![Frederic Weisbecker](/assets/img/avatar_default.png)
Drop the obsolete "profile" naming used by perf for trace events. Perf can now do more than simple events counting, so generalize the API naming. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com>
1489 lines
35 KiB
C
1489 lines
35 KiB
C
/*
|
|
* Kprobes-based tracing events
|
|
*
|
|
* Created by Masami Hiramatsu <mhiramat@redhat.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/types.h>
|
|
#include <linux/string.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/perf_event.h>
|
|
|
|
#include "trace.h"
|
|
#include "trace_output.h"
|
|
|
|
#define MAX_TRACE_ARGS 128
|
|
#define MAX_ARGSTR_LEN 63
|
|
#define MAX_EVENT_NAME_LEN 64
|
|
#define KPROBE_EVENT_SYSTEM "kprobes"
|
|
|
|
/* Reserved field names */
|
|
#define FIELD_STRING_IP "__probe_ip"
|
|
#define FIELD_STRING_NARGS "__probe_nargs"
|
|
#define FIELD_STRING_RETIP "__probe_ret_ip"
|
|
#define FIELD_STRING_FUNC "__probe_func"
|
|
|
|
const char *reserved_field_names[] = {
|
|
"common_type",
|
|
"common_flags",
|
|
"common_preempt_count",
|
|
"common_pid",
|
|
"common_tgid",
|
|
"common_lock_depth",
|
|
FIELD_STRING_IP,
|
|
FIELD_STRING_NARGS,
|
|
FIELD_STRING_RETIP,
|
|
FIELD_STRING_FUNC,
|
|
};
|
|
|
|
struct fetch_func {
|
|
unsigned long (*func)(struct pt_regs *, void *);
|
|
void *data;
|
|
};
|
|
|
|
static __kprobes unsigned long call_fetch(struct fetch_func *f,
|
|
struct pt_regs *regs)
|
|
{
|
|
return f->func(regs, f->data);
|
|
}
|
|
|
|
/* fetch handlers */
|
|
static __kprobes unsigned long fetch_register(struct pt_regs *regs,
|
|
void *offset)
|
|
{
|
|
return regs_get_register(regs, (unsigned int)((unsigned long)offset));
|
|
}
|
|
|
|
static __kprobes unsigned long fetch_stack(struct pt_regs *regs,
|
|
void *num)
|
|
{
|
|
return regs_get_kernel_stack_nth(regs,
|
|
(unsigned int)((unsigned long)num));
|
|
}
|
|
|
|
static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr)
|
|
{
|
|
unsigned long retval;
|
|
|
|
if (probe_kernel_address(addr, retval))
|
|
return 0;
|
|
return retval;
|
|
}
|
|
|
|
static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
|
|
void *dummy)
|
|
{
|
|
return regs_return_value(regs);
|
|
}
|
|
|
|
static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs,
|
|
void *dummy)
|
|
{
|
|
return kernel_stack_pointer(regs);
|
|
}
|
|
|
|
/* Memory fetching by symbol */
|
|
struct symbol_cache {
|
|
char *symbol;
|
|
long offset;
|
|
unsigned long addr;
|
|
};
|
|
|
|
static unsigned long update_symbol_cache(struct symbol_cache *sc)
|
|
{
|
|
sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
|
|
if (sc->addr)
|
|
sc->addr += sc->offset;
|
|
return sc->addr;
|
|
}
|
|
|
|
static void free_symbol_cache(struct symbol_cache *sc)
|
|
{
|
|
kfree(sc->symbol);
|
|
kfree(sc);
|
|
}
|
|
|
|
static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
|
|
{
|
|
struct symbol_cache *sc;
|
|
|
|
if (!sym || strlen(sym) == 0)
|
|
return NULL;
|
|
sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
|
|
if (!sc)
|
|
return NULL;
|
|
|
|
sc->symbol = kstrdup(sym, GFP_KERNEL);
|
|
if (!sc->symbol) {
|
|
kfree(sc);
|
|
return NULL;
|
|
}
|
|
sc->offset = offset;
|
|
|
|
update_symbol_cache(sc);
|
|
return sc;
|
|
}
|
|
|
|
static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data)
|
|
{
|
|
struct symbol_cache *sc = data;
|
|
|
|
if (sc->addr)
|
|
return fetch_memory(regs, (void *)sc->addr);
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/* Special indirect memory access interface */
|
|
struct indirect_fetch_data {
|
|
struct fetch_func orig;
|
|
long offset;
|
|
};
|
|
|
|
static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data)
|
|
{
|
|
struct indirect_fetch_data *ind = data;
|
|
unsigned long addr;
|
|
|
|
addr = call_fetch(&ind->orig, regs);
|
|
if (addr) {
|
|
addr += ind->offset;
|
|
return fetch_memory(regs, (void *)addr);
|
|
} else
|
|
return 0;
|
|
}
|
|
|
|
static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
|
|
{
|
|
if (data->orig.func == fetch_indirect)
|
|
free_indirect_fetch_data(data->orig.data);
|
|
else if (data->orig.func == fetch_symbol)
|
|
free_symbol_cache(data->orig.data);
|
|
kfree(data);
|
|
}
|
|
|
|
/**
|
|
* Kprobe event core functions
|
|
*/
|
|
|
|
struct probe_arg {
|
|
struct fetch_func fetch;
|
|
const char *name;
|
|
};
|
|
|
|
/* Flags for trace_probe */
|
|
#define TP_FLAG_TRACE 1
|
|
#define TP_FLAG_PROFILE 2
|
|
|
|
struct trace_probe {
|
|
struct list_head list;
|
|
struct kretprobe rp; /* Use rp.kp for kprobe use */
|
|
unsigned long nhit;
|
|
