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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html><head><title>Python: module ranger.ext.debug</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head><body bgcolor="#f0f0f8">

<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="heading">
<tr bgcolor="#7799ee">
<td valign=bottom>&nbsp;<br>
<font color="#ffffff" face="helvetica, arial">&nbsp;<br><big><big><strong><a href="ranger.html"><font color="#ffffff">ranger</font></a>.<a href="ranger.ext.html"><font color="#ffffff">ext</font></a>.debug</strong></big></big></font></td
><td align=right valign=bottom
><font color="#ffffff" face="helvetica, arial"><a href=".">index</a><br><a href="file:/home/hut/work/ranger/ranger/ext/debug.py">/home/hut/work/ranger/ranger/ext/debug.py</a></font></td></tr></table>
    <p><tt>#&nbsp;Copyright&nbsp;(c)&nbsp;2009,&nbsp;2010&nbsp;hut&nbsp;&lt;hut@lavabit.com&gt;<br>
#<br>
#&nbsp;Permission&nbsp;to&nbsp;use,&nbsp;copy,&nbsp;modify,&nbsp;and/or&nbsp;distribute&nbsp;this&nbsp;software&nbsp;for&nbsp;any<br>
#&nbsp;purpose&nbsp;with&nbsp;or&nbsp;without&nbsp;fee&nbsp;is&nbsp;hereby&nbsp;granted,&nbsp;provided&nbsp;that&nbsp;the&nbsp;above<br>
#&nbsp;copyright&nbsp;notice&nbsp;and&nbsp;this&nbsp;permission&nbsp;notice&nbsp;appear&nbsp;in&nbsp;all&nbsp;copies.<br>
#<br>
#&nbsp;THE&nbsp;SOFTWARE&nbsp;IS&nbsp;PROVIDED&nbsp;"AS&nbsp;IS"&nbsp;AND&nbsp;THE&nbsp;AUTHOR&nbsp;DISCLAIMS&nbsp;ALL&nbsp;WARRANTIES<br>
#&nbsp;WITH&nbsp;REGARD&nbsp;TO&nbsp;THIS&nbsp;SOFTWARE&nbsp;INCLUDING&nbsp;ALL&nbsp;IMPLIED&nbsp;WARRANTIES&nbsp;OF<br>
#&nbsp;MERCHANTABILITY&nbsp;AND&nbsp;FITNESS.&nbsp;IN&nbsp;NO&nbsp;EVENT&nbsp;SHALL&nbsp;THE&nbsp;AUTHOR&nbsp;BE&nbsp;LIABLE&nbsp;FOR<br>
#&nbsp;ANY&nbsp;SPECIAL,&nbsp;DIRECT,&nbsp;INDIRECT,&nbsp;OR&nbsp;CONSEQUENTIAL&nbsp;DAMAGES&nbsp;OR&nbsp;ANY&nbsp;DAMAGES<br>
#&nbsp;WHATSOEVER&nbsp;RESULTING&nbsp;FROM&nbsp;LOSS&nbsp;OF&nbsp;USE,&nbsp;DATA&nbsp;OR&nbsp;PROFITS,&nbsp;WHETHER&nbsp;IN&nbsp;AN<br>
#&nbsp;ACTION&nbsp;OF&nbsp;CONTRACT,&nbsp;NEGLIGENCE&nbsp;OR&nbsp;OTHER&nbsp;TORTIOUS&nbsp;ACTION,&nbsp;ARISING&nbsp;OUT&nbsp;OF<br>
#&nbsp;OR&nbsp;IN&nbsp;CONNECTION&nbsp;WITH&nbsp;THE&nbsp;USE&nbsp;OR&nbsp;PERFORMANCE&nbsp;OF&nbsp;THIS&nbsp;SOFTWARE.</tt></p>
<p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#eeaa77">
<td colspan=3 valign=bottom>&nbsp;<br>
<font color="#ffffff" face="helvetica, arial"><big><strong>Functions</strong></big></font></td></tr>
    
