PR_SET_MM_EXE_FILE(2const) — Linux manual page

PR_SET_MM_EXE_FILE(2const)                     PR_SET_MM_EXE_FILE(2const)

NAME         top

       PR_SET_MM_EXE_FILE - modify kernel memory map descriptor fields

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #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         top

       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         top

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

ERRORS         top

       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         top

       /proc/pid/exe

STANDARDS         top

       Linux.

HISTORY         top

       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         top

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

COLOPHON         top

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.15.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2025-08-11.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to
       [email protected]

Linux man-pages 6.15            2025-05-17     PR_SET_MM_EXE_FILE(2const)

Pages that refer to this page: PR_SET_MM(2const),  PR_SET_MM_MAP(2const)

HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.