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
51 3.14 /proc/<pid/ksm_stat - Information about the process's ksm status.
62 ------------------------
72 https://www.kernel.org/doc/html/latest/filesystems/proc.html
75 ---------------
85 ---------------
86 * Investigating the properties of the pseudo file system /proc and its
88 * Examining /proc's structure
92 ------------------------------------------------------------------------------
94 The proc file system acts as an interface to internal data structures in the
98 First, we'll take a look at the read-only parts of /proc. In Chapter 2, we
99 show you how you can use /proc/sys to change settings.
101 1.1 Process-Specific Subdirectories
102 -----------------------------------
104 The directory /proc contains (among other things) one subdirectory for each
105 process running on the system, which is named after the process ID (PID).
108 subdirectory has the entries listed in Table 1-1.
110 A process can read its own information from /proc/PID/* with no extra
111 permissions. When reading /proc/PID/* information for other processes, reading
114 capability. This applies to all read-only information like `maps`, `environ`,
115 `pagemap`, etc. The only exception is `mem` file due to its read-write nature,
118 to /proc/PID/mem for other processes.
120 Note that an open file descriptor to /proc/<pid> or to any of its
123 open /proc/<pid> file descriptors corresponding to dead processes
125 also assigned the process ID <pid>. Instead, operations on these FDs
128 .. table:: Table 1-1: Process specific entries in /proc
147 symbol the task is blocked in - or "0" if not blocked.
159 read the file /proc/PID/status::
161 >cat /proc/self/status
210 the ps command. In fact, ps uses the proc file system to obtain its
212 file /proc/PID/status. It fields are described in table 1-2.
215 memory usage. Its seven fields are explained in Table 1-3. The stat file
217 explained in Table 1-4.
223 snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
226 .. table:: Table 1-2: Contents of the status fields (as of 4.19)
236 Tgid thread group ID
237 Ngid NUMA group ID (0 if none)
238 Pid process id
239 PPid process id of the parent process
246 NStgid descendant namespace thread group ID hierarchy
247 NSpid descendant namespace process ID hierarchy
248 NSpgid descendant namespace process group ID hierarchy
249 NSsid descendant namespace session ID hierarchy
301 .. table:: Table 1-3: Contents of the statm fields (as of 2.6.8-rc3)
319 .. table:: Table 1-4: Contents of the stat fields (as of 2.6.30-rc7)
324 pid process id
328 ppid process id of the parent process
330 sid session id
360 use /proc/PID/wchan instead)
381 The /proc/PID/maps file contains the currently mapped memory regions and
388 08048000-08049000 r-xp 00000000 03:00 8312 /opt/test
389 08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test
390 0804a000-0806b000 rw-p 00000000 00:00 0 [heap]
391 a7cb1000-a7cb2000 ---p 00000000 00:00 0
392 a7cb2000-a7eb2000 rw-p 00000000 00:00 0
393 a7eb2000-a7eb3000 ---p 00000000 00:00 0
394 a7eb3000-a7ed5000 rw-p 00000000 00:00 0
395 a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6
396 a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6
397 a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6
398 a800b000-a800e000 rw-p 00000000 00:00 0
399 a800e000-a8022000 r-xp 00000000 03:00 14462 /lib/libpthread.so.0
400 a8022000-a8023000 r--p 00013000 03:00 14462 /lib/libpthread.so.0
401 a8023000-a8024000 rw-p 00014000 03:00 14462 /lib/libpthread.so.0
402 a8024000-a8027000 rw-p 00000000 00:00 0
403 a8027000-a8043000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2
404 a8043000-a8044000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2
405 a8044000-a8045000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2
406 aff35000-aff4a000 rw-p 00000000 00:00 0 [stack]
407 ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
437 Starting with 6.11 kernel, /proc/PID/maps provides an alternative
438 ioctl()-based API that gives ability to flexibly and efficiently query and
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 the mapping in /proc/PID/maps. Following lines show the size of the
522 "KSM" reports how many of the pages are KSM pages. Note that KSM-placed zeropages
540 "Swap" shows how much would-be-anonymous memory is also used, but out on swap.
543 replaced by copy-on-write) part of the underlying shmem object out on swap.
