strings: fix crash bug parsing foo = bar ?: baz

[smatch.git] / check_kernel_printf.c

/*
 * Copyright (C) 2015 Rasmus Villemoes.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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, see http://www.gnu.org/copyleft/gpl.txt
 */

#define _GNU_SOURCE

#include <assert.h>
#include <ctype.h>
#include <string.h>
#include "smatch.h"
#include "smatch_slist.h"

#define spam(args...) do {                      \
        if (option_spammy)                      \
                sm_msg(args);                   \
        } while (0)

static int my_id;

/*
 * Much of this is taken directly from the kernel (mostly vsprintf.c),
 * with a few modifications here and there.
 */

#define KERN_SOH_ASCII  '\001'

typedef unsigned char u8;
typedef signed short s16;

#define SIGN    1               /* unsigned/signed, must be 1 */
#define LEFT    2               /* left justified */
#define PLUS    4               /* show plus */
#define SPACE   8               /* space if plus */
#define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */

enum format_type {
        FORMAT_TYPE_NONE, /* Just a string part */
        FORMAT_TYPE_WIDTH,
        FORMAT_TYPE_PRECISION,
        FORMAT_TYPE_CHAR,
        FORMAT_TYPE_STR,
        FORMAT_TYPE_PTR,
        FORMAT_TYPE_PERCENT_CHAR,
        FORMAT_TYPE_INVALID,
        FORMAT_TYPE_LONG_LONG,
        FORMAT_TYPE_ULONG,
        FORMAT_TYPE_LONG,
        FORMAT_TYPE_UBYTE,
        FORMAT_TYPE_BYTE,
        FORMAT_TYPE_USHORT,
        FORMAT_TYPE_SHORT,
        FORMAT_TYPE_UINT,
        FORMAT_TYPE_INT,
        FORMAT_TYPE_SIZE_T,
        FORMAT_TYPE_PTRDIFF,
        FORMAT_TYPE_NRCHARS, /* Reintroduced for this checker */
        FORMAT_TYPE_FLOAT, /* for various floating point formatters */
};

struct printf_spec {
        unsigned int    type:8;         /* format_type enum */
        signed int      field_width:24; /* width of output field */
        unsigned int    flags:8;        /* flags to number() */
        unsigned int    base:8;         /* number base, 8, 10 or 16 only */
        signed int      precision:16;   /* # of digits/chars */
} __packed;
#define FIELD_WIDTH_MAX ((1 << 23) - 1)
#define PRECISION_MAX ((1 << 15) - 1)
extern char __check_printf_spec[1-2*(sizeof(struct printf_spec) != 8)];

static int
skip_atoi(const char **s)
{
        int i = 0;

        while (isdigit(**s))
                i = i*10 + *((*s)++) - '0';

        return i;
}

static int
format_decode(const char *fmt, struct printf_spec *spec)
{
        const char *start = fmt;
        char qualifier;

        /* we finished early by reading the field width */
        if (spec->type == FORMAT_TYPE_WIDTH) {
                if (spec->field_width < 0) {
                        spec->field_width = -spec->field_width;
                        spec->flags |= LEFT;
                }
                spec->type = FORMAT_TYPE_NONE;
                goto precision;
        }

        /* we finished early by reading the precision */
        if (spec->type == FORMAT_TYPE_PRECISION) {
                if (spec->precision < 0)
                        spec->precision = 0;

                spec->type = FORMAT_TYPE_NONE;
                goto qualifier;
        }

        /* By default */
        spec->type = FORMAT_TYPE_NONE;

        for (; *fmt ; ++fmt) {
                if (*fmt == '%')
                        break;
        }

        /* Return the current non-format string */
        if (fmt != start || !*fmt)
                return fmt - start;

        /* Process flags */
        spec->flags = 0;

        while (1) { /* this also skips first '%' */
                bool found = true;

                ++fmt;

                switch (*fmt) {
                case '-': spec->flags |= LEFT;    break;
                case '+': spec->flags |= PLUS;    break;
                case ' ': spec->flags |= SPACE;   break;
                case '#': spec->flags |= SPECIAL; break;
                case '0': spec->flags |= ZEROPAD; break;
                default:  found = false;
                }

                if (!found)
                        break;
        }

        /* get field width */
        spec->field_width = -1;

        if (isdigit(*fmt))
                spec->field_width = skip_atoi(&fmt);
        else if (*fmt == '*') {
                /* it's the next argument */
                spec->type = FORMAT_TYPE_WIDTH;
                return ++fmt - start;
        }

precision:
        /* get the precision */
        spec->precision = -1;
        if (*fmt == '.') {
                ++fmt;
                if (isdigit(*fmt)) {
                        spec->precision = skip_atoi(&fmt);
                        if (spec->precision < 0)
                                spec->precision = 0;
                } else if (*fmt == '*') {
                        /* it's the next argument */
                        spec->type = FORMAT_TYPE_PRECISION;
                        return ++fmt - start;
                }
        }

qualifier:
        /* get the conversion qualifier */
        qualifier = 0;
        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
            _tolower(*fmt) == 'z' || *fmt == 't') {
                qualifier = *fmt++;
                if (qualifier == *fmt) {
                        if (qualifier == 'l') {
                                qualifier = 'L';
                                ++fmt;
                        } else if (qualifier == 'h') {
                                qualifier = 'H';
                                ++fmt;
                        } else {
                                sm_warning("invalid repeated qualifier '%c'", *fmt);
                        }
                }
        }

        /* default base */
        spec->base = 10;
        switch (*fmt) {
        case 'c':
                if (qualifier)
                        sm_warning("qualifier '%c' ignored for %%c specifier", qualifier);

                spec->type = FORMAT_TYPE_CHAR;
                return ++fmt - start;

        case 's':
                if (qualifier && qualifier != 'l')
                        sm_warning("qualifier '%c' ignored for %%s specifier", qualifier);

                spec->type = FORMAT_TYPE_STR;
                return ++fmt - start;

        case 'p':
                spec->type = FORMAT_TYPE_PTR;
                return ++fmt - start;

        case '%':
                spec->type = FORMAT_TYPE_PERCENT_CHAR;
                return ++fmt - start;

        /* integer number formats - set up the flags and "break" */
        case 'o':
                spec->base = 8;
                break;

        case 'x':
                spec->flags |= SMALL;

        case 'X':
                spec->base = 16;
                break;

        case 'd':
        case 'i':
                spec->flags |= SIGN;
        case 'u':
                break;

        case 'n':
                spec->type = FORMAT_TYPE_NRCHARS;
                return ++fmt - start;

        case 'a': case 'A':
        case 'e': case 'E':
        case 'f': case 'F':
        case 'g': case 'G':
                spec->type = FORMAT_TYPE_FLOAT;
                return ++fmt - start;

        default:
                spec->type = FORMAT_TYPE_INVALID;
                /* Unlike the kernel code, we 'consume' the invalid
                 * character so that it can get included in the
                 * report. After that, we bail out. */
                return ++fmt - start;
        }

        if (qualifier == 'L')
                spec->type = FORMAT_TYPE_LONG_LONG;
        else if (qualifier == 'l') {
                if (spec->flags & SIGN)
                        spec->type = FORMAT_TYPE_LONG;
                else
                        spec->type = FORMAT_TYPE_ULONG;
        } else if (_tolower(qualifier) == 'z') {
                spec->type = FORMAT_TYPE_SIZE_T;
        } else if (qualifier == 't') {
                spec->type = FORMAT_TYPE_PTRDIFF;
        } else if (qualifier == 'H') {
                if (spec->flags & SIGN)
                        spec->type = FORMAT_TYPE_BYTE;
                else
                        spec->type = FORMAT_TYPE_UBYTE;
        } else if (qualifier == 'h') {
                if (spec->flags & SIGN)
                        spec->type = FORMAT_TYPE_SHORT;
                else
                        spec->type = FORMAT_TYPE_USHORT;
        } else {
                if (spec->flags & SIGN)
                        spec->type = FORMAT_TYPE_INT;
                else
                        spec->type = FORMAT_TYPE_UINT;
        }

        return ++fmt - start;
}

static int is_struct_tag(struct symbol *type, const char *tag)
{
        return type->type == SYM_STRUCT && type->ident && !strcmp(type->ident->name, tag);
}

static int has_struct_tag(struct symbol *type, const char *tag)
{
        struct symbol *tmp;

        if (type->type == SYM_STRUCT)
                return is_struct_tag(type, tag);
        if (type->type == SYM_UNION) {
                FOR_EACH_PTR(type->symbol_list, tmp) {
                        tmp = get_real_base_type(tmp);
                        if (tmp && is_struct_tag(tmp, tag))
                                return 1;
                } END_FOR_EACH_PTR(tmp);
        }
        return 0;
}

static int is_char_type(struct symbol *type)
{
        return type == &uchar_ctype || type == &char_ctype || type == &schar_ctype;
}