<tr><td bgcolor="#eeaa77"><tt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</tt></td><td>&nbsp;</td>
<td width="100%"><dl><dt><a name="-log"><strong>log</strong></a>(*objects, **keywords)</dt><dd><tt>Writes&nbsp;objects&nbsp;to&nbsp;a&nbsp;logfile.<br>
Has&nbsp;the&nbsp;same&nbsp;arguments&nbsp;as&nbsp;print()&nbsp;in&nbsp;python3</tt></dd></dl>
 <dl><dt><a name="-trace"><strong>trace</strong></a>()</dt></dl>
</td></tr></table><p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#55aa55">
<td colspan=3 valign=bottom>&nbsp;<br>
<font color="#ffffff" face="helvetica, arial"><big><strong>Data</strong></big></font></td></tr>
    
<tr><td bgcolor="#55aa55"><tt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</tt></td><td>&nbsp;</td>
<td width="100%"><strong>LOGFILE</strong> = '/tmp/errorlog'</td></tr></table>
</body></html>
ef='#n789'>789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979
/*
 *  Tiny C Memory and bounds checker
 * 
 *  Copyright (c) 2002 Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>

#if !defined(__FreeBSD__) \
 && !defined(__FreeBSD_kernel__) \
 && !defined(__DragonFly__) \
 && !defined(__OpenBSD__) \
 && !defined(__NetBSD__)
#include <malloc.h>
#endif

#if !defined(_WIN32)
#include <unistd.h>
#endif

/* #define BOUND_DEBUG */

#ifdef BOUND_DEBUG
 #define dprintf(a...) fprintf(a)
#else
 #define dprintf(a...)
#endif

/* define so that bound array is static (faster, but use memory if
   bound checking not used) */
/* #define BOUND_STATIC */

/* use malloc hooks. Currently the code cannot be reliable if no hooks */
#define CONFIG_TCC_MALLOC_HOOKS
#define HAVE_MEMALIGN

#if defined(__FreeBSD__) \
 || defined(__FreeBSD_kernel__) \
 || defined(__DragonFly__) \
 || defined(__OpenBSD__) \
 || defined(__NetBSD__) \
 || defined(__dietlibc__) \
 || defined(_WIN32)
//#warning Bound checking does not support malloc (etc.) in this environment.
#undef CONFIG_TCC_MALLOC_HOOKS
#undef HAVE_MEMALIGN
#endif

#define BOUND_T1_BITS 13
#define BOUND_T2_BITS 11
#define BOUND_T3_BITS (sizeof(size_t)*8 - BOUND_T1_BITS - BOUND_T2_BITS)
#define BOUND_E_BITS  (sizeof(size_t))

#define BOUND_T1_SIZE ((size_t)1 << BOUND_T1_BITS)
#define BOUND_T2_SIZE ((size_t)1 << BOUND_T2_BITS)
#define BOUND_T3_SIZE ((size_t)1 << BOUND_T3_BITS)

#define BOUND_T23_BITS (BOUND_T2_BITS + BOUND_T3_BITS)
#define BOUND_T23_SIZE ((size_t)1 << BOUND_T23_BITS)


/* this pointer is generated when bound check is incorrect */
#define INVALID_POINTER ((void *)(-2))
/* size of an empty region */
#define EMPTY_SIZE  ((size_t)(-1))
/* size of an invalid region */
#define INVALID_SIZE      0

typedef struct BoundEntry {
    size_t start;
    size_t size;
    struct BoundEntry *next;
    size_t is_invalid; /* true if pointers outside region are invalid */
} BoundEntry;

/* external interface */
void __bound_init(void);
void __bound_new_region(void *p, size_t size);
int __bound_delete_region(void *p);

#ifdef __attribute__
  /* an __attribute__ macro is defined in the system headers */
  #undef __attribute__ 
#endif
#define FASTCALL __attribute__((regparm(3)))

void *__bound_malloc(size_t size, const void *caller);
void *__bound_memalign(size_t size, size_t align, const void *caller);
void __bound_free(void *ptr, const void *caller);
void *__bound_realloc(void *ptr, size_t size, const void *caller);
static void *libc_malloc(size_t size);
static void libc_free(void *ptr);
static void install_malloc_hooks(void);
static void restore_malloc_hooks(void);

