---
name: "proc_pid"
section: "5"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/proc_pid"
---

# proc\_pid(5)

process information

## NAME

/proc/pid/, /proc/self/ - process information

## DESCRIPTION

- */proc/*pid*/*

  There is a numerical subdirectory for each running process; the subdirectory is named by the process ID. Each */proc/*pid subdirectory contains the pseudo-files and directories described below.

-

  The files inside each */proc/*pid directory are normally owned by the effective user and effective group ID of the process. However, as a security measure, the ownership is made *root:root* if the process's "dumpable" attribute is set to a value other than 1.

-

  Before Linux 4.11, *root:root* meant the "global" root user ID and group ID (i.e., UID 0 and GID 0 in the initial user namespace). Since Linux 4.11, if when the last time the process called [**execve**(2)](/execve/2.md), it was in a noninitial user namespace that has a valid mapping for user (group) ID 0 inside the namespace, then the user (group) ownership of the files under */proc/*pid is instead made the same as the root user (group) ID of the namespace. This means that inside a container, things work as expected for the container "root" user.

-

  The process's "dumpable" attribute may change for the following reasons:

  - •

    The attribute was explicitly set via the [**prctl**(2)](/prctl/2.md) **PR\_SET\_DUMPABLE** operation.

  - •

    The attribute was reset to the value in the file */proc/sys/fs/suid\_dumpable* (described below), for the reasons described in [**prctl**(2)](/prctl/2.md).

-

  Resetting the "dumpable" attribute to 1 reverts the ownership of the */proc/*pid*/\** files to the process's effective UID and GID. Note, however, that if the effective UID or GID is subsequently modified, then the "dumpable" attribute may be reset, as described in [**prctl**(2)](/prctl/2.md). Therefore, it may be desirable to reset the "dumpable" attribute *after* making any desired changes to the process's effective UID or GID.

-

  See also:

  - [**proc\_pid\_attr**(5)](/proc_pid_attr/5.md) [**proc\_pid\_autogroup**(5)](/proc_pid_autogroup/5.md) [**proc\_pid\_auxv**(5)](/proc_pid_auxv/5.md) [**proc\_pid\_cgroup**(5)](/proc_pid_cgroup/5.md) [**proc\_pid\_clear\_refs**(5)](/proc_pid_clear_refs/5.md) [**proc\_pid\_cmdline**(5)](/proc_pid_cmdline/5.md) [**proc\_pid\_comm**(5)](/proc_pid_comm/5.md) [**proc\_pid\_coredump\_filter**(5)](/proc_pid_coredump_filter/5.md) [**proc\_pid\_cpuset**(5)](/proc_pid_cpuset/5.md) [**proc\_pid\_cwd**(5)](/proc_pid_cwd/5.md) [**proc\_pid\_environ**(5)](/proc_pid_environ/5.md) [**proc\_pid\_exe**(5)](/proc_pid_exe/5.md) [**proc\_pid\_fd**(5)](/proc_pid_fd/5.md) [**proc\_pid\_fdinfo**(5)](/proc_pid_fdinfo/5.md) [**proc\_pid\_gid\_map**(5)](/proc_pid_gid_map/5.md) [**proc\_pid\_io**(5)](/proc_pid_io/5.md) [**proc\_pid\_limits**(5)](/proc_pid_limits/5.md) [**proc\_pid\_map\_files**(5)](/proc_pid_map_files/5.md) [**proc\_pid\_maps**(5)](/proc_pid_maps/5.md) [**proc\_pid\_mem**(5)](/proc_pid_mem/5.md) [**proc\_pid\_mountinfo**(5)](/proc_pid_mountinfo/5.md) [**proc\_pid\_mounts**(5)](/proc_pid_mounts/5.md) [**proc\_pid\_mountstats**(5)](/proc_pid_mountstats/5.md) [**proc\_pid\_net**(5)](/proc_pid_net/5.md) [**proc\_pid\_ns**(5)](/proc_pid_ns/5.md) [**proc\_pid\_numa\_maps**(5)](/proc_pid_numa_maps/5.md) [**proc\_pid\_oom\_adj**(5)](/proc_pid_oom_adj/5.md) [**proc\_pid\_oom\_score**(5)](/proc_pid_oom_score/5.md) [**proc\_pid\_oom\_score\_adj**(5)](/proc_pid_oom_score_adj/5.md) [**proc\_pid\_pagemap**(5)](/proc_pid_pagemap/5.md) [**proc\_pid\_personality**(5)](/proc_pid_personality/5.md) [**proc\_pid\_projid\_map**(5)](/proc_pid_projid_map/5.md) [**proc\_pid\_root**(5)](/proc_pid_root/5.md) [**proc\_pid\_seccomp**(5)](/proc_pid_seccomp/5.md) [**proc\_pid\_setgroups**(5)](/proc_pid_setgroups/5.md) [**proc\_pid\_smaps**(5)](/proc_pid_smaps/5.md) [**proc\_pid\_stack**(5)](/proc_pid_stack/5.md) [**proc\_pid\_stat**(5)](/proc_pid_stat/5.md) [**proc\_pid\_statm**(5)](/proc_pid_statm/5.md) [**proc\_pid\_status**(5)](/proc_pid_status/5.md) [**proc\_pid\_syscall**(5)](/proc_pid_syscall/5.md) [**proc\_pid\_task**(5)](/proc_pid_task/5.md) [**proc\_pid\_timers**(5)](/proc_pid_timers/5.md) [**proc\_pid\_timerslack\_ns**(5)](/proc_pid_timerslack_ns/5.md) [**proc\_pid\_uid\_map**(5)](/proc_pid_uid_map/5.md) [**proc\_pid\_wchan**(5)](/proc_pid_wchan/5.md)

    - */proc/self/*

  This directory refers to the process accessing the */proc* filesystem, and is identical to the */proc* directory named by the process ID of the same process.

## SEE ALSO

[**proc**(5)](/proc/5.md)