kernel/trace/trace_kprobe.c

   1 /*
   2  * Kprobes-based tracing events
   3  *
   4  * Created by Masami Hiramatsu <mhiramat@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/kprobes.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/slab.h>
  25 #include <linux/smp.h>
  26 #include <linux/debugfs.h>
  27 #include <linux/types.h>
  28 #include <linux/string.h>
  29 #include <linux/ctype.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/perf_event.h>
  32 #include <linux/stringify.h>
  33 #include <linux/limits.h>
  34 #include <asm/bitsperlong.h>
  35
  36 #include "trace.h"
  37 #include "trace_output.h"
  38
  39 #define MAX_TRACE_ARGS 128
  40 #define MAX_ARGSTR_LEN 63
  41 #define MAX_EVENT_NAME_LEN 64
  42 #define MAX_STRING_SIZE PATH_MAX
  43 #define KPROBE_EVENT_SYSTEM "kprobes"
  44
  45 /* Reserved field names */
  46 #define FIELD_STRING_IP "__probe_ip"
  47 #define FIELD_STRING_RETIP "__probe_ret_ip"
  48 #define FIELD_STRING_FUNC "__probe_func"
  49
  50 const char *reserved_field_names[] = {
  51         "common_type",
  52         "common_flags",
  53         "common_preempt_count",
  54         "common_pid",
  55         "common_tgid",
  56         "common_lock_depth",
  57         FIELD_STRING_IP,
  58         FIELD_STRING_RETIP,
  59         FIELD_STRING_FUNC,
  60 };
  61
  62 /* Printing function type */
  63 typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *,
  64                                  void *);
  65 #define PRINT_TYPE_FUNC_NAME(type)      print_type_##type
  66 #define PRINT_TYPE_FMT_NAME(type)       print_type_format_##type
  67
  68 /* Printing  in basic type function template */
  69 #define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast)                   \
  70 static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s,    \
  71                                                 const char *name,       \
  72                                                 void *data, void *ent)\
  73 {                                                                       \
  74         return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
  75 }                                                                       \
  76 static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
  77
  78 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
  79 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
  80 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
  81 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
  82 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
  83 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
  84 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
  85 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
  86
  87 /* data_rloc: data relative location, compatible with u32 */
  88 #define make_data_rloc(len, roffs)      \
  89         (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
  90 #define get_rloc_len(dl)        ((u32)(dl) >> 16)
  91 #define get_rloc_offs(dl)       ((u32)(dl) & 0xffff)
  92
  93 static inline void *get_rloc_data(u32 *dl)
  94 {
  95         return (u8 *)dl + get_rloc_offs(*dl);
  96 }
  97
  98 /* For data_loc conversion */
  99 static inline void *get_loc_data(u32 *dl, void *ent)
 100 {
 101         return (u8 *)ent + get_rloc_offs(*dl);
 102 }
 103
 104 /*
 105  * Convert data_rloc to data_loc:
 106  *  data_rloc stores the offset from data_rloc itself, but data_loc
 107  *  stores the offset from event entry.
 108  */
 109 #define convert_rloc_to_loc(dl, offs)   ((u32)(dl) + (offs))
 110
 111 /* For defining macros, define string/string_size types */
 112 typedef u32 string;
 113 typedef u32 string_size;
 114
 115 /* Print type function for string type */
 116 static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
 117                                                   const char *name,
 118                                                   void *data, void *ent)
 119 {
 120         int len = *(u32 *)data >> 16;
 121
 122         if (!len)
 123                 return trace_seq_printf(s, " %s=(fault)", name);
 124         else
 125                 return trace_seq_printf(s, " %s=\"%s\"", name,
 126                                         (const char *)get_loc_data(data, ent));
 127 }
 128 static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
 129
 130 /* Data fetch function type */
 131 typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
 132
 133 struct fetch_param {
 134         fetch_func_t    fn;
 135         void *data;
 136 };
 137
 138 static __kprobes void call_fetch(struct fetch_param *fprm,
 139                                  struct pt_regs *regs, void *dest)
 140 {
 141         return fprm->fn(regs, fprm->data, dest);
 142 }
 143
 144 #define FETCH_FUNC_NAME(method, type)   fetch_##method##_##type
 145 /*
 146  * Define macro for basic types - we don't need to define s* types, because
 147  * we have to care only about bitwidth at recording time.
 148  */
 149 #define DEFINE_BASIC_FETCH_FUNCS(method) \
 150 DEFINE_FETCH_##method(u8)               \
 151 DEFINE_FETCH_##method(u16)              \
 152 DEFINE_FETCH_##method(u32)              \
 153 DEFINE_FETCH_##method(u64)
 154
 155 #define CHECK_FETCH_FUNCS(method, fn)                   \
 156         (((FETCH_FUNC_NAME(method, u8) == fn) ||        \
 157           (FETCH_FUNC_NAME(method, u16) == fn) ||       \
 158           (FETCH_FUNC_NAME(method, u32) == fn) ||       \
 159           (FETCH_FUNC_NAME(method, u64) == fn) ||       \
 160           (FETCH_FUNC_NAME(method, string) == fn) ||    \
 161           (FETCH_FUNC_NAME(method, string_size) == fn)) \
 162          && (fn != NULL))
 163
 164 /* Data fetch function templates */
 165 #define DEFINE_FETCH_reg(type)                                          \
 166 static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs,  \
 167                                         void *offset, void *dest)       \
 168 {                                                                       \
 169         *(type *)dest = (type)regs_get_register(regs,                   \
 170                                 (unsigned int)((unsigned long)offset)); \
 171 }
 172 DEFINE_BASIC_FETCH_FUNCS(reg)
 173 /* No string on the register */
 174 #define fetch_reg_string NULL
 175 #define fetch_reg_string_size NULL
 176
 177 #define DEFINE_FETCH_stack(type)                                        \
 178 static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
 179                                           void *offset, void *dest)     \
 180 {                                                                       \
 181         *(type *)dest = (type)regs_get_kernel_stack_nth(regs,           \
 182                                 (unsigned int)((unsigned long)offset)); \
 183 }
 184 DEFINE_BASIC_FETCH_FUNCS(stack)
 185 /* No string on the stack entry */
 186 #define fetch_stack_string NULL
 187 #define fetch_stack_string_size NULL
 188
 189 #define DEFINE_FETCH_retval(type)                                       \
 190 static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
 191                                           void *dummy, void *dest)      \
 192 {                                                                       \
 193         *(type *)dest = (type)regs_return_value(regs);                  \
 194 }
 195 DEFINE_BASIC_FETCH_FUNCS(retval)
 196 /* No string on the retval */
 197 #define fetch_retval_string NULL
 198 #define fetch_retval_string_size NULL
 199
 200 #define DEFINE_FETCH_memory(type)                                       \
 201 static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
 202                                           void *addr, void *dest)       \
 203 {                                                                       \
 204         type retval;                                                    \
 205         if (probe_kernel_address(addr, retval))                         \
 206                 *(type *)dest = 0;                                      \
 207         else                                                            \
 208                 *(type *)dest = retval;                                 \
 209 }
 210 DEFINE_BASIC_FETCH_FUNCS(memory)
 211 /*
 212  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 213  * length and relative data location.
 214  */
 215 static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
 216                                                       void *addr, void *dest)
 217 {
 218         long ret;
 219         int maxlen = get_rloc_len(*(u32 *)dest);
 220         u8 *dst = get_rloc_data(dest);
 221         u8 *src = addr;
 222         mm_segment_t old_fs = get_fs();
 223         if (!maxlen)
 224                 return;
 225         /*
 226          * Try to get string again, since the string can be changed while
 227          * probing.
