Lines Matching +full:proc +full:- +full:id
1 .. SPDX-License-Identifier: GPL-2.0
4 The /proc Filesystem
8 /proc/sys Terrehon Bowden <terrehon@pacbell.net>, October 7 1999
11 move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009
24 1.1 Process-Specific Subdirectories
26 1.3 IDE devices in /proc/ide
27 1.4 Networking info in /proc/net
29 1.6 Parallel port info in /proc/parport
30 1.7 TTY info in /proc/tty
31 1.8 Miscellaneous kernel statistics in /proc/stat
36 3 Per-Process Parameters
37 3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj - Adjust the oom-killer
39 3.2 /proc/<pid>/oom_score - Display current oom-killer score
40 3.3 /proc/<pid>/io - Display the IO accounting fields
41 3.4 /proc/<pid>/coredump_filter - Core dump filtering settings
42 3.5 /proc/<pid>/mountinfo - Information about mounts
43 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
44 3.7 /proc/<pid>/task/<tid>/children - Information about task children
45 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
46 3.9 /proc/<pid>/map_files - Information about memory mapped files
47 3.10 /proc/<pid>/timerslack_ns - Task timerslack value
48 3.11 /proc/<pid>/patch_state - Livepatch patch operation state
49 3.12 /proc/<pid>/arch_status - Task architecture specific information
50 3.13 /proc/<pid>/fd - List of symlinks to open files
61 ------------------------
65 /proc file system and we've used many freely available sources to write these
69 we know, it is the first 'all-in-one' document about the /proc file system. It
72 It also only covers IPv4 networking, not IPv6 nor other protocols - sorry. But
88 https://www.kernel.org/doc/html/latest/filesystems/proc.html
91 mailing list at linux-kernel@vger.kernel.org and/or try to reach me at
95 ---------------
105 ---------------
106 * Investigating the properties of the pseudo file system /proc and its
108 * Examining /proc's structure
112 ------------------------------------------------------------------------------
114 The proc file system acts as an interface to internal data structures in the
118 First, we'll take a look at the read-only parts of /proc. In Chapter 2, we
119 show you how you can use /proc/sys to change settings.
121 1.1 Process-Specific Subdirectories
122 -----------------------------------
124 The directory /proc contains (among other things) one subdirectory for each
125 process running on the system, which is named after the process ID (PID).
128 subdirectory has the entries listed in Table 1-1.
130 Note that an open file descriptor to /proc/<pid> or to any of its
133 open /proc/<pid> file descriptors corresponding to dead processes
135 also assigned the process ID <pid>. Instead, operations on these FDs
138 .. table:: Table 1-1: Process specific entries in /proc
157 symbol the task is blocked in - or "0" if not blocked.
169 read the file /proc/PID/status::
171 >cat /proc/self/status
220 the ps command. In fact, ps uses the proc file system to obtain its
222 file /proc/PID/status. It fields are described in table 1-2.
225 memory usage. Its seven fields are explained in Table 1-3. The stat file
227 explained in Table 1-4.
233 snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
236 .. table:: Table 1-2: Contents of the status fields (as of 4.19)
246 Tgid thread group ID
247 Ngid NUMA group ID (0 if none)
248 Pid process id
249 PPid process id of the parent process
256 NStgid descendant namespace thread group ID hierarchy
257 NSpid descendant namespace process ID hierarchy
258 NSpgid descendant namespace process group ID hierarchy
259 NSsid descendant namespace session ID hierarchy
310 .. table:: Table 1-3: Contents of the statm fields (as of 2.6.8-rc3)
328 .. table:: Table 1-4: Contents of the stat fields (as of 2.6.30-rc7)
333 pid process id
337 ppid process id of the parent process
339 sid session id
369 use /proc/PID/wchan instead)
390 The /proc/PID/maps file contains the currently mapped memory regions and
397 08048000-08049000 r-xp 00000000 03:00 8312 /opt/test
398 08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test
399 0804a000-0806b000 rw-p 00000000 00:00 0 [heap]
400 a7cb1000-a7cb2000 ---p 00000000 00:00 0
401 a7cb2000-a7eb2000 rw-p 00000000 00:00 0
402 a7eb2000-a7eb3000 ---p 00000000 00:00 0
403 a7eb3000-a7ed5000 rw-p 00000000 00:00 0
404 a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6
405 a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6
406 a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6
407 a800b000-a800e000 rw-p 00000000 00:00 0
408 a800e000-a8022000 r-xp 00000000 03:00 14462 /lib/libpthread.so.0
409 a8022000-a8023000 r--p 00013000 03:00 14462 /lib/libpthread.so.0
410 a8023000-a8024000 rw-p 00014000 03:00 14462 /lib/libpthread.so.0
411 a8024000-a8027000 rw-p 00000000 00:00 0
412 a8027000-a8043000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2
413 a8043000-a8044000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2
414 a8044000-a8045000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2
415 aff35000-aff4a000 rw-p 00000000 00:00 0 [stack]
416 ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
446 The /proc/PID/smaps is an extension based on maps, showing the memory
450 08048000-080bc000 r-xp 00000000 03:02 13130 /bin/bash
479 mapping in /proc/PID/maps. Following lines show the size of the mapping
505 "KSM" reports how many of the pages are KSM pages. Note that KSM-placed zeropages
523 "Swap" shows how much would-be-anonymous memory is also used, but out on swap.