/*
 * I have absolutely no idea if this is how one is supposed to get the
 * symbol representing a typedef, but it seems to work.
 */
struct typedef_lookup {
        const char *name;
        struct symbol *sym;
        int failed;
};

static struct symbol *_typedef_lookup(const char *name)
{
        struct ident *id;
        struct symbol *node;

        id = built_in_ident(name);
        if (!id)
                return NULL;
        node = lookup_symbol(id, NS_TYPEDEF);
        if (!node || node->type != SYM_NODE)
                return NULL;
        return get_real_base_type(node);
}

static void typedef_lookup(struct typedef_lookup *tl)
{
        if (tl->sym || tl->failed)
                return;
        tl->sym = _typedef_lookup(tl->name);
        if (!tl->sym) {
                sm_perror(" could not find typedef '%s'", tl->name);
                tl->failed = 1;
        }
}


static void ip4(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        enum { ENDIAN_BIG, ENDIAN_LITTLE, ENDIAN_HOST } endian = ENDIAN_BIG;

        assert(fmt[0] == 'i' || fmt[0] == 'I');
        assert(fmt[1] == '4');

        if (isalnum(fmt[2])) {
                switch (fmt[2]) {
                case 'h':
                        endian = ENDIAN_HOST;
                        break;
                case 'l':
                        endian = ENDIAN_LITTLE;
                        break;
                case 'n':
                case 'b':
                        endian = ENDIAN_BIG;
                        break;
                default:
                        sm_warning("'%%p%c4' can only be followed by one of [hnbl], not '%c'", fmt[0], fmt[2]);
                }
                if (isalnum(fmt[3]))
                        sm_warning("'%%p%c4' can only be followed by precisely one of [hnbl]", fmt[0]);
        }


        if (type->ctype.modifiers & MOD_NODEREF)
                sm_error("passing __user pointer to '%%p%c4'", fmt[0]);

        /*
         * If we have a pointer to char/u8/s8, we expect the caller to
         * handle endianness; I don't think there's anything we can
         * do. I'd like to check that if we're passed a pointer to a
         * __bitwise u32 (most likely a __be32), we should have endian
         * == ENDIAN_BIG. But I can't figure out how to get that
         * information (it also seems to require ensuring certain
         * macros are defined). But struct in_addr certainly consists
         * of only a single __be32, so in that case we can do a check.
         */
        if (is_char_type(basetype))
                return;

        if (is_struct_tag(basetype, "in_addr") && endian != ENDIAN_BIG)
                sm_warning("passing struct in_addr* to '%%p%c4%c', is the endianness ok?", fmt[0], fmt[2]);

        /* ... */
}

static void ip6(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(fmt[0] == 'i' || fmt[0] == 'I');
        assert(fmt[1] == '6');

        if (isalnum(fmt[2])) {
                if (fmt[2] != 'c')
                        sm_warning("'%%p%c6' can only be followed by c", fmt[0]);
                else if (fmt[0] == 'i')
                        sm_warning("'%%pi6' does not allow flag c");
                if (isalnum(fmt[3]))
                        sm_warning("'%%p%c6%c' cannot be followed by other alphanumerics", fmt[0], fmt[2]);
        }

        if (type->ctype.modifiers & MOD_NODEREF)
                sm_error("passing __user pointer to '%%p%c6'", fmt[0]);
}

static void ipS(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        const char *f;

        assert(tolower(fmt[0]) == 'i');
        assert(fmt[1] == 'S');

        for (f = fmt+2; isalnum(*f); ++f) {
                /* It's probably too anal checking for duplicate flags. */
                if (!strchr("pfschnbl", *f))
                        sm_warning("'%%p%cS' cannot be followed by '%c'", fmt[0], *f);
        }

        /*
         * XXX: Should we also allow passing a pointer to a union, one
         * member of which is a struct sockaddr? It may be slightly
         * cleaner actually passing &u.raw instead of just &u, though
         * the generated code is of course exactly the same. For now,
         * we do accept struct sockaddr_in and struct sockaddr_in6,
         * since those are easy to handle and rather harmless.
         */
        if (!has_struct_tag(basetype, "sockaddr") &&
            !has_struct_tag(basetype, "sockaddr_in") &&
            !has_struct_tag(basetype, "sockaddr_in6") &&
            !has_struct_tag(basetype, "__kernel_sockaddr_storage"))
                sm_error("'%%p%cS' expects argument of type struct sockaddr *, "
                        "argument %d has type '%s'", fmt[0], vaidx, type_to_str(type));
}

static void hex_string(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(fmt[0] == 'h');
        if (isalnum(fmt[1])) {
                if (!strchr("CDN", fmt[1]))
                        sm_warning("'%%ph' cannot be followed by '%c'", fmt[1]);
                if (isalnum(fmt[2]))
                        sm_warning("'%%ph' can be followed by at most one of [CDN], and no other alphanumerics");
        }
        if (type->ctype.modifiers & MOD_NODEREF)
                sm_error("passing __user pointer to %%ph");
}

static void escaped_string(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(fmt[0] == 'E');
        while (isalnum(*++fmt)) {
                if (!strchr("achnops", *fmt))
                        sm_warning("%%pE can only be followed by a combination of [achnops]");
        }
        if (type->ctype.modifiers & MOD_NODEREF)
                sm_error("passing __user pointer to %%pE");
}

static void resource_string(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(tolower(fmt[0]) == 'r');
        if (!is_struct_tag(basetype, "resource")) {
                sm_error("'%%p%c' expects argument of type struct resource *, "
                        "but argument %d has type '%s'", fmt[0], vaidx, type_to_str(type));
        }
        if (isalnum(fmt[1]))
                sm_warning("'%%p%c' cannot be followed by '%c'", fmt[0], fmt[1]);
}

static void mac_address_string(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(tolower(fmt[0]) == 'm');
        if (isalnum(fmt[1])) {
                if (!(fmt[1] == 'F' || fmt[1] == 'R'))
                        sm_warning("'%%p%c' cannot be followed by '%c'", fmt[0], fmt[1]);
                if (fmt[0] == 'm' && fmt[1] == 'F')
                        sm_warning("it is pointless to pass flag F to %%pm");
                if (isalnum(fmt[2]))
                        sm_warning("'%%p%c%c' cannot be followed by other alphanumeric", fmt[0], fmt[1]);
        }
        /* Technically, bdaddr_t is a typedef for an anonymous struct, but this still seems to work. */
        if (!is_char_type(basetype) && !is_struct_tag(basetype, "bdaddr_t") && basetype != &void_ctype) {
                sm_warning("'%%p%c' expects argument of type u8 * or bdaddr_t *, argument %d has type '%s'",
                        fmt[0], vaidx, type_to_str(type));
        }
        if (type->ctype.modifiers & MOD_NODEREF)
                sm_error("passing __user pointer to '%%p%c'", fmt[0]);
}

static void dentry_file(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        const char *tag;

        assert(tolower(fmt[0]) == 'd');
        tag = fmt[0] == 'd' ? "dentry" : "file";

        if (isalnum(fmt[1])) {
                if (!strchr("234", fmt[1]))
                        sm_warning("'%%p%c' can only be followed by one of [234]", fmt[0]);
                if (isalnum(fmt[2]))
                        sm_warning("'%%p%c%c' cannot be followed by '%c'", fmt[0], fmt[1], fmt[2]);
        }

        if (!is_struct_tag(basetype, tag))
                sm_error("'%%p%c' expects argument of type struct '%s*', argument %d has type '%s'",
                        fmt[0], tag, vaidx, type_to_str(type));
}

static void time_and_date(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(tolower(fmt[0]) == 't');

