mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-29 20:30:35 +00:00
![Masami Hiramatsu](/assets/img/avatar_default.png)
Prohibit user to specify negative offset from symbols. Since kprobe.offset is unsigned int, the offset must be always positive value. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jason Baron <jbaron@redhat.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <20090910235314.22412.64631.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
1228 lines
28 KiB
C
1228 lines
28 KiB
C
/*
|
|
* kprobe based kernel tracer
|
|
*
|
|
* 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 "trace.h"
|
|
#include "trace_output.h"
|
|
|
|
#define MAX_TRACE_ARGS 128
|
|
#define MAX_ARGSTR_LEN 63
|
|
#define MAX_EVENT_NAME_LEN 64
|
|
|
|
/* currently, trace_kprobe only supports X86. */
|
|
|
|
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_argument(struct pt_regs *regs, void *num)
|
|
{
|
|
return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num));
|
|
}
|
|
|
|
static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
|
|
void *dummy)
|
|
{
|
|
return regs_return_value(regs);
|
|
}
|
|
|
|
static __kprobes unsigned long fetch_ip(struct pt_regs *regs, void *dummy)
|
|
{
|
|
return instruction_pointer(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_trace_core
|
|
*/
|
|
|
|
struct trace_probe {
|
|
struct list_head list;
|
|
union {
|
|
struct kprobe kp;
|
|
struct kretprobe rp;
|
|
};
|
|
unsigned long nhit;
|
|
const char *symbol; /* symbol name */
|
|
struct ftrace_event_call call;
|
|
struct trace_event event;
|
|
unsigned int nr_args;
|
|
struct fetch_func args[];
|
|
};
|
|
|
|
#define SIZEOF_TRACE_PROBE(n) \
|
|
(offsetof(struct trace_probe, args) + \
|
|
(sizeof(struct fetch_func) * (n)))
|
|
|
|
static int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs);
|
|
static int kretprobe_trace_func(struct kretprobe_instance *ri,
|
|
struct pt_regs *regs);
|
|
|
|
static __kprobes int probe_is_return(struct trace_probe *tp)
|
|
{
|
|
return (tp->rp.handler == kretprobe_trace_func);
|
|
}
|
|
|
|
static __kprobes const char *probe_symbol(struct trace_probe *tp)
|
|
{
|
|
return tp->symbol ? tp->symbol : "unknown";
|
|
}
|
|
|
|
static __kprobes unsigned int probe_offset(struct trace_probe *tp)
|
|
{
|
|
return (probe_is_return(tp)) ? tp->rp.kp.offset : tp->kp.offset;
|
|
}
|
|
|
|
static __kprobes void *probe_address(struct trace_probe *tp)
|
|
{
|
|
return (probe_is_return(tp)) ? tp->rp.kp.addr : tp->kp.addr;
|
|
}
|
|
|
|
static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
|
|
{
|
|
int ret = -EINVAL;
|
|
|
|
if (ff->func == fetch_argument)
|
|
ret = snprintf(buf, n, "a%lu", (unsigned long)ff->data);
|
|
else 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, "s%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;
|
|
ret = snprintf(buf, n, "@%s%+ld", sc->symbol, sc->offset);
|
|
} else if (ff->func == fetch_retvalue)
|
|
ret = snprintf(buf, n, "rv");
|
|
else if (ff->func == fetch_ip)
|
|
ret = snprintf(buf, n, "ra");
|
|
else if (ff->func == fetch_stack_address)
|
|
ret = snprintf(buf, n, "sa");
|
|
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 struct trace_probe *alloc_trace_probe(const char *symbol,
|
|
const char *event, int nargs)
|
|
{
|
|
struct trace_probe *tp;
|
|
|
|
tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
|
|
if (!tp)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (symbol) {
