PR_SET_MM_EXE_FILE(2const) — Linux manual page

PR_SET_MM_EXE_FILE(2const)                    PR_SET_MM_EXE_FILE(2const)

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)

COLOPHON

       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-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  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
       man-pages@man7.org

Linux man-pages 6.9.1          2024-06-01     PR_SET_MM_EXE_FILE(2const)

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

---