unsigned int flags; /* For TP_FLAG_* */
|
|
const char *symbol; /* symbol name */
|
|
struct ftrace_event_call call;
|
|
struct trace_event event;
|
|
unsigned int nr_args;
|
|
struct probe_arg args[];
|
|
};
|
|
|
|
#define SIZEOF_TRACE_PROBE(n) \
|
|
(offsetof(struct trace_probe, args) + \
|
|
(sizeof(struct probe_arg) * (n)))
|
|
|
|
static __kprobes int probe_is_return(struct trace_probe *tp)
|
|
{
|
|
return tp->rp.handler != NULL;
|
|
}
|
|
|
|
static __kprobes const char *probe_symbol(struct trace_probe *tp)
|
|
{
|
|
return tp->symbol ? tp->symbol : "unknown";
|
|
}
|
|
|
|
static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
|
|
{
|
|
int ret = -EINVAL;
|
|
|
|
if (ff->func == fetch_register) {
|
|
const char *name;
|
|
name = regs_query_register_name((unsigned int)((long)ff->data));
|
|
ret = snprintf(buf, n, "%%%s", name);
|
|
} else if (ff->func == fetch_stack)
|
|
ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data);
|
|
else if (ff->func == fetch_memory)
|
|
ret = snprintf(buf, n, "@0x%p", ff->data);
|
|
else if (ff->func == fetch_symbol) {
|
|
struct symbol_cache *sc = ff->data;
|
|
if (sc->offset)
|
|
ret = snprintf(buf, n, "@%s%+ld", sc->symbol,
|
|
sc->offset);
|
|
else
|
|
ret = snprintf(buf, n, "@%s", sc->symbol);
|
|
} else if (ff->func == fetch_retvalue)
|
|
ret = snprintf(buf, n, "$retval");
|
|
else if (ff->func == fetch_stack_address)
|
|
ret = snprintf(buf, n, "$stack");
|
|
else if (ff->func == fetch_indirect) {
|
|
struct indirect_fetch_data *id = ff->data;
|
|
size_t l = 0;
|
|
ret = snprintf(buf, n, "%+ld(", id->offset);
|
|
if (ret >= n)
|
|
goto end;
|
|
l += ret;
|
|
ret = probe_arg_string(buf + l, n - l, &id->orig);
|
|
if (ret < 0)
|
|
goto end;
|
|
l += ret;
|
|
ret = snprintf(buf + l, n - l, ")");
|
|
ret += l;
|
|
}
|
|
end:
|
|
if (ret >= n)
|
|
return -ENOSPC;
|
|
return ret;
|
|
}
|
|
|
|
static int register_probe_event(struct trace_probe *tp);
|
|
static void unregister_probe_event(struct trace_probe *tp);
|
|
|
|
static DEFINE_MUTEX(probe_lock);
|
|
static LIST_HEAD(probe_list);
|
|
|
|
static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
|
|
static int kretprobe_dispatcher(struct kretprobe_instance *ri,
|
|
struct pt_regs *regs);
|
|
|
|
/* Check the name is good for event/group */
|
|
static int check_event_name(const char *name)
|
|
{
|
|
if (!isalpha(*name) && *name != '_')
|
|
return 0;
|
|
while (*++name != '\0') {
|
|
if (!isalpha(*name) && !isdigit(*name) && *name != '_')
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Allocate new trace_probe and initialize it (including kprobes).
|
|
*/
|
|
static struct trace_probe *alloc_trace_probe(const char *group,
|
|
const char *event,
|
|
void *addr,
|
|
const char *symbol,
|
|
unsigned long offs,
|
|
int nargs, int is_return)
|
|
{
|
|
struct trace_probe *tp;
|
|
int ret = -ENOMEM;
|
|
|
|
tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
|
|
if (!tp)
|
|
return ERR_PTR(ret);
|
|
|
|
if (symbol) {
|
|
tp->symbol = kstrdup(symbol, GFP_KERNEL);
|
|
if (!tp->symbol)
|
|
goto error;
|
|
tp->rp.kp.symbol_name = tp->symbol;
|
|
tp->rp.kp.offset = offs;
|
|
} else
|
|
tp->rp.kp.addr = addr;
|
|
|
|
if (is_return)
|
|
tp->rp.handler = kretprobe_dispatcher;
|
|
else
|
|
tp->rp.kp.pre_handler = kprobe_dispatcher;
|
|
|
|
if (!event || !check_event_name(event)) {
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
tp->call.name = kstrdup(event, GFP_KERNEL);
|
|
if (!tp->call.name)
|
|
goto error;
|
|
|
|
if (!group || !check_event_name(group)) {
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
tp->call.system = kstrdup(group, GFP_KERNEL);
|
|
if (!tp->call.system)
|
|
goto error;
|
|
|
|
INIT_LIST_HEAD(&tp->list);
|
|
return tp;
|
|
error:
|
|
kfree(tp->call.name);
|
|
kfree(tp->symbol);
|
|
kfree(tp);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static void free_probe_arg(struct probe_arg *arg)
|
|
{
|
|
if (arg->fetch.func == fetch_symbol)
|
|
free_symbol_cache(arg->fetch.data);
|
|
else if (arg->fetch.func == fetch_indirect)
|
|
free_indirect_fetch_data(arg->fetch.data);
|
|
kfree(arg->name);
|
|
}
|
|
|
|
static void free_trace_probe(struct trace_probe *tp)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
free_probe_arg(&tp->args[i]);
|
|
|
|
kfree(tp->call.system);
|
|
kfree(tp->call.name);
|
|
kfree(tp->symbol);
|
|
kfree(tp);
|
|
}
|
|
|
|
static struct trace_probe *find_probe_event(const char *event,
|
|
const char *group)
|
|
{
|
|
struct trace_probe *tp;
|
|
|
|
list_for_each_entry(tp, &probe_list, list)
|
|
if (strcmp(tp->call.name, event) == 0 &&
|
|