588 uw userfaultfd wr-protect tracking
599 be vanished or the reverse -- new added. Interpretation of their meaning
606 Note: reading /proc/PID/maps or /proc/PID/smaps is inherently racy (consistent
618 The /proc/PID/smaps_rollup file includes the same fields as /proc/PID/smaps,
622 - Pss_Anon
623 - Pss_File
624 - Pss_Shmem
632 The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG
634 soft-dirty bit on pte (see Documentation/admin-guide/mm/soft-dirty.rst
638 > echo 1 > /proc/PID/clear_refs
642 > echo 2 > /proc/PID/clear_refs
646 > echo 3 > /proc/PID/clear_refs
648 To clear the soft-dirty bit::
650 > echo 4 > /proc/PID/clear_refs
655 > echo 5 > /proc/PID/clear_refs
657 Any other value written to /proc/PID/clear_refs will have no effect.
659 The /proc/pid/pagemap gives the PFN, which can be used to find the pageflags
660 using /proc/kpageflags and number of times a page is mapped using
661 /proc/kpagecount. For detailed explanation, see
662 Documentation/admin-guide/mm/pagemap.rst.
664 The /proc/pid/numa_maps is an extension based on maps, showing the memory
673 3206000000 default file=/lib64/ld-2.12.so mapped=26 mapmax=6 N0=24 N3=2 kernelpagesize_kB=4
674 320621f000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
675 3206220000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
677 …3206800000 default file=/lib64/libc-2.12.so mapped=59 mapmax=21 active=55 N0=41 N3=18 kernelpagesi…
678 320698b000 default file=/lib64/libc-2.12.so
679 3206b8a000 default file=/lib64/libc-2.12.so anon=2 dirty=2 N3=2 kernelpagesize_kB=4
680 3206b8e000 default file=/lib64/libc-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4
692 "policy" reports the NUMA memory policy set for the mapping (see Documentation/admin-guide/mm/numa_…
704 ---------------
708 /proc and are listed in Table 1-5. Not all of these will be present in your
712 .. table:: Table 1-5: Kernel info in /proc
761 pci Deprecated info of PCI bus (new way -> /proc/bus/pci/,
779 they are used for by looking in the file /proc/interrupts::
781 > cat /proc/interrupts
783 0: 8728810 XT-PIC timer
784 1: 895 XT-PIC keyboard
785 2: 0 XT-PIC cascade
786 3: 531695 XT-PIC aha152x
787 4: 2014133 XT-PIC serial
788 5: 44401 XT-PIC pcnet_cs
789 8: 2 XT-PIC rtc
790 11: 8 XT-PIC i82365
791 12: 182918 XT-PIC PS/2 Mouse
792 13: 1 XT-PIC fpu
793 14: 1232265 XT-PIC ide0
794 15: 7 XT-PIC ide1
800 > cat /proc/interrupts
803 0: 1243498 1214548 IO-APIC-edge timer
804 1: 8949 8958 IO-APIC-edge keyboard
805 2: 0 0 XT-PIC cascade
806 5: 11286 10161 IO-APIC-edge soundblaster
807 8: 1 0 IO-APIC-edge rtc
808 9: 27422 27407 IO-APIC-edge 3c503
809 12: 113645 113873 IO-APIC-edge PS/2 Mouse
810 13: 0 0 XT-PIC fpu
811 14: 22491 24012 IO-APIC-edge ide0
812 15: 2183 2415 IO-APIC-edge ide1
813 17: 30564 30414 IO-APIC-level eth0
814 18: 177 164 IO-APIC-level bttv
824 ERR is incremented in the case of errors in the IO-APIC bus (the bus that
826 the IO-APIC automatically retry the transmission, so it should not be a big
827 problem, but you should read the SMP-FAQ.
829 In 2.6.2* /proc/interrupts was expanded again. This time the goal was for
830 /proc/interrupts to display every IRQ vector in use by the system, not
861 Of some interest is the introduction of the /proc/irq directory to 2.4.
869 > ls /proc/irq/
872 > ls /proc/irq/0/
878 > echo 1 > /proc/irq/10/smp_affinity
885 > cat /proc/irq/0/smp_affinity
891 > cat /proc/irq/0/smp_affinity_list
892 1024-1031
894 The default_smp_affinity mask applies to all non-active IRQs, which are the
896 /proc/irq/[0-9]* directory.