        if (fmt[1] == 'R' && !is_struct_tag(basetype, "rtc_time"))
                sm_error("'%%ptR' expects argument of type struct 'rtc_time', argument %d has type '%s'",
                         vaidx, type_to_str(type));
}

static void check_clock(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(fmt[0] == 'C');
        if (isalnum(fmt[1])) {
                if (!strchr("nr", fmt[1]))
                        sm_warning("'%%pC' can only be followed by one of [nr]");
                if (isalnum(fmt[2]))
                        sm_warning("'%%pC%c' cannot be followed by '%c'", fmt[1], fmt[2]);
        }
        if (!is_struct_tag(basetype, "clk"))
                sm_error("'%%pC' expects argument of type 'struct clk*', argument %d has type '%s'",
                       vaidx, type_to_str(type));
}

static void va_format(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        assert(fmt[0] == 'V');
        if (isalnum(fmt[1]))
                sm_warning("%%pV cannot be followed by any alphanumerics");
        if (!is_struct_tag(basetype, "va_format"))
                sm_error("%%pV expects argument of type struct va_format*, argument %d has type '%s'", vaidx, type_to_str(type));
}

static void netdev_feature(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        static struct typedef_lookup netdev = { .name = "netdev_features_t" };

        assert(fmt[0] == 'N');
        if (fmt[1] != 'F') {
                sm_error("%%pN must be followed by 'F'");
                return;
        }
        if (isalnum(fmt[2]))
                sm_warning("%%pNF cannot be followed by '%c'", fmt[2]);

        typedef_lookup(&netdev);
        if (!netdev.sym)
                return;
        if (basetype != netdev.sym)
                sm_error("%%pNF expects argument of type netdev_features_t*, argument %d has type '%s'",
                        vaidx, type_to_str(type));

}
static void address_val(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        static struct typedef_lookup dma = { .name = "dma_addr_t" };
        static struct typedef_lookup phys = { .name = "phys_addr_t" };
        struct typedef_lookup *which = &phys;
        const char *suf = "";
        assert(fmt[0] == 'a');

        if (isalnum(fmt[1])) {
                switch (fmt[1]) {
                case 'd':
                        which = &dma;
                        suf = "d";
                        break;
                case 'p':
                        suf = "p";
                        break;
                default:
                        sm_error("'%%pa' can only be followed by one of [dp]");
                }
                if (isalnum(fmt[2]))
                        sm_error("'%%pa%c' cannot be followed by '%c'", fmt[1], fmt[2]);
        }

        typedef_lookup(which);
        if (!which->sym)
                return;
        if (basetype != which->sym) {
                sm_error("'%%pa%s' expects argument of type '%s*', argument %d has type '%s'",
                        suf, which->name, vaidx, type_to_str(type));
        }
}

static void block_device(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        const char *tag = "block_device";

        assert(fmt[0] == 'g');
        if (isalnum(fmt[1])) {
                sm_warning("%%pg cannot be followed by '%c'", fmt[1]);
        }
        if (!is_struct_tag(basetype, tag))
                sm_error("'%%p%c' expects argument of type struct '%s*', argument %d has type '%s'",
                        fmt[0], tag, vaidx, type_to_str(type));
}

static void flag_string(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        static struct typedef_lookup gfp = { .name = "gfp_t" };

        assert(fmt[0] == 'G');
        if (!isalnum(fmt[1])) {
                sm_error("%%pG must be followed by one of [gpv]");
                return;
        }
        switch (fmt[1]) {
        case 'p':
        case 'v':
                if (basetype != &ulong_ctype)
                        sm_error("'%%pG%c' expects argument of type 'unsigned long *', argument %d has type '%s'",
                                fmt[1], vaidx, type_to_str(type));
                break;
        case 'g':
                typedef_lookup(&gfp);
                if (basetype != gfp.sym)
                        sm_error("'%%pGg' expects argument of type 'gfp_t *', argument %d has type '%s'",
                                vaidx, type_to_str(type));
                break;
        default:
                sm_error("'%%pG' must be followed by one of [gpv]");
        }
}

static void device_node_string(const char *fmt, struct symbol *type, struct symbol *basetype, int vaidx)
{
        if (fmt[1] != 'F') {
                sm_error("%%pO can only be followed by 'F'");
                return;
        }
        if (!is_struct_tag(basetype, "device_node"))
                sm_error("'%%pOF' expects argument of type 'struct device_node*', argument %d has type '%s'",
                       vaidx, type_to_str(type));
}

static void
pointer(const char *fmt, struct expression *arg, int vaidx)
{
        struct symbol *type, *basetype;

        type = get_type(arg);
        if (!type) {
                sm_warning("could not determine type of argument %d", vaidx);
                return;
        }
        if (!is_ptr_type(type)) {
                sm_error("%%p expects pointer argument, but argument %d has type '%s'",
                        vaidx, type_to_str(type));
                return;
        }

        /* error pointers */
        if (*fmt == 'e')
                fmt++;


        /* Just plain %p, nothing to check. */
        if (!isalnum(*fmt))
                return;

        basetype = get_real_base_type(type);
        if (is_void_type(basetype))
                return;
        /*
         * Passing a pointer-to-array is harmless, but most likely one
         * meant to pass pointer-to-first-element. If basetype is
         * array type, we issue a notice and "dereference" the types
         * once more.
         */
        if (basetype->type == SYM_ARRAY) {
                spam("note: passing pointer-to-array; is the address-of redundant?");
                type = basetype;
                basetype = get_real_base_type(type);
        }

        /*
         * We pass both the type and the basetype to the helpers. If,
         * for example, the pointer is really a decayed array which is
         * passed to %pI4, we might want to check that it is in fact
         * an array of four bytes. But most are probably only
         * interested in whether the basetype makes sense. Also, the
         * pointer may carry some annotation such as __user which
         * might be worth checking in the handlers which actually
         * dereference the pointer.
         */

        switch (*fmt) {
        case 'b':
        case 'F':
        case 'f':
        case 'S':
        case 's':
        case 'B':
                /* Can we do anything sensible? Check that the arg is a function pointer, for example? */
                break;

        case 'R':
        case 'r':
                resource_string(fmt, type, basetype, vaidx);
                break;
        case 'M':
        case 'm':
                mac_address_string(fmt, type, basetype, vaidx);
                break;
        case 'I':
        case 'i':
                switch (fmt[1]) {
                case '4':
                        ip4(fmt, type, basetype, vaidx);
                        break;
                case '6':
                        ip6(fmt, type, basetype, vaidx);
                        break;
                case 'S':
                        ipS(fmt, type, basetype, vaidx);
                        break;
                default:
                        sm_warning("'%%p%c' must be followed by one of [46S]", fmt[0]);
                        break;
                }
                break;
       /*
        * %pE and %ph can handle any valid pointer. We still check
        * whether all the subsequent alphanumerics are valid for the
        * particular %pX conversion.
        */
        case 'E':
                escaped_string(fmt, type, basetype, vaidx);
                break;
        case 'h':
                hex_string(fmt, type, basetype, vaidx);
                break;
        case 'U': /* TODO */
                break;
        case 'V':
                va_format(fmt, type, basetype, vaidx);
                break;
        case 'K': /* TODO */
                break;
        case 'N':
                netdev_feature(fmt, type, basetype, vaidx);
                break;
        case 'a':
                address_val(fmt, type, basetype, vaidx);
                break;
        case 'D':
        case 'd':
                dentry_file(fmt, type, basetype, vaidx);
                break;
        case 't':
                time_and_date(fmt, type, basetype, vaidx);
                break;
        case 'C':
                check_clock(fmt, type, basetype, vaidx);
                break;
        case 'g':
                block_device(fmt, type, basetype, vaidx);
                break;
        case 'G':
                flag_string(fmt, type, basetype, vaidx);
                break;
        case 'O':
                device_node_string(fmt, type, basetype, vaidx);
                break;
        case 'x':
                /* 'x' is for an unhashed pointer */
                break;
        case '4':
                if (strncmp(fmt, "4cc", 3) != 0)
                        sm_warning("unrecognized format '%%p4%c'. Was '%%p4cc' intended?", fmt[1]);
                break;
        default:
                sm_error("unrecognized %%p extension '%c', treated as normal %%p", *fmt);
        }
}

