aboutsummaryrefslogtreecommitdiff
path: root/Documentation/admin-guide/sysctl
AgeCommit message (Collapse)AuthorFilesLines
2020-05-16netns: enable to inherit devconf from current netnsNicolas Dichtel1-1/+3
The goal is to be able to inherit the initial devconf parameters from the current netns, ie the netns where this new netns has been created. This is useful in a containers environment where /proc/sys is read only. For example, if a pod is created with specifics devconf parameters and has the capability to create netns, the user expects to get the same parameters than his 'init_net', which is not the real init_net in this case. Signed-off-by: Nicolas Dichtel <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-05-15docs: sysctl/kernel: document ngroups_maxStephen Kitt1-0/+9
This is a read-only export of NGROUPS_MAX, so this patch also changes the declarations in kernel/sysctl.c to const. Signed-off-by: Stephen Kitt <[email protected]> Reviewed-by: Kees Cook <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Corbet <[email protected]>
2020-05-05docs: sysctl/kernel: document firmware_configStephen Kitt1-0/+13
Based on the firmware fallback mechanisms documentation and the implementation in drivers/base/firmware_loader/fallback.c. Signed-off-by: Stephen Kitt <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Corbet <[email protected]>
2020-05-05docs: sysctl/kernel: document ftrace entriesStephen Kitt1-0/+48
Based on the ftrace documentation, the tp_printk boot parameter documentation, and the implementation in kernel/trace/trace.c. Signed-off-by: Stephen Kitt <[email protected]> Acked-by: Steven Rostedt (VMware) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Corbet <[email protected]>
2020-05-05docs: filesystems: convert devpts.txt to ReSTMauro Carvalho Chehab1-1/+1
- Add a SPDX header; - Add a document title; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <[email protected]> Link: https://lore.kernel.org/r/4ac8f3a7edd4d817acf0d173ead7ef74fe010c6c.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <[email protected]>
2020-04-28docs: networking: convert ipvs-sysctl.txt to ReSTMauro Carvalho Chehab1-2/+2
- add SPDX header; - add a document title; - mark lists as such; - mark code blocks and literals as such; - adjust identation, whitespaces and blank lines; - add to networking/index.rst. Signed-off-by: Mauro Carvalho Chehab <[email protected]> Acked-by: Simon Horman <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-04-28docs: networking: convert ip-sysctl.txt to ReSTMauro Carvalho Chehab1-1/+1
- add SPDX header; - adjust titles and chapters, adding proper markups; - mark code blocks and literals as such; - mark lists as such; - mark tables as such; - use footnote markup; - adjust identation, whitespaces and blank lines; - add to networking/index.rst. Signed-off-by: Mauro Carvalho Chehab <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-04-28docs: sysctl/kernel: document cad_pidStephen Kitt1-0/+10
Based on the implementation in kernel/sysctl.c (the proc_do_cad_pid() function), kernel/reboot.c, and include/linux/sched/signal.h. Signed-off-by: Stephen Kitt <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Corbet <[email protected]>
2020-04-22Merge tag 'perf-core-for-mingo-5.8-20200420' of ↵Ingo Molnar1-5/+11
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core fixes and improvements from Arnaldo Carvalho de Melo: kernel + tools/perf: Alexey Budankov: - Introduce CAP_PERFMON to kernel and user space. callchains: Adrian Hunter: - Allow using Intel PT to synthesize callchains for regular events. Kan Liang: - Stitch LBR records from multiple samples to get deeper backtraces, there are caveats, see the csets for details. perf script: Andreas Gerstmayr: - Add flamegraph.py script BPF: Jiri Olsa: - Synthesize bpf_trampoline/dispatcher ksymbol events. perf stat: Arnaldo Carvalho de Melo: - Honour --timeout for forked workloads. Stephane Eranian: - Force error in fallback on :k events, to avoid counting nothing when the user asks for kernel events but is not allowed to. perf bench: Ian Rogers: - Add event synthesis benchmark. tools api fs: Stephane Eranian: - Make xxx__mountpoint() more scalable libtraceevent: He Zhe: - Handle return value of asprintf. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-20docs: sysctl/kernel: document BPF entriesStephen Kitt1-0/+24
Based on the implementation in kernel/bpf/syscall.c, kernel/bpf/trampoline.c, include/linux/filter.h, and the documentation in bpftool-prog.rst. Signed-off-by: Stephen Kitt <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Corbet <[email protected]>
2020-04-16doc/admin-guide: update kernel.rst with CAP_PERFMON informationAlexey Budankov1-5/+11
