term% cat index.txt SEGBRK(2) System Calls Manual SEGBRK(2)
NAME
segbrk - change memory allocation
SYNOPSIS
#include <u.h>
#include <libc.h>
void* segbrk(void *saddr, void *addr)
DESCRIPTION
Segbrk sets the system's idea of the lowest unused location of a seg‐
ment to addr rounded up to the next multiple of a page size, typically
4096 bytes. The segment is identified by saddr which may be any valid
address within the segment.
A call to segbrk with a zero addr argument returns the address of the
top of bss.
The system will prevent segments from overlapping and will not allow
the length of the text, data, or stack segment to be altered.
SOURCE
/sys/src/libc/9syscall
SEE ALSO
brk(2), segattach(2), segflush(2)
/proc/*/segment
DIAGNOSTICS
Sets errstr. Segbrk returns (void*)-1 on error.
BUGS
Segbrk is not fully defined or implemented. In particular, it cannot
always return the top of bss when called with a zero addr argument.
The segbrk system call may go away or be re-implemented to give more
general segment control, subsuming the functions of brk(2), segflush(2)
and segfree in segattach(2).
SEGBRK(2)