#ifdef CONFIG_TCC_MALLOC_HOOKS
static void *saved_malloc_hook;
static void *saved_free_hook;
static void *saved_realloc_hook;
static void *saved_memalign_hook;
#endif

/* TCC definitions */
extern char __bounds_start; /* start of static bounds table */
/* error message, just for TCC */
const char *__bound_error_msg;

/* runtime error output */
extern void rt_error(size_t pc, const char *fmt, ...);

#ifdef BOUND_STATIC
static BoundEntry *__bound_t1[BOUND_T1_SIZE]; /* page table */
#else
static BoundEntry **__bound_t1; /* page table */
#endif
static BoundEntry *__bound_empty_t2;   /* empty page, for unused pages */
static BoundEntry *__bound_invalid_t2; /* invalid page, for invalid pointers */

static BoundEntry *__bound_find_region(BoundEntry *e1, void *p)
{
    size_t addr, tmp;
    BoundEntry *e;

    e = e1;
    while (e != NULL) {
        addr = (size_t)p;
        addr -= e->start;
        if (addr <= e->size) {
            /* put region at the head */
            tmp = e1->start;
            e1->start = e->start;
            e->start = tmp;
            tmp = e1->size;
            e1->size = e->size;
            e->size = tmp;
            return e1;
        }
        e = e->next;
    }
    /* no entry found: return empty entry or invalid entry */
    if (e1->is_invalid)
        return __bound_invalid_t2;
    else
        return __bound_empty_t2;
}

/* print a bound error message */
static void bound_error(const char *fmt, ...)
{
    __bound_error_msg = fmt;
    fprintf(stderr,"%s %s: %s\n", __FILE__, __FUNCTION__, fmt);
    *(void **)0 = 0; /* force a runtime error */
}

static void bound_alloc_error(void)
{
    bound_error("not enough memory for bound checking code");
}

/* return '(p + offset)' for pointer arithmetic (a pointer can reach
   the end of a region in this case */
void * FASTCALL __bound_ptr_add(void *p, size_t offset)
{
    size_t addr = (size_t)p;
    BoundEntry *e;

    dprintf(stderr, "%s %s: %p %x\n",
        __FILE__, __FUNCTION__, p, (unsigned)offset);

    __bound_init();

    e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];
    e = (BoundEntry *)((char *)e + 
                       ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) & 
                        ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));
    addr -= e->start;
    if (addr > e->size) {
        e = __bound_find_region(e, p);
        addr = (size_t)p - e->start;
    }
    addr += offset;
    if (addr >= e->size) {
	fprintf(stderr,"%s %s: %p is outside of the region\n",
            __FILE__, __FUNCTION__, p + offset);
        return INVALID_POINTER; /* return an invalid pointer */
    }
    return p + offset;
}

/* return '(p + offset)' for pointer indirection (the resulting must
   be strictly inside the region */
#define BOUND_PTR_INDIR(dsize)                                          \
void * FASTCALL __bound_ptr_indir ## dsize (void *p, size_t offset)     \
{                                                                       \
    size_t addr = (size_t)p;                                            \
    BoundEntry *e;                                                      \
                                                                        \
    dprintf(stderr, "%s %s: %p %x start\n",                             \
        __FILE__, __FUNCTION__, p, (unsigned)offset);	                \
									\
    __bound_init();							\
    e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];            \
    e = (BoundEntry *)((char *)e +                                      \
                       ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) &      \
                        ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));        \
    addr -= e->start;                                                   \
    if (addr > e->size) {                                               \
        e = __bound_find_region(e, p);                                  \
        addr = (size_t)p - e->start;                                    \
    }                                                                   \
    addr += offset + dsize;                                             \
    if (addr > e->size) {                                               \
	fprintf(stderr,"%s %s: %p is outside of the region\n",          \
            __FILE__, __FUNCTION__, p + offset);                        \
        return INVALID_POINTER; /* return an invalid pointer */         \
    }									\
    dprintf(stderr, "%s %s: return p+offset = %p\n",                    \
        __FILE__, __FUNCTION__, p + offset);                            \
    return p + offset;                                                  \
}

