# proc_pid_maps - mapped memory regions - man(5) - [phpMan]

[_proc_pid_maps_(5)](https://www.chedong.com/phpMan.php/man/procpidmaps/5/markdown)                         File Formats Manual                        [_proc_pid_maps_(5)](https://www.chedong.com/phpMan.php/man/procpidmaps/5/markdown)

## NAME
       /proc/pid/maps - mapped memory regions

## DESCRIPTION
       _/proc/_pid_/maps_
              A  file  containing  the currently mapped memory regions and their access permissions.
              See [**mmap**(2)](https://www.chedong.com/phpMan.php/man/mmap/2/markdown) for some further information about memory mappings.

              Permission  to  access   this   file   is   governed   by   a   ptrace   access   mode
              **PTRACE_MODE_READ_FSCREDS **check; see [**ptrace**(2)](https://www.chedong.com/phpMan.php/man/ptrace/2/markdown).

              The format of the file is:

                  _address_           _perms_ _offset_  _dev_   _inode_       _pathname_
                  00400000-00452000 r-xp 00000000 08:02 173521      /usr/bin/dbus-daemon
                  00651000-00652000 r--p 00051000 08:02 173521      /usr/bin/dbus-daemon
                  00652000-00655000 rw-p 00052000 08:02 173521      /usr/bin/dbus-daemon
                  00e03000-00e24000 rw-p 00000000 00:00 0           [heap]
                  00e24000-011f7000 rw-p 00000000 00:00 0           [heap]
                  ...
                  35b1800000-35b1820000 r-xp 00000000 08:02 135522  /usr/lib64/ld-2.15.so
                  35b1a1f000-35b1a20000 r--p 0001f000 08:02 135522  /usr/lib64/ld-2.15.so
                  35b1a20000-35b1a21000 rw-p 00020000 08:02 135522  /usr/lib64/ld-2.15.so
                  35b1a21000-35b1a22000 rw-p 00000000 00:00 0
                  35b1c00000-35b1dac000 r-xp 00000000 08:02 135870  /usr/lib64/libc-2.15.so
                  35b1dac000-35b1fac000 ---p 001ac000 08:02 135870  /usr/lib64/libc-2.15.so
                  35b1fac000-35b1fb0000 r--p 001ac000 08:02 135870  /usr/lib64/libc-2.15.so
                  35b1fb0000-35b1fb2000 rw-p 001b0000 08:02 135870  /usr/lib64/libc-2.15.so
                  ...
                  f2c6ff8c000-7f2c7078c000 rw-p 00000000 00:00 0    [stack:986]
                  ...
                  7fffb2c0d000-7fffb2c2e000 rw-p 00000000 00:00 0   [stack]
                  7fffb2d48000-7fffb2d49000 r-xp 00000000 00:00 0   [vdso]

              The  _address_ field is the address space in the process that the mapping occupies.  The
              _perms_ field is a set of permissions:

                  r = read
                  w = write
                  x = execute
                  s = shared
                  p = private (copy on write)

              The _offset_ field is the offset into the file/whatever; _dev_ is  the  device  (major:mi‐
              nor); _inode_ is the inode on that device.  0 indicates that no inode is associated with
              the memory region, as would be the case with BSS (uninitialized data).

              The  _pathname_  field  will  usually  be the file that is backing the mapping.  For ELF
              files, you can easily coordinate with the _offset_ field by looking at the Offset  field
              in the ELF program headers (_readelf_ _-l_).

              There are additional helpful pseudo-paths:

              _[stack]_
                     The initial process's (also known as the main thread's) stack.

              _[stack:_tid_]_ (from Linux 3.4 to Linux 4.4)
                     A  thread's  stack  (where  the  _tid_  is  a  thread ID).  It corresponds to the
                     _/proc/_pid_/task/_tid_/_ path.  This field was removed in Linux 4.5, since providing
                     this information for a process with large numbers of threads is expensive.

              _[vdso]_ The virtual dynamically linked shared object.  See [**vdso**(7)](https://www.chedong.com/phpMan.php/man/vdso/7/markdown).

              _[heap]_ The process's heap.

              _[anon:_name_]_ (since Linux 5.17)
                     A named private anonymous mapping.  Set with [**prctl**(2)](https://www.chedong.com/phpMan.php/man/prctl/2/markdown) **PR_SET_VMA_ANON_NAME**.

              _[anon_shmem:_name_]_ (since Linux 6.2)
                     A named shared anonymous mapping.  Set with [**prctl**(2)](https://www.chedong.com/phpMan.php/man/prctl/2/markdown) **PR_SET_VMA_ANON_NAME**.

              If the _pathname_ field is blank, this is an anonymous mapping as obtained via  [**mmap**(2)](https://www.chedong.com/phpMan.php/man/mmap/2/markdown).
              There  is  no easy way to coordinate this back to a process's source, short of running
              it through [**gdb**(1)](https://www.chedong.com/phpMan.php/man/gdb/1/markdown), [**strace**(1)](https://www.chedong.com/phpMan.php/man/strace/1/markdown), or similar.

              _pathname_ is shown unescaped except for newline characters, which are replaced with  an
              octal escape sequence.  As a result, it is not possible to determine whether the orig‐
              inal pathname contained a newline character or the literal _\012_ character sequence.

              If  the  mapping is file-backed and the file has been deleted, the string " (deleted)"
              is appended to the pathname.  Note that this is ambiguous too.

              Under Linux 2.0, there is no field giving pathname.

## SEE ALSO
       [**proc**(5)](https://www.chedong.com/phpMan.php/man/proc/5/markdown)

Linux man-pages 6.7                          2023-09-07                             [_proc_pid_maps_(5)](https://www.chedong.com/phpMan.php/man/procpidmaps/5/markdown)