|
|
tp->symbol = kstrdup(symbol, GFP_KERNEL);
|
|
if (!tp->symbol)
|
|
goto error;
|
|
}
|
|
if (!event)
|
|
goto error;
|
|
tp->call.name = kstrdup(event, GFP_KERNEL);
|
|
if (!tp->call.name)
|
|
goto error;
|
|
|
|
INIT_LIST_HEAD(&tp->list);
|
|
return tp;
|
|
error:
|
|
kfree(tp->symbol);
|
|
kfree(tp);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
static void free_trace_probe(struct trace_probe *tp)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
if (tp->args[i].func == fetch_symbol)
|
|
free_symbol_cache(tp->args[i].data);
|
|
else if (tp->args[i].func == fetch_indirect)
|
|
free_indirect_fetch_data(tp->args[i].data);
|
|
|
|
kfree(tp->call.name);
|
|
kfree(tp->symbol);
|
|
kfree(tp);
|
|
}
|
|
|
|
static struct trace_probe *find_probe_event(const char *event)
|
|
{
|
|
struct trace_probe *tp;
|
|
|
|
list_for_each_entry(tp, &probe_list, list)
|
|
if (!strcmp(tp->call.name, event))
|
|
return tp;
|
|
return NULL;
|
|
}
|
|
|
|
static void __unregister_trace_probe(struct trace_probe *tp)
|
|
{
|
|
if (probe_is_return(tp))
|
|
unregister_kretprobe(&tp->rp);
|
|
else
|
|
unregister_kprobe(&tp->kp);
|
|
}
|
|
|
|
/* Unregister a trace_probe and probe_event: call with locking probe_lock */
|
|
static void unregister_trace_probe(struct trace_probe *tp)
|
|
{
|
|
unregister_probe_event(tp);
|
|
__unregister_trace_probe(tp);
|
|
list_del(&tp->list);
|
|
}
|
|
|
|
/* 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);
|
|
|
|
if (probe_is_return(tp))
|
|
ret = register_kretprobe(&tp->rp);
|
|
else
|
|
ret = register_kprobe(&tp->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",
|
|
probe_address(tp));
|
|
ret = -EINVAL;
|
|
}
|
|
goto end;
|
|
}
|
|
/* register as an event */
|
|
old_tp = find_probe_event(tp->call.name);
|
|
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);
|
|
__unregister_trace_probe(tp);
|
|
}
|
|
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_arg(char *arg, struct fetch_func *ff, int is_return)
|
|
{
|
|
int ret = 0;
|
|
unsigned long param;
|
|
long offset;
|
|
char *tmp;
|
|
|
|
switch (arg[0]) {
|
|
case 'a': /* argument */
|
|
ret = strict_strtoul(arg + 1, 10, ¶m);
|
|
if (ret || param > PARAM_MAX_ARGS)
|
|
ret = -EINVAL;
|
|
else {
|
|
ff->func = fetch_argument;
|
|
ff->data = (void *)param;
|
|
}
|
|
break;
|
|
case 'r': /* retval or retaddr */
|
|
if (is_return && arg[1] == 'v') {
|
|
ff->func = fetch_retvalue;
|
|
ff->data = NULL;
|
|
} else if (is_return && arg[1] == 'a') {
|
|
ff->func = fetch_ip;
|
|
ff->data = NULL;
|
|
} else
|
|
ret = -EINVAL;
|
|
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 's': /* stack */
|
|
if (arg[1] == 'a') {
|
|
ff->func = fetch_stack_address;
|
|
ff->data = NULL;
|
|
} else {
|
|
ret = strict_strtoul(arg + 1, 10, ¶m);
|
|
if (ret || param > PARAM_MAX_STACK)
|
|
ret = -EINVAL;
|
|
else {
|
|
ff->func = fetch_stack;
|
|
ff->data = (void *)param;
|
|
}
|
|
}
|
|
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;
|
|
}
|
|
|
|
static int create_trace_probe(int argc, char **argv)
|
|
{
|
|
/*
|
|
* Argument syntax:
|
|
* - Add kprobe: p[:EVENT] SYMBOL[+OFFS]|ADDRESS [FETCHARGS]
|
|
* - Add kretprobe: r[:EVENT] SYMBOL[+0] [FETCHARGS]
|
|
* Fetch args:
|
|
* aN : fetch Nth of function argument. (N:0-)
|
|
* rv : fetch return value
|
|
* ra : fetch return address
|
|
* sa : fetch stack address
|
|
* sN : 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.