BOUND_PTR_INDIR(1)
BOUND_PTR_INDIR(2)
BOUND_PTR_INDIR(4)
BOUND_PTR_INDIR(8)
BOUND_PTR_INDIR(12)
BOUND_PTR_INDIR(16)

#if defined(__GNUC__) && (__GNUC__ >= 6)
/*
 * At least gcc 6.2 complains when __builtin_frame_address is used with
 * nonzero argument.
 */
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wframe-address"
#endif

/* return the frame pointer of the caller */
#define GET_CALLER_FP(fp)\
{\
    fp = (size_t)__builtin_frame_address(1);\
}

/* called when entering a function to add all the local regions */
void FASTCALL __bound_local_new(void *p1) 
{
    size_t addr, size, fp, *p = p1;

    dprintf(stderr, "%s, %s start p1=%p\n", __FILE__, __FUNCTION__, p);
    GET_CALLER_FP(fp);
    for(;;) {
        addr = p[0];
        if (addr == 0)
            break;
        addr += fp;
        size = p[1];
        p += 2;
        __bound_new_region((void *)addr, size);
    }
    dprintf(stderr, "%s, %s end\n", __FILE__, __FUNCTION__);
}

/* called when leaving a function to delete all the local regions */
void FASTCALL __bound_local_delete(void *p1) 
{
    size_t addr, fp, *p = p1;
    GET_CALLER_FP(fp);
    for(;;) {
        addr = p[0];
        if (addr == 0)
            break;
        addr += fp;
        p += 2;
        __bound_delete_region((void *)addr);
    }
}

#if defined(__GNUC__) && (__GNUC__ >= 6)
#pragma GCC diagnostic pop
#endif

static BoundEntry *__bound_new_page(void)
{
    BoundEntry *page;
    size_t i;

    page = libc_malloc(sizeof(BoundEntry) * BOUND_T2_SIZE);
    if (!page)
        bound_alloc_error();
    for(i=0;i<BOUND_T2_SIZE;i++) {
        /* put empty entries */
        page[i].start = 0;
        page[i].size = EMPTY_SIZE;
        page[i].next = NULL;
        page[i].is_invalid = 0;
    }
    return page;
}

/* currently we use malloc(). Should use bound_new_page() */
static BoundEntry *bound_new_entry(void)
{
    BoundEntry *e;
    e = libc_malloc(sizeof(BoundEntry));
    return e;
}

static void bound_free_entry(BoundEntry *e)
{
    libc_free(e);
}

static BoundEntry *get_page(size_t index)
{
    BoundEntry *page;
    page = __bound_t1[index];
    if (!page || page == __bound_empty_t2 || page == __bound_invalid_t2) {
        /* create a new page if necessary */
        page = __bound_new_page();
        __bound_t1[index] = page;
    }
    return page;
}

/* mark a region as being invalid (can only be used during init) */
static void mark_invalid(size_t addr, size_t size)
{
    size_t start, end;
    BoundEntry *page;
    size_t t1_start, t1_end, i, j, t2_start, t2_end;

    start = addr;
    end = addr + size;

    t2_start = (start + BOUND_T3_SIZE - 1) >> BOUND_T3_BITS;
    if (end != 0)
        t2_end = end >> BOUND_T3_BITS;
    else
        t2_end = 1 << (BOUND_T1_BITS + BOUND_T2_BITS);

#if 0
    dprintf(stderr, "mark_invalid: start = %x %x\n", t2_start, t2_end);
#endif
    
    /* first we handle full pages */
    t1_start = (t2_start + BOUND_T2_SIZE - 1) >> BOUND_T2_BITS;
    t1_end = t2_end >> BOUND_T2_BITS;

    i = t2_start & (BOUND_T2_SIZE - 1);
    j = t2_end & (BOUND_T2_SIZE - 1);
    