526 replaced by copy-on-write) part of the underlying shmem object out on swap.
532 pages as well as the THP is PMD mappable or not - 1 if true, 0 otherwise.
572 uw userfaultfd wr-protect tracking
578 be vanished or the reverse -- new added. Interpretation of their meaning
585 Note: reading /proc/PID/maps or /proc/PID/smaps is inherently racy (consistent
597 The /proc/PID/smaps_rollup file includes the same fields as /proc/PID/smaps,
601 - Pss_Anon
602 - Pss_File
603 - Pss_Shmem
611 The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG
613 soft-dirty bit on pte (see Documentation/admin-guide/mm/soft-dirty.rst
617 > echo 1 > /proc/PID/clear_refs
621 > echo 2 > /proc/PID/clear_refs
625 > echo 3 > /proc/PID/clear_refs
627 To clear the soft-dirty bit::
629 > echo 4 > /proc/PID/clear_refs
634 > echo 5 > /proc/PID/clear_refs
636 Any other value written to /proc/PID/clear_refs will have no effect.
638 The /proc/pid/pagemap gives the PFN, which can be used to find the pageflags
639 using /proc/kpageflags and number of times a page is mapped using
640 /proc/kpagecount. For detailed explanation, see
641 Documentation/admin-guide/mm/pagemap.rst.
643 The /proc/pid/numa_maps is an extension based on maps, showing the memory
652 3206000000 default file=/lib64/ld-2.12.so mapped=26 mapmax=6 N0=24 N3=2 kernelpagesize_kB=4
653 320621f000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
654 3206220000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
656 …3206800000 default file=/lib64/libc-2.12.so mapped=59 mapmax=21 active=55 N0=41 N3=18 kernelpagesi…
657 320698b000 default file=/lib64/libc-2.12.so
658 3206b8a000 default file=/lib64/libc-2.12.so anon=2 dirty=2 N3=2 kernelpagesize_kB=4
659 3206b8e000 default file=/lib64/libc-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
671 "policy" reports the NUMA memory policy set for the mapping (see Documentation/admin-guide/mm/numa_…
678 ---------------
682 /proc and are listed in Table 1-5. Not all of these will be present in your
686 .. table:: Table 1-5: Kernel info in /proc
728 pci Deprecated info of PCI bus (new way -> /proc/bus/pci/,
746 they are used for by looking in the file /proc/interrupts::
748 > cat /proc/interrupts
750 0: 8728810 XT-PIC timer
751 1: 895 XT-PIC keyboard
752 2: 0 XT-PIC cascade
753 3: 531695 XT-PIC aha152x
754 4: 2014133 XT-PIC serial
755 5: 44401 XT-PIC pcnet_cs
756 8: 2 XT-PIC rtc
757 11: 8 XT-PIC i82365
758 12: 182918 XT-PIC PS/2 Mouse
759 13: 1 XT-PIC fpu
760 14: 1232265 XT-PIC ide0
761 15: 7 XT-PIC ide1
767 > cat /proc/interrupts
770 0: 1243498 1214548 IO-APIC-edge timer
771 1: 8949 8958 IO-APIC-edge keyboard
772 2: 0 0 XT-PIC cascade
773 5: 11286 10161 IO-APIC-edge soundblaster
774 8: 1 0 IO-APIC-edge rtc
775 9: 27422 27407 IO-APIC-edge 3c503
776 12: 113645 113873 IO-APIC-edge PS/2 Mouse
777 13: 0 0 XT-PIC fpu
778 14: 22491 24012 IO-APIC-edge ide0
779 15: 2183 2415 IO-APIC-edge ide1
780 17: 30564 30414 IO-APIC-level eth0
781 18: 177 164 IO-APIC-level bttv
791 ERR is incremented in the case of errors in the IO-APIC bus (the bus that
793 the IO-APIC automatically retry the transmission, so it should not be a big
794 problem, but you should read the SMP-FAQ.