 228          */
 229         set_fs(KERNEL_DS);
 230         pagefault_disable();
 231         do
 232                 ret = __copy_from_user_inatomic(dst++, src++, 1);
 233         while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
 234         dst[-1] = '\0';
 235         pagefault_enable();
 236         set_fs(old_fs);
 237
 238         if (ret < 0) {  /* Failed to fetch string */
 239                 ((u8 *)get_rloc_data(dest))[0] = '\0';
 240                 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
 241         } else
 242                 *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
 243                                               get_rloc_offs(*(u32 *)dest));
 244 }
 245 /* Return the length of string -- including null terminal byte */
 246 static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
 247                                                         void *addr, void *dest)
 248 {
 249         int ret, len = 0;
 250         u8 c;
 251         mm_segment_t old_fs = get_fs();
 252
 253         set_fs(KERNEL_DS);
 254         pagefault_disable();
 255         do {
 256                 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
 257                 len++;
 258         } while (c && ret == 0 && len < MAX_STRING_SIZE);
 259         pagefault_enable();
 260         set_fs(old_fs);
 261
 262         if (ret < 0)    /* Failed to check the length */
 263                 *(u32 *)dest = 0;
 264         else
 265                 *(u32 *)dest = len;
 266 }
 267
 268 /* Memory fetching by symbol */
 269 struct symbol_cache {
 270         char *symbol;
 271         long offset;
 272         unsigned long addr;
 273 };
 274
 275 static unsigned long update_symbol_cache(struct symbol_cache *sc)
 276 {
 277         sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
 278         if (sc->addr)
 279                 sc->addr += sc->offset;
 280         return sc->addr;
 281 }
 282
 283 static void free_symbol_cache(struct symbol_cache *sc)
 284 {
 285         kfree(sc->symbol);
 286         kfree(sc);
 287 }
 288
 289 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
 290 {
 291         struct symbol_cache *sc;
 292
 293         if (!sym || strlen(sym) == 0)
 294                 return NULL;
 295         sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
 296         if (!sc)
 297                 return NULL;
 298
 299         sc->symbol = kstrdup(sym, GFP_KERNEL);
 300         if (!sc->symbol) {
 301                 kfree(sc);
 302                 return NULL;
 303         }
 304         sc->offset = offset;
 305
 306         update_symbol_cache(sc);
 307         return sc;
 308 }
 309
 310 #define DEFINE_FETCH_symbol(type)                                       \
 311 static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
 312                                           void *data, void *dest)       \
 313 {                                                                       \
 314         struct symbol_cache *sc = data;                                 \
 315         if (sc->addr)                                                   \
 316                 fetch_memory_##type(regs, (void *)sc->addr, dest);      \
 317         else                                                            \
 318                 *(type *)dest = 0;                                      \
 319 }
 320 DEFINE_BASIC_FETCH_FUNCS(symbol)
 321 DEFINE_FETCH_symbol(string)
 322 DEFINE_FETCH_symbol(string_size)
 323
 324 /* Dereference memory access function */
 325 struct deref_fetch_param {
 326         struct fetch_param orig;
 327         long offset;
 328 };
 329
 330 #define DEFINE_FETCH_deref(type)                                        \
 331 static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
 332                                             void *data, void *dest)     \
 333 {                                                                       \
 334         struct deref_fetch_param *dprm = data;                          \
 335         unsigned long addr;                                             \
 336         call_fetch(&dprm->orig, regs, &addr);                           \
 337         if (addr) {                                                     \
 338                 addr += dprm->offset;                                   \
 339                 fetch_memory_##type(regs, (void *)addr, dest);          \
 340         } else                                                          \
 341                 *(type *)dest = 0;                                      \
 342 }
 343 DEFINE_BASIC_FETCH_FUNCS(deref)
 344 DEFINE_FETCH_deref(string)
 345 DEFINE_FETCH_deref(string_size)
 346
 347 static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
 348 {
 349         if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
 350                 free_deref_fetch_param(data->orig.data);
 351         else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
 352                 free_symbol_cache(data->orig.data);
 353         kfree(data);
 354 }
 355
 356 /* Bitfield fetch function */
 357 struct bitfield_fetch_param {
 358         struct fetch_param orig;
 359         unsigned char hi_shift;
 360         unsigned char low_shift;
 361 };
 362
 363 #define DEFINE_FETCH_bitfield(type)                                     \
 364 static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
 365                                             void *data, void *dest)     \
 366 {                                                                       \
 367         struct bitfield_fetch_param *bprm = data;                       \
 368         type buf = 0;                                                   \
 369         call_fetch(&bprm->orig, regs, &buf);                            \
 370         if (buf) {                                                      \
 371                 buf <<= bprm->hi_shift;                                 \
 372                 buf >>= bprm->low_shift;                                \
 373         }                                                               \
 374         *(type *)dest = buf;                                            \
 375 }
 376 DEFINE_BASIC_FETCH_FUNCS(bitfield)
 377 #define fetch_bitfield_string NULL
 378 #define fetch_bitfield_string_size NULL
 379
 380 static __kprobes void
 381 free_bitfield_fetch_param(struct bitfield_fetch_param *data)
 382 {
 383         /*
 384          * Don't check the bitfield itself, because this must be the
 385          * last fetch function.
 386          */
 387         if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
 388                 free_deref_fetch_param(data->orig.data);
 389         else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
 390                 free_symbol_cache(data->orig.data);
 391         kfree(data);
 392 }
 393 /* Default (unsigned long) fetch type */
 394 #define __DEFAULT_FETCH_TYPE(t) u##t
 395 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
 396 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
 397 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
 398
 399 /* Fetch types */
 400 enum {
 401         FETCH_MTD_reg = 0,
 402         FETCH_MTD_stack,
 403         FETCH_MTD_retval,
 404         FETCH_MTD_memory,
 405         FETCH_MTD_symbol,
 406         FETCH_MTD_deref,
 407         FETCH_MTD_bitfield,
 408         FETCH_MTD_END,
 409 };
 410
 411 #define ASSIGN_FETCH_FUNC(method, type) \
 412         [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
 413
 414 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
 415         {.name = _name,                         \
 416          .size = _size,                                 \
 417          .is_signed = sign,                             \
 418          .print = PRINT_TYPE_FUNC_NAME(ptype),          \
 419          .fmt = PRINT_TYPE_FMT_NAME(ptype),             \
 420          .fmttype = _fmttype,                           \
 421          .fetch = {                                     \
 422 ASSIGN_FETCH_FUNC(reg, ftype),                          \
 423 ASSIGN_FETCH_FUNC(stack, ftype),                        \
 424 ASSIGN_FETCH_FUNC(retval, ftype),                       \
 425 ASSIGN_FETCH_FUNC(memory, ftype),                       \
 426 ASSIGN_FETCH_FUNC(symbol, ftype),                       \
 427 ASSIGN_FETCH_FUNC(deref, ftype),                        \
 428 ASSIGN_FETCH_FUNC(bitfield, ftype),                     \
 429           }                                             \
 430         }
 431
 432 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                   \
 433         __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
 434
 435 #define FETCH_TYPE_STRING 0
 436 #define FETCH_TYPE_STRSIZE 1
 437
 438 /* Fetch type information table */
 439 static const struct fetch_type {
 440         const char      *name;          /* Name of type */
 441         size_t          size;           /* Byte size of type */
 442         int             is_signed;      /* Signed flag */
 443         print_type_func_t       print;  /* Print functions */
 444         const char      *fmt;           /* Fromat string */
 445         const char      *fmttype;       /* Name in format file */
 446         /* Fetch functions */
 447         fetch_func_t    fetch[FETCH_MTD_END];
 448 } fetch_type_table[] = {
 449         /* Special types */
 450         [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
 451                                         sizeof(u32), 1, "__data_loc char[]"),
 452         [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
 453                                         string_size, sizeof(u32), 0, "u32"),
 454         /* Basic types */
 455         ASSIGN_FETCH_TYPE(u8,  u8,  0),
 456         ASSIGN_FETCH_TYPE(u16, u16, 0),
 457         ASSIGN_FETCH_TYPE(u32, u32, 0),
 458         ASSIGN_FETCH_TYPE(u64, u64, 0),
 459         ASSIGN_FETCH_TYPE(s8,  u8,  1),