    if (t1_start == t1_end) {
        page = get_page(t2_start >> BOUND_T2_BITS);
        for(; i < j; i++) {
            page[i].size = INVALID_SIZE;
            page[i].is_invalid = 1;
        }
    } else {
        if (i > 0) {
            page = get_page(t2_start >> BOUND_T2_BITS);
            for(; i < BOUND_T2_SIZE; i++) {
                page[i].size = INVALID_SIZE;
                page[i].is_invalid = 1;
            }
        }
        for(i = t1_start; i < t1_end; i++) {
            __bound_t1[i] = __bound_invalid_t2;
        }
        if (j != 0) {
            page = get_page(t1_end);
            for(i = 0; i < j; i++) {
                page[i].size = INVALID_SIZE;
                page[i].is_invalid = 1;
            }
        }
    }
}

void __bound_init(void)
{
    size_t i;
    BoundEntry *page;
    size_t start, size;
    size_t *p;

    static int inited;
    if (inited)
	return;

    inited = 1;

    dprintf(stderr, "%s, %s() start\n", __FILE__, __FUNCTION__);

    /* save malloc hooks and install bound check hooks */
    install_malloc_hooks();

#ifndef BOUND_STATIC
    __bound_t1 = libc_malloc(BOUND_T1_SIZE * sizeof(BoundEntry *));
    if (!__bound_t1)
        bound_alloc_error();
#endif
    __bound_empty_t2 = __bound_new_page();
    for(i=0;i<BOUND_T1_SIZE;i++) {
        __bound_t1[i] = __bound_empty_t2;
    }

    page = __bound_new_page();
    for(i=0;i<BOUND_T2_SIZE;i++) {
        /* put invalid entries */
        page[i].start = 0;
        page[i].size = INVALID_SIZE;
        page[i].next = NULL;
        page[i].is_invalid = 1;
    }
    __bound_invalid_t2 = page;

    /* invalid pointer zone */
    start = (size_t)INVALID_POINTER & ~(BOUND_T23_SIZE - 1);
    size = BOUND_T23_SIZE;
    mark_invalid(start, size);

#if defined(CONFIG_TCC_MALLOC_HOOKS)
    /* malloc zone is also marked invalid. can only use that with
     * hooks because all libs should use the same malloc. The solution
     * would be to build a new malloc for tcc.
     *
     * usually heap (= malloc zone) comes right after bss, i.e. after _end, but
     * not always - either if we are running from under `tcc -b -run`, or if
     * address space randomization is turned on(a), heap start will be separated
     * from bss end.
     *
     * So sbrk(0) will be a good approximation for start_brk:
     *
     *   - if we are a separately compiled program, __bound_init() runs early,
     *     and sbrk(0) should be equal or very near to start_brk(b) (in case other
     *     constructors malloc something), or
     *
     *   - if we are running from under `tcc -b -run`, sbrk(0) will return
     *     start of heap portion which is under this program control, and not
     *     mark as invalid earlier allocated memory.
     *
     *
     * (a) /proc/sys/kernel/randomize_va_space = 2, on Linux;
     *     usually turned on by default.
     *
     * (b) on Linux >= v3.3, the alternative is to read
     *     start_brk from /proc/self/stat
     */
    start = (size_t)sbrk(0);
    size = 128 * 0x100000;
    mark_invalid(start, size);
#endif

    /* add all static bound check values */
    p = (size_t *)&__bounds_start;
    while (p[0] != 0) {
        __bound_new_region((void *)p[0], p[1]);
        p += 2;
    }

    dprintf(stderr, "%s, %s() end\n\n", __FILE__, __FUNCTION__);
}

void __bound_main_arg(void **p)
{
    void *start = p;
    while (*p++);

    dprintf(stderr, "%s, %s calling __bound_new_region(%p %x)\n",
            __FILE__, __FUNCTION__, start, (unsigned)((void *)p - start));

    __bound_new_region(start, (void *) p - start);
}

void __bound_exit(void)
{
    dprintf(stderr, "%s, %s()\n", __FILE__, __FUNCTION__);
    restore_malloc_hooks();
}

static inline void add_region(BoundEntry *e, 
                              size_t start, size_t size)
{
    BoundEntry *e1;
    if (e->start == 0) {
        /* no region : add it */
        e->start = start;
        e->size = size;
    } else {
        /* already regions in the list: add it at the head */
        e1 = bound_new_entry();
        e1->start = e->start;
        e1->size = e->size;
        e1->next = e->next;
        e->start = start;
        e->size = size;
        e->next = e1;
    }
}

