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 */
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 */
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#include <libc.h>
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#include <libc.h>
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#include <unistd.h>
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#include <unistd.h>
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/** Mremap syscall */
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void *mremap(void *address, size_t size, unsigned long flags)
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void *mremap(void *address, size_t size, unsigned long flags)
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{
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{
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    return (void *) __SYSCALL3(SYS_MREMAP, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
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    return (void *) __SYSCALL3(SYS_MREMAP, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
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}
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}
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static size_t heapsize = 0;
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/* Start of heap linker symbol */
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extern char _heap;
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/** Sbrk emulation
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 *
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 * @param size New area that should be allocated or negative,
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               if it should be shrinked
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 * @return Pointer to newly allocated area
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 */
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void *sbrk(ssize_t incr)
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{
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    void *res;
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    /* Check for invalid values */
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    if (incr < 0 && -incr > heapsize)
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        return NULL;
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    /* Check for too large value */
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    if (incr > 0 && incr+heapsize < heapsize)
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        return NULL;
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    /* Check for too small values */
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    if (incr < 0 && incr+heapsize > heapsize)
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        return NULL;
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    res = mremap(&_heap, heapsize + incr,0);
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    if (!res)
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        return NULL;
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    res = (void *)&_heap + incr;
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    heapsize += incr;
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    return res;
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}