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NAME | DESCRIPTION | SEE ALSO | COLOPHON |
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proc_pid_map_files(5) File Formats Manual proc_pid_map_files(5)
/proc/pid/map_files/ - memory-mapped files
/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 symbolic links to the mapped
files themselves. Here is an example, with the output
wrapped and reformatted to fit on an 80-column display:
# 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 (regions 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_CHECKPOINT_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_RESTORE in the
initial (i.e. root) user namespace.
proc(5)
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 2024-05-02 proc_pid_map_files(5)
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HTML rendering created 2024-06-26 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. |
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