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PR_SET_UNALIGN - set unaligned access control bits

NAME  LIBRARY  SYNOPSIS  DESCRIPTION  RETURN VALUE  ERRORS  STANDARDS  HISTORY  SEE ALSO 

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:

ia64, since Linux 2.3.48

parisc, since Linux 2.6.15

PowerPC, since Linux 2.6.18

Alpha, since Linux 2.6.22

sh, since Linux 2.6.34

tile, since Linux 3.12

SEE ALSO

prctl(2), PR_GET_UNALIGN(2const)


Updated 2026-06-01 - jenkler.se | uex.se