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 per-
formed only once in a process's lifetime; attempting to perform the op-
eration 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)
Linux man-pages 6.9.1 2024-06-01 PR_SET_MM_EXE_FILE(2const)
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