/*
 * A common error is to pass a "char" or "signed char" to %02x (or
 * %.2X or some other variant). This can actually be a security
 * problem, because a lot of code expects this to produce exactly two
 * characters of output. Unfortunately this also produces false
 * positives, since we're sometimes in arch-specific code on an arch
 * where char is always unsigned.
 */
static void
hexbyte(const char *fmt, int fmt_len, struct expression *arg, int vaidx, struct printf_spec spec)
{
        struct symbol *type;

        /*
         * For now, just check the most common and obvious, which is
         * roughly %[.0]2[xX].
         */
        if (spec.field_width != 2 && spec.precision != 2)
                return;
        if (spec.base != 16)
                return;

        type = get_type(arg);
        if (!type) {
                sm_warning("could not determine type of argument %d", vaidx);
                return;
        }
        if (type_signed(type) && (type == &char_ctype || type == &schar_ctype))
                sm_warning("argument %d to %.*s specifier has type '%s'",
                       vaidx, fmt_len, fmt, type_to_str(type));
}

static int
check_format_string(const char *fmt, const char *caller)
{
        const char *f;

        for (f = fmt; *f; ++f) {
                unsigned char c = *f;
                switch (c) {
                case KERN_SOH_ASCII:
                        /*
                         * This typically arises from bad conversion
                         * to pr_*, e.g. pr_warn(KERN_WARNING "something").
                         */
                        if (f != fmt)
                                sm_warning("KERN_* level not at start of string");
                        /*
                         * In a very few cases, the level is actually
                         * computed and passed via %c, as in KERN_SOH
                         * "%c...". printk explicitly supports
                         * this.
                         */
                        if (!(('0' <= f[1] && f[1] <= '7') ||
                              f[1] == 'd' || /* KERN_DEFAULT */
                              f[1] == 'c' || /* KERN_CONT */
                              (f[1] == '%' && f[2] == 'c')))
                                sm_warning("invalid KERN_* level: KERN_SOH_ASCII followed by '\\x%02x'", (unsigned char)f[1]);
                        break;
                case '\t':
                case '\n':
                case '\r':
                case 0x20 ... 0x7e:
                        break;
                case 0x80 ... 0xff:
                        sm_warning("format string contains non-ascii character '\\x%02x'", c);
                        break;
                case 0x08:
                        if (f == fmt)
                                break;
                        /* fall through */
                default:
                        sm_warning("format string contains unusual character '\\x%02x'", c);
                        break;
                }
        }

        f = strstr(fmt, caller);
        if (f && strstr(f+1, caller))
                sm_warning("format string contains name of enclosing function '%s' twice", caller);

        return f != NULL;
}

static int arg_is___func__(struct expression *arg)
{
        if (arg->type != EXPR_SYMBOL)
                return 0;
        return !strcmp(arg->symbol_name->name, "__func__") ||
               !strcmp(arg->symbol_name->name, "__FUNCTION__") ||
               !strcmp(arg->symbol_name->name, "__PRETTY_FUNCTION__");
}
static int arg_contains_caller(struct expression *arg, const char *caller)
{
        if (arg->type != EXPR_STRING)
                return 0;
        return strstr(arg->string->data, caller) != NULL;
}

static int is_array_of_const_char(struct symbol *sym)
{
        struct symbol *base = sym->ctype.base_type;
        if (base->type != SYM_ARRAY)
                return 0;
        if (!(base->ctype.modifiers & MOD_CONST))
                return 0;
        if (!is_char_type(base->ctype.base_type)) {
                spam("weird: format argument is array of const '%s'", type_to_str(base->ctype.base_type));
                return 0;
        }
        return 1;
}

static int is_const_pointer_to_const_char(struct symbol *sym)
{
        struct symbol *base = sym->ctype.base_type;
        if (!(sym->ctype.modifiers & MOD_CONST))
                return 0;
        if (base->type != SYM_PTR)
                return 0;
        if (!(base->ctype.modifiers & MOD_CONST))
                return 0;
        if (!is_char_type(base->ctype.base_type)) {
                spam("weird: format argument is pointer to const '%s'", type_to_str(base->ctype.base_type));
                return 0;
        }
        return 1;
}

static int unknown_format(struct expression *expr)
{
        struct state_list *slist;

        slist = get_strings(expr);
        if (!slist)
                return 1;
        if (slist_has_state(slist, &undefined))
                return 1;
        free_slist(&slist);
        return 0;
}

static bool has_hex_prefix(const char *orig_fmt, const char *old_fmt)
{
        return old_fmt >= orig_fmt + 2 &&
                old_fmt[-2] == '0' && _tolower(old_fmt[-1]) == 'x';
}

static bool is_integer_specifier(int type)
{
        switch (type) {
        case FORMAT_TYPE_LONG_LONG:
        case FORMAT_TYPE_ULONG:
        case FORMAT_TYPE_LONG:
        case FORMAT_TYPE_UBYTE:
        case FORMAT_TYPE_BYTE:
        case FORMAT_TYPE_USHORT:
        case FORMAT_TYPE_SHORT:
        case FORMAT_TYPE_UINT:
        case FORMAT_TYPE_INT:
        case FORMAT_TYPE_SIZE_T:
        case FORMAT_TYPE_PTRDIFF:
                return true;
        default:
                return false;
        }
}

static int
is_cast_expr(struct expression *expr)
{
        if (!expr)
                return 0;

        switch (expr->type) {
        case EXPR_CAST:
        case EXPR_FORCE_CAST:
                /* not EXPR_IMPLIED_CAST for our purposes */
                return 1;
        default:
                return 0;
        }
}

static void
check_cast_from_pointer(const char *fmt, int len, struct expression *arg, int va_idx)
{
        /*
         * This can easily be fooled by passing 0+(long)ptr or doing
         * "long local_var = (long)ptr" and passing local_var to
         * %lx. Tough.
         */
        if (!is_cast_expr(arg))
                return;
        while (is_cast_expr(arg))
                arg = arg->cast_expression;
        if (is_ptr_type(get_final_type(arg)))
                sm_warning("argument %d to %.*s specifier is cast from pointer",
                        va_idx, len, fmt);
}

static void
check_precision_intended(struct printf_spec *spec,  struct expression *prev_arg, struct expression *arg)
{
        char *name;

        if (!option_spammy)
                return;

        if (spec->type != FORMAT_TYPE_WIDTH)
                return;
        if (is_nul_terminated(arg))
                return;

        name = expr_to_str(prev_arg);
        if (name && (strcasestr(name, "width") || strcasestr(name, "level")))
                goto free;

        sm_msg("warn: was precision intended? '%s'", name);
free:
        free_string(name);
}

static void
do_check_printf_call(const char *caller, const char *name, struct expression *callexpr, struct expression *fmtexpr, int vaidx)
{
        struct printf_spec spec = {0};
        struct printf_spec prev_spec = {0};
        struct expression *arg;
        struct expression *prev_arg = NULL;
        const char *fmt, *orig_fmt;
        int caller_in_fmt;

        fmtexpr = strip_parens(fmtexpr);
        if (fmtexpr->type == EXPR_CONDITIONAL) {
                do_check_printf_call(caller, name, callexpr, fmtexpr->cond_true ? : fmtexpr->conditional, vaidx);
                do_check_printf_call(caller, name, callexpr, fmtexpr->cond_false, vaidx);
                return;
        }
        if (fmtexpr->type == EXPR_SYMBOL) {
                /*
                 * If the symbol has an initializer, we can handle
                 *
                 *   const char foo[] = "abc";         and
                 *   const char * const foo = "abc";
                 *
                 * We simply replace fmtexpr with the initializer
                 * expression. If foo is not one of the above, or if
                 * the initializer expression is somehow not a string
                 * literal, fmtexpr->type != EXPR_STRING will trigger
                 * below and we'll spam+return.
                 */
                struct symbol *sym = fmtexpr->symbol;
                if (sym && sym->initializer &&
                    (is_array_of_const_char(sym) ||
                     is_const_pointer_to_const_char(sym))) {
                        fmtexpr = strip_parens(sym->initializer);
                }
        }

        if (fmtexpr->type != EXPR_STRING) {
                if (!unknown_format(fmtexpr))
                        return;
                /*
                 * Since we're now handling both ?: and static const
                 * char[] arguments, we don't get as much noise. It's
                 * still spammy, though.
                 */
                spam("warn: call of '%s' with non-constant format argument", name);
                return;
        }

        orig_fmt = fmt = fmtexpr->string->data;
        caller_in_fmt = check_format_string(fmt, caller);

        while (*fmt) {
                const char *old_fmt = fmt;
                int read = format_decode(fmt, &spec);

                fmt += read;
                if (spec.type == FORMAT_TYPE_NONE ||
                    spec.type == FORMAT_TYPE_PERCENT_CHAR) {
                        prev_spec = spec;
                        prev_arg = NULL;
                        continue;
                }

