plucky (2) PR_SET_MM_EXE_FILE.2const.gz

NAME

       PR_SET_MM_EXE_FILE - modify kernel memory map descriptor fields

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

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

       int prctl(PR_SET_MM, PR_SET_MM_EXE_FILE, long fd, 0L, 0L);

DESCRIPTION

       Supersede  the /proc/pid/exe symbolic link with a new one pointing to a new executable file identified by
       the file descriptor provided in the fd argument.  The file descriptor should be obtained with  a  regular
       open(2) call.

       To  change  the  symbolic  link, one needs to unmap all existing executable memory areas, including those
       created by the kernel itself (for example the kernel usually creates at least one executable memory  area
       for the ELF .text section).

RETURN VALUE

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

ERRORS

       EACCES The file is not executable.

       EBADF  The file descriptor passed in fd is not valid.

       EBUSY  This the second attempt to change the /proc/pid/exe symbolic link.

FILES

       /proc/pid/exe

STANDARDS

       Linux.

HISTORY

       Linux 3.5.

       In  Linux  4.9  and  earlier,  the PR_SET_MM_EXE_FILE operation can be performed only once in a process's
       lifetime; attempting to perform the operation a second time results in the error EPERM.  This restriction
       was enforced for security reasons that were subsequently deemed specious, and the restriction was removed
       in Linux 4.10 because some user-space applications needed to perform this operation more than once.

SEE ALSO

       prctl(2), PR_SET_MM(2const), proc_pid_exe(5)