strcmp(tp->call.system, group) == 0)
|
|
return tp;
|
|
return NULL;
|
|
}
|
|
|
|
/* Unregister a trace_probe and probe_event: call with locking probe_lock */
|
|
static void unregister_trace_probe(struct trace_probe *tp)
|
|
{
|
|
if (probe_is_return(tp))
|
|
unregister_kretprobe(&tp->rp);
|
|
else
|
|
unregister_kprobe(&tp->rp.kp);
|
|
list_del(&tp->list);
|
|
unregister_probe_event(tp);
|
|
}
|
|
|
|
/* Register a trace_probe and probe_event */
|
|
static int register_trace_probe(struct trace_probe *tp)
|
|
{
|
|
struct trace_probe *old_tp;
|
|
int ret;
|
|
|
|
mutex_lock(&probe_lock);
|
|
|
|
/* register as an event */
|
|
old_tp = find_probe_event(tp->call.name, tp->call.system);
|
|
if (old_tp) {
|
|
/* delete old event */
|
|
unregister_trace_probe(old_tp);
|
|
free_trace_probe(old_tp);
|
|
}
|
|
ret = register_probe_event(tp);
|
|
if (ret) {
|
|
pr_warning("Faild to register probe event(%d)\n", ret);
|
|
goto end;
|
|
}
|
|
|
|
tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
|
|
if (probe_is_return(tp))
|
|
ret = register_kretprobe(&tp->rp);
|
|
else
|
|
ret = register_kprobe(&tp->rp.kp);
|
|
|
|
if (ret) {
|
|
pr_warning("Could not insert probe(%d)\n", ret);
|
|
if (ret == -EILSEQ) {
|
|
pr_warning("Probing address(0x%p) is not an "
|
|
"instruction boundary.\n",
|
|
tp->rp.kp.addr);
|
|
ret = -EINVAL;
|
|
}
|
|
unregister_probe_event(tp);
|
|
} else
|
|
list_add_tail(&tp->list, &probe_list);
|
|
end:
|
|
mutex_unlock(&probe_lock);
|
|
return ret;
|
|
}
|
|
|
|
/* Split symbol and offset. */
|
|
static int split_symbol_offset(char *symbol, unsigned long *offset)
|
|
{
|
|
char *tmp;
|
|
int ret;
|
|
|
|
if (!offset)
|
|
return -EINVAL;
|
|
|
|
tmp = strchr(symbol, '+');
|
|
if (tmp) {
|
|
/* skip sign because strict_strtol doesn't accept '+' */
|
|
ret = strict_strtoul(tmp + 1, 0, offset);
|
|
if (ret)
|
|
return ret;
|
|
*tmp = '\0';
|
|
} else
|
|
*offset = 0;
|
|
return 0;
|
|
}
|
|
|
|
#define PARAM_MAX_ARGS 16
|
|
#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
|
|
|
|
static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
|
|
{
|
|
int ret = 0;
|
|
unsigned long param;
|
|
|
|
if (strcmp(arg, "retval") == 0) {
|
|
if (is_return) {
|
|
ff->func = fetch_retvalue;
|
|
ff->data = NULL;
|
|
} else
|
|
ret = -EINVAL;
|
|
} else if (strncmp(arg, "stack", 5) == 0) {
|
|
if (arg[5] == '\0') {
|
|
ff->func = fetch_stack_address;
|
|
ff->data = NULL;
|
|
} else if (isdigit(arg[5])) {
|
|
ret = strict_strtoul(arg + 5, 10, ¶m);
|
|
if (ret || param > PARAM_MAX_STACK)
|
|
ret = -EINVAL;
|
|
else {
|
|
ff->func = fetch_stack;
|
|
ff->data = (void *)param;
|
|
}
|
|
} else
|
|
ret = -EINVAL;
|
|
} else
|
|
ret = -EINVAL;
|
|
return ret;
|
|
}
|
|
|
|
/* Recursive argument parser */
|
|
static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
|
|
{
|
|
int ret = 0;
|
|
unsigned long param;
|
|
long offset;
|
|
char *tmp;
|
|
|
|
switch (arg[0]) {
|
|
case '$':
|
|
ret = parse_probe_vars(arg + 1, ff, is_return);
|
|
break;
|
|
case '%': /* named register */
|
|
ret = regs_query_register_offset(arg + 1);
|
|
if (ret >= 0) {
|
|
ff->func = fetch_register;
|
|
ff->data = (void *)(unsigned long)ret;
|
|
ret = 0;
|
|
}
|
|
break;
|
|
case '@': /* memory or symbol */
|
|
if (isdigit(arg[1])) {
|
|
ret = strict_strtoul(arg + 1, 0, ¶m);
|
|
if (ret)
|
|
break;
|
|
ff->func = fetch_memory;
|
|
ff->data = (void *)param;
|
|
} else {
|
|
ret = split_symbol_offset(arg + 1, &offset);
|
|
if (ret)
|
|
break;
|
|
ff->data = alloc_symbol_cache(arg + 1, offset);
|
|
if (ff->data)
|
|
ff->func = fetch_symbol;
|
|
else
|
|
ret = -EINVAL;
|
|
}
|
|
break;
|
|
case '+': /* indirect memory */
|
|
case '-':
|
|
tmp = strchr(arg, '(');
|
|
if (!tmp) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
*tmp = '\0';
|
|
ret = strict_strtol(arg + 1, 0, &offset);
|
|
if (ret)
|
|
break;
|
|
if (arg[0] == '-')
|
|
offset = -offset;
|
|
arg = tmp + 1;
|
|
tmp = strrchr(arg, ')');
|
|
if (tmp) {
|
|
struct indirect_fetch_data *id;
|
|
*tmp = '\0';
|
|
id = kzalloc(sizeof(struct indirect_fetch_data),
|
|
GFP_KERNEL);
|
|
if (!id)
|
|
return -ENOMEM;
|
|
id->offset = offset;
|
|
ret = __parse_probe_arg(arg, &id->orig, is_return);
|
|
if (ret)
|
|
kfree(id);
|
|
else {
|
|
ff->func = fetch_indirect;
|
|
ff->data = (void *)id;
|
|
}
|
|
} else
|
|
ret = -EINVAL;
|
|
break;
|
|
default:
|
|
/* TODO: support custom handler */
|
|
ret = -EINVAL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* String length checking wrapper */
|
|
static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
|
|
{