Update the kernel.rst documentation file with the information related to usage of CAP_PERFMON capability to secure performance monitoring and observability operations in system. Signed-off-by: Alexey Budankov <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Igor Lubashev <[email protected]> Cc: James Morris <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Serge Hallyn <[email protected]> Cc: Song Liu <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2020-04-15docs: admin-guide: merge sections for the kernel.modprobe sysctlEric Biggers1-28/+19
Documentation for the kernel.modprobe sysctl was added both by commit 0317c5371e6a ("docs: merge debugging-modules.txt into sysctl/kernel.rst") and by commit 6e7158250625 ("docs: admin-guide: document the kernel.modprobe sysctl"), resulting in the same sysctl being documented in two places. Merge these into one place. Signed-off-by: Eric Biggers <[email protected]> Reviewed-by: Stephen Kitt <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Corbet <[email protected]>
2020-04-12Merge tag 'timers-urgent-2020-04-12' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull time(keeping) updates from Thomas Gleixner: - Fix the time_for_children symlink in /proc/$PID/ so it properly reflects that it part of the 'time' namespace - Add the missing userns limit for the allowed number of time namespaces, which was half defined but the actual array member was not added. This went unnoticed as the array has an exessive empty member at the end but introduced a user visible regression as the output was corrupted. - Prevent further silent ucount corruption by adding a BUILD_BUG_ON() to catch half updated data. * tag 'timers-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ucount: Make sure ucounts in /proc/sys/user don't regress again time/namespace: Add max_time_namespaces ucount time/namespace: Fix time_for_children symlink
2020-04-10docs: admin-guide: document the kernel.modprobe sysctlEric Biggers1-0/+21
Document the kernel.modprobe sysctl in the same place that all the other kernel.* sysctls are documented. Make sure to mention how to use this sysctl to completely disable module autoloading, and how this sysctl relates to CONFIG_STATIC_USERMODEHELPER. [[email protected]: v5] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Eric Biggers <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Jeff Vander Stoep <[email protected]> Cc: Jessica Yu <[email protected]> Cc: Kees Cook <[email protected]> Cc: Luis Chamberlain <[email protected]> Cc: NeilBrown <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-04-07time/namespace: Add max_time_namespaces ucountDmitry Safonov1-0/+6
Michael noticed that userns limit for number of time namespaces is missing. Furthermore, time namespace introduced UCOUNT_TIME_NAMESPACES, but didn't introduce an array member in user_table[]. It would make array's initialisation OOB write, but by luck the user_table array has an excessive empty member (all accesses to the array are limited with UCOUNT_COUNTS - so it silently reuses the last free member. Fixes user-visible regression: max_inotify_instances by reason of the missing UCOUNT_ENTRY() has limited max number of namespaces instead of the number of inotify instances. Fixes: 769071ac9f20 ("ns: Introduce Time Namespace") Reported-by: Michael Kerrisk (man-pages) <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: Andrei Vagin <[email protected]> Acked-by: Vincenzo Frascino <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected]
2020-04-02mm/compaction: Disable compact_unevictable_allowed on RTSebastian Andrzej Siewior1-0/+3
Since commit 5bbe3547aa3ba ("mm: allow compaction of unevictable pages") it is allowed to examine mlocked pages and compact them by default. On -RT even minor pagefaults are problematic because it may take a few 100us to resolve them and until then the task is blocked. Make compact_unevictable_allowed = 0 default and issue a warning on RT if it is changed. [[email protected]: v5] Link: https://lore.kernel.org/linux-mm/[email protected]/ Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Acked-by: Mel Gorman <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Luis Chamberlain <[email protected]> Cc: Kees Cook <[email protected]> Cc: Iurii Zaikin <[email protected]> Cc: Vlastimil Babka <[email protected]> Link: https://lore.kernel.org/linux-mm/[email protected]/ Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-03-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-1/+2