                /*
                 * vaidx is currently the correct 0-based index for
                 * get_argument_from_call_expr. We post-increment it
                 * here so that it is the correct 1-based index for
                 * all the handlers below. This of course requires
                 * that we handle all FORMAT_TYPE_* things not taking
                 * an argument above.
                 */
                arg = get_argument_from_call_expr(callexpr->args, vaidx++);

                if (spec.flags & SPECIAL && has_hex_prefix(orig_fmt, old_fmt))
                        sm_warning("'%.2s' prefix is redundant when # flag is used", old_fmt-2);
                if (is_integer_specifier(spec.type)) {
                        if (spec.base != 16 && has_hex_prefix(orig_fmt, old_fmt))
                                sm_warning("'%.2s' prefix is confusing together with '%.*s' specifier",
                                       old_fmt-2, (int)(fmt-old_fmt), old_fmt);

                        check_cast_from_pointer(old_fmt, read, arg, vaidx);
                }

                switch (spec.type) {
                /* case FORMAT_TYPE_NONE: */
                /* case FORMAT_TYPE_PERCENT_CHAR: */
                /*      break; */

                case FORMAT_TYPE_INVALID:
                        sm_error("format specifier '%.*s' invalid", read, old_fmt);
                        return;

                case FORMAT_TYPE_FLOAT:
                        sm_error("no floats in the kernel; invalid format specifier '%.*s'", read, old_fmt);
                        return;

                case FORMAT_TYPE_NRCHARS:
                        sm_error("%%n not supported in kernel");
                        return;

                case FORMAT_TYPE_WIDTH:
                case FORMAT_TYPE_PRECISION:
                        /* check int argument */
                        break;

                case FORMAT_TYPE_STR:
                        check_precision_intended(&prev_spec, prev_arg, arg);

                        /*
                         * If the format string already contains the
                         * function name, it probably doesn't make
                         * sense to pass __func__ as well (or rather
                         * vice versa: If pr_fmt(fmt) has been defined
                         * to '"%s: " fmt, __func__', it doesn't make
                         * sense to use a format string containing the
                         * function name).
                         *
                         * This produces a lot of hits. They are not
                         * false positives, but it is easier to handle
                         * the things which don't occur that often
                         * first, so we use spam().
                         */
                        if (caller_in_fmt) {
                                if (arg_is___func__(arg))
                                        spam("warn: passing __func__ while the format string already contains the name of the function '%s'",
                                             caller);
                                else if (arg_contains_caller(arg, caller))
                                        sm_warning("passing string constant '%s' containing '%s' which is already part of the format string",
                                               arg->string->data, caller);
                        }
                        break;

                case FORMAT_TYPE_PTR:
                        /* This is the most important part: Checking %p extensions. */
                        pointer(fmt, arg, vaidx);
                        while (isalnum(*fmt))
                                fmt++;
                        break;

                case FORMAT_TYPE_CHAR:

                case FORMAT_TYPE_UBYTE:
                case FORMAT_TYPE_BYTE:
                case FORMAT_TYPE_USHORT:
                case FORMAT_TYPE_SHORT:
                case FORMAT_TYPE_INT:
                        /* argument should have integer type of width <= sizeof(int) */
                        break;

                case FORMAT_TYPE_UINT:
                        hexbyte(old_fmt, fmt-old_fmt, arg, vaidx, spec);
                case FORMAT_TYPE_LONG:
                case FORMAT_TYPE_ULONG:
                case FORMAT_TYPE_LONG_LONG:
                case FORMAT_TYPE_PTRDIFF:
                case FORMAT_TYPE_SIZE_T:
                        break;
                }
                prev_spec = spec;
                prev_arg = arg;
        }

        if (get_argument_from_call_expr(callexpr->args, vaidx))
                sm_warning("excess argument passed to '%s'", name);
}

static void
check_printf_call(const char *name, struct expression *callexpr, void *_info)
{
        /*
         * Note: attribute(printf) uses 1-based indexing, but
         * get_argument_from_call_expr() uses 0-based indexing.
         */
        int info = PTR_INT(_info);
        int fmtidx = (info & 0xff) - 1;
        int vaidx = ((info >> 8) & 0xff) - 1;
        struct expression *fmtexpr;
        const char *caller = get_function();

        if (!caller)
                return;

        /*
         * Calling a v*printf function with a literal format arg is
         * extremely rare, so we don't bother doing the only checking
         * we could do, namely checking that the format string is
         * valid.
         */
        if (vaidx < 0)
                return;

        /*
         * For the things we use the name of the calling function for,
         * it is more appropriate to skip a potential SyS_ prefix; the
         * same goes for leading underscores.
         */
        if (!strncmp(caller, "SyS_", 4))
                caller += 4;
        while (*caller == '_')
                ++caller;

        /* Lack of format argument is a bug. */
        fmtexpr = get_argument_from_call_expr(callexpr->args, fmtidx);
        if (!fmtexpr) {
                sm_error("call of '%s' with no format argument", name);
                return;
        }

        do_check_printf_call(caller, name, callexpr, fmtexpr, vaidx);
}


void check_kernel_printf(int id)
{
        if (option_project != PROJ_KERNEL)
                return;

        my_id = id;

#define printf_hook(func, fmt, first_to_check)  \
        add_function_hook(#func, check_printf_call, INT_PTR(fmt + (first_to_check << 8)))

        /* Extracted using stupid perl script. */

#if 0
        printf_hook(srm_printk, 1, 2);                    /* arch/alpha/include/asm/console.h */
        printf_hook(die_if_kernel, 1, 2);                 /* arch/frv/include/asm/bug.h */
        printf_hook(ia64_mca_printk, 1, 2);               /* arch/ia64/include/asm/mca.h */
        printf_hook(nfprint, 1, 2);                       /* arch/m68k/include/asm/natfeat.h */
        printf_hook(gdbstub_printk, 1, 2);                /* arch/mn10300/include/asm/gdb-stub.h */
        printf_hook(DBG, 1, 2);                           /* arch/powerpc/boot/ps3.c */
        printf_hook(printf, 1, 2);                        /* arch/powerpc/boot/stdio.h */
        printf_hook(udbg_printf, 1, 2);                   /* arch/powerpc/include/asm/udbg.h */
        printf_hook(__debug_sprintf_event, 3, 4);         /* arch/s390/include/asm/debug.h */
        printf_hook(__debug_sprintf_exception, 3, 4);     /* arch/s390/include/asm/debug.h */
        printf_hook(prom_printf, 1, 2);                   /* arch/sparc/include/asm/oplib_32.h */

        printf_hook(fail, 1, 2);                          /* arch/x86/vdso/vdso2c.c */
#endif