|
|
if (strlen(arg) > MAX_ARGSTR_LEN) {
|
|
pr_info("Argument is too long.: %s\n", arg);
|
|
return -ENOSPC;
|
|
}
|
|
return __parse_probe_arg(arg, ff, is_return);
|
|
}
|
|
|
|
/* Return 1 if name is reserved or already used by another argument */
|
|
static int 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;
|
|
}
|
|
|
|
static int create_trace_probe(int argc, char **argv)
|
|
{
|
|
/*
|
|
* Argument syntax:
|
|
* - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
|
|
* - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
|
|
* Fetch args:
|
|
* $retval : fetch return value
|
|
* $stack : fetch stack address
|
|
* $stackN : fetch Nth of stack (N:0-)
|
|
* @ADDR : fetch memory at ADDR (ADDR should be in kernel)
|
|
* @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
|
|
* %REG : fetch register REG
|
|
* Indirect memory fetch:
|
|
* +|-offs(ARG) : fetch memory at ARG +|- offs address.
|
|
* Alias name of args:
|
|
* NAME=FETCHARG : set NAME as alias of FETCHARG.
|
|
*/
|
|
struct trace_probe *tp;
|
|
int i, ret = 0;
|
|
int is_return = 0, is_delete = 0;
|
|
char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
|
|
unsigned long offset = 0;
|
|
void *addr = NULL;
|
|
char buf[MAX_EVENT_NAME_LEN];
|
|
|
|
/* argc must be >= 1 */
|
|
if (argv[0][0] == 'p')
|
|
is_return = 0;
|
|
else if (argv[0][0] == 'r')
|
|
is_return = 1;
|
|
else if (argv[0][0] == '-')
|
|
is_delete = 1;
|
|
else {
|
|
pr_info("Probe definition must be started with 'p', 'r' or"
|
|
" '-'.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (argv[0][1] == ':') {
|
|
event = &argv[0][2];
|
|
if (strchr(event, '/')) {
|
|
group = event;
|
|
event = strchr(group, '/') + 1;
|
|
event[-1] = '\0';
|
|
if (strlen(group) == 0) {
|
|
pr_info("Group name is not specified\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (strlen(event) == 0) {
|
|
pr_info("Event name is not specified\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (!group)
|
|
group = KPROBE_EVENT_SYSTEM;
|
|
|
|
if (is_delete) {
|
|
if (!event) {
|
|
pr_info("Delete command needs an event name.\n");
|
|
return -EINVAL;
|
|
}
|
|
tp = find_probe_event(event, group);
|
|
if (!tp) {
|
|
pr_info("Event %s/%s doesn't exist.\n", group, event);
|
|
return -ENOENT;
|
|
}
|
|
/* delete an event */
|
|
unregister_trace_probe(tp);
|
|
free_trace_probe(tp);
|
|
return 0;
|
|
}
|
|
|
|
if (argc < 2) {
|
|
pr_info("Probe point is not specified.\n");
|
|
return -EINVAL;
|
|
}
|
|
if (isdigit(argv[1][0])) {
|
|
if (is_return) {
|
|
pr_info("Return probe point must be a symbol.\n");
|
|
return -EINVAL;
|
|
}
|
|
/* an address specified */
|
|
ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
|
|
if (ret) {
|
|
pr_info("Failed to parse address.\n");
|
|
return ret;
|
|
}
|
|
} else {
|
|
/* a symbol specified */
|
|
symbol = argv[1];
|
|
/* TODO: support .init module functions */
|
|
ret = split_symbol_offset(symbol, &offset);
|
|
if (ret) {
|
|
pr_info("Failed to parse symbol.\n");
|
|
return ret;
|
|
}
|
|
if (offset && is_return) {
|
|
pr_info("Return probe must be used without offset.\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
argc -= 2; argv += 2;
|
|
|
|
/* setup a probe */
|
|
if (!event) {
|
|
/* Make a new event name */
|
|
if (symbol)
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
|
|
is_return ? 'r' : 'p', symbol, offset);
|
|
else
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
|
|
is_return ? 'r' : 'p', addr);
|
|
event = buf;
|
|
}
|
|
tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
|
|
is_return);
|
|
if (IS_ERR(tp)) {
|
|
pr_info("Failed to allocate trace_probe.(%d)\n",
|
|
(int)PTR_ERR(tp));
|
|
return PTR_ERR(tp);
|
|
}
|
|
|
|
/* parse arguments */
|
|
ret = 0;
|
|
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
|
|
/* Parse argument name */
|
|
arg = strchr(argv[i], '=');
|
|
if (arg)
|
|
*arg++ = '\0';
|
|
else
|
|
arg = argv[i];
|
|
|
|
if (conflict_field_name(argv[i], tp->args, i)) {
|
|
pr_info("Argument%d name '%s' conflicts with "
|
|
"another field.\n", i, argv[i]);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
|
|
if (!tp->args[i].name) {
|
|
pr_info("Failed to allocate argument%d name '%s'.\n",
|
|
i, argv[i]);
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
/* Parse fetch argument */
|
|
ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
|
|
if (ret) {
|
|
pr_info("Parse error at argument%d. (%d)\n", i, ret);
|
|
kfree(tp->args[i].name);
|
|
goto error;
|
|
}
|
|
|
|
tp->nr_args++;
|
|
}
|
|
|
|
ret = register_trace_probe(tp);
|
|
if (ret)
|
|
goto error;
|
