trace_probe.h

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/*
 * Common header file for probe-based Dynamic events.
 *
 * 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
 *
 * This code was copied from kernel/trace/trace_kprobe.h written by
 * Masami Hiramatsu <[email protected]>
 *
 * Updates to make this generic:
 * Copyright (C) IBM Corporation, 2010-2011
 * Author:     Srikar Dronamraju
 */

#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/debugfs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/ptrace.h>
#include <linux/perf_event.h>
#include <linux/kprobes.h>
#include <linux/stringify.h>
#include <linux/limits.h>
#include <linux/uaccess.h>
#include <asm/bitsperlong.h>

#include "trace.h"
#include "trace_output.h"

#define MAX_TRACE_ARGS      128
#define MAX_ARGSTR_LEN      63
#define MAX_EVENT_NAME_LEN  64
#define MAX_STRING_SIZE     PATH_MAX

/* Reserved field names */
#define FIELD_STRING_IP     "__probe_ip"
#define FIELD_STRING_RETIP  "__probe_ret_ip"
#define FIELD_STRING_FUNC   "__probe_func"

#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)


/* Flags for trace_probe */
#define TP_FLAG_TRACE       1
#define TP_FLAG_PROFILE     2
#define TP_FLAG_REGISTERED  4
#define TP_FLAG_UPROBE      8


/* data_rloc: data relative location, compatible with u32 */
#define make_data_rloc(len, roffs)  \
    (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
#define get_rloc_len(dl)        ((u32)(dl) >> 16)
#define get_rloc_offs(dl)       ((u32)(dl) & 0xffff)

/*
 * Convert data_rloc to data_loc:
 *  data_rloc stores the offset from data_rloc itself, but data_loc
 *  stores the offset from event entry.
 */
#define convert_rloc_to_loc(dl, offs)   ((u32)(dl) + (offs))

/* Data fetch function type */
typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
/* Printing function type */
typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);

/* Fetch types */
enum {
    FETCH_MTD_reg = 0,
    FETCH_MTD_stack,
    FETCH_MTD_retval,
    FETCH_MTD_memory,
    FETCH_MTD_symbol,
    FETCH_MTD_deref,
    FETCH_MTD_bitfield,
    FETCH_MTD_END,
};

/* Fetch type information table */
struct fetch_type {
    const char      *name;      /* Name of type */
    size_t          size;       /* Byte size of type */
    int         is_signed;  /* Signed flag */
    print_type_func_t   print;      /* Print functions */
    const char      *fmt;       /* Fromat string */
    const char      *fmttype;   /* Name in format file */
    /* Fetch functions */
    fetch_func_t        fetch[FETCH_MTD_END];
};

struct fetch_param {
    fetch_func_t        fn;
    void            *data;
};

struct probe_arg {
    struct fetch_param  fetch;
    struct fetch_param  fetch_size;
    unsigned int        offset; /* Offset from argument entry */
    const char      *name;  /* Name of this argument */
    const char      *comm;  /* Command of this argument */
    const struct fetch_type *type;  /* Type of this argument */
};

static inline __kprobes void call_fetch(struct fetch_param *fprm,
                 struct pt_regs *regs, void *dest)
{
    return fprm->fn(regs, fprm->data, dest);
}

/* Check the name is good for event/group/fields */
static inline int is_good_name(const char *name)
{
    if (!isalpha(*name) && *name != '_')
        return 0;
    while (*++name != '\0') {
        if (!isalpha(*name) && !isdigit(*name) && *name != '_')
            return 0;
    }
    return 1;
}

extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
           struct probe_arg *parg, bool is_return, bool is_kprobe);

extern int traceprobe_conflict_field_name(const char *name,
                   struct probe_arg *args, int narg);

extern void traceprobe_update_arg(struct probe_arg *arg);
extern void traceprobe_free_probe_arg(struct probe_arg *arg);

extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);

extern ssize_t traceprobe_probes_write(struct file *file,
        const char __user *buffer, size_t count, loff_t *ppos,
        int (*createfn)(int, char**));

extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));