pr_get_tid_address(2const)

NAME#

PR_GET_TID_ADDRESS - get the clear_child_tid address

LIBRARY#

Standard C library (libc, -lc)

SYNOPSIS#

#include <linux/prctl.h>\n  /* Definition of \nPR_*\n constants */
\n#include <sys/prctl.h>

int prctl(PR_GET_TID_ADDRESS, int **\naddrp\n);

DESCRIPTION#

Return the clear_child_tid address set by set_tid_address(2) and the clone(2) CLONE_CHILD_CLEARTID flag, in the location pointed to by addrp.

This feature is available only if the kernel is built with the CONFIG_CHECKPOINT_RESTORE option enabled.

RETURN VALUE#

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

ERRORS#

EFAULT

addrp is an invalid address.

STANDARDS#

Linux.

HISTORY#

Linux 3.5.

CAVEATS#

Note that since the prctl() system call does not have a compat implementation for the AMD64 x32 and MIPS n32 ABIs, and the kernel writes out a pointer using the kernel's pointer size, this operation expects a user-space buffer of 8 (not 4) bytes on these ABIs.

SEE ALSO#

prctl(2)