 460         ASSIGN_FETCH_TYPE(s16, u16, 1),
 461         ASSIGN_FETCH_TYPE(s32, u32, 1),
 462         ASSIGN_FETCH_TYPE(s64, u64, 1),
 463 };
 464
 465 static const struct fetch_type *find_fetch_type(const char *type)
 466 {
 467         int i;
 468
 469         if (!type)
 470                 type = DEFAULT_FETCH_TYPE_STR;
 471
 472         /* Special case: bitfield */
 473         if (*type == 'b') {
 474                 unsigned long bs;
 475                 type = strchr(type, '/');
 476                 if (!type)
 477                         goto fail;
 478                 type++;
 479                 if (strict_strtoul(type, 0, &bs))
 480                         goto fail;
 481                 switch (bs) {
 482                 case 8:
 483                         return find_fetch_type("u8");
 484                 case 16:
 485                         return find_fetch_type("u16");
 486                 case 32:
 487                         return find_fetch_type("u32");
 488                 case 64:
 489                         return find_fetch_type("u64");
 490                 default:
 491                         goto fail;
 492                 }
 493         }
 494
 495         for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
 496                 if (strcmp(type, fetch_type_table[i].name) == 0)
 497                         return &fetch_type_table[i];
 498 fail:
 499         return NULL;
 500 }
 501
 502 /* Special function : only accept unsigned long */
 503 static __kprobes void fetch_stack_address(struct pt_regs *regs,
 504                                           void *dummy, void *dest)
 505 {
 506         *(unsigned long *)dest = kernel_stack_pointer(regs);
 507 }
 508
 509 static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
 510                                             fetch_func_t orig_fn)
 511 {
 512         int i;
 513
 514         if (type != &fetch_type_table[FETCH_TYPE_STRING])
 515                 return NULL;    /* Only string type needs size function */
 516         for (i = 0; i < FETCH_MTD_END; i++)
 517                 if (type->fetch[i] == orig_fn)
 518                         return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
 519
 520         WARN_ON(1);     /* This should not happen */
 521         return NULL;
 522 }
 523
 524 /**
 525  * Kprobe event core functions
 526  */
 527
 528 struct probe_arg {
 529         struct fetch_param      fetch;
 530         struct fetch_param      fetch_size;
 531         unsigned int            offset; /* Offset from argument entry */
 532         const char              *name;  /* Name of this argument */
 533         const char              *comm;  /* Command of this argument */
 534         const struct fetch_type *type;  /* Type of this argument */
 535 };
 536
 537 /* Flags for trace_probe */
 538 #define TP_FLAG_TRACE   1
 539 #define TP_FLAG_PROFILE 2
 540
 541 struct trace_probe {
 542         struct list_head        list;
 543         struct kretprobe        rp;     /* Use rp.kp for kprobe use */
 544         unsigned long           nhit;
 545         unsigned int            flags;  /* For TP_FLAG_* */
 546         const char              *symbol;        /* symbol name */
 547         struct ftrace_event_class       class;
 548         struct ftrace_event_call        call;
 549         ssize_t                 size;           /* trace entry size */
 550         unsigned int            nr_args;
 551         struct probe_arg        args[];
 552 };
 553
 554 #define SIZEOF_TRACE_PROBE(n)                   \
 555         (offsetof(struct trace_probe, args) +   \
 556         (sizeof(struct probe_arg) * (n)))
 557
 558
 559 static __kprobes int probe_is_return(struct trace_probe *tp)
 560 {
 561         return tp->rp.handler != NULL;
 562 }
 563
 564 static __kprobes const char *probe_symbol(struct trace_probe *tp)
 565 {
 566         return tp->symbol ? tp->symbol : "unknown";
 567 }
 568
 569 static int register_probe_event(struct trace_probe *tp);
 570 static void unregister_probe_event(struct trace_probe *tp);
 571
 572 static DEFINE_MUTEX(probe_lock);
 573 static LIST_HEAD(probe_list);
 574
 575 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 576 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 577                                 struct pt_regs *regs);
 578
 579 /* Check the name is good for event/group/fields */
 580 static int is_good_name(const char *name)
 581 {
 582         if (!isalpha(*name) && *name != '_')
 583                 return 0;
 584         while (*++name != '\0') {
 585                 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
 586                         return 0;
 587         }
 588         return 1;
 589 }
 590
 591 /*
 592  * Allocate new trace_probe and initialize it (including kprobes).
 593  */
 594 static struct trace_probe *alloc_trace_probe(const char *group,
 595                                              const char *event,
 596                                              void *addr,
 597                                              const char *symbol,
 598                                              unsigned long offs,
 599                                              int nargs, int is_return)
 600 {
 601         struct trace_probe *tp;
 602         int ret = -ENOMEM;
 603
 604         tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
 605         if (!tp)
 606                 return ERR_PTR(ret);
 607
 608         if (symbol) {
 609                 tp->symbol = kstrdup(symbol, GFP_KERNEL);
 610                 if (!tp->symbol)
 611                         goto error;
 612                 tp->rp.kp.symbol_name = tp->symbol;
 613                 tp->rp.kp.offset = offs;
 614         } else
 615                 tp->rp.kp.addr = addr;
 616
 617         if (is_return)
 618                 tp->rp.handler = kretprobe_dispatcher;
 619         else
 620                 tp->rp.kp.pre_handler = kprobe_dispatcher;
 621
 622         if (!event || !is_good_name(event)) {
 623                 ret = -EINVAL;
 624                 goto error;
 625         }
 626
 627         tp->call.class = &tp->class;
 628         tp->call.name = kstrdup(event, GFP_KERNEL);
 629         if (!tp->call.name)
 630                 goto error;
 631
 632         if (!group || !is_good_name(group)) {
 633                 ret = -EINVAL;
 634                 goto error;
 635         }
 636
 637         tp->class.system = kstrdup(group, GFP_KERNEL);
 638         if (!tp->class.system)
 639                 goto error;
 640
 641         INIT_LIST_HEAD(&tp->list);
 642         return tp;
 643 error:
 644         kfree(tp->call.name);
 645         kfree(tp->symbol);
 646         kfree(tp);
 647         return ERR_PTR(ret);
 648 }
 649
 650 static void free_probe_arg(struct probe_arg *arg)
 651 {
 652         if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
 653                 free_bitfield_fetch_param(arg->fetch.data);
 654         else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
 655                 free_deref_fetch_param(arg->fetch.data);
 656         else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
 657                 free_symbol_cache(arg->fetch.data);
 658         kfree(arg->name);
 659         kfree(arg->comm);
 660 }
 661
 662 static void free_trace_probe(struct trace_probe *tp)
 663 {
 664         int i;
 665
 666         for (i = 0; i < tp->nr_args; i++)
 667                 free_probe_arg(&tp->args[i]);
 668
 669         kfree(tp->call.class->system);
 670         kfree(tp->call.name);
 671         kfree(tp->symbol);
 672         kfree(tp);
 673 }
 674
 675 static struct trace_probe *find_probe_event(const char *event,
 676                                             const char *group)
 677 {
 678         struct trace_probe *tp;
 679
 680         list_for_each_entry(tp, &probe_list, list)
 681                 if (strcmp(tp->call.name, event) == 0 &&
 682                     strcmp(tp->call.class->system, group) == 0)
 683                         return tp;
 684         return NULL;
 685 }
 686
 687 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
 688 static void unregister_trace_probe(struct trace_probe *tp)
 689 {
 690         if (probe_is_return(tp))
 691                 unregister_kretprobe(&tp->rp);
 692         else
 693                 unregister_kprobe(&tp->rp.kp);
 694         list_del(&tp->list);
 695         unregister_probe_event(tp);
 696 }
 697
 698 /* Register a trace_probe and probe_event */
 699 static int register_trace_probe(struct trace_probe *tp)
 700 {
 701         struct trace_probe *old_tp;
 702         int ret;
 703
 704         mutex_lock(&probe_lock);
 705
 706         /* register as an event */
 707         old_tp = find_probe_event(tp->call.name, tp->call.class->system);
 708         if (old_tp) {
 709                 /* delete old event */
 710                 unregister_trace_probe(old_tp);
 711                 free_trace_probe(old_tp);
 712         }
 713         ret = register_probe_event(tp);
 714         if (ret) {
 715                 pr_warning("Failed to register probe event(%d)\n", ret);
 716                 goto end;
 717         }
 718
 719         tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
 720         if (probe_is_return(tp))
 721                 ret = register_kretprobe(&tp->rp);
 722         else
 723                 ret = register_kprobe(&tp->rp.kp);
 724
 725         if (ret) {
 726                 pr_warning("Could not insert probe(%d)\n", ret);
 727                 if (ret == -EILSEQ) {
 728                         pr_warning("Probing address(0x%p) is not an "
 729                                    "instruction boundary.\n",
 730                                    tp->rp.kp.addr);
 731                         ret = -EINVAL;
 732                 }
 733                 unregister_probe_event(tp);
 734         } else
 735                 list_add_tail(&tp->list, &probe_list);
