Attachment 61478 Details for Bug 139376

a test case that shows the problem

test.c (text/x-csrc), 997 bytes, created by Petr Mladek on 2005-12-20 16:52:30 UTC

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Creator: Petr Mladek

Created: 2005-12-20 16:52:30 UTC

Size: 997 bytes

patch

obsolete

>#include <stdio.h>
>#include <stdlib.h>
>
>/**
> * Maximum value of a (void*) - use to indicate the limit of an 'infinite' buffer.
> * In fact, buffer sizes must not exceed 2GB so that the difference between
> * the buffer limit and the buffer start can be expressed in an int32_t.
> *
> * The definition of U_MAX_PTR must fulfill the following conditions:
> * - return the largest possible pointer greater than base
> * - return a valid pointer according to the machine architecture (AS/400, 64-bit, etc.)
> * - avoid wrapping around at high addresses
> * - make sure that the returned pointer is not farther from base than 0x7fffffff
> *
> * @param base The beginning of a buffer to find the maximum offset from
> * @internal
> */
>#    define U_MAX_PTR(base) ((void *)(((char *)(base)+0x7fffffff) > (char *)(base) ? ((char *)(base)+0x7fffffff) : (char *)-1))
>
>int main()
>{
>    char *p1=(char*)0xffffa0ec;
>    char *p2=(char*)U_MAX_PTR(p1);
>    printf ("p1=%p\n",p1);
>    printf ("p2=%p\n",p2);
>    return 0;
>
>}

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Attachments on bug 139376: 61478