/* create a new region. It should not already exist in the region list */
void __bound_new_region(void *p, size_t size)
{
    size_t start, end;
    BoundEntry *page, *e, *e2;
    size_t t1_start, t1_end, i, t2_start, t2_end;

    dprintf(stderr, "%s, %s(%p, %x) start\n",
        __FILE__, __FUNCTION__, p, (unsigned)size);

    __bound_init();

    start = (size_t)p;
    end = start + size;
    t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
    t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);

    /* start */
    page = get_page(t1_start);
    t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) & 
        ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
    t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) & 
        ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);


    e = (BoundEntry *)((char *)page + t2_start);
    add_region(e, start, size);

    if (t1_end == t1_start) {
        /* same ending page */
        e2 = (BoundEntry *)((char *)page + t2_end);
        if (e2 > e) {
            e++;
            for(;e<e2;e++) {
                e->start = start;
                e->size = size;
            }
            add_region(e, start, size);
        }
    } else {
        /* mark until end of page */
        e2 = page + BOUND_T2_SIZE;
        e++;
        for(;e<e2;e++) {
            e->start = start;
            e->size = size;
        }
        /* mark intermediate pages, if any */
        for(i=t1_start+1;i<t1_end;i++) {
            page = get_page(i);
            e2 = page + BOUND_T2_SIZE;
            for(e=page;e<e2;e++) {
                e->start = start;
                e->size = size;
            }
        }
        /* last page */
        page = get_page(t1_end);
        e2 = (BoundEntry *)((char *)page + t2_end);
        for(e=page;e<e2;e++) {
            e->start = start;
            e->size = size;
        }
        add_region(e, start, size);
    }

    dprintf(stderr, "%s, %s end\n", __FILE__, __FUNCTION__);
}

/* delete a region */
static inline void delete_region(BoundEntry *e, void *p, size_t empty_size)
{
    size_t addr;
    BoundEntry *e1;

    addr = (size_t)p;
    addr -= e->start;
    if (addr <= e->size) {
        /* region found is first one */
        e1 = e->next;
        if (e1 == NULL) {
            /* no more region: mark it empty */
            e->start = 0;
            e->size = empty_size;
        } else {
            /* copy next region in head */
            e->start = e1->start;
            e->size = e1->size;
            e->next = e1->next;
            bound_free_entry(e1);
        }
    } else {
        /* find the matching region */
        for(;;) {
            e1 = e;
            e = e->next;
            /* region not found: do nothing */
            if (e == NULL)
                break;
            addr = (size_t)p - e->start;
            if (addr <= e->size) {
                /* found: remove entry */
                e1->next = e->next;
                bound_free_entry(e);
                break;
            }
        }
    }
}

/* WARNING: 'p' must be the starting point of the region. */
/* return non zero if error */
int __bound_delete_region(void *p)
{
    size_t start, end, addr, size, empty_size;
    BoundEntry *page, *e, *e2;
    size_t t1_start, t1_end, t2_start, t2_end, i;

    dprintf(stderr, "%s %s() start\n", __FILE__, __FUNCTION__);

    __bound_init();

    start = (size_t)p;
    t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
    t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) & 
        ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
    
    /* find region size */
    page = __bound_t1[t1_start];
    e = (BoundEntry *)((char *)page + t2_start);
    addr = start - e->start;
    if (addr > e->size)
        e = __bound_find_region(e, p);
    /* test if invalid region */
    if (e->size == EMPTY_SIZE || (size_t)p != e->start) 
        return -1;
    /* compute the size we put in invalid regions */
    if (e->is_invalid)
        empty_size = INVALID_SIZE;
    else
        empty_size = EMPTY_SIZE;
    size = e->size;
    end = start + size;