 736 end:
 737         mutex_unlock(&probe_lock);
 738         return ret;
 739 }
 740
 741 /* Split symbol and offset. */
 742 static int split_symbol_offset(char *symbol, unsigned long *offset)
 743 {
 744         char *tmp;
 745         int ret;
 746
 747         if (!offset)
 748                 return -EINVAL;
 749
 750         tmp = strchr(symbol, '+');
 751         if (tmp) {
 752                 /* skip sign because strict_strtol doesn't accept '+' */
 753                 ret = strict_strtoul(tmp + 1, 0, offset);
 754                 if (ret)
 755                         return ret;
 756                 *tmp = '\0';
 757         } else
 758                 *offset = 0;
 759         return 0;
 760 }
 761
 762 #define PARAM_MAX_ARGS 16
 763 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
 764
 765 static int parse_probe_vars(char *arg, const struct fetch_type *t,
 766                             struct fetch_param *f, int is_return)
 767 {
 768         int ret = 0;
 769         unsigned long param;
 770
 771         if (strcmp(arg, "retval") == 0) {
 772                 if (is_return)
 773                         f->fn = t->fetch[FETCH_MTD_retval];
 774                 else
 775                         ret = -EINVAL;
 776         } else if (strncmp(arg, "stack", 5) == 0) {
 777                 if (arg[5] == '\0') {
 778                         if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
 779                                 f->fn = fetch_stack_address;
 780                         else
 781                                 ret = -EINVAL;
 782                 } else if (isdigit(arg[5])) {
 783                         ret = strict_strtoul(arg + 5, 10, &param);
 784                         if (ret || param > PARAM_MAX_STACK)
 785                                 ret = -EINVAL;
 786                         else {
 787                                 f->fn = t->fetch[FETCH_MTD_stack];
 788                                 f->data = (void *)param;
 789                         }
 790                 } else
 791                         ret = -EINVAL;
 792         } else
 793                 ret = -EINVAL;
 794         return ret;
 795 }
 796
 797 /* Recursive argument parser */
 798 static int __parse_probe_arg(char *arg, const struct fetch_type *t,
 799                              struct fetch_param *f, int is_return)
 800 {
 801         int ret = 0;
 802         unsigned long param;
 803         long offset;
 804         char *tmp;
 805
 806         switch (arg[0]) {
 807         case '$':
 808                 ret = parse_probe_vars(arg + 1, t, f, is_return);
 809                 break;
 810         case '%':       /* named register */
 811                 ret = regs_query_register_offset(arg + 1);
 812                 if (ret >= 0) {
 813                         f->fn = t->fetch[FETCH_MTD_reg];
 814                         f->data = (void *)(unsigned long)ret;
 815                         ret = 0;
 816                 }
 817                 break;
 818         case '@':       /* memory or symbol */
 819                 if (isdigit(arg[1])) {
 820                         ret = strict_strtoul(arg + 1, 0, &param);
 821                         if (ret)
 822                                 break;
 823                         f->fn = t->fetch[FETCH_MTD_memory];
 824                         f->data = (void *)param;
 825                 } else {
 826                         ret = split_symbol_offset(arg + 1, &offset);
 827                         if (ret)
 828                                 break;
 829                         f->data = alloc_symbol_cache(arg + 1, offset);
 830                         if (f->data)
 831                                 f->fn = t->fetch[FETCH_MTD_symbol];
 832                 }
 833                 break;
 834         case '+':       /* deref memory */
 835                 arg++;  /* Skip '+', because strict_strtol() rejects it. */
 836         case '-':
 837                 tmp = strchr(arg, '(');
 838                 if (!tmp)
 839                         break;
 840                 *tmp = '\0';
 841                 ret = strict_strtol(arg, 0, &offset);
 842                 if (ret)
 843                         break;
 844                 arg = tmp + 1;
 845                 tmp = strrchr(arg, ')');
 846                 if (tmp) {
 847                         struct deref_fetch_param *dprm;
 848                         const struct fetch_type *t2 = find_fetch_type(NULL);
 849                         *tmp = '\0';
 850                         dprm = kzalloc(sizeof(struct deref_fetch_param),
 851                                        GFP_KERNEL);
 852                         if (!dprm)
 853                                 return -ENOMEM;
 854                         dprm->offset = offset;
 855                         ret = __parse_probe_arg(arg, t2, &dprm->orig,
 856                                                 is_return);
 857                         if (ret)
 858                                 kfree(dprm);
 859                         else {
 860                                 f->fn = t->fetch[FETCH_MTD_deref];
 861                                 f->data = (void *)dprm;
 862                         }
 863                 }
 864                 break;
 865         }
 866         if (!ret && !f->fn) {   /* Parsed, but do not find fetch method */
 867                 pr_info("%s type has no corresponding fetch method.\n",
 868                         t->name);
 869                 ret = -EINVAL;
 870         }
 871         return ret;
 872 }
 873
 874 #define BYTES_TO_BITS(nb)       ((BITS_PER_LONG * (nb)) / sizeof(long))
 875
 876 /* Bitfield type needs to be parsed into a fetch function */
 877 static int __parse_bitfield_probe_arg(const char *bf,
 878                                       const struct fetch_type *t,
 879                                       struct fetch_param *f)
 880 {
 881         struct bitfield_fetch_param *bprm;
 882         unsigned long bw, bo;
 883         char *tail;
 884
 885         if (*bf != 'b')
 886                 return 0;
 887
 888         bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
 889         if (!bprm)
 890                 return -ENOMEM;
 891         bprm->orig = *f;
 892         f->fn = t->fetch[FETCH_MTD_bitfield];
 893         f->data = (void *)bprm;
 894
 895         bw = simple_strtoul(bf + 1, &tail, 0);  /* Use simple one */
 896         if (bw == 0 || *tail != '@')
 897                 return -EINVAL;
 898
 899         bf = tail + 1;
 900         bo = simple_strtoul(bf, &tail, 0);
 901         if (tail == bf || *tail != '/')
 902                 return -EINVAL;
 903
 904         bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
 905         bprm->low_shift = bprm->hi_shift + bo;
 906         return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
 907 }
 908
 909 /* String length checking wrapper */
 910 static int parse_probe_arg(char *arg, struct trace_probe *tp,
 911                            struct probe_arg *parg, int is_return)
 912 {
 913         const char *t;
 914         int ret;
 915
 916         if (strlen(arg) > MAX_ARGSTR_LEN) {
 917                 pr_info("Argument is too long.: %s\n",  arg);
 918                 return -ENOSPC;
 919         }
 920         parg->comm = kstrdup(arg, GFP_KERNEL);
 921         if (!parg->comm) {
 922                 pr_info("Failed to allocate memory for command '%s'.\n", arg);
 923                 return -ENOMEM;
 924         }
 925         t = strchr(parg->comm, ':');
 926         if (t) {
 927                 arg[t - parg->comm] = '\0';
 928                 t++;
 929         }
 930         parg->type = find_fetch_type(t);
 931         if (!parg->type) {
 932                 pr_info("Unsupported type: %s\n", t);
 933                 return -EINVAL;
 934         }
 935         parg->offset = tp->size;
 936         tp->size += parg->type->size;
 937         ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
 938         if (ret >= 0 && t != NULL)
 939                 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
 940         if (ret >= 0) {
 941                 parg->fetch_size.fn = get_fetch_size_function(parg->type,
 942                                                               parg->fetch.fn);
 943                 parg->fetch_size.data = parg->fetch.data;
 944         }
 945         return ret;
 946 }
 947
 948 /* Return 1 if name is reserved or already used by another argument */
 949 static int conflict_field_name(const char *name,
 950                                struct probe_arg *args, int narg)
 951 {
 952         int i;
 953         for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
 954                 if (strcmp(reserved_field_names[i], name) == 0)
 955                         return 1;
 956         for (i = 0; i < narg; i++)
 957                 if (strcmp(args[i].name, name) == 0)
 958                         return 1;
 959         return 0;
 960 }
 961
 962 static int create_trace_probe(int argc, char **argv)
 963 {
 964         /*
 965          * Argument syntax:
 966          *  - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
 967          *  - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
 968          * Fetch args:
 969          *  $retval     : fetch return value
 970          *  $stack      : fetch stack address
 971          *  $stackN     : fetch Nth of stack (N:0-)
 972          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
 973          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 974          *  %REG        : fetch register REG
 975          * Dereferencing memory fetch:
 976          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 977          * Alias name of args:
 978          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 979          * Type of args:
 980          *  FETCHARG:TYPE : use TYPE instead of unsigned long.