796 In 2.6.2* /proc/interrupts was expanded again. This time the goal was for
797 /proc/interrupts to display every IRQ vector in use by the system, not
828 Of some interest is the introduction of the /proc/irq directory to 2.4.
836 > ls /proc/irq/
839 > ls /proc/irq/0/
845 > echo 1 > /proc/irq/10/smp_affinity
852 > cat /proc/irq/0/smp_affinity
858 > cat /proc/irq/0/smp_affinity_list
859 1024-1031
861 The default_smp_affinity mask applies to all non-active IRQs, which are the
863 /proc/irq/[0-9]* directory.
872 The way IRQs are routed is handled by the IO-APIC, and it's Round Robin
875 best choice for almost everyone. [Note this applies only to those IO-APIC's
878 There are three more important subdirectories in /proc: net, scsi, and sys.
891 > cat /proc/buddyinfo
910 > cat /proc/pagetypeinfo
933 X86-64. By keeping pages grouped based on their ability to move, the kernel
934 can reclaim pages within a page block to satisfy a high-order allocation.
938 by migrate-type and finishes with details on how many page blocks of each
959 /proc/net/sockstat for TCP memory allocations.
965 > cat /proc/meminfo
1043 In-memory cache for files read from the disk (the
1087 Non-file backed pages mapped into userspace page tables
1097 in-kernel data structures cache
1125 CommitLimit = ([total RAM pages] - [total huge TLB pages]) *
1133 in mm/overcommit-accounting.
1168 Non-file backed huge pages mapped into userspace page tables
1184 See Documentation/admin-guide/mm/hugetlbpage.rst.
1211 > cat /proc/vmallocinfo
1212 0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204 ...
1214 0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204 ...
1216 0xffffc20000302000-0xffffc20000304000 8192 acpi_tb_verify_table+0x21/0x4f...
1218 0xffffc20000304000-0xffffc20000307000 12288 acpi_tb_verify_table+0x21/0x4f...
1220 0xffffc2000031d000-0xffffc2000031f000 8192 init_vdso_vars+0x112/0x210
1221 0xffffc2000031f000-0xffffc2000032b000 49152 cramfs_uncompress_init+0x2e ...
1223 0xffffc2000033a000-0xffffc2000033d000 12288 sys_swapon+0x640/0xac0 ...
1225 0xffffc20000347000-0xffffc2000034c000 20480 xt_alloc_table_info+0xfe ...
1227 0xffffffffa0000000-0xffffffffa000f000 61440 sys_init_module+0xc27/0x1d00 ...
1229 0xffffffffa000f000-0xffffffffa0014000 20480 sys_init_module+0xc27/0x1d00 ...
1231 0xffffffffa0014000-0xffffffffa0017000 12288 sys_init_module+0xc27/0x1d00 ...
1233 0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ...
1244 > cat /proc/softirqs
1256 1.3 Networking info in /proc/net
1257 --------------------------------
1259 The subdirectory /proc/net follows the usual pattern. Table 1-8 shows the
1261 support this. Table 1-9 lists the files and their meaning.
1264 .. table:: Table 1-8: IPv6 info in /proc/net
1280 .. table:: Table 1-9: Network info in /proc/net
1302 softnet_stat Per-CPU incoming packets queues statistics of online CPUs
1317 > cat /proc/net/dev
1318 Inter-|Receive |[...
1331 example, the bond0 device will have a directory called /proc/net/bond0/.