    /* now we can free each entry */
    t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);
    t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) & 
        ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);

    delete_region(e, p, empty_size);
    if (t1_end == t1_start) {
        /* same ending page */
        e2 = (BoundEntry *)((char *)page + t2_end);
        if (e2 > e) {
            e++;
            for(;e<e2;e++) {
                e->start = 0;
                e->size = empty_size;
            }
            delete_region(e, p, empty_size);
        }
    } else {
        /* mark until end of page */
        e2 = page + BOUND_T2_SIZE;
        e++;
        for(;e<e2;e++) {
            e->start = 0;
            e->size = empty_size;
        }
        /* mark intermediate pages, if any */
        /* XXX: should free them */
        for(i=t1_start+1;i<t1_end;i++) {
            page = get_page(i);
            e2 = page + BOUND_T2_SIZE;
            for(e=page;e<e2;e++) {
                e->start = 0;
                e->size = empty_size;
            }
        }
        /* last page */
        page = get_page(t1_end);
        e2 = (BoundEntry *)((char *)page + t2_end);
        for(e=page;e<e2;e++) {
            e->start = 0;
            e->size = empty_size;
        }
        delete_region(e, p, empty_size);
    }

    dprintf(stderr, "%s %s() end\n", __FILE__, __FUNCTION__);

    return 0;
}

/* return the size of the region starting at p, or EMPTY_SIZE if non
   existent region. */
static size_t get_region_size(void *p)
{
    size_t addr = (size_t)p;
    BoundEntry *e;

    e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];
    e = (BoundEntry *)((char *)e + 
                       ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) & 
                        ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));
    addr -= e->start;
    if (addr > e->size)
        e = __bound_find_region(e, p);
    if (e->start != (size_t)p)
        return EMPTY_SIZE;
    return e->size;
}

/* patched memory functions */

/* force compiler to perform stores coded up to this point */
#define barrier()   __asm__ __volatile__ ("": : : "memory")

static void install_malloc_hooks(void)
{
#ifdef CONFIG_TCC_MALLOC_HOOKS
    saved_malloc_hook = __malloc_hook;
    saved_free_hook = __free_hook;
    saved_realloc_hook = __realloc_hook;
    saved_memalign_hook = __memalign_hook;
    __malloc_hook = __bound_malloc;
    __free_hook = __bound_free;
    __realloc_hook = __bound_realloc;
    __memalign_hook = __bound_memalign;

    barrier();
#endif
}

static void restore_malloc_hooks(void)
{
#ifdef CONFIG_TCC_MALLOC_HOOKS
    __malloc_hook = saved_malloc_hook;
    __free_hook = saved_free_hook;
    __realloc_hook = saved_realloc_hook;
    __memalign_hook = saved_memalign_hook;

    barrier();
#endif
}

static void *libc_malloc(size_t size)
{
    void *ptr;
    restore_malloc_hooks();
    ptr = malloc(size);
    install_malloc_hooks();
    return ptr;
}

static void libc_free(void *ptr)
{
    restore_malloc_hooks();
    free(ptr);
    install_malloc_hooks();
}

/* XXX: we should use a malloc which ensure that it is unlikely that
   two malloc'ed data have the same address if 'free' are made in
   between. */
void *__bound_malloc(size_t size, const void *caller)
{
    void *ptr;
    
    /* we allocate one more byte to ensure the regions will be
       separated by at least one byte. With the glibc malloc, it may
       be in fact not necessary */
    ptr = libc_malloc(size + 1);
    
    if (!ptr)
        return NULL;

    dprintf(stderr, "%s, %s calling __bound_new_region(%p, %x)\n",
           __FILE__, __FUNCTION__, ptr, (unsigned)size);

    __bound_new_region(ptr, size);
    return ptr;
}

void *__bound_memalign(size_t size, size_t align, const void *caller)
{
    void *ptr;

    restore_malloc_hooks();

#ifndef HAVE_MEMALIGN
    if (align > 4) {
        /* XXX: handle it ? */
        ptr = NULL;
    } else {
        /* we suppose that malloc aligns to at least four bytes */
        ptr = malloc(size + 1);
    }
#else
    /* we allocate one more byte to ensure the regions will be
       separated by at least one byte. With the glibc malloc, it may
       be in fact not necessary */
    ptr = memalign(size + 1, align);
#endif
    
    install_malloc_hooks();
    
    if (!ptr)
        return NULL;

    dprintf(stderr, "%s, %s calling __bound_new_region(%p, %x)\n",
           __FILE__, __FUNCTION__, ptr, (unsigned)size);