|
return 0;
|
|
|
|
error:
|
|
free_trace_probe(tp);
|
|
return ret;
|
|
}
|
|
|
|
static void cleanup_all_probes(void)
|
|
{
|
|
struct trace_probe *tp;
|
|
|
|
mutex_lock(&probe_lock);
|
|
/* TODO: Use batch unregistration */
|
|
while (!list_empty(&probe_list)) {
|
|
tp = list_entry(probe_list.next, struct trace_probe, list);
|
|
unregister_trace_probe(tp);
|
|
free_trace_probe(tp);
|
|
}
|
|
mutex_unlock(&probe_lock);
|
|
}
|
|
|
|
|
|
/* Probes listing interfaces */
|
|
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
mutex_lock(&probe_lock);
|
|
return seq_list_start(&probe_list, *pos);
|
|
}
|
|
|
|
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
return seq_list_next(v, &probe_list, pos);
|
|
}
|
|
|
|
static void probes_seq_stop(struct seq_file *m, void *v)
|
|
{
|
|
mutex_unlock(&probe_lock);
|
|
}
|
|
|
|
static int probes_seq_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_probe *tp = v;
|
|
int i, ret;
|
|
char buf[MAX_ARGSTR_LEN + 1];
|
|
|
|
seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
|
|
seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
|
|
|
|
if (!tp->symbol)
|
|
seq_printf(m, " 0x%p", tp->rp.kp.addr);
|
|
else if (tp->rp.kp.offset)
|
|
seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
|
|
else
|
|
seq_printf(m, " %s", probe_symbol(tp));
|
|
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
|
|
if (ret < 0) {
|
|
pr_warning("Argument%d decoding error(%d).\n", i, ret);
|
|
return ret;
|
|
}
|
|
seq_printf(m, " %s=%s", tp->args[i].name, buf);
|
|
}
|
|
seq_printf(m, "\n");
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations probes_seq_op = {
|
|
.start = probes_seq_start,
|
|
.next = probes_seq_next,
|
|
.stop = probes_seq_stop,
|
|
.show = probes_seq_show
|
|
};
|
|
|
|
static int probes_open(struct inode *inode, struct file *file)
|
|
{
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
(file->f_flags & O_TRUNC))
|
|
cleanup_all_probes();
|
|
|
|
return seq_open(file, &probes_seq_op);
|
|
}
|
|
|
|
static int command_trace_probe(const char *buf)
|
|
{
|
|
char **argv;
|
|
int argc = 0, ret = 0;
|
|
|
|
argv = argv_split(GFP_KERNEL, buf, &argc);
|
|
if (!argv)
|
|
return -ENOMEM;
|
|
|
|
if (argc)
|
|
ret = create_trace_probe(argc, argv);
|
|
|
|
argv_free(argv);
|
|
return ret;
|
|
}
|
|
|
|
#define WRITE_BUFSIZE 128
|
|
|
|
static ssize_t probes_write(struct file *file, const char __user *buffer,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
char *kbuf, *tmp;
|
|
int ret;
|
|
size_t done;
|
|
size_t size;
|
|
|
|
kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
|
|
if (!kbuf)
|
|
return -ENOMEM;
|
|
|
|
ret = done = 0;
|
|
while (done < count) {
|
|
size = count - done;
|
|
if (size >= WRITE_BUFSIZE)
|
|
size = WRITE_BUFSIZE - 1;
|
|
if (copy_from_user(kbuf, buffer + done, size)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
kbuf[size] = '\0';
|
|
tmp = strchr(kbuf, '\n');
|
|
if (tmp) {
|
|
*tmp = '\0';
|
|
size = tmp - kbuf + 1;
|
|
} else if (done + size < count) {
|
|
pr_warning("Line length is too long: "
|
|
"Should be less than %d.", WRITE_BUFSIZE);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
done += size;
|
|
/* Remove comments */
|
|
tmp = strchr(kbuf, '#');
|
|
if (tmp)
|
|
*tmp = '\0';
|
|
|
|
ret = command_trace_probe(kbuf);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
ret = done;
|
|
out:
|
|
kfree(kbuf);
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations kprobe_events_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = probes_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
.write = probes_write,
|
|
};
|
|
|
|
/* Probes profiling interfaces */
|
|
static int probes_profile_seq_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_probe *tp = v;
|
|
|
|
seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
|
|
tp->rp.kp.nmissed);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations profile_seq_op = {
|
|
.start = probes_seq_start,
|
|
.next = probes_seq_next,
|
|
.stop = probes_seq_stop,
|
|
.show = probes_profile_seq_show
|
|
};
|
|
|
|
static int profile_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &profile_seq_op);
|
|
}
|
|
|
|
static const struct file_operations kprobe_profile_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = profile_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
/* Kprobe handler */
|
|
static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
|
|
struct kprobe_trace_entry *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
int size, i, pc;
|
|
unsigned long irq_flags;
|
|