Pull networking updates from David Miller: "Highlights: 1) Fix the iwlwifi regression, from Johannes Berg. 2) Support BSS coloring and 802.11 encapsulation offloading in hardware, from John Crispin. 3) Fix some potential Spectre issues in qtnfmac, from Sergey Matyukevich. 4) Add TTL decrement action to openvswitch, from Matteo Croce. 5) Allow paralleization through flow_action setup by not taking the RTNL mutex, from Vlad Buslov. 6) A lot of zero-length array to flexible-array conversions, from Gustavo A. R. Silva. 7) Align XDP statistics names across several drivers for consistency, from Lorenzo Bianconi. 8) Add various pieces of infrastructure for offloading conntrack, and make use of it in mlx5 driver, from Paul Blakey. 9) Allow using listening sockets in BPF sockmap, from Jakub Sitnicki. 10) Lots of parallelization improvements during configuration changes in mlxsw driver, from Ido Schimmel. 11) Add support to devlink for generic packet traps, which report packets dropped during ACL processing. And use them in mlxsw driver. From Jiri Pirko. 12) Support bcmgenet on ACPI, from Jeremy Linton. 13) Make BPF compatible with RT, from Thomas Gleixnet, Alexei Starovoitov, and your's truly. 14) Support XDP meta-data in virtio_net, from Yuya Kusakabe. 15) Fix sysfs permissions when network devices change namespaces, from Christian Brauner. 16) Add a flags element to ethtool_ops so that drivers can more simply indicate which coalescing parameters they actually support, and therefore the generic layer can validate the user's ethtool request. Use this in all drivers, from Jakub Kicinski. 17) Offload FIFO qdisc in mlxsw, from Petr Machata. 18) Support UDP sockets in sockmap, from Lorenz Bauer. 19) Fix stretch ACK bugs in several TCP congestion control modules, from Pengcheng Yang. 20) Support virtual functiosn in octeontx2 driver, from Tomasz Duszynski. 21) Add region operations for devlink and use it in ice driver to dump NVM contents, from Jacob Keller. 22) Add support for hw offload of MACSEC, from Antoine Tenart. 23) Add support for BPF programs that can be attached to LSM hooks, from KP Singh. 24) Support for multiple paths, path managers, and counters in MPTCP. From Peter Krystad, Paolo Abeni, Florian Westphal, Davide Caratti, and others. 25) More progress on adding the netlink interface to ethtool, from Michal Kubecek" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2121 commits) net: ipv6: rpl_iptunnel: Fix potential memory leak in rpl_do_srh_inline cxgb4/chcr: nic-tls stats in ethtool net: dsa: fix oops while probing Marvell DSA switches net/bpfilter: remove superfluous testing message net: macb: Fix handling of fixed-link node net: dsa: ksz: Select KSZ protocol tag netdevsim: dev: Fix memory leak in nsim_dev_take_snapshot_write net: stmmac: add EHL 2.5Gbps PCI info and PCI ID net: stmmac: add EHL PSE0 & PSE1 1Gbps PCI info and PCI ID net: stmmac: create dwmac-intel.c to contain all Intel platform net: dsa: bcm_sf2: Support specifying VLAN tag egress rule net: dsa: bcm_sf2: Add support for matching VLAN TCI net: dsa: bcm_sf2: Move writing of CFP_DATA(5) into slicing functions net: dsa: bcm_sf2: Check earlier for FLOW_EXT and FLOW_MAC_EXT net: dsa: bcm_sf2: Disable learning for ASP port net: dsa: b53: Deny enslaving port 7 for 7278 into a bridge net: dsa: b53: Prevent tagged VLAN on port 7 for 7278 net: dsa: b53: Restore VLAN entries upon (re)configuration net: dsa: bcm_sf2: Fix overflow checks hv_netvsc: Remove unnecessary round_up for recv_completion_cnt ...
2020-03-10Documentation: Better document the softlockup_panic sysctlGuilherme G. Piccoli1-0/+14
Commit 9c44bc03fff4 ("softlockup: allow panic on lockup") added the softlockup_panic sysctl, but didn't add information about it to the file Documentation/admin-guide/sysctl/kernel.rst (which in that time certainly wasn't rst and had other name!). This patch just adds the respective documentation and references it from the corresponding entry in Documentation/admin-guide/kernel-parameters.txt. This patch was strongly based on Scott Wood's commit d22881dc13b6 ("Documentation: Better document the hardlockup_panic sysctl"). Reviewed-by: Kees Cook <[email protected]> Signed-off-by: Guilherme G. Piccoli <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Corbet <[email protected]>
2020-03-05bpf, doc: Add BPF JIT for RV32G to BPF documentationLuke Nelson1-1/+2
Update filter.txt and admin-guide to mention the BPF JIT for RV32G. Co-developed-by: Xi Wang <[email protected]> Signed-off-by: Xi Wang <[email protected]> Signed-off-by: Luke Nelson <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: Björn Töpel <[email protected]> Acked-by: Björn Töpel <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-02-25docs: add a script to check sysctl docsStephen Kitt1-0/+3
This script allows