905 The way IRQs are routed is handled by the IO-APIC, and it's Round Robin
908 best choice for almost everyone. [Note this applies only to those IO-APIC's
911 There are three more important subdirectories in /proc: net, scsi, and sys.
924 > cat /proc/buddyinfo
943 > cat /proc/pagetypeinfo
966 X86-64. By keeping pages grouped based on their ability to move, the kernel
967 can reclaim pages within a page block to satisfy a high-order allocation.
971 by migrate-type and finishes with details on how many page blocks of each
1010 > tail -n +3 /proc/allocinfo | sort -rn
1015 13377536 234 block/blk-mq.c:3421 func:blk_mq_alloc_rqs
1034 /proc/net/sockstat for TCP memory allocations.
1040 > cat /proc/meminfo
1120 In-memory cache for files read from the disk (the
1164 Non-file backed pages mapped into userspace page tables. Note that
1180 in-kernel data structures cache
1210 CommitLimit = ([total RAM pages] - [total huge TLB pages]) *
1218 in mm/overcommit-accounting.
1253 Non-file backed huge pages mapped into userspace page tables
1273 See Documentation/admin-guide/mm/hugetlbpage.rst.
1300 > cat /proc/vmallocinfo
1301 0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204 ...
1303 0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204 ...
1305 0xffffc20000302000-0xffffc20000304000 8192 acpi_tb_verify_table+0x21/0x4f...
1307 0xffffc20000304000-0xffffc20000307000 12288 acpi_tb_verify_table+0x21/0x4f...
1309 0xffffc2000031d000-0xffffc2000031f000 8192 init_vdso_vars+0x112/0x210
1310 0xffffc2000031f000-0xffffc2000032b000 49152 cramfs_uncompress_init+0x2e ...
1312 0xffffc2000033a000-0xffffc2000033d000 12288 sys_swapon+0x640/0xac0 ...
1314 0xffffc20000347000-0xffffc2000034c000 20480 xt_alloc_table_info+0xfe ...
1316 0xffffffffa0000000-0xffffffffa000f000 61440 sys_init_module+0xc27/0x1d00 ...
1318 0xffffffffa000f000-0xffffffffa0014000 20480 sys_init_module+0xc27/0x1d00 ...
1320 0xffffffffa0014000-0xffffffffa0017000 12288 sys_init_module+0xc27/0x1d00 ...
1322 0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ...
1333 > cat /proc/softirqs
1345 1.3 Networking info in /proc/net
1346 --------------------------------
1348 The subdirectory /proc/net follows the usual pattern. Table 1-8 shows the
1350 support this. Table 1-9 lists the files and their meaning.
1353 .. table:: Table 1-8: IPv6 info in /proc/net
1369 .. table:: Table 1-9: Network info in /proc/net
1391 softnet_stat Per-CPU incoming packets queues statistics of online CPUs
1406 > cat /proc/net/dev
1407 Inter-|Receive |[...
1420 example, the bond0 device will have a directory called /proc/net/bond0/.
1426 -------------
1429 subdirectory named after the driver for this adapter in /proc/scsi.
1430 You'll also see a list of all recognized SCSI devices in /proc/scsi::
1432 >cat /proc/scsi/scsi
1434 Host: scsi0 Channel: 00 Id: 00 Lun: 00
1436 Type: Direct-Access ANSI SCSI revision: 03
1437 Host: scsi0 Channel: 00 Id: 06 Lun: 00
1438 Vendor: PIONEER Model: CD-ROM DR-U06S Rev: 1.04
1439 Type: CD-ROM ANSI SCSI revision: 02
1446 AHA-2940 SCSI adapter::
1448 > cat /proc/scsi/aic7xxx/0
1456 SCSI Adapter: Adaptec AHA-294X Ultra SCSI host adapter
1488 1.5 Parallel port info in /proc/parport
1489 ---------------------------------------
1491 The directory /proc/parport contains information about the parallel ports of
1495 These directories contain the four files shown in Table 1-10.
1498 .. table:: Table 1-10: Files in /proc/parport
1503 autoprobe Any IEEE-1284 device ID information that has been acquired.