1337 -------------
1340 subdirectory named after the driver for this adapter in /proc/scsi.
1341 You'll also see a list of all recognized SCSI devices in /proc/scsi::
1343 >cat /proc/scsi/scsi
1345 Host: scsi0 Channel: 00 Id: 00 Lun: 00
1347 Type: Direct-Access ANSI SCSI revision: 03
1348 Host: scsi0 Channel: 00 Id: 06 Lun: 00
1349 Vendor: PIONEER Model: CD-ROM DR-U06S Rev: 1.04
1350 Type: CD-ROM ANSI SCSI revision: 02
1357 AHA-2940 SCSI adapter::
1359 > cat /proc/scsi/aic7xxx/0
1367 SCSI Adapter: Adaptec AHA-294X Ultra SCSI host adapter
1399 1.5 Parallel port info in /proc/parport
1400 ---------------------------------------
1402 The directory /proc/parport contains information about the parallel ports of
1406 These directories contain the four files shown in Table 1-10.
1409 .. table:: Table 1-10: Files in /proc/parport
1414 autoprobe Any IEEE-1284 device ID information that has been acquired.
1424 1.6 TTY info in /proc/tty
1425 -------------------------
1428 directory /proc/tty. You'll find entries for drivers and line disciplines in
1429 this directory, as shown in Table 1-11.
1432 .. table:: Table 1-11: Files in /proc/tty
1443 /proc/tty/drivers::
1445 > cat /proc/tty/drivers
1446 pty_slave /dev/pts 136 0-255 pty:slave
1447 pty_master /dev/ptm 128 0-255 pty:master
1448 pty_slave /dev/ttyp 3 0-255 pty:slave
1449 pty_master /dev/pty 2 0-255 pty:master
1450 serial /dev/cua 5 64-67 serial:callout
1451 serial /dev/ttyS 4 64-67 serial
1456 unknown /dev/tty 4 1-63 console
1459 1.7 Miscellaneous kernel statistics in /proc/stat
1460 -------------------------------------------------
1463 /proc/stat file. All of the numbers reported in this file are aggregates
1466 > cat /proc/stat
1485 - user: normal processes executing in user mode
1486 - nice: niced processes executing in user mode
1487 - system: processes executing in kernel mode
1488 - idle: twiddling thumbs
1489 - iowait: In a word, iowait stands for waiting for I/O to complete. But there
1495 2. In a multi-core CPU, the task waiting for I/O to complete is not running
1497 3. The value of iowait field in /proc/stat will decrease in certain
1500 So, the iowait is not reliable by reading from /proc/stat.
1501 - irq: servicing interrupts
1502 - softirq: servicing softirqs
1503 - steal: involuntary wait
1504 - guest: running a normal guest
1505 - guest_nice: running a niced guest
1535 -------------------------------
1538 /proc/fs/ext4. Each mounted filesystem will have a directory in
1539 /proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or
1540 /proc/fs/ext4/sda9 or /proc/fs/ext4/dm-0). The files in each per-device
1541 directory are shown in Table 1-12, below.
1543 .. table:: Table 1-12: Files in /proc/fs/ext4/<devname>
1550 1.9 /proc/consoles
1551 -------------------
1555 /dev/console, you may simply look into the file /proc/consoles::
1557 > cat /proc/consoles
1558 tty0 -WU (ECp) 4:7
1559 ttyS0 -W- (Ep) 4:64
1563 +--------------------+-------------------------------------------------------+
1569 +--------------------+-------------------------------------------------------+
1576 +--------------------+-------------------------------------------------------+
1579 +--------------------+-------------------------------------------------------+
1582 -------
1584 The /proc file system serves information about the running system. It not only
1588 The directory structure of /proc reflects the types of information and makes
1595 ---------------
1597 * Modifying kernel parameters by writing into files found in /proc/sys
1599 * Review of the /proc/sys file tree
1601 ------------------------------------------------------------------------------
1603 A very interesting part of /proc is the directory /proc/sys. This is not only
1615 The files in /proc/sys can be used to fine tune and monitor miscellaneous and
1619 very careful when writing to any of these files. The entries in /proc may
1625 Please see: Documentation/admin-guide/sysctl/ directory for descriptions of
1629 -------
1633 /proc/sys tree can not only be read, but also modified. You can use the echo
1638 Chapter 3: Per-process Parameters
1641 3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj- Adjust the oom-killer score
1642 --------------------------------------------------------------------------------
1663 The value of /proc/<pid>/oom_score_adj is added to the badness score before it
1664 is used to determine which task to kill. Acceptable values range from -1000
1667 task or completely disabling it. The lowest possible value, -1000, is
1672 consider for each task. Setting a /proc/<pid>/oom_score_adj value of +500, for
1675 50% more memory. A value of -500, on the other hand, would be roughly
1679 For backwards compatibility with previous kernels, /proc/<pid>/oom_adj may also
1680 be used to tune the badness score. Its acceptable values range from -16
1681 (OOM_ADJUST_MIN) to +15 (OOM_ADJUST_MAX) and a special value of -17
1683 scaled linearly with /proc/<pid>/oom_score_adj.