        printf_hook(_ldm_printk, 3, 4);                   /* block/partitions/ldm.c */
        printf_hook(rbd_warn, 2, 3);                      /* drivers/block/rbd.c */
        printf_hook(fw_err, 2, 3);                        /* drivers/firewire/core.h */
        printf_hook(fw_notice, 2, 3);                     /* drivers/firewire/core.h */
        printf_hook(i915_error_printf, 2, 3);             /* drivers/gpu/drm/i915/i915_drv.h */
        printf_hook(i915_handle_error, 3, 4);             /* drivers/gpu/drm/i915/i915_drv.h */
        printf_hook(nv_printk_, 3, 4);                    /* drivers/gpu/drm/nouveau/core/include/core/printk.h */
        printf_hook(host1x_debug_output, 2, 3);           /* drivers/gpu/host1x/debug.h */
        printf_hook(callc_debug, 2, 3);                   /* drivers/isdn/hisax/callc.c */
        printf_hook(link_debug, 3, 4);                    /* drivers/isdn/hisax/callc.c */
        printf_hook(HiSax_putstatus, 3, 4);               /* drivers/isdn/hisax/hisax.h */
        printf_hook(VHiSax_putstatus, 3, 0);              /* drivers/isdn/hisax/hisax.h */
        printf_hook(debugl1, 2, 3);                       /* drivers/isdn/hisax/isdnl1.h */
        printf_hook(l3m_debug, 2, 3);                     /* drivers/isdn/hisax/isdnl3.c */
        printf_hook(dout_debug, 2, 3);                    /* drivers/isdn/hisax/st5481_d.c */
        printf_hook(l1m_debug, 2, 3);                     /* drivers/isdn/hisax/st5481_d.c */
        printf_hook(bch_cache_set_error, 2, 3);           /* drivers/md/bcache/bcache.h */
        printf_hook(_tda_printk, 4, 5);                   /* drivers/media/tuners/tda18271-priv.h */
        printf_hook(i40evf_debug_d, 3, 4);                /* drivers/net/ethernet/intel/i40evf/i40e_osdep.h */
        printf_hook(en_print, 3, 4);                      /* drivers/net/ethernet/mellanox/mlx4/mlx4_en.h */
        printf_hook(_ath_dbg, 3, 4);                      /* drivers/net/wireless/ath/ath.h */
        printf_hook(ath_printk, 3, 4);                    /* drivers/net/wireless/ath/ath.h */
        printf_hook(ath10k_dbg, 3, 4);                    /* drivers/net/wireless/ath/ath10k/debug.h */
        printf_hook(ath10k_err, 2, 3);                    /* drivers/net/wireless/ath/ath10k/debug.h */
        printf_hook(ath10k_info, 2, 3);                   /* drivers/net/wireless/ath/ath10k/debug.h */
        printf_hook(ath10k_warn, 2, 3);                   /* drivers/net/wireless/ath/ath10k/debug.h */
        printf_hook(_ath5k_printk, 3, 4);                 /* drivers/net/wireless/ath/ath5k/ath5k.h */
        printf_hook(ATH5K_DBG, 3, 4);                     /* drivers/net/wireless/ath/ath5k/debug.h */
        printf_hook(ATH5K_DBG_UNLIMIT, 3, 4);             /* drivers/net/wireless/ath/ath5k/debug.h */
        printf_hook(ath6kl_printk, 2, 3);                 /* drivers/net/wireless/ath/ath6kl/common.h */
        printf_hook(ath6kl_err, 1, 2);                    /* drivers/net/wireless/ath/ath6kl/debug.h */
        printf_hook(ath6kl_info, 1, 2);                   /* drivers/net/wireless/ath/ath6kl/debug.h */
        printf_hook(ath6kl_warn, 1, 2);                   /* drivers/net/wireless/ath/ath6kl/debug.h */
        printf_hook(wil_dbg_trace, 2, 3);                 /* drivers/net/wireless/ath/wil6210/wil6210.h */
        printf_hook(wil_err, 2, 3);                       /* drivers/net/wireless/ath/wil6210/wil6210.h */
        printf_hook(wil_err_ratelimited, 2, 3);           /* drivers/net/wireless/ath/wil6210/wil6210.h */
        printf_hook(wil_info, 2, 3);                      /* drivers/net/wireless/ath/wil6210/wil6210.h */
        printf_hook(b43dbg, 2, 3);                        /* drivers/net/wireless/b43/b43.h */
        printf_hook(b43err, 2, 3);                        /* drivers/net/wireless/b43/b43.h */
        printf_hook(b43info, 2, 3);                       /* drivers/net/wireless/b43/b43.h */
        printf_hook(b43warn, 2, 3);                       /* drivers/net/wireless/b43/b43.h */
        printf_hook(b43legacydbg, 2, 3);                  /* drivers/net/wireless/b43legacy/b43legacy.h */
        printf_hook(b43legacyerr, 2, 3);                  /* drivers/net/wireless/b43legacy/b43legacy.h */
        printf_hook(b43legacyinfo, 2, 3);                 /* drivers/net/wireless/b43legacy/b43legacy.h */
        printf_hook(b43legacywarn, 2, 3);                 /* drivers/net/wireless/b43legacy/b43legacy.h */
        printf_hook(__brcmf_dbg, 3, 4);                   /* drivers/net/wireless/brcm80211/brcmfmac/debug.h */
        printf_hook(__brcmf_err, 2, 3);                   /* drivers/net/wireless/brcm80211/brcmfmac/debug.h */
        printf_hook(__brcms_crit, 2, 3);                  /* drivers/net/wireless/brcm80211/brcmsmac/debug.h */
        printf_hook(__brcms_dbg, 4, 5);                   /* drivers/net/wireless/brcm80211/brcmsmac/debug.h */
        printf_hook(__brcms_err, 2, 3);                   /* drivers/net/wireless/brcm80211/brcmsmac/debug.h */
        printf_hook(__brcms_info, 2, 3);                  /* drivers/net/wireless/brcm80211/brcmsmac/debug.h */
        printf_hook(__brcms_warn, 2, 3);                  /* drivers/net/wireless/brcm80211/brcmsmac/debug.h */
        printf_hook(brcmu_dbg_hex_dump, 3, 4);            /* drivers/net/wireless/brcm80211/include/brcmu_utils.h */
        printf_hook(__iwl_crit, 2, 3);                    /* drivers/net/wireless/iwlwifi/iwl-debug.h */
        printf_hook(__iwl_dbg, 5, 6);                     /* drivers/net/wireless/iwlwifi/iwl-debug.h */
        printf_hook(__iwl_err, 3, 4);                     /* drivers/net/wireless/iwlwifi/iwl-debug.h */
        printf_hook(__iwl_info, 2, 3);                    /* drivers/net/wireless/iwlwifi/iwl-debug.h */
        printf_hook(__iwl_warn, 2, 3);                    /* drivers/net/wireless/iwlwifi/iwl-debug.h */
        printf_hook(rsi_dbg, 2, 3);                       /* drivers/net/wireless/rsi/rsi_main.h */
        printf_hook(RTPRINT, 4, 5);                       /* drivers/net/wireless/rtlwifi/debug.h */
        printf_hook(RT_ASSERT, 2, 3);                     /* drivers/net/wireless/rtlwifi/debug.h */
        printf_hook(RT_TRACE, 4, 5);                      /* drivers/net/wireless/rtlwifi/debug.h */
        printf_hook(__of_node_dup, 2, 3);                 /* drivers/of/of_private.h */
        printf_hook(BNX2FC_HBA_DBG, 2, 3);                /* drivers/scsi/bnx2fc/bnx2fc_debug.h */
        printf_hook(BNX2FC_IO_DBG, 2, 3);                 /* drivers/scsi/bnx2fc/bnx2fc_debug.h */
        printf_hook(BNX2FC_TGT_DBG, 2, 3);                /* drivers/scsi/bnx2fc/bnx2fc_debug.h */
        printf_hook(ql_dbg, 4, 5);                        /* drivers/scsi/qla2xxx/qla_dbg.h */
        printf_hook(ql_dbg_pci, 4, 5);                    /* drivers/scsi/qla2xxx/qla_dbg.h */
        printf_hook(ql_log, 4, 5);                        /* drivers/scsi/qla2xxx/qla_dbg.h */
        printf_hook(ql_log_pci, 4, 5);                    /* drivers/scsi/qla2xxx/qla_dbg.h */
        printf_hook(libcfs_debug_msg, 2, 3);              /* drivers/staging/lustre/include/linux/libcfs/libcfs_debug.h */
        printf_hook(libcfs_debug_vmsg2, 4, 5);            /* drivers/staging/lustre/include/linux/libcfs/libcfs_debug.h */
        printf_hook(_ldlm_lock_debug, 3, 4);              /* drivers/staging/lustre/lustre/include/lustre_dlm.h */
        printf_hook(_debug_req, 3, 4);                    /* drivers/staging/lustre/lustre/include/lustre_net.h */