struct ftrace_event_call *call = &tp->call;
|
|
|
|
tp->nhit++;
|
|
|
|
local_save_flags(irq_flags);
|
|
pc = preempt_count();
|
|
|
|
size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
|
|
|
|
event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
|
|
irq_flags, pc);
|
|
if (!event)
|
|
return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->nargs = tp->nr_args;
|
|
entry->ip = (unsigned long)kp->addr;
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
|
|
|
|
if (!filter_current_check_discard(buffer, call, entry, event))
|
|
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
|
|
}
|
|
|
|
/* Kretprobe handler */
|
|
static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
|
|
struct kretprobe_trace_entry *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
int size, i, pc;
|
|
unsigned long irq_flags;
|
|
struct ftrace_event_call *call = &tp->call;
|
|
|
|
local_save_flags(irq_flags);
|
|
pc = preempt_count();
|
|
|
|
size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
|
|
|
|
event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
|
|
irq_flags, pc);
|
|
if (!event)
|
|
return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->nargs = tp->nr_args;
|
|
entry->func = (unsigned long)tp->rp.kp.addr;
|
|
entry->ret_ip = (unsigned long)ri->ret_addr;
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
|
|
|
|
if (!filter_current_check_discard(buffer, call, entry, event))
|
|
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
|
|
}
|
|
|
|
/* Event entry printers */
|
|
enum print_line_t
|
|
print_kprobe_event(struct trace_iterator *iter, int flags)
|
|
{
|
|
struct kprobe_trace_entry *field;
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_event *event;
|
|
struct trace_probe *tp;
|
|
int i;
|
|
|
|
field = (struct kprobe_trace_entry *)iter->ent;
|
|
event = ftrace_find_event(field->ent.type);
|
|
tp = container_of(event, struct trace_probe, event);
|
|
|
|
if (!trace_seq_printf(s, "%s: (", tp->call.name))
|
|
goto partial;
|
|
|
|
if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, ")"))
|
|
goto partial;
|
|
|
|
for (i = 0; i < field->nargs; i++)
|
|
if (!trace_seq_printf(s, " %s=%lx",
|
|
tp->args[i].name, field->args[i]))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, "\n"))
|
|
goto partial;
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
enum print_line_t
|
|
print_kretprobe_event(struct trace_iterator *iter, int flags)
|
|
{
|
|
struct kretprobe_trace_entry *field;
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_event *event;
|
|
struct trace_probe *tp;
|
|
int i;
|
|
|
|
field = (struct kretprobe_trace_entry *)iter->ent;
|
|
event = ftrace_find_event(field->ent.type);
|
|
tp = container_of(event, struct trace_probe, event);
|
|
|
|
if (!trace_seq_printf(s, "%s: (", tp->call.name))
|
|
goto partial;
|
|
|
|
if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, " <- "))
|
|
goto partial;
|
|
|
|
if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, ")"))
|
|
goto partial;
|
|
|
|
for (i = 0; i < field->nargs; i++)
|
|
if (!trace_seq_printf(s, " %s=%lx",
|
|
tp->args[i].name, field->args[i]))
|
|
goto partial;
|
|
|
|
if (!trace_seq_puts(s, "\n"))
|
|
goto partial;
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
static int probe_event_enable(struct ftrace_event_call *call)
|
|
{
|
|
struct trace_probe *tp = (struct trace_probe *)call->data;
|
|
|
|
tp->flags |= TP_FLAG_TRACE;
|
|
if (probe_is_return(tp))
|
|
return enable_kretprobe(&tp->rp);
|
|
else
|
|
return enable_kprobe(&tp->rp.kp);
|
|
}
|
|
|
|
static void probe_event_disable(struct ftrace_event_call *call)
|
|
{
|
|
struct trace_probe *tp = (struct trace_probe *)call->data;
|
|
|
|
tp->flags &= ~TP_FLAG_TRACE;
|
|
if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
|
|
if (probe_is_return(tp))
|
|
disable_kretprobe(&tp->rp);
|
|
else
|
|
disable_kprobe(&tp->rp.kp);
|
|
}
|
|
}
|
|
|
|
static int probe_event_raw_init(struct ftrace_event_call *event_call)
|
|
{
|
|
INIT_LIST_HEAD(&event_call->fields);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#undef DEFINE_FIELD
|
|
#define DEFINE_FIELD(type, item, name, is_signed) \
|
|
do { \
|
|
ret = trace_define_field(event_call, #type, name, \
|
|
offsetof(typeof(field), item), \
|
|
sizeof(field.item), is_signed, \
|
|
FILTER_OTHER); \
|
|
if (ret) \
|
|
return ret; \
|
|
} while (0)
|
|
|
|
static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
|
|
{
|
|
int ret, i;
|
|
struct kprobe_trace_entry field;
|
|
struct trace_probe *tp = (struct trace_probe *)event_call->data;
|
|
|
|