1685 The value of /proc/<pid>/oom_score_adj may be reduced no lower than the last
1690 3.2 /proc/<pid>/oom_score - Display current oom-killer score
1691 -------------------------------------------------------------
1693 This file can be used to check the current score used by the oom-killer for
1694 any given <pid>. Use it together with /proc/<pid>/oom_score_adj to tune which
1695 process should be killed in an out-of-memory situation.
1701 3.3 /proc/<pid>/io - Display the IO accounting fields
1702 -------------------------------------------------------
1714 test:/tmp # cat /proc/3828/io
1768 accurate for block-backed filesystems. <please add status regarding NFS and
1777 the storage layer. This is done at page-dirtying time.
1796 At its current implementation state, this is a bit racy on 32-bit machines:
1797 if process A reads process B's /proc/pid/io while process B is updating one
1798 of those 64-bit counters, process A could see an intermediate result.
1804 3.4 /proc/<pid>/coredump_filter - Core dump filtering settings
1805 ---------------------------------------------------------------
1809 Conversely, sometimes we want to save file-backed memory segments into a core
1812 /proc/<pid>/coredump_filter allows you to customize which memory segments
1819 - (bit 0) anonymous private memory
1820 - (bit 1) anonymous shared memory
1821 - (bit 2) file-backed private memory
1822 - (bit 3) file-backed shared memory
1823 - (bit 4) ELF header pages in file-backed private memory areas (it is
1825 - (bit 5) hugetlb private memory
1826 - (bit 6) hugetlb shared memory
1827 - (bit 7) DAX private memory
1828 - (bit 8) DAX shared memory
1833 Note that bits 0-4 don't affect hugetlb or DAX memory. hugetlb memory is
1834 only affected by bit 5-6, and DAX is only affected by bits 7-8.
1840 write 0x31 to the process's proc file::
1842 $ echo 0x31 > /proc/1234/coredump_filter
1848 $ echo 0x7 > /proc/self/coredump_filter
1851 3.5 /proc/<pid>/mountinfo - Information about mounts
1852 --------------------------------------------------------
1856 36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue
1859 (1) mount ID: unique identifier of the mount (may be reused after umount)
1860 (2) parent ID: ID of parent (or of self for the top of the mount tree)
1891 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
1892 --------------------------------------------------------
1900 3.7 /proc/<pid>/task/<tid>/children - Information about task children
1901 -------------------------------------------------------------------------
1906 Note the "first level" here -- if a child has its own children they will
1907 not be listed here; one needs to read /proc/<children-pid>/task/<tid>/children
1917 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
1918 ---------------------------------------------------------------
1920 files have at least four fields -- 'pos', 'flags', 'mnt_id' and 'ino'.
1924 mount ID of the file system containing the opened file [see 3.5
1925 /proc/<pid>/mountinfo for details]. 'ino' represents the inode number of
1951 eventfd-count: 5a
1953 where 'eventfd-count' is hex value of a counter.
