linux_mremap() with MREMAP_MAYMOVE - not implemented?

[u-klys at aetey.se]

Hello,

I am to run Linux binaries (i386) under FreeBSD 11.0-RELEASE (amd64).

The behaviour which surprises me is as follows

$ truss ./rea
linux_set_thread_area(0xffffcc3c)                = 0 (0x0)
linux_set_tid_address(0x804fb2c)                 = 75293 (0x1261d)
linux_mmap2(0x0,0x101000,0x3,0x22,0xffffffff,0x0) = 671412224 (0x2804f000)
linux_mremap(0x2804f000,0x101000,0x201000,0x1,0x0) ERR#-12 'Cannot allocate memory'
linux_ioctl(0x1,0x5413,0xffffcae4)               = 0 (0x0)
FAILED REALLOCATING from 1 M to 2 M
linux_writev(0x1,0xffffcab4,0x2)                 = 35 (0x23)
linux_exit_group(0x0)
process exit, rval = 0
$

The test binary is compiled under Linux from 

$ cat rea.c
#include <stdio.h>
#include <stdlib.h>

#define DELTA (1024*1024)

int main( int argc, char **argv ){
  unsigned int i = DELTA;
  char *p, *q;

  if( !(p = malloc(i)) ) return 1;

  while( (q=realloc(p, (i+=DELTA))) )
    p = q;

  printf("FAILED REALLOCATING from %u M to %u M\n", i/DELTA-1, i/DELTA);

  return 0;
}
$

and statically linked against musl standard C library which relies
on mremap() in its malloc implementation.

Is support for MREMAP_MAYMOVE missing?

Regards,
Rune