|
|
*/
|
|
struct trace_probe *tp;
|
|
struct kprobe *kp;
|
|
int i, ret = 0;
|
|
int is_return = 0;
|
|
char *symbol = NULL, *event = NULL;
|
|
unsigned long offset = 0;
|
|
void *addr = NULL;
|
|
|
|
if (argc < 2)
|
|
return -EINVAL;
|
|
|
|
if (argv[0][0] == 'p')
|
|
is_return = 0;
|
|
else if (argv[0][0] == 'r')
|
|
is_return = 1;
|
|
else
|
|
return -EINVAL;
|
|
|
|
if (argv[0][1] == ':') {
|
|
event = &argv[0][2];
|
|
if (strlen(event) == 0) {
|
|
pr_info("Event name is not specifiled\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (isdigit(argv[1][0])) {
|
|
if (is_return)
|
|
return -EINVAL;
|
|
/* an address specified */
|
|
ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr);
|
|
if (ret)
|
|
return ret;
|
|
} else {
|
|
/* a symbol specified */
|
|
symbol = argv[1];
|
|
/* TODO: support .init module functions */
|
|
ret = split_symbol_offset(symbol, &offset);
|
|
if (ret)
|
|
return ret;
|
|
if (offset && is_return)
|
|
return -EINVAL;
|
|
}
|
|
argc -= 2; argv += 2;
|
|
|
|
/* setup a probe */
|
|
if (!event) {
|
|
/* Make a new event name */
|
|
char buf[MAX_EVENT_NAME_LEN];
|
|
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);
|
|
tp = alloc_trace_probe(symbol, buf, argc);
|
|
} else
|
|
tp = alloc_trace_probe(symbol, event, argc);
|
|
if (IS_ERR(tp))
|
|
return PTR_ERR(tp);
|
|
|
|
if (is_return) {
|
|
kp = &tp->rp.kp;
|
|
tp->rp.handler = kretprobe_trace_func;
|
|
} else {
|
|
kp = &tp->kp;
|
|
tp->kp.pre_handler = kprobe_trace_func;
|
|
}
|
|
|
|
if (tp->symbol) {
|
|
kp->symbol_name = tp->symbol;
|
|
kp->offset = (unsigned int)offset;
|
|
} else
|
|
kp->addr = addr;
|
|
|
|
/* parse arguments */
|
|
ret = 0;
|
|
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
|
|
if (strlen(argv[i]) > MAX_ARGSTR_LEN) {
|
|
pr_info("Argument%d(%s) is too long.\n", i, argv[i]);
|
|
ret = -ENOSPC;
|
|
goto error;
|
|
}
|
|
ret = parse_probe_arg(argv[i], &tp->args[i], is_return);
|
|
if (ret)
|
|
goto error;
|
|
}
|
|
tp->nr_args = i;
|
|
|
|
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", tp->call.name);
|
|
|
|
if (tp->symbol)
|
|
seq_printf(m, " %s+%u", probe_symbol(tp), probe_offset(tp));
|
|
else
|
|
seq_printf(m, " 0x%p", probe_address(tp));
|
|
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
|
|
if (ret < 0) {
|
|
pr_warning("Argument%d decoding error(%d).\n", i, ret);
|
|
return ret;
|
|
}
|
|
seq_printf(m, " %s", 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,
|
|
probe_is_return(tp) ? tp->rp.kp.nmissed : tp->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 int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
|
|
{
|
|
struct trace_probe *tp = container_of(kp, struct trace_probe, 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 0;
|
|
|
|
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], regs);
|
|
|
|
if (!filter_current_check_discard(buffer, call, entry, event))
|
|
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
|
|
return 0;
|
|
}
|
|
|
|
/* Kretprobe handler */
|
|
static __kprobes int 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 0;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->nargs = tp->nr_args;
|
|
entry->func = (unsigned long)probe_address(tp);
|
|
entry->ret_ip = (unsigned long)ri->ret_addr;
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