1513 1.6 TTY info in /proc/tty
1514 -------------------------
1517 directory /proc/tty. You'll find entries for drivers and line disciplines in
1518 this directory, as shown in Table 1-11.
1521 .. table:: Table 1-11: Files in /proc/tty
1532 /proc/tty/drivers::
1534 > cat /proc/tty/drivers
1535 pty_slave /dev/pts 136 0-255 pty:slave
1536 pty_master /dev/ptm 128 0-255 pty:master
1537 pty_slave /dev/ttyp 3 0-255 pty:slave
1538 pty_master /dev/pty 2 0-255 pty:master
1539 serial /dev/cua 5 64-67 serial:callout
1540 serial /dev/ttyS 4 64-67 serial
1545 unknown /dev/tty 4 1-63 console
1548 1.7 Miscellaneous kernel statistics in /proc/stat
1549 -------------------------------------------------
1552 /proc/stat file. All of the numbers reported in this file are aggregates
1555 > cat /proc/stat
1574 - user: normal processes executing in user mode
1575 - nice: niced processes executing in user mode
1576 - system: processes executing in kernel mode
1577 - idle: twiddling thumbs
1578 - iowait: In a word, iowait stands for waiting for I/O to complete. But there
1584 2. In a multi-core CPU, the task waiting for I/O to complete is not running
1586 3. The value of iowait field in /proc/stat will decrease in certain
1589 So, the iowait is not reliable by reading from /proc/stat.
1590 - irq: servicing interrupts
1591 - softirq: servicing softirqs
1592 - steal: involuntary wait
1593 - guest: running a normal guest
1594 - guest_nice: running a niced guest
1624 -------------------------------
1627 /proc/fs/ext4. Each mounted filesystem will have a directory in
1628 /proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or
1629 /proc/fs/ext4/sda9 or /proc/fs/ext4/dm-0). The files in each per-device
1630 directory are shown in Table 1-12, below.
1632 .. table:: Table 1-12: Files in /proc/fs/ext4/<devname>
1639 1.9 /proc/consoles
1640 -------------------
1644 /dev/console, you may simply look into the file /proc/consoles::
1646 > cat /proc/consoles
1647 tty0 -WU (ECp) 4:7
1648 ttyS0 -W- (Ep) 4:64
1652 +--------------------+-------------------------------------------------------+
1658 +--------------------+-------------------------------------------------------+
1665 +--------------------+-------------------------------------------------------+
1668 +--------------------+-------------------------------------------------------+
1671 -------
1673 The /proc file system serves information about the running system. It not only
1677 The directory structure of /proc reflects the types of information and makes
1684 ---------------
1686 * Modifying kernel parameters by writing into files found in /proc/sys
1688 * Review of the /proc/sys file tree
1690 ------------------------------------------------------------------------------
1692 A very interesting part of /proc is the directory /proc/sys. This is not only
1704 The files in /proc/sys can be used to fine tune and monitor miscellaneous and
1708 very careful when writing to any of these files. The entries in /proc may
1714 Please see: Documentation/admin-guide/sysctl/ directory for descriptions of
1718 -------
1722 /proc/sys tree can not only be read, but also modified. You can use the echo
1727 Chapter 3: Per-process Parameters
1730 3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj- Adjust the oom-killer score
1731 --------------------------------------------------------------------------------
1752 The value of /proc/<pid>/oom_score_adj is added to the badness score before it
1753 is used to determine which task to kill. Acceptable values range from -1000
1756 task or completely disabling it. The lowest possible value, -1000, is
1761 consider for each task. Setting a /proc/<pid>/oom_score_adj value of +500, for
1764 50% more memory. A value of -500, on the other hand, would be roughly
1768 For backwards compatibility with previous kernels, /proc/<pid>/oom_adj may also
1769 be used to tune the badness score. Its acceptable values range from -16
1770 (OOM_ADJUST_MIN) to +15 (OOM_ADJUST_MAX) and a special value of -17
1772 scaled linearly with /proc/<pid>/oom_score_adj.