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
|
|
DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
|
|
/* Set argument names as fields */
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
|
|
return 0;
|
|
}
|
|
|
|
static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
|
|
{
|
|
int ret, i;
|
|
struct kretprobe_trace_entry field;
|
|
struct trace_probe *tp = (struct trace_probe *)event_call->data;
|
|
|
|
DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
|
|
DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
|
|
DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
|
|
/* Set argument names as fields */
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
|
|
return 0;
|
|
}
|
|
|
|
static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
|
|
{
|
|
int i;
|
|
int pos = 0;
|
|
|
|
const char *fmt, *arg;
|
|
|
|
if (!probe_is_return(tp)) {
|
|
fmt = "(%lx)";
|
|
arg = "REC->" FIELD_STRING_IP;
|
|
} else {
|
|
fmt = "(%lx <- %lx)";
|
|
arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
|
|
}
|
|
|
|
/* When len=0, we just calculate the needed length */
|
|
#define LEN_OR_ZERO (len ? len - pos : 0)
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
|
|
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx",
|
|
tp->args[i].name);
|
|
}
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
|
|
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
|
|
tp->args[i].name);
|
|
}
|
|
|
|
#undef LEN_OR_ZERO
|
|
|
|
/* return the length of print_fmt */
|
|
return pos;
|
|
}
|
|
|
|
static int set_print_fmt(struct trace_probe *tp)
|
|
{
|
|
int len;
|
|
char *print_fmt;
|
|
|
|
/* First: called with 0 length to calculate the needed length */
|
|
len = __set_print_fmt(tp, NULL, 0);
|
|
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);
|
|
tp->call.print_fmt = print_fmt;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
|
|
/* Kprobe profile handler */
|
|
static __kprobes void kprobe_perf_func(struct kprobe *kp,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
|
|
struct ftrace_event_call *call = &tp->call;
|
|
struct kprobe_trace_entry *entry;
|
|
int size, __size, i;
|
|
unsigned long irq_flags;
|
|
int rctx;
|
|
|
|
__size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
|
|
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
|
size -= sizeof(u32);
|
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
|
|
"profile buffer not large enough"))
|
|
return;
|
|
|
|
entry = perf_trace_buf_prepare(size, call->id, &rctx, &irq_flags);
|
|
if (!entry)
|
|
return;
|
|
|
|
entry->nargs = tp->nr_args;
|
|
entry->ip = (unsigned long)kp->addr;
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
|
|
|
|
perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags, regs);
|
|
}
|
|
|
|
/* Kretprobe profile handler */
|
|
static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
|
|
struct ftrace_event_call *call = &tp->call;
|
|
struct kretprobe_trace_entry *entry;
|
|
int size, __size, i;
|
|
unsigned long irq_flags;
|
|
int rctx;
|
|
|
|
__size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
|
|
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
|
size -= sizeof(u32);
|
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
|
|
"profile buffer not large enough"))
|
|
return;
|
|
|
|
entry = perf_trace_buf_prepare(size, call->id, &rctx, &irq_flags);
|
|
if (!entry)
|
|
return;
|
|
|
|
entry->nargs = tp->nr_args;
|
|
entry->func = (unsigned long)tp->rp.kp.addr;
|
|
entry->ret_ip = (unsigned long)ri->ret_addr;
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
|
|
|
|
perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1,
|
|
irq_flags, regs);
|
|
}
|
|
|
|
static int probe_perf_enable(struct ftrace_event_call *call)
|
|
{
|
|
struct trace_probe *tp = (struct trace_probe *)call->data;
|
|
|
|
tp->flags |= TP_FLAG_PROFILE;
|
|
|
|
if (probe_is_return(tp))
|
|
return enable_kretprobe(&tp->rp);
|
|
else
|
|
return enable_kprobe(&tp->rp.kp);
|
|
}
|
|
|
|
static void probe_perf_disable(struct ftrace_event_call *call)
|
|
{
|
|
struct trace_probe *tp = (struct trace_probe *)call->data;
|
|
|
|
tp->flags &= ~TP_FLAG_PROFILE;
|
|
|
|
if (!(tp->flags & TP_FLAG_TRACE)) {
|
|
if (probe_is_return(tp))
|
|
disable_kretprobe(&tp->rp);
|
|
else
|
|
disable_kprobe(&tp->rp.kp);
|
|
}
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
|
|
static __kprobes
|
|
int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
|
|
|
|
if (tp->flags & TP_FLAG_TRACE)
|
|
kprobe_trace_func(kp, regs);
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tp->flags & TP_FLAG_PROFILE)