entry->args[i] = call_fetch(&tp->args[i], regs);
|
|
|
|
if (!filter_current_check_discard(buffer, call, entry, event))
|
|
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* 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;
|
|
int i;
|
|
|
|
field = (struct kprobe_trace_entry *)iter->ent;
|
|
|
|
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, " 0x%lx", 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;
|
|
int i;
|
|
|
|
field = (struct kretprobe_trace_entry *)iter->ent;
|
|
|
|
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, " 0x%lx", 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;
|
|
|
|
if (probe_is_return(tp))
|
|
return enable_kretprobe(&tp->rp);
|
|
else
|
|
return enable_kprobe(&tp->kp);
|
|
}
|
|
|
|
static void probe_event_disable(struct ftrace_event_call *call)
|
|
{
|
|
struct trace_probe *tp = (struct trace_probe *)call->data;
|
|
|
|
if (probe_is_return(tp))
|
|
disable_kretprobe(&tp->rp);
|
|
else
|
|
disable_kprobe(&tp->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;
|
|
char buf[MAX_ARGSTR_LEN + 1];
|
|
struct trace_probe *tp = (struct trace_probe *)event_call->data;
|
|
|
|
ret = trace_define_common_fields(event_call);
|
|
if (!ret)
|
|
return ret;
|
|
|
|
DEFINE_FIELD(unsigned long, ip, "ip", 0);
|
|
DEFINE_FIELD(int, nargs, "nargs", 1);
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
/* Set argN as a field */
|
|
sprintf(buf, "arg%d", i);
|
|
DEFINE_FIELD(unsigned long, args[i], buf, 0);
|
|
/* Set argument string as an alias field */
|
|
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
|
|
if (ret < 0)
|
|
return ret;
|
|
DEFINE_FIELD(unsigned long, args[i], buf, 0);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
|
|
{
|
|
int ret, i;
|
|
struct kretprobe_trace_entry field;
|
|
char buf[MAX_ARGSTR_LEN + 1];
|
|
struct trace_probe *tp = (struct trace_probe *)event_call->data;
|
|
|
|
ret = trace_define_common_fields(event_call);
|
|
if (!ret)
|
|
return ret;
|
|
|
|
DEFINE_FIELD(unsigned long, func, "func", 0);
|
|
DEFINE_FIELD(unsigned long, ret_ip, "ret_ip", 0);
|
|
DEFINE_FIELD(int, nargs, "nargs", 1);
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
/* Set argN as a field */
|
|
sprintf(buf, "arg%d", i);
|
|
DEFINE_FIELD(unsigned long, args[i], buf, 0);
|
|
/* Set argument string as an alias field */
|
|
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
|
|
if (ret < 0)
|
|
return ret;
|
|
DEFINE_FIELD(unsigned long, args[i], buf, 0);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int __probe_event_show_format(struct trace_seq *s,
|
|
struct trace_probe *tp, const char *fmt,
|
|
const char *arg)
|
|
{
|
|
int i, ret;
|
|
char buf[MAX_ARGSTR_LEN + 1];
|
|
|
|
/* Show aliases */
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (!trace_seq_printf(s, "\talias: %s;\toriginal: arg%d;\n",
|
|
buf, i))
|
|
return 0;
|
|
}
|
|
/* Show format */
|
|
if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt))
|
|
return 0;
|
|
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
if (!trace_seq_puts(s, " 0x%lx"))
|
|
return 0;
|
|
|
|
if (!trace_seq_printf(s, "\", %s", arg))
|
|
return 0;
|
|
|
|
for (i = 0; i < tp->nr_args; i++)
|
|
if (!trace_seq_printf(s, ", arg%d", i))
|
|
return 0;
|
|
|
|
return trace_seq_puts(s, "\n");
|
|
}
|
|
|
|
#undef SHOW_FIELD
|
|
#define SHOW_FIELD(type, item, name) \