    __bound_new_region(ptr, size);
    return ptr;
}

void __bound_free(void *ptr, const void *caller)
{
    if (ptr == NULL)
        return;
    if (__bound_delete_region(ptr) != 0)
        bound_error("freeing invalid region");

    libc_free(ptr);
}

void *__bound_realloc(void *ptr, size_t size, const void *caller)
{
    void *ptr1;
    size_t old_size;

    if (size == 0) {
        __bound_free(ptr, caller);
        return NULL;
    } else {
        ptr1 = __bound_malloc(size, caller);
        if (ptr == NULL || ptr1 == NULL)
            return ptr1;
        old_size = get_region_size(ptr);
        if (old_size == EMPTY_SIZE)
            bound_error("realloc'ing invalid pointer");
        memcpy(ptr1, ptr, old_size);
        __bound_free(ptr, caller);
        return ptr1;
    }
}

#ifndef CONFIG_TCC_MALLOC_HOOKS
void *__bound_calloc(size_t nmemb, size_t size)
{
    void *ptr;
    size = size * nmemb;
    ptr = __bound_malloc(size, NULL);
    if (!ptr)
        return NULL;
    memset(ptr, 0, size);
    return ptr;
}
#endif

#if 0
static void bound_dump(void)
{
    BoundEntry *page, *e;
    size_t i, j;

    fprintf(stderr, "region dump:\n");
    for(i=0;i<BOUND_T1_SIZE;i++) {
        page = __bound_t1[i];
        for(j=0;j<BOUND_T2_SIZE;j++) {
            e = page + j;
            /* do not print invalid or empty entries */
            if (e->size != EMPTY_SIZE && e->start != 0) {
                fprintf(stderr, "%08x:", 
                       (i << (BOUND_T2_BITS + BOUND_T3_BITS)) + 
                       (j << BOUND_T3_BITS));
                do {
                    fprintf(stderr, " %08lx:%08lx", e->start, e->start + e->size);
                    e = e->next;
                } while (e != NULL);
                fprintf(stderr, "\n");
            }
        }
    }
}
#endif

/* some useful checked functions */

/* check that (p ... p + size - 1) lies inside 'p' region, if any */
static void __bound_check(const void *p, size_t size)
{
    if (size == 0)
        return;
    p = __bound_ptr_add((void *)p, size - 1);
    if (p == INVALID_POINTER)
        bound_error("invalid pointer");
}

void *__bound_memcpy(void *dst, const void *src, size_t size)
{
    void* p;

    dprintf(stderr, "%s %s: start, dst=%p src=%p size=%x\n",
            __FILE__, __FUNCTION__, dst, src, (unsigned)size);

    __bound_check(dst, size);
    __bound_check(src, size);
    /* check also region overlap */
    if (src >= dst && src < dst + size)
        bound_error("overlapping regions in memcpy()");

    p = memcpy(dst, src, size);

    dprintf(stderr, "%s %s: end, p=%p\n", __FILE__, __FUNCTION__, p);
    return p;
}

void *__bound_memmove(void *dst, const void *src, size_t size)
{
    __bound_check(dst, size);
    __bound_check(src, size);
    return memmove(dst, src, size);
}

void *__bound_memset(void *dst, int c, size_t size)
{
    __bound_check(dst, size);
    return memset(dst, c, size);
}

/* XXX: could be optimized */
int __bound_strlen(const char *s)
{
    const char *p;
    size_t len;

    len = 0;
    for(;;) {
        p = __bound_ptr_indir1((char *)s, len);
        if (p == INVALID_POINTER)
            bound_error("bad pointer in strlen()");
        if (*p == '\0')
            break;
        len++;
    }
    return len;
}

char *__bound_strcpy(char *dst, const char *src)
{
    size_t len;
    void *p;

    dprintf(stderr, "%s %s: strcpy start, dst=%p src=%p\n",
            __FILE__, __FUNCTION__, dst, src);
    len = __bound_strlen(src);
    p = __bound_memcpy(dst, src, len + 1);
    dprintf(stderr, "%s %s: strcpy end, p = %p\n",
            __FILE__, __FUNCTION__, p);
    return p;
}