call(tp);
int ret;
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;
tracing/probe: Fix to check the difference of nr_args before adding probe Steven reported that a test triggered: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_kprobe_create+0xa9e/0xe40 Read of size 8 at addr ffff8880c4f25a48 by task ftracetest/4798 CPU: 2 PID: 4798 Comm: ftracetest Not tainted 5.3.0-rc6-test+ #30 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 Call Trace: dump_stack+0x7c/0xc0 ? trace_kprobe_create+0xa9e/0xe40 print_address_description+0x6c/0x332 ? trace_kprobe_create+0xa9e/0xe40 ? trace_kprobe_create+0xa9e/0xe40 __kasan_report.cold.6+0x1a/0x3b ? trace_kprobe_create+0xa9e/0xe40 kasan_report+0xe/0x12 trace_kprobe_create+0xa9e/0xe40 ? print_kprobe_event+0x280/0x280 ? match_held_lock+0x1b/0x240 ? find_held_lock+0xac/0xd0 ? fs_reclaim_release.part.112+0x5/0x20 ? lock_downgrade+0x350/0x350 ? kasan_unpoison_shadow+0x30/0x40 ? __kasan_kmalloc.constprop.6+0xc1/0xd0 ? trace_kprobe_create+0xe40/0xe40 ? trace_kprobe_create+0xe40/0xe40 create_or_delete_trace_kprobe+0x2e/0x60 trace_run_command+0xc3/0xe0 ? trace_panic_handler+0x20/0x20 ? kasan_unpoison_shadow+0x30/0x40 trace_parse_run_command+0xdc/0x163 vfs_write+0xe1/0x240 ksys_write+0xba/0x150 ? __ia32_sys_read+0x50/0x50 ? tracer_hardirqs_on+0x61/0x180 ? trace_hardirqs_off_caller+0x43/0x110 ? mark_held_locks+0x29/0xa0 ? do_syscall_64+0x14/0x260 do_syscall_64+0x68/0x260 Fix to check the difference of nr_args before adding probe on existing probes. This also may set the error log index bigger than the number of command parameters. In that case it sets the error position is next to the last parameter. Link: http://lkml.kernel.org/r/156966474783.3478.13217501608215769150.stgit@devnote2 Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support") Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-28 16:53:29 +07:00
/* 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;
}