|
|
do { \
|
|
ret = trace_seq_printf(s, "\tfield: " #type " %s;\t" \
|
|
"offset:%u;\tsize:%u;\n", name, \
|
|
(unsigned int)offsetof(typeof(field), item),\
|
|
(unsigned int)sizeof(type)); \
|
|
if (!ret) \
|
|
return 0; \
|
|
} while (0)
|
|
|
|
static int kprobe_event_show_format(struct ftrace_event_call *call,
|
|
struct trace_seq *s)
|
|
{
|
|
struct kprobe_trace_entry field __attribute__((unused));
|
|
int ret, i;
|
|
char buf[8];
|
|
struct trace_probe *tp = (struct trace_probe *)call->data;
|
|
|
|
SHOW_FIELD(unsigned long, ip, "ip");
|
|
SHOW_FIELD(int, nargs, "nargs");
|
|
|
|
/* Show fields */
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
sprintf(buf, "arg%d", i);
|
|
SHOW_FIELD(unsigned long, args[i], buf);
|
|
}
|
|
trace_seq_puts(s, "\n");
|
|
|
|
return __probe_event_show_format(s, tp, "%lx:", "ip");
|
|
}
|
|
|
|
static int kretprobe_event_show_format(struct ftrace_event_call *call,
|
|
struct trace_seq *s)
|
|
{
|
|
struct kretprobe_trace_entry field __attribute__((unused));
|
|
int ret, i;
|
|
char buf[8];
|
|
struct trace_probe *tp = (struct trace_probe *)call->data;
|
|
|
|
SHOW_FIELD(unsigned long, func, "func");
|
|
SHOW_FIELD(unsigned long, ret_ip, "ret_ip");
|
|
SHOW_FIELD(int, nargs, "nargs");
|
|
|
|
/* Show fields */
|
|
for (i = 0; i < tp->nr_args; i++) {
|
|
sprintf(buf, "arg%d", i);
|
|
SHOW_FIELD(unsigned long, args[i], buf);
|
|
}
|
|
trace_seq_puts(s, "\n");
|
|
|
|
return __probe_event_show_format(s, tp, "%lx <- %lx:",
|
|
"func, ret_ip");
|
|
}
|
|
|
|
static int register_probe_event(struct trace_probe *tp)
|
|
{
|
|
struct ftrace_event_call *call = &tp->call;
|
|
int ret;
|
|
|
|
/* Initialize ftrace_event_call */
|
|
call->system = "kprobes";
|
|
if (probe_is_return(tp)) {
|
|
tp->event.trace = print_kretprobe_event;
|
|
call->raw_init = probe_event_raw_init;
|
|
call->show_format = kretprobe_event_show_format;
|
|
call->define_fields = kretprobe_event_define_fields;
|
|
} else {
|
|
tp->event.trace = print_kprobe_event;
|
|
call->raw_init = probe_event_raw_init;
|
|
call->show_format = kprobe_event_show_format;
|
|
call->define_fields = kprobe_event_define_fields;
|
|
}
|
|
call->event = &tp->event;
|
|
call->id = register_ftrace_event(&tp->event);
|
|
if (!call->id)
|
|
return -ENODEV;
|
|
call->enabled = 1;
|
|
call->regfunc = probe_event_enable;
|
|
call->unregfunc = probe_event_disable;
|
|
call->data = tp;
|
|
ret = trace_add_event_call(call);
|
|
if (ret) {
|
|
pr_info("Failed to register kprobe event: %s\n", call->name);
|
|
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);
|
|
}
|
|
|
|
/* 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;
|
|
int (*target)(int, int, int, int, int, int);
|
|
|
|
target = kprobe_trace_selftest_target;
|
|
|
|
pr_info("Testing kprobe tracing: ");
|
|
|
|
ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
|
|
"a1 a2 a3 a4 a5 a6");
|
|
if (WARN_ON_ONCE(ret))
|
|
pr_warning("error enabling function entry\n");
|
|
|
|
ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
|
|
"ra rv");
|
|
if (WARN_ON_ONCE(ret))
|
|
pr_warning("error enabling function return\n");
|
|
|
|
ret = target(1, 2, 3, 4, 5, 6);
|
|
|
|
cleanup_all_probes();
|
|
|
|
pr_cont("OK\n");
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(kprobe_trace_self_tests_init);
|
|
|
|
#endif
|