        printf_hook(iscsi_change_param_sprintf, 2, 3);    /* drivers/target/iscsi/iscsi_target_login.c */
        printf_hook(dbg, 1, 2);                           /* drivers/tty/serial/samsung.c */
        printf_hook(_usb_stor_dbg, 2, 3);                 /* drivers/usb/storage/debug.h */
        printf_hook(usb_stor_dbg, 2, 3);                  /* drivers/usb/storage/debug.h */
        printf_hook(vringh_bad, 1, 2);                    /* drivers/vhost/vringh.c */
        printf_hook(__adfs_error, 3, 4);                  /* fs/adfs/adfs.h */
        printf_hook(affs_error, 3, 4);                    /* fs/affs/affs.h */
        printf_hook(affs_warning, 3, 4);                  /* fs/affs/affs.h */
        printf_hook(befs_debug, 2, 3);                    /* fs/befs/befs.h */
        printf_hook(befs_error, 2, 3);                    /* fs/befs/befs.h */
        printf_hook(befs_warning, 2, 3);                  /* fs/befs/befs.h */
        printf_hook(__btrfs_panic, 5, 6);                 /* fs/btrfs/ctree.h */
        printf_hook(__btrfs_std_error, 5, 6);             /* fs/btrfs/ctree.h */
        printf_hook(btrfs_printk, 2, 3);                  /* fs/btrfs/ctree.h */
        printf_hook(cifs_vfs_err, 1, 2);                  /* fs/cifs/cifs_debug.h */
        printf_hook(__ecryptfs_printk, 1, 2);             /* fs/ecryptfs/ecryptfs_kernel.h */
        printf_hook(ext2_error, 3, 4);                    /* fs/ext2/ext2.h */
        printf_hook(ext2_msg, 3, 4);                      /* fs/ext2/ext2.h */
        printf_hook(ext3_abort, 3, 4);                    /* fs/ext3/ext3.h */
        printf_hook(ext3_error, 3, 4);                    /* fs/ext3/ext3.h */
        printf_hook(ext3_msg, 3, 4);                      /* fs/ext3/ext3.h */
        printf_hook(ext3_warning, 3, 4);                  /* fs/ext3/ext3.h */
        printf_hook(__ext4_abort, 4, 5);                  /* fs/ext4/ext4.h */
        printf_hook(__ext4_error, 4, 5);                  /* fs/ext4/ext4.h */
        printf_hook(__ext4_error_file, 5, 6);             /* fs/ext4/ext4.h */
        printf_hook(__ext4_error_inode, 5, 6);            /* fs/ext4/ext4.h */
        printf_hook(__ext4_grp_locked_error, 7, 8);       /* fs/ext4/ext4.h */
        printf_hook(__ext4_msg, 3, 4);                    /* fs/ext4/ext4.h */
        printf_hook(__ext4_warning, 4, 5);                /* fs/ext4/ext4.h */
        printf_hook(f2fs_msg, 3, 4);                      /* fs/f2fs/f2fs.h */
        printf_hook(__fat_fs_error, 3, 4);                /* fs/fat/fat.h */
        printf_hook(fat_msg, 3, 4);                       /* fs/fat/fat.h */
        printf_hook(gfs2_print_dbg, 2, 3);                /* fs/gfs2/glock.h */
        printf_hook(gfs2_lm_withdraw, 2, 3);              /* fs/gfs2/util.h */
        printf_hook(hpfs_error, 2, 3);                    /* fs/hpfs/hpfs_fn.h */
        printf_hook(jfs_error, 2, 3);                     /* fs/jfs/jfs_superblock.h */
        printf_hook(nilfs_error, 3, 4);                   /* fs/nilfs2/nilfs.h */
        printf_hook(nilfs_warning, 3, 4);                 /* fs/nilfs2/nilfs.h */
        printf_hook(__ntfs_debug, 4, 5);                  /* fs/ntfs/debug.h */
        printf_hook(__ntfs_error, 3, 4);                  /* fs/ntfs/debug.h */
        printf_hook(__ntfs_warning, 3, 4);                /* fs/ntfs/debug.h */
        printf_hook(__ocfs2_abort, 3, 4);                 /* fs/ocfs2/super.h */
        printf_hook(__ocfs2_error, 3, 4);                 /* fs/ocfs2/super.h */
        printf_hook(_udf_err, 3, 4);                      /* fs/udf/udfdecl.h */
        printf_hook(_udf_warn, 3, 4);                     /* fs/udf/udfdecl.h */
        printf_hook(ufs_error, 3, 4);                     /* fs/ufs/ufs.h */
        printf_hook(ufs_panic, 3, 4);                     /* fs/ufs/ufs.h */
        printf_hook(ufs_warning, 3, 4);                   /* fs/ufs/ufs.h */
        printf_hook(xfs_alert, 2, 3);                     /* fs/xfs/xfs_message.h */
        printf_hook(xfs_alert_tag, 3, 4);                 /* fs/xfs/xfs_message.h */
        printf_hook(xfs_crit, 2, 3);                      /* fs/xfs/xfs_message.h */
        printf_hook(xfs_debug, 2, 3);                     /* fs/xfs/xfs_message.h */
        printf_hook(xfs_emerg, 2, 3);                     /* fs/xfs/xfs_message.h */
        printf_hook(xfs_err, 2, 3);                       /* fs/xfs/xfs_message.h */
        printf_hook(xfs_info, 2, 3);                      /* fs/xfs/xfs_message.h */
        printf_hook(xfs_notice, 2, 3);                    /* fs/xfs/xfs_message.h */
        printf_hook(xfs_warn, 2, 3);                      /* fs/xfs/xfs_message.h */
        printf_hook(warn_slowpath_fmt, 3, 4);             /* include/asm-generic/bug.h */
        printf_hook(warn_slowpath_fmt_taint, 4, 5);       /* include/asm-generic/bug.h */
        printf_hook(drm_err, 1, 2);                       /* include/drm/drmP.h */
        printf_hook(drm_ut_debug_printk, 2, 3);           /* include/drm/drmP.h */
        printf_hook(__acpi_handle_debug, 3, 4);           /* include/linux/acpi.h */
        printf_hook(acpi_handle_printk, 3, 4);            /* include/linux/acpi.h */
        printf_hook(audit_log, 4, 5);                     /* include/linux/audit.h */
        printf_hook(audit_log_format, 2, 3);              /* include/linux/audit.h */
        printf_hook(bdi_register, 3, 4);                  /* include/linux/backing-dev.h */
        printf_hook(__trace_note_message, 2, 3);          /* include/linux/blktrace_api.h */
        printf_hook(_dev_info, 2, 3);                     /* include/linux/device.h */
        printf_hook(dev_alert, 2, 3);                     /* include/linux/device.h */
        printf_hook(dev_crit, 2, 3);                      /* include/linux/device.h */
        printf_hook(dev_emerg, 2, 3);                     /* include/linux/device.h */
        printf_hook(dev_err, 2, 3);                       /* include/linux/device.h */
        printf_hook(dev_notice, 2, 3);                    /* include/linux/device.h */
        printf_hook(dev_printk, 3, 4);                    /* include/linux/device.h */
        printf_hook(dev_printk_emit, 3, 4);               /* include/linux/device.h */
        printf_hook(dev_set_name, 2, 3);                  /* include/linux/device.h */
        printf_hook(dev_vprintk_emit, 3, 0);              /* include/linux/device.h */
        printf_hook(dev_warn, 2, 3);                      /* include/linux/device.h */
        printf_hook(device_create, 5, 6);                 /* include/linux/device.h */
        printf_hook(device_create_with_groups, 6, 7);     /* include/linux/device.h */
        printf_hook(devm_kasprintf, 3, 4);                /* include/linux/device.h */
        printf_hook(__dynamic_dev_dbg, 3, 4);             /* include/linux/dynamic_debug.h */
        printf_hook(__dynamic_netdev_dbg, 3, 4);          /* include/linux/dynamic_debug.h */
        printf_hook(__dynamic_pr_debug, 2, 3);            /* include/linux/dynamic_debug.h */
        printf_hook(__simple_attr_check_format, 1, 2);    /* include/linux/fs.h */
        printf_hook(fscache_init_cache, 3, 4);            /* include/linux/fscache-cache.h */
        printf_hook(gameport_set_phys, 2, 3);             /* include/linux/gameport.h */
        printf_hook(iio_trigger_alloc, 1, 2);             /* include/linux/iio/trigger.h */
        printf_hook(__check_printsym_format, 1, 2);       /* include/linux/kallsyms.h */
        printf_hook(kdb_printf, 1, 2);                    /* include/linux/kdb.h */
