PR_GET_TID_ADDRESS - get the clear_child_tid address

NAME  LIBRARY  SYNOPSIS  DESCRIPTION  RETURN VALUE  ERRORS  STANDARDS  HISTORY  CAVEATS  SEE ALSO 

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NAME

PR_GET_TID_ADDRESS − get the clear_child_tid address

LIBRARY

Standard C library (libc, −lc)

SYNOPSIS

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

int prctl(PR_GET_TID_ADDRESS, int **addrp);

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)

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