PR_SET_UNALIGN(2const)                                  PR_SET_UNALIGN(2const)

NAME
       PR_SET_UNALIGN - set unaligned access control bits

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <linux/prctl.h>  /* Definition of PR_* constants */
       #include <sys/prctl.h>

       int prctl(PR_SET_UNALIGN, unsigned long flag);

DESCRIPTION
       Set unaligned access control bits to arg2.

       Pass PR_UNALIGN_NOPRINT to silently fix up unaligned user accesses, or
       PR_UNALIGN_SIGBUS to generate SIGBUS on unaligned user access.

       Alpha also supports an additional flag with the value of 4 and no
       corresponding named constant, which instructs kernel to not fix up
       unaligned accesses (it is analogous to providing the UAC_NOFIX flag in
       SSI_NVPAIRS operation of the setsysinfo() system call on Tru64).

RETURN VALUE
       On success, 0 is returned.  On error, -1 is returned, and errno is set
       to indicate the error.

ERRORS
       EINVAL flag is not a valid value.

STANDARDS
       Linux.

HISTORY
       Only on:

       o  ia64, since Linux 2.3.48
       o  parisc, since Linux 2.6.15
       o  PowerPC, since Linux 2.6.18
       o  Alpha, since Linux 2.6.22
       o  sh, since Linux 2.6.34
       o  tile, since Linux 3.12

SEE ALSO
       prctl(2), PR_GET_UNALIGN(2const)

Linux man-pages 6.18              2026-02-08            PR_SET_UNALIGN(2const)