add clang

05/tcc-final-old/lib/bcheck.c

@@ -0,0 +1,979 @@
+/*
+ *  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;
+}