1774 The value of /proc/<pid>/oom_score_adj may be reduced no lower than the last
1779 3.2 /proc/<pid>/oom_score - Display current oom-killer score
1780 -------------------------------------------------------------
1782 This file can be used to check the current score used by the oom-killer for
1783 any given <pid>. Use it together with /proc/<pid>/oom_score_adj to tune which
1784 process should be killed in an out-of-memory situation.
1790 3.3 /proc/<pid>/io - Display the IO accounting fields
1791 -------------------------------------------------------
1803 test:/tmp # cat /proc/3828/io
1857 accurate for block-backed filesystems. <please add status regarding NFS and
1866 the storage layer. This is done at page-dirtying time.
1885 At its current implementation state, this is a bit racy on 32-bit machines:
1886 if process A reads process B's /proc/pid/io while process B is updating one
1887 of those 64-bit counters, process A could see an intermediate result.
1893 3.4 /proc/<pid>/coredump_filter - Core dump filtering settings
1894 ---------------------------------------------------------------
1898 Conversely, sometimes we want to save file-backed memory segments into a core
1901 /proc/<pid>/coredump_filter allows you to customize which memory segments
1908 - (bit 0) anonymous private memory
1909 - (bit 1) anonymous shared memory
1910 - (bit 2) file-backed private memory
1911 - (bit 3) file-backed shared memory
1912 - (bit 4) ELF header pages in file-backed private memory areas (it is
1914 - (bit 5) hugetlb private memory
1915 - (bit 6) hugetlb shared memory
1916 - (bit 7) DAX private memory
1917 - (bit 8) DAX shared memory
1922 Note that bits 0-4 don't affect hugetlb or DAX memory. hugetlb memory is
1923 only affected by bit 5-6, and DAX is only affected by bits 7-8.
1929 write 0x31 to the process's proc file::
1931 $ echo 0x31 > /proc/1234/coredump_filter
1937 $ echo 0x7 > /proc/self/coredump_filter
1940 3.5 /proc/<pid>/mountinfo - Information about mounts
1941 --------------------------------------------------------
1945 36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue
1948 (1) mount ID: unique identifier of the mount (may be reused after umount)
1949 (2) parent ID: ID of parent (or of self for the top of the mount tree)
1980 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
1981 --------------------------------------------------------
1989 3.7 /proc/<pid>/task/<tid>/children - Information about task children
1990 -------------------------------------------------------------------------
1995 Note the "first level" here -- if a child has its own children they will
1996 not be listed here; one needs to read /proc/<children-pid>/task/<tid>/children
2006 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
2007 ---------------------------------------------------------------
2009 files have at least four fields -- 'pos', 'flags', 'mnt_id' and 'ino'.
2013 mount ID of the file system containing the opened file [see 3.5
2014 /proc/<pid>/mountinfo for details]. 'ino' represents the inode number of
2040 eventfd-count: 5a
2042 where 'eventfd-count' is hex value of a counter.
2085 …inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_han…
2094 fields 'fhandle-bytes', 'fhandle-type' and 'f_handle', all in hex
2108 fanotify flags:10 event-flags:0
2110 …fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type…
2112 where fanotify 'flags' and 'event-flags' are values used in fanotify_init
2158 exp_name: system-heap
2172 vfio-device-syspath: /sys/devices/pci0000:e0/0000:e0:01.1/0000:e1:00.0/0000:e2:05.0/0000:e8:00.0
2174 where 'vfio-device-syspath' is the sysfs path corresponding to the VFIO device
2177 3.9 /proc/<pid>/map_files - Information about memory mapped files
2178 ---------------------------------------------------------------------
2182 | lr-------- 1 root root 64 Jan 27 11:24 333c600000-333c620000 -> /usr/lib64/ld-2.18.so
2183 | lr-------- 1 root root 64 Jan 27 11:24 333c81f000-333c820000 -> /usr/lib64/ld-2.18.so
2184 | lr-------- 1 root root 64 Jan 27 11:24 333c820000-333c821000 -> /usr/lib64/ld-2.18.so
2186 | lr-------- 1 root root 64 Jan 27 11:24 35d0421000-35d0422000 -> /usr/lib64/libselinux.so.1
2187 | lr-------- 1 root root 64 Jan 27 11:24 400000-41a000 -> /usr/bin/ls
2190 vm_area_struct::vm_start-vm_area_struct::vm_end.