 981          */
 982         struct trace_probe *tp;
 983         int i, ret = 0;
 984         int is_return = 0, is_delete = 0;
 985         char *symbol = NULL, *event = NULL, *group = NULL;
 986         char *arg;
 987         unsigned long offset = 0;
 988         void *addr = NULL;
 989         char buf[MAX_EVENT_NAME_LEN];
 990
 991         /* argc must be >= 1 */
 992         if (argv[0][0] == 'p')
 993                 is_return = 0;
 994         else if (argv[0][0] == 'r')
 995                 is_return = 1;
 996         else if (argv[0][0] == '-')
 997                 is_delete = 1;
 998         else {
 999                 pr_info("Probe definition must be started with 'p', 'r' or"
1000                         " '-'.\n");
1001                 return -EINVAL;
1002         }
1003
1004         if (argv[0][1] == ':') {
1005                 event = &argv[0][2];
1006                 if (strchr(event, '/')) {
1007                         group = event;
1008                         event = strchr(group, '/') + 1;
1009                         event[-1] = '\0';
1010                         if (strlen(group) == 0) {
1011                                 pr_info("Group name is not specified\n");
1012                                 return -EINVAL;
1013                         }
1014                 }
1015                 if (strlen(event) == 0) {
1016                         pr_info("Event name is not specified\n");
1017                         return -EINVAL;
1018                 }
1019         }
1020         if (!group)
1021                 group = KPROBE_EVENT_SYSTEM;
1022
1023         if (is_delete) {
1024                 if (!event) {
1025                         pr_info("Delete command needs an event name.\n");
1026                         return -EINVAL;
1027                 }
1028                 mutex_lock(&probe_lock);
1029                 tp = find_probe_event(event, group);
1030                 if (!tp) {
1031                         mutex_unlock(&probe_lock);
1032                         pr_info("Event %s/%s doesn't exist.\n", group, event);
1033                         return -ENOENT;
1034                 }
1035                 /* delete an event */
1036                 unregister_trace_probe(tp);
1037                 free_trace_probe(tp);
1038                 mutex_unlock(&probe_lock);
1039                 return 0;
1040         }
1041
1042         if (argc < 2) {
1043                 pr_info("Probe point is not specified.\n");
1044                 return -EINVAL;
1045         }
1046         if (isdigit(argv[1][0])) {
1047                 if (is_return) {
1048                         pr_info("Return probe point must be a symbol.\n");
1049                         return -EINVAL;
1050                 }
1051                 /* an address specified */
1052                 ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
1053                 if (ret) {
1054                         pr_info("Failed to parse address.\n");
1055                         return ret;
1056                 }
1057         } else {
1058                 /* a symbol specified */
1059                 symbol = argv[1];
1060                 /* TODO: support .init module functions */
1061                 ret = split_symbol_offset(symbol, &offset);
1062                 if (ret) {
1063                         pr_info("Failed to parse symbol.\n");
1064                         return ret;
1065                 }
1066                 if (offset && is_return) {
1067                         pr_info("Return probe must be used without offset.\n");
1068                         return -EINVAL;
1069                 }
1070         }
1071         argc -= 2; argv += 2;
1072
1073         /* setup a probe */
1074         if (!event) {
1075                 /* Make a new event name */
1076                 if (symbol)
1077                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
1078                                  is_return ? 'r' : 'p', symbol, offset);
1079                 else
1080                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
1081                                  is_return ? 'r' : 'p', addr);
1082                 event = buf;
1083         }
1084         tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
1085                                is_return);
1086         if (IS_ERR(tp)) {
1087                 pr_info("Failed to allocate trace_probe.(%d)\n",
1088                         (int)PTR_ERR(tp));
1089                 return PTR_ERR(tp);
1090         }
1091
1092         /* parse arguments */
1093         ret = 0;
1094         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
1095                 /* Increment count for freeing args in error case */
1096                 tp->nr_args++;
1097
1098                 /* Parse argument name */
1099                 arg = strchr(argv[i], '=');
1100                 if (arg) {
1101                         *arg++ = '\0';
1102                         tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
1103                 } else {
1104                         arg = argv[i];
1105                         /* If argument name is omitted, set "argN" */
1106                         snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
1107                         tp->args[i].name = kstrdup(buf, GFP_KERNEL);
1108                 }
1109
1110                 if (!tp->args[i].name) {
1111                         pr_info("Failed to allocate argument[%d] name.\n", i);
1112                         ret = -ENOMEM;
1113                         goto error;
1114                 }
1115
1116                 if (!is_good_name(tp->args[i].name)) {
1117                         pr_info("Invalid argument[%d] name: %s\n",
1118                                 i, tp->args[i].name);
1119                         ret = -EINVAL;
1120                         goto error;
1121                 }
1122
1123                 if (conflict_field_name(tp->args[i].name, tp->args, i)) {
1124                         pr_info("Argument[%d] name '%s' conflicts with "
1125                                 "another field.\n", i, argv[i]);
1126                         ret = -EINVAL;
1127                         goto error;
1128                 }
1129
1130                 /* Parse fetch argument */
1131                 ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
1132                 if (ret) {
1133                         pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
1134                         goto error;
1135                 }
1136         }
1137
1138         ret = register_trace_probe(tp);
1139         if (ret)
1140                 goto error;
1141         return 0;
1142
1143 error:
1144         free_trace_probe(tp);
1145         return ret;
1146 }
1147
1148 static void cleanup_all_probes(void)
1149 {
1150         struct trace_probe *tp;
1151
1152         mutex_lock(&probe_lock);
1153         /* TODO: Use batch unregistration */
1154         while (!list_empty(&probe_list)) {
1155                 tp = list_entry(probe_list.next, struct trace_probe, list);
1156                 unregister_trace_probe(tp);
1157                 free_trace_probe(tp);
1158         }
1159         mutex_unlock(&probe_lock);
1160 }
1161
1162
1163 /* Probes listing interfaces */
1164 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
1165 {
1166         mutex_lock(&probe_lock);
1167         return seq_list_start(&probe_list, *pos);
1168 }
1169
1170 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
1171 {
1172         return seq_list_next(v, &probe_list, pos);
1173 }
1174
1175 static void probes_seq_stop(struct seq_file *m, void *v)
1176 {
1177         mutex_unlock(&probe_lock);
1178 }
1179
1180 static int probes_seq_show(struct seq_file *m, void *v)
1181 {
1182         struct trace_probe *tp = v;
1183         int i;
1184
1185         seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
1186         seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
1187
1188         if (!tp->symbol)
1189                 seq_printf(m, " 0x%p", tp->rp.kp.addr);
1190         else if (tp->rp.kp.offset)
1191                 seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
1192         else
1193                 seq_printf(m, " %s", probe_symbol(tp));
1194
1195         for (i = 0; i < tp->nr_args; i++)
1196                 seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
1197         seq_printf(m, "\n");
1198
1199         return 0;
1200 }
1201
1202 static const struct seq_operations probes_seq_op = {
1203         .start  = probes_seq_start,
1204         .next   = probes_seq_next,
1205         .stop   = probes_seq_stop,
1206         .show   = probes_seq_show
1207 };
1208
1209 static int probes_open(struct inode *inode, struct file *file)
1210 {
1211         if ((file->f_mode & FMODE_WRITE) &&
1212             (file->f_flags & O_TRUNC))
1213                 cleanup_all_probes();
1214
1215         return seq_open(file, &probes_seq_op);
1216 }
1217
1218 static int command_trace_probe(const char *buf)
