From 3af6d22bb3850ab2bac67287e3a3d3b0e32868e5 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 15 Apr 2024 21:41:07 +0200 Subject: Merging upstream version 6.7. Signed-off-by: Daniel Baumann --- man5/proc_pid_map_files.5 | 72 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 man5/proc_pid_map_files.5 (limited to 'man5/proc_pid_map_files.5') diff --git a/man5/proc_pid_map_files.5 b/man5/proc_pid_map_files.5 new file mode 100644 index 0000000..5b50c45 --- /dev/null +++ b/man5/proc_pid_map_files.5 @@ -0,0 +1,72 @@ +.\" Copyright (C) 1994, 1995, Daniel Quinlan +.\" Copyright (C) 2002-2008, 2017, Michael Kerrisk +.\" Copyright (C) 2023, Alejandro Colomar +.\" +.\" SPDX-License-Identifier: GPL-3.0-or-later +.\" +.TH proc_pid_map_files 5 2023-08-15 "Linux man-pages 6.7" +.SH NAME +/proc/pid/map_files/ \- memory-mapped files +.SH DESCRIPTION +.TP +.IR /proc/ pid /map_files/ " (since Linux 3.3)" +.\" commit 640708a2cff7f81e246243b0073c66e6ece7e53e +This subdirectory contains entries corresponding to memory-mapped +files (see +.BR mmap (2)). +Entries are named by memory region start and end +address pair (expressed as hexadecimal numbers), +and are symbolic links to the mapped files themselves. +Here is an example, +with the output wrapped and reformatted to fit on an 80-column display: +.IP +.in +4n +.EX +.RB "#" " ls \-l /proc/self/map_files/" +lr\-\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:31 + 3252e00000\-3252e20000 \-> /usr/lib64/ld\-2.15.so +\&... +.EE +.in +.IP +Although these entries are present for memory regions that were +mapped with the +.B MAP_FILE +flag, the way anonymous shared memory (regions created with the +.B 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 +.I /dev/zero +one: +.IP +.in +4n +.EX +lrw\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:33 + 7fc075d2f000\-7fc075e6f000 \-> /dev/zero (deleted) +.EE +.in +.IP +Permission to access this file is governed by a ptrace access mode +.B PTRACE_MODE_READ_FSCREDS +check; see +.BR ptrace (2). +.IP +Until Linux 4.3, +.\" commit bdb4d100afe9818aebd1d98ced575c5ef143456c +this directory appeared only if the +.B CONFIG_CHECKPOINT_RESTORE +kernel configuration option was enabled. +.IP +Capabilities are required to read the contents of the symbolic links in +this directory: before Linux 5.9, the reading process requires +.B CAP_SYS_ADMIN +in the initial user namespace; +since Linux 5.9, the reading process must have either +.B CAP_SYS_ADMIN +or +.B CAP_CHECKPOINT_RESTORE +in the initial (i.e. root) user namespace. +.SH SEE ALSO +.BR proc (5) -- cgit v1.2.3