proc_pid_map_files(5)	       File Formats Manual	   proc_pid_map_files(5)

NAME
     /proc/pid/map_files/ - memory-mapped files

DESCRIPTION
     /proc/pid/map_files/ (since Linux 3.3)
	    This  subdirectory	contains  entries corresponding to memory-mapped
	    files (see mmap(2)).  Entries are named by memory region  start  and
	    end	 address  pair	(expressed as hexadecimal numbers), and are sym-
	    bolic links to the mapped files themselves.	  Here	is  an	example,
	    with  the output wrapped and reformatted to fit on an 80-column dis-
	    play:

		# ls -l /proc/self/map_files/
		lr-------- 1 root root 64 Apr 16 21:31
			    3252e00000-3252e20000 -> /usr/lib64/ld-2.15.so
		...

	    Although these entries are present	for  memory  regions  that  were
	    mapped  with the MAP_FILE flag, the way anonymous shared memory (re-
	    gions created with the MAP_ANON | MAP_SHARED flags)	 is  implemented
	    in	Linux  means  that  such  regions also appear on this directory.
	    Here is an example where the target file is	 the  deleted  /dev/zero
	    one:

		lrw------- 1 root root 64 Apr 16 21:33
			    7fc075d2f000-7fc075e6f000 -> /dev/zero (deleted)

	    Permission	to  access this file is governed by a ptrace access mode
	    PTRACE_MODE_READ_FSCREDS check; see ptrace(2).

	    Until Linux 4.3, this directory appeared only if  the  CONFIG_CHECK-
	    POINT_RESTORE kernel configuration option was enabled.

	    Capabilities are required to read the contents of the symbolic links
	    in	this  directory:  before Linux 5.9, the reading process requires
	    CAP_SYS_ADMIN in the initial user namespace; since	Linux  5.9,  the
	    reading process must have either CAP_SYS_ADMIN or CAP_CHECKPOINT_RE-
	    STORE in the initial (i.e., root) user namespace.

SEE ALSO
     proc(5)

Linux man-pages 6.18		   2026-02-08		   proc_pid_map_files(5)