2193 files in a fast way instead of parsing /proc/<pid>/maps or
2194 /proc/<pid>/smaps, both of which contain many more records. At the same
2199 3.10 /proc/<pid>/timerslack_ns - Task timerslack value
2200 ---------------------------------------------------------
2210 Valid values are from 0 - ULLONG_MAX
2215 3.11 /proc/<pid>/patch_state - Livepatch patch operation state
2216 -----------------------------------------------------------------
2220 A value of '-1' indicates that no patch is in transition.
2232 3.12 /proc/<pid>/arch_status - task architecture specific status
2233 -------------------------------------------------------------------
2242 $ cat /proc/6753/arch_status
2273 A special value of '-1' indicates that no AVX512 usage was recorded, thus
2277 3.13 /proc/<pid>/fd - List of symlinks to open files
2278 -------------------------------------------------------
2282 lr-x------ 1 root root 64 Sep 20 17:53 0 -> /dev/null
2283 l-wx------ 1 root root 64 Sep 20 17:53 1 -> /dev/null
2284 lrwx------ 1 root root 64 Sep 20 17:53 10 -> 'socket:[12539]'
2285 lrwx------ 1 root root 64 Sep 20 17:53 11 -> 'socket:[12540]'
2286 lrwx------ 1 root root 64 Sep 20 17:53 12 -> 'socket:[12542]'
2289 of stat() output for /proc/<pid>/fd for fast access.
2290 -------------------------------------------------------
2292 3.14 /proc/<pid/ksm_stat - Information about the process's ksm status
2293 ---------------------------------------------------------------------
2302 / # cat /proc/self/ksm_stat
2318 addresses. KSM will generate a ksm_rmap_item for each ksm-scanned page of
2332 /proc/<pid>/ksm_merging_pages shows.
2358 Documentation/admin-guide/mm/ksm.rst.
2365 ---------------------
2370 hidepid= Set /proc/<pid>/ access mode.
2376 hidepid=off or hidepid=0 means classic mode - everybody may access all
2377 /proc/<pid>/ directories (default).
2379 hidepid=noaccess or hidepid=1 means users may not access any /proc/<pid>/
2383 behaviour). As an additional bonus, as /proc/<pid>/cmdline is unaccessible for
2387 hidepid=invisible or hidepid=2 means hidepid=1 plus all /proc/<pid>/ will be
2390 by "kill -0 $PID"), but it hides process's uid and gid, which may be learned by
2391 stat()'ing /proc/<pid>/ otherwise. It greatly complicates an intruder's task of
2397 /proc/<pid>/ directories that the caller can ptrace.
2407 `/proc/$pid/ns/pid`, or a file descriptor when using `FSCONFIG_SET_FD`) that
2411 so will give an `-EBUSY` error).
2423 # grep ^proc /proc/mounts
2424 proc /proc proc rw,relatime,hidepid=2 0 0
2426 # strace -e mount mount -o hidepid=1 -t proc proc /tmp/proc
2427 mount("proc", "/tmp/proc", "proc", 0, "hidepid=1") = 0
2430 # grep ^proc /proc/mounts
2431 proc /proc proc rw,relatime,hidepid=2 0 0
2432 proc /tmp/proc proc rw,relatime,hidepid=2 0 0
2437 # mount -o remount,hidepid=1 -t proc proc /tmp/proc
2439 # grep ^proc /proc/mounts
2440 proc /proc proc rw,relatime,hidepid=1 0 0
2441 proc /tmp/proc proc rw,relatime,hidepid=1 0 0
2450 # mount -o hidepid=invisible -t proc proc /proc
2451 # mount -o hidepid=noaccess -t proc proc /tmp/proc
2452 # grep ^proc /proc/mounts
2453 proc /proc proc rw,relatime,hidepid=invisible 0 0
2454 proc /tmp/proc proc rw,relatime,hidepid=noaccess 0 0