        printf_hook(vkdb_printf, 1, 0);                   /* include/linux/kdb.h */
        printf_hook(____trace_printk_check_format, 1, 2);  /* include/linux/kernel.h */
        printf_hook(__trace_bprintk, 2, 3);               /* include/linux/kernel.h */
        printf_hook(__trace_printk, 2, 3);                /* include/linux/kernel.h */
        printf_hook(kasprintf, 2, 3);                     /* include/linux/kernel.h */
        printf_hook(panic, 1, 2);                         /* include/linux/kernel.h */
        printf_hook(scnprintf, 3, 4);                     /* include/linux/kernel.h */
        printf_hook(snprintf, 3, 4);                      /* include/linux/kernel.h */
        printf_hook(sprintf, 2, 3);                       /* include/linux/kernel.h */
        printf_hook(trace_printk, 1, 2);                  /* include/linux/kernel.h */
        printf_hook(vscnprintf, 3, 0);                    /* include/linux/kernel.h */
        printf_hook(vsnprintf, 3, 0);                     /* include/linux/kernel.h */
        printf_hook(vsprintf, 2, 0);                      /* include/linux/kernel.h */
        printf_hook(vmcoreinfo_append_str, 1, 2);         /* include/linux/kexec.h */
        printf_hook(__request_module, 2, 3);              /* include/linux/kmod.h */
        printf_hook(add_uevent_var, 2, 3);                /* include/linux/kobject.h */
        printf_hook(kobject_add, 3, 4);                   /* include/linux/kobject.h */
        printf_hook(kobject_init_and_add, 4, 5);          /* include/linux/kobject.h */
        printf_hook(kobject_set_name, 2, 3);              /* include/linux/kobject.h */
        printf_hook(kthread_create_on_node, 4, 5);        /* include/linux/kthread.h */
        printf_hook(__ata_ehi_push_desc, 2, 3);           /* include/linux/libata.h */
        printf_hook(ata_dev_printk, 3, 4);                /* include/linux/libata.h */
        printf_hook(ata_ehi_push_desc, 2, 3);             /* include/linux/libata.h */
        printf_hook(ata_link_printk, 3, 4);               /* include/linux/libata.h */
        printf_hook(ata_port_desc, 2, 3);                 /* include/linux/libata.h */
        printf_hook(ata_port_printk, 3, 4);               /* include/linux/libata.h */
        printf_hook(warn_alloc_failed, 3, 4);             /* include/linux/mm.h */
        printf_hook(mmiotrace_printk, 1, 2);              /* include/linux/mmiotrace.h */
        printf_hook(netdev_alert, 2, 3);                  /* include/linux/netdevice.h */
        printf_hook(netdev_crit, 2, 3);                   /* include/linux/netdevice.h */
        printf_hook(netdev_emerg, 2, 3);                  /* include/linux/netdevice.h */
        printf_hook(netdev_err, 2, 3);                    /* include/linux/netdevice.h */
        printf_hook(netdev_info, 2, 3);                   /* include/linux/netdevice.h */
        printf_hook(netdev_notice, 2, 3);                 /* include/linux/netdevice.h */
        printf_hook(netdev_printk, 3, 4);                 /* include/linux/netdevice.h */
        printf_hook(netdev_warn, 2, 3);                   /* include/linux/netdevice.h */
        printf_hook(early_printk, 1, 2);                  /* include/linux/printk.h */
        printf_hook(no_printk, 1, 2);                     /* include/linux/printk.h */
        printf_hook(printk, 1, 2);                        /* include/linux/printk.h */
        printf_hook(printk_deferred, 1, 2);               /* include/linux/printk.h */
        printf_hook(printk_emit, 5, 6);                   /* include/linux/printk.h */
        printf_hook(vprintk, 1, 0);                       /* include/linux/printk.h */
        printf_hook(vprintk_emit, 5, 0);                  /* include/linux/printk.h */
        printf_hook(__quota_error, 3, 4);                 /* include/linux/quotaops.h */
        printf_hook(seq_buf_printf, 2, 3);                /* include/linux/seq_buf.h */
        printf_hook(seq_buf_vprintf, 2, 0);               /* include/linux/seq_buf.h */
        printf_hook(seq_printf, 2, 3);                    /* include/linux/seq_file.h */
        printf_hook(seq_vprintf, 2, 0);                   /* include/linux/seq_file.h */
        printf_hook(bprintf, 3, 4);                       /* include/linux/string.h */
        printf_hook(trace_seq_printf, 2, 3);              /* include/linux/trace_seq.h */
        printf_hook(trace_seq_vprintf, 2, 0);             /* include/linux/trace_seq.h */
        printf_hook(__alloc_workqueue_key, 1, 6);         /* include/linux/workqueue.h */
        printf_hook(set_worker_desc, 1, 2);               /* include/linux/workqueue.h */
        printf_hook(_p9_debug, 3, 4);                     /* include/net/9p/9p.h */
        printf_hook(bt_err, 1, 2);                        /* include/net/bluetooth/bluetooth.h */
        printf_hook(bt_info, 1, 2);                       /* include/net/bluetooth/bluetooth.h */
        printf_hook(nf_ct_helper_log, 3, 4);              /* include/net/netfilter/nf_conntrack_helper.h */
        printf_hook(nf_log_buf_add, 2, 3);                /* include/net/netfilter/nf_log.h */
        printf_hook(nf_log_packet, 8, 9);                 /* include/net/netfilter/nf_log.h */
        printf_hook(SOCK_DEBUG, 2, 3);                    /* include/net/sock.h */
        printf_hook(__snd_printk, 4, 5);                  /* include/sound/core.h */
        printf_hook(_snd_printd, 2, 3);                   /* include/sound/core.h */
        printf_hook(snd_printd, 1, 2);                    /* include/sound/core.h */
        printf_hook(snd_printdd, 1, 2);                   /* include/sound/core.h */
        printf_hook(snd_iprintf, 2, 3);                   /* include/sound/info.h */
        printf_hook(snd_seq_create_kernel_client, 3, 4);  /* include/sound/seq_kernel.h */
        printf_hook(xen_raw_printk, 1, 2);                /* include/xen/hvc-console.h */
        printf_hook(xenbus_dev_error, 3, 4);              /* include/xen/xenbus.h */
        printf_hook(xenbus_dev_fatal, 3, 4);              /* include/xen/xenbus.h */
        printf_hook(xenbus_printf, 4, 5);                 /* include/xen/xenbus.h */
        printf_hook(xenbus_watch_pathfmt, 4, 5);          /* include/xen/xenbus.h */
        printf_hook(batadv_fdebug_log, 2, 3);             /* net/batman-adv/debugfs.c */
        printf_hook(_batadv_dbg, 4, 5);                   /* net/batman-adv/main.h */
        printf_hook(batadv_debug_log, 2, 3);              /* net/batman-adv/main.h */
        printf_hook(__sdata_dbg, 2, 3);                   /* net/mac80211/debug.h */
        printf_hook(__sdata_err, 1, 2);                   /* net/mac80211/debug.h */
        printf_hook(__sdata_info, 1, 2);                  /* net/mac80211/debug.h */
        printf_hook(__wiphy_dbg, 3, 4);                   /* net/mac80211/debug.h */
        printf_hook(mac80211_format_buffer, 4, 5);        /* net/mac80211/debugfs.h */
        printf_hook(__rds_conn_error, 2, 3);              /* net/rds/rds.h */
        printf_hook(rdsdebug, 1, 2);                      /* net/rds/rds.h */
        printf_hook(printl, 1, 2);                        /* net/sctp/probe.c */
        printf_hook(svc_printk, 2, 3);                    /* net/sunrpc/svc.c */
        printf_hook(tomoyo_io_printf, 2, 3);              /* security/tomoyo/common.c */
        printf_hook(tomoyo_supervisor, 2, 3);             /* security/tomoyo/common.h */
        printf_hook(tomoyo_write_log, 2, 3);              /* security/tomoyo/common.h */
        printf_hook(cmp_error, 2, 3);                     /* sound/firewire/cmp.c */
}