1219 {
1220         char **argv;
1221         int argc = 0, ret = 0;
1222
1223         argv = argv_split(GFP_KERNEL, buf, &argc);
1224         if (!argv)
1225                 return -ENOMEM;
1226
1227         if (argc)
1228                 ret = create_trace_probe(argc, argv);
1229
1230         argv_free(argv);
1231         return ret;
1232 }
1233
1234 #define WRITE_BUFSIZE 4096
1235
1236 static ssize_t probes_write(struct file *file, const char __user *buffer,
1237                             size_t count, loff_t *ppos)
1238 {
1239         char *kbuf, *tmp;
1240         int ret;
1241         size_t done;
1242         size_t size;
1243
1244         kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
1245         if (!kbuf)
1246                 return -ENOMEM;
1247
1248         ret = done = 0;
1249         while (done < count) {
1250                 size = count - done;
1251                 if (size >= WRITE_BUFSIZE)
1252                         size = WRITE_BUFSIZE - 1;
1253                 if (copy_from_user(kbuf, buffer + done, size)) {
1254                         ret = -EFAULT;
1255                         goto out;
1256                 }
1257                 kbuf[size] = '\0';
1258                 tmp = strchr(kbuf, '\n');
1259                 if (tmp) {
1260                         *tmp = '\0';
1261                         size = tmp - kbuf + 1;
1262                 } else if (done + size < count) {
1263                         pr_warning("Line length is too long: "
1264                                    "Should be less than %d.", WRITE_BUFSIZE);
1265                         ret = -EINVAL;
1266                         goto out;
1267                 }
1268                 done += size;
1269                 /* Remove comments */
1270                 tmp = strchr(kbuf, '#');
1271                 if (tmp)
1272                         *tmp = '\0';
1273
1274                 ret = command_trace_probe(kbuf);
1275                 if (ret)
1276                         goto out;
1277         }
1278         ret = done;
1279 out:
1280         kfree(kbuf);
1281         return ret;
1282 }
1283
1284 static const struct file_operations kprobe_events_ops = {
1285         .owner          = THIS_MODULE,
1286         .open           = probes_open,
1287         .read           = seq_read,
1288         .llseek         = seq_lseek,
1289         .release        = seq_release,
1290         .write          = probes_write,
1291 };
1292
1293 /* Probes profiling interfaces */
1294 static int probes_profile_seq_show(struct seq_file *m, void *v)
1295 {
1296         struct trace_probe *tp = v;
1297
1298         seq_printf(m, "  %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
1299                    tp->rp.kp.nmissed);
1300
1301         return 0;
1302 }
1303
1304 static const struct seq_operations profile_seq_op = {
1305         .start  = probes_seq_start,
1306         .next   = probes_seq_next,
1307         .stop   = probes_seq_stop,
1308         .show   = probes_profile_seq_show
1309 };
1310
1311 static int profile_open(struct inode *inode, struct file *file)
1312 {
1313         return seq_open(file, &profile_seq_op);
1314 }
1315
1316 static const struct file_operations kprobe_profile_ops = {
1317         .owner          = THIS_MODULE,
1318         .open           = profile_open,
1319         .read           = seq_read,
1320         .llseek         = seq_lseek,
1321         .release        = seq_release,
1322 };
1323
1324 /* Sum up total data length for dynamic arraies (strings) */
1325 static __kprobes int __get_data_size(struct trace_probe *tp,
1326                                      struct pt_regs *regs)
1327 {
1328         int i, ret = 0;
1329         u32 len;
1330
1331         for (i = 0; i < tp->nr_args; i++)
1332                 if (unlikely(tp->args[i].fetch_size.fn)) {
1333                         call_fetch(&tp->args[i].fetch_size, regs, &len);
1334                         ret += len;
1335                 }
1336
1337         return ret;
1338 }
1339
1340 /* Store the value of each argument */
1341 static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
1342                                        struct pt_regs *regs,
1343                                        u8 *data, int maxlen)
1344 {
1345         int i;
1346         u32 end = tp->size;
1347         u32 *dl;        /* Data (relative) location */
1348
1349         for (i = 0; i < tp->nr_args; i++) {
1350                 if (unlikely(tp->args[i].fetch_size.fn)) {
1351                         /*
1352                          * First, we set the relative location and
1353                          * maximum data length to *dl
1354                          */
1355                         dl = (u32 *)(data + tp->args[i].offset);
1356                         *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
1357                         /* Then try to fetch string or dynamic array data */
1358                         call_fetch(&tp->args[i].fetch, regs, dl);
1359                         /* Reduce maximum length */
1360                         end += get_rloc_len(*dl);
1361                         maxlen -= get_rloc_len(*dl);
1362                         /* Trick here, convert data_rloc to data_loc */
1363                         *dl = convert_rloc_to_loc(*dl,
1364                                  ent_size + tp->args[i].offset);
1365                 } else
1366                         /* Just fetching data normally */
1367                         call_fetch(&tp->args[i].fetch, regs,
1368                                    data + tp->args[i].offset);
1369         }
1370 }
1371
1372 /* Kprobe handler */
1373 static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
1374 {
1375         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1376         struct kprobe_trace_entry_head *entry;
1377         struct ring_buffer_event *event;
1378         struct ring_buffer *buffer;
1379         int size, dsize, pc;
1380         unsigned long irq_flags;
1381         struct ftrace_event_call *call = &tp->call;
1382
1383         tp->nhit++;
1384
1385         local_save_flags(irq_flags);
1386         pc = preempt_count();
1387
1388         dsize = __get_data_size(tp, regs);
1389         size = sizeof(*entry) + tp->size + dsize;
1390
1391         event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
1392                                                   size, irq_flags, pc);
1393         if (!event)
1394                 return;
1395
1396         entry = ring_buffer_event_data(event);
1397         entry->ip = (unsigned long)kp->addr;
1398         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1399
1400         if (!filter_current_check_discard(buffer, call, entry, event))
1401                 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
1402 }
1403
1404 /* Kretprobe handler */
1405 static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
1406                                           struct pt_regs *regs)
1407 {
1408         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1409         struct kretprobe_trace_entry_head *entry;
1410         struct ring_buffer_event *event;
1411         struct ring_buffer *buffer;
1412         int size, pc, dsize;
1413         unsigned long irq_flags;
1414         struct ftrace_event_call *call = &tp->call;
1415
1416         local_save_flags(irq_flags);
1417         pc = preempt_count();
1418
1419         dsize = __get_data_size(tp, regs);
1420         size = sizeof(*entry) + tp->size + dsize;
1421
1422         event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
1423                                                   size, irq_flags, pc);
1424         if (!event)
1425                 return;
1426
1427         entry = ring_buffer_event_data(event);
1428         entry->func = (unsigned long)tp->rp.kp.addr;
1429         entry->ret_ip = (unsigned long)ri->ret_addr;
1430         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1431
1432         if (!filter_current_check_discard(buffer, call, entry, event))
1433                 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
1434 }
1435
1436 /* Event entry printers */
1437 enum print_line_t
1438 print_kprobe_event(struct trace_iterator *iter, int flags,
1439                    struct trace_event *event)
1440 {
1441         struct kprobe_trace_entry_head *field;
1442         struct trace_seq *s = &iter->seq;
1443         struct trace_probe *tp;
1444         u8 *data;
1445         int i;
1446
1447         field = (struct kprobe_trace_entry_head *)iter->ent;
1448         tp = container_of(event, struct trace_probe, call.event);
1449
1450         if (!trace_seq_printf(s, "%s: (", tp->call.name))
1451                 goto partial;
1452
1453         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1454                 goto partial;
1455
1456         if (!trace_seq_puts(s, ")"))
1457                 goto partial;
1458
1459         data = (u8 *)&field[1];
1460         for (i = 0; i < tp->nr_args; i++)