|
|
kprobe_perf_func(kp, regs);
|
|
#endif
|
|
return 0; /* We don't tweek kernel, so just return 0 */
|
|
}
|
|
|
|
static __kprobes
|
|
int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
|
|
|
|
if (tp->flags & TP_FLAG_TRACE)
|
|
kretprobe_trace_func(ri, regs);
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tp->flags & TP_FLAG_PROFILE)
|
|
kretprobe_perf_func(ri, regs);
|
|
#endif
|
|
return 0; /* We don't tweek kernel, so just return 0 */
|
|
}
|
|
|
|
static int register_probe_event(struct trace_probe *tp)
|
|
{
|
|
struct ftrace_event_call *call = &tp->call;
|
|
int ret;
|
|
|
|
/* Initialize ftrace_event_call */
|
|
if (probe_is_return(tp)) {
|
|
tp->event.trace = print_kretprobe_event;
|
|
call->raw_init = probe_event_raw_init;
|
|
call->define_fields = kretprobe_event_define_fields;
|
|
} else {
|
|
tp->event.trace = print_kprobe_event;
|
|
call->raw_init = probe_event_raw_init;
|
|
call->define_fields = kprobe_event_define_fields;
|
|
}
|
|
if (set_print_fmt(tp) < 0)
|
|
return -ENOMEM;
|
|
call->event = &tp->event;
|
|
call->id = register_ftrace_event(&tp->event);
|
|
if (!call->id) {
|
|
kfree(call->print_fmt);
|
|
return -ENODEV;
|
|
}
|
|
call->enabled = 0;
|
|
call->regfunc = probe_event_enable;
|
|
call->unregfunc = probe_event_disable;
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
call->perf_event_enable = probe_perf_enable;
|
|
call->perf_event_disable = probe_perf_disable;
|
|
#endif
|
|
call->data = tp;
|
|
ret = trace_add_event_call(call);
|
|
if (ret) {
|
|
pr_info("Failed to register kprobe event: %s\n", call->name);
|
|
kfree(call->print_fmt);
|
|
unregister_ftrace_event(&tp->event);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void unregister_probe_event(struct trace_probe *tp)
|
|
{
|
|
/* tp->event is unregistered in trace_remove_event_call() */
|
|
trace_remove_event_call(&tp->call);
|
|
kfree(tp->call.print_fmt);
|
|
}
|
|
|
|
/* Make a debugfs interface for controling probe points */
|
|
static __init int init_kprobe_trace(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
struct dentry *entry;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return 0;
|
|
|
|
entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
|
|
NULL, &kprobe_events_ops);
|
|
|
|
/* Event list interface */
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'kprobe_events' entry\n");
|
|
|
|
/* Profile interface */
|
|
entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
|
|
NULL, &kprobe_profile_ops);
|
|
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'kprobe_profile' entry\n");
|
|
return 0;
|
|
}
|
|
fs_initcall(init_kprobe_trace);
|
|
|
|
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
|
|
|
static int kprobe_trace_selftest_target(int a1, int a2, int a3,
|
|
int a4, int a5, int a6)
|
|
{
|
|
return a1 + a2 + a3 + a4 + a5 + a6;
|
|
}
|
|
|
|
static __init int kprobe_trace_self_tests_init(void)
|
|
{
|
|
int ret, warn = 0;
|
|
int (*target)(int, int, int, int, int, int);
|
|
struct trace_probe *tp;
|
|
|
|
target = kprobe_trace_selftest_target;
|
|
|
|
pr_info("Testing kprobe tracing: ");
|
|
|
|
ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
|
|
"$stack $stack0 +0($stack)");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on probing function entry.\n");
|
|
warn++;
|
|
} else {
|
|
/* Enable trace point */
|
|
tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tp == NULL)) {
|
|
pr_warning("error on getting new probe.\n");
|
|
warn++;
|
|
} else
|
|
probe_event_enable(&tp->call);
|
|
}
|
|
|
|
ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
|
|
"$retval");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on probing function return.\n");
|
|
warn++;
|
|
} else {
|
|
/* Enable trace point */
|
|
tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM);
|
|
if (WARN_ON_ONCE(tp == NULL)) {
|
|
pr_warning("error on getting new probe.\n");
|
|
warn++;
|
|
} else
|
|
probe_event_enable(&tp->call);
|
|
}
|
|
|
|
if (warn)
|
|
goto end;
|
|
|
|
ret = target(1, 2, 3, 4, 5, 6);
|
|
|
|
ret = command_trace_probe("-:testprobe");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on deleting a probe.\n");
|
|
warn++;
|
|
}
|
|
|
|
ret = command_trace_probe("-:testprobe2");
|
|
if (WARN_ON_ONCE(ret)) {
|
|
pr_warning("error on deleting a probe.\n");
|
|
warn++;
|
|
}
|
|
|
|
end:
|
|
cleanup_all_probes();
|
|
if (warn)
|
|
pr_cont("NG: Some tests are failed. Please check them.\n");
|
|
else
|
|
pr_cont("OK\n");
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(kprobe_trace_self_tests_init);
|
|
|
|
#endif
|