42 lines
848 B
C
42 lines
848 B
C
/* libc/sys/linux/brk.c - Change data segment size */
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/* Written 2000 by Werner Almesberger */
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#include <stddef.h> /* for NULL */
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#include <sys/types.h>
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#include <sys/unistd.h>
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#include <machine/syscall.h>
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static char *curr_brk = NULL;
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#define __NR___brk __NR_brk /* Linux brk ain't no brk(2) */
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static _syscall1(void *,__brk,void *,end_data_segment)
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int brk(void *end_data_segment)
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{
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char *new_brk;
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new_brk = __brk(end_data_segment);
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if (new_brk != end_data_segment) return -1;
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curr_brk = new_brk;
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return 0;
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}
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void *sbrk(size_t increment) /* SHOULD be ptrdiff_t */
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{
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char *old_brk,*new_brk;
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if (!curr_brk) curr_brk = __brk(NULL);
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new_brk = __brk(curr_brk+increment);
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if (new_brk != curr_brk+increment) return (void *) -1;
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old_brk = curr_brk;
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curr_brk = new_brk;
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return old_brk;
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}
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