1461                 if (!tp->args[i].type->print(s, tp->args[i].name,
1462                                              data + tp->args[i].offset, field))
1463                         goto partial;
1464
1465         if (!trace_seq_puts(s, "\n"))
1466                 goto partial;
1467
1468         return TRACE_TYPE_HANDLED;
1469 partial:
1470         return TRACE_TYPE_PARTIAL_LINE;
1471 }
1472
1473 enum print_line_t
1474 print_kretprobe_event(struct trace_iterator *iter, int flags,
1475                       struct trace_event *event)
1476 {
1477         struct kretprobe_trace_entry_head *field;
1478         struct trace_seq *s = &iter->seq;
1479         struct trace_probe *tp;
1480         u8 *data;
1481         int i;
1482
1483         field = (struct kretprobe_trace_entry_head *)iter->ent;
1484         tp = container_of(event, struct trace_probe, call.event);
1485
1486         if (!trace_seq_printf(s, "%s: (", tp->call.name))
1487                 goto partial;
1488
1489         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1490                 goto partial;
1491
1492         if (!trace_seq_puts(s, " <- "))
1493                 goto partial;
1494
1495         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1496                 goto partial;
1497
1498         if (!trace_seq_puts(s, ")"))
1499                 goto partial;
1500
1501         data = (u8 *)&field[1];
1502         for (i = 0; i < tp->nr_args; i++)
1503                 if (!tp->args[i].type->print(s, tp->args[i].name,
1504                                              data + tp->args[i].offset, field))
1505                         goto partial;
1506
1507         if (!trace_seq_puts(s, "\n"))
1508                 goto partial;
1509
1510         return TRACE_TYPE_HANDLED;
1511 partial:
1512         return TRACE_TYPE_PARTIAL_LINE;
1513 }
1514
1515 static int probe_event_enable(struct ftrace_event_call *call)
1516 {
1517         struct trace_probe *tp = (struct trace_probe *)call->data;
1518
1519         tp->flags |= TP_FLAG_TRACE;
1520         if (probe_is_return(tp))
1521                 return enable_kretprobe(&tp->rp);
1522         else
1523                 return enable_kprobe(&tp->rp.kp);
1524 }
1525
1526 static void probe_event_disable(struct ftrace_event_call *call)
1527 {
1528         struct trace_probe *tp = (struct trace_probe *)call->data;
1529
1530         tp->flags &= ~TP_FLAG_TRACE;
1531         if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
1532                 if (probe_is_return(tp))
1533                         disable_kretprobe(&tp->rp);
1534                 else
1535                         disable_kprobe(&tp->rp.kp);
1536         }
1537 }
1538
1539 #undef DEFINE_FIELD
1540 #define DEFINE_FIELD(type, item, name, is_signed)                       \
1541         do {                                                            \
1542                 ret = trace_define_field(event_call, #type, name,       \
1543                                          offsetof(typeof(field), item), \
1544                                          sizeof(field.item), is_signed, \
1545                                          FILTER_OTHER);                 \
1546                 if (ret)                                                \
1547                         return ret;                                     \
1548         } while (0)
1549
1550 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1551 {
1552         int ret, i;
1553         struct kprobe_trace_entry_head field;
1554         struct trace_probe *tp = (struct trace_probe *)event_call->data;
1555
1556         DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1557         /* Set argument names as fields */
1558         for (i = 0; i < tp->nr_args; i++) {
1559                 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1560                                          tp->args[i].name,
1561                                          sizeof(field) + tp->args[i].offset,
1562                                          tp->args[i].type->size,
1563                                          tp->args[i].type->is_signed,
1564                                          FILTER_OTHER);
1565                 if (ret)
1566                         return ret;
1567         }
1568         return 0;
1569 }
1570
1571 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1572 {
1573         int ret, i;
1574         struct kretprobe_trace_entry_head field;
1575         struct trace_probe *tp = (struct trace_probe *)event_call->data;
1576
1577         DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1578         DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1579         /* Set argument names as fields */
1580         for (i = 0; i < tp->nr_args; i++) {
1581                 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1582                                          tp->args[i].name,
1583                                          sizeof(field) + tp->args[i].offset,
1584                                          tp->args[i].type->size,
1585                                          tp->args[i].type->is_signed,
1586                                          FILTER_OTHER);
1587                 if (ret)
1588                         return ret;
1589         }
1590         return 0;
1591 }
1592
1593 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1594 {
1595         int i;
1596         int pos = 0;
1597
1598         const char *fmt, *arg;
1599
1600         if (!probe_is_return(tp)) {
1601                 fmt = "(%lx)";
1602                 arg = "REC->" FIELD_STRING_IP;
1603         } else {
1604                 fmt = "(%lx <- %lx)";
1605                 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1606         }
1607
1608         /* When len=0, we just calculate the needed length */
1609 #define LEN_OR_ZERO (len ? len - pos : 0)
1610
1611         pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1612
1613         for (i = 0; i < tp->nr_args; i++) {
1614                 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
1615                                 tp->args[i].name, tp->args[i].type->fmt);
1616         }
1617
1618         pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1619
1620         for (i = 0; i < tp->nr_args; i++) {
1621                 if (strcmp(tp->args[i].type->name, "string") == 0)
1622                         pos += snprintf(buf + pos, LEN_OR_ZERO,
1623                                         ", __get_str(%s)",
1624                                         tp->args[i].name);
1625                 else
1626                         pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1627                                         tp->args[i].name);
1628         }
1629
1630 #undef LEN_OR_ZERO
1631
1632         /* return the length of print_fmt */
1633         return pos;
1634 }
1635
1636 static int set_print_fmt(struct trace_probe *tp)
1637 {
1638         int len;
1639         char *print_fmt;
1640
1641         /* First: called with 0 length to calculate the needed length */
1642         len = __set_print_fmt(tp, NULL, 0);
1643         print_fmt = kmalloc(len + 1, GFP_KERNEL);
1644         if (!print_fmt)
1645                 return -ENOMEM;
1646
1647         /* Second: actually write the @print_fmt */
1648         __set_print_fmt(tp, print_fmt, len + 1);
1649         tp->call.print_fmt = print_fmt;
1650
1651         return 0;
1652 }
1653
1654 #ifdef CONFIG_PERF_EVENTS
1655
1656 /* Kprobe profile handler */
1657 static __kprobes void kprobe_perf_func(struct kprobe *kp,
1658                                          struct pt_regs *regs)
1659 {
1660         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1661         struct ftrace_event_call *call = &tp->call;
1662         struct kprobe_trace_entry_head *entry;
1663         struct hlist_head *head;
1664         int size, __size, dsize;
1665         int rctx;
1666
1667         dsize = __get_data_size(tp, regs);
1668         __size = sizeof(*entry) + tp->size + dsize;
1669         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1670         size -= sizeof(u32);
1671         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1672                      "profile buffer not large enough"))
1673                 return;
1674
1675         entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1676         if (!entry)
1677                 return;
1678
1679         entry->ip = (unsigned long)kp->addr;
1680         memset(&entry[1], 0, dsize);
1681         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1682
1683         head = this_cpu_ptr(call->perf_events);
1684         perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
1685 }
1686
1687 /* Kretprobe profile handler */
1688 static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
1689                                             struct pt_regs *regs)
1690 {
1691         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1692         struct ftrace_event_call *call = &tp->call;