1996 …inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_han…
2005 fields 'fhandle-bytes', 'fhandle-type' and 'f_handle', all in hex
2019 fanotify flags:10 event-flags:0
2021 …fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type…
2023 where fanotify 'flags' and 'event-flags' are values used in fanotify_init
2069 exp_name: system-heap
2074 3.9 /proc/<pid>/map_files - Information about memory mapped files
2075 ---------------------------------------------------------------------
2079 | lr-------- 1 root root 64 Jan 27 11:24 333c600000-333c620000 -> /usr/lib64/ld-2.18.so
2080 | lr-------- 1 root root 64 Jan 27 11:24 333c81f000-333c820000 -> /usr/lib64/ld-2.18.so
2081 | lr-------- 1 root root 64 Jan 27 11:24 333c820000-333c821000 -> /usr/lib64/ld-2.18.so
2083 | lr-------- 1 root root 64 Jan 27 11:24 35d0421000-35d0422000 -> /usr/lib64/libselinux.so.1
2084 | lr-------- 1 root root 64 Jan 27 11:24 400000-41a000 -> /usr/bin/ls
2087 vm_area_struct::vm_start-vm_area_struct::vm_end.
2090 files in a fast way instead of parsing /proc/<pid>/maps or
2091 /proc/<pid>/smaps, both of which contain many more records. At the same
2096 3.10 /proc/<pid>/timerslack_ns - Task timerslack value
2097 ---------------------------------------------------------
2107 Valid values are from 0 - ULLONG_MAX
2112 3.11 /proc/<pid>/patch_state - Livepatch patch operation state
2113 -----------------------------------------------------------------
2117 A value of '-1' indicates that no patch is in transition.
2129 3.12 /proc/<pid>/arch_status - task architecture specific status
2130 -------------------------------------------------------------------
2139 $ cat /proc/6753/arch_status
2170 A special value of '-1' indicates that no AVX512 usage was recorded, thus
2174 3.13 /proc/<pid>/fd - List of symlinks to open files
2175 -------------------------------------------------------
2179 lr-x------ 1 root root 64 Sep 20 17:53 0 -> /dev/null
2180 l-wx------ 1 root root 64 Sep 20 17:53 1 -> /dev/null
2181 lrwx------ 1 root root 64 Sep 20 17:53 10 -> 'socket:[12539]'
2182 lrwx------ 1 root root 64 Sep 20 17:53 11 -> 'socket:[12540]'
2183 lrwx------ 1 root root 64 Sep 20 17:53 12 -> 'socket:[12542]'
2186 of stat() output for /proc/<pid>/fd for fast access.
2187 -------------------------------------------------------
2194 ---------------------
2199 hidepid= Set /proc/<pid>/ access mode.
2204 hidepid=off or hidepid=0 means classic mode - everybody may access all
2205 /proc/<pid>/ directories (default).
2207 hidepid=noaccess or hidepid=1 means users may not access any /proc/<pid>/
2211 behaviour). As an additional bonus, as /proc/<pid>/cmdline is unaccessible for
2215 hidepid=invisible or hidepid=2 means hidepid=1 plus all /proc/<pid>/ will be
2218 by "kill -0 $PID"), but it hides process' uid and gid, which may be learned by
2219 stat()'ing /proc/<pid>/ otherwise. It greatly complicates an intruder's task of
2225 /proc/<pid>/ directories that the caller can ptrace.
2244 # grep ^proc /proc/mounts
2245 proc /proc proc rw,relatime,hidepid=2 0 0
2247 # strace -e mount mount -o hidepid=1 -t proc proc /tmp/proc
2248 mount("proc", "/tmp/proc", "proc", 0, "hidepid=1") = 0
2251 # grep ^proc /proc/mounts
2252 proc /proc proc rw,relatime,hidepid=2 0 0
2253 proc /tmp/proc proc rw,relatime,hidepid=2 0 0
2258 # mount -o remount,hidepid=1 -t proc proc /tmp/proc
2260 # grep ^proc /proc/mounts
2261 proc /proc proc rw,relatime,hidepid=1 0 0
2262 proc /tmp/proc proc rw,relatime,hidepid=1 0 0
2271 # mount -o hidepid=invisible -t proc proc /proc
2272 # mount -o hidepid=noaccess -t proc proc /tmp/proc
2273 # grep ^proc /proc/mounts
2274 proc /proc proc rw,relatime,hidepid=invisible 0 0
2275 proc /tmp/proc proc rw,relatime,hidepid=noaccess 0 0