1693         struct kretprobe_trace_entry_head *entry;
1694         struct hlist_head *head;
1695         int size, __size, dsize;
1696         int rctx;
1697
1698         dsize = __get_data_size(tp, regs);
1699         __size = sizeof(*entry) + tp->size + dsize;
1700         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1701         size -= sizeof(u32);
1702         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1703                      "profile buffer not large enough"))
1704                 return;
1705
1706         entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1707         if (!entry)
1708                 return;
1709
1710         entry->func = (unsigned long)tp->rp.kp.addr;
1711         entry->ret_ip = (unsigned long)ri->ret_addr;
1712         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1713
1714         head = this_cpu_ptr(call->perf_events);
1715         perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
1716 }
1717
1718 static int probe_perf_enable(struct ftrace_event_call *call)
1719 {
1720         struct trace_probe *tp = (struct trace_probe *)call->data;
1721
1722         tp->flags |= TP_FLAG_PROFILE;
1723
1724         if (probe_is_return(tp))
1725                 return enable_kretprobe(&tp->rp);
1726         else
1727                 return enable_kprobe(&tp->rp.kp);
1728 }
1729
1730 static void probe_perf_disable(struct ftrace_event_call *call)
1731 {
1732         struct trace_probe *tp = (struct trace_probe *)call->data;
1733
1734         tp->flags &= ~TP_FLAG_PROFILE;
1735
1736         if (!(tp->flags & TP_FLAG_TRACE)) {
1737                 if (probe_is_return(tp))
1738                         disable_kretprobe(&tp->rp);
1739                 else
1740                         disable_kprobe(&tp->rp.kp);
1741         }
1742 }
1743 #endif  /* CONFIG_PERF_EVENTS */
1744
1745 static __kprobes
1746 int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)
1747 {
1748         switch (type) {
1749         case TRACE_REG_REGISTER:
1750                 return probe_event_enable(event);
1751         case TRACE_REG_UNREGISTER:
1752                 probe_event_disable(event);
1753                 return 0;
1754
1755 #ifdef CONFIG_PERF_EVENTS
1756         case TRACE_REG_PERF_REGISTER:
1757                 return probe_perf_enable(event);
1758         case TRACE_REG_PERF_UNREGISTER:
1759                 probe_perf_disable(event);
1760                 return 0;
1761 #endif
1762         }
1763         return 0;
1764 }
1765
1766 static __kprobes
1767 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1768 {
1769         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1770
1771         if (tp->flags & TP_FLAG_TRACE)
1772                 kprobe_trace_func(kp, regs);
1773 #ifdef CONFIG_PERF_EVENTS
1774         if (tp->flags & TP_FLAG_PROFILE)
1775                 kprobe_perf_func(kp, regs);
1776 #endif
1777         return 0;       /* We don't tweek kernel, so just return 0 */
1778 }
1779
1780 static __kprobes
1781 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1782 {
1783         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1784
1785         if (tp->flags & TP_FLAG_TRACE)
1786                 kretprobe_trace_func(ri, regs);
1787 #ifdef CONFIG_PERF_EVENTS
1788         if (tp->flags & TP_FLAG_PROFILE)
1789                 kretprobe_perf_func(ri, regs);
1790 #endif
1791         return 0;       /* We don't tweek kernel, so just return 0 */
1792 }
1793
1794 static struct trace_event_functions kretprobe_funcs = {
1795         .trace          = print_kretprobe_event
1796 };
1797
1798 static struct trace_event_functions kprobe_funcs = {
1799         .trace          = print_kprobe_event
1800 };
1801
1802 static int register_probe_event(struct trace_probe *tp)
1803 {
1804         struct ftrace_event_call *call = &tp->call;
1805         int ret;
1806
1807         /* Initialize ftrace_event_call */
1808         INIT_LIST_HEAD(&call->class->fields);
1809         if (probe_is_return(tp)) {
1810                 call->event.funcs = &kretprobe_funcs;
1811                 call->class->define_fields = kretprobe_event_define_fields;
1812         } else {
1813                 call->event.funcs = &kprobe_funcs;
1814                 call->class->define_fields = kprobe_event_define_fields;
1815         }
1816         if (set_print_fmt(tp) < 0)
1817                 return -ENOMEM;
1818         ret = register_ftrace_event(&call->event);
1819         if (!ret) {
1820                 kfree(call->print_fmt);
1821                 return -ENODEV;
1822         }
1823         call->flags = 0;
1824         call->class->reg = kprobe_register;
1825         call->data = tp;
1826         ret = trace_add_event_call(call);
1827         if (ret) {
1828                 pr_info("Failed to register kprobe event: %s\n", call->name);
1829                 kfree(call->print_fmt);
1830                 unregister_ftrace_event(&call->event);
1831         }
1832         return ret;
1833 }
1834
1835 static void unregister_probe_event(struct trace_probe *tp)
1836 {
1837         /* tp->event is unregistered in trace_remove_event_call() */
1838         trace_remove_event_call(&tp->call);
1839         kfree(tp->call.print_fmt);
1840 }
1841
1842 /* Make a debugfs interface for controling probe points */
1843 static __init int init_kprobe_trace(void)
1844 {
1845         struct dentry *d_tracer;
1846         struct dentry *entry;
1847
1848         d_tracer = tracing_init_dentry();
1849         if (!d_tracer)
1850                 return 0;
1851
1852         entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1853                                     NULL, &kprobe_events_ops);
1854
1855         /* Event list interface */
1856         if (!entry)
1857                 pr_warning("Could not create debugfs "
1858                            "'kprobe_events' entry\n");
1859
1860         /* Profile interface */
1861         entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1862                                     NULL, &kprobe_profile_ops);
1863
1864         if (!entry)
1865                 pr_warning("Could not create debugfs "
1866                            "'kprobe_profile' entry\n");
1867         return 0;
1868 }
1869 fs_initcall(init_kprobe_trace);
1870
1871
1872 #ifdef CONFIG_FTRACE_STARTUP_TEST
1873
1874 static int kprobe_trace_selftest_target(int a1, int a2, int a3,
1875                                         int a4, int a5, int a6)
1876 {
1877         return a1 + a2 + a3 + a4 + a5 + a6;
1878 }
1879
1880 static __init int kprobe_trace_self_tests_init(void)
1881 {
1882         int ret, warn = 0;
1883         int (*target)(int, int, int, int, int, int);
1884         struct trace_probe *tp;
1885
1886         target = kprobe_trace_selftest_target;
1887
1888         pr_info("Testing kprobe tracing: ");
1889
1890         ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
1891                                   "$stack $stack0 +0($stack)");
1892         if (WARN_ON_ONCE(ret)) {
1893                 pr_warning("error on probing function entry.\n");
1894                 warn++;
1895         } else {
1896                 /* Enable trace point */
1897                 tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM);
1898                 if (WARN_ON_ONCE(tp == NULL)) {
1899                         pr_warning("error on getting new probe.\n");
1900                         warn++;
1901                 } else
1902                         probe_event_enable(&tp->call);
1903         }
1904
1905         ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
1906                                   "$retval");
1907         if (WARN_ON_ONCE(ret)) {
1908                 pr_warning("error on probing function return.\n");
1909                 warn++;
1910         } else {
1911                 /* Enable trace point */
1912                 tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM);
1913                 if (WARN_ON_ONCE(tp == NULL)) {
1914                         pr_warning("error on getting new probe.\n");
1915                         warn++;
1916                 } else
1917                         probe_event_enable(&tp->call);
1918         }
1919
1920         if (warn)
1921                 goto end;
1922
1923         ret = target(1, 2, 3, 4, 5, 6);
1924
1925         ret = command_trace_probe("-:testprobe");
1926         if (WARN_ON_ONCE(ret)) {
1927                 pr_warning("error on deleting a probe.\n");
1928                 warn++;
1929         }
1930
1931         ret = command_trace_probe("-:testprobe2");
1932         if (WARN_ON_ONCE(ret)) {
1933                 pr_warning("error on deleting a probe.\n");
1934                 warn++;
1935         }
1936
1937 end:
1938         cleanup_all_probes();
1939         if (warn)
1940                 pr_cont("NG: Some tests are failed. Please check them.\n");
1941         else
1942                 pr_cont("OK\n");
1943         return 0;
1944 }
1945
1946 late_initcall(kprobe_trace_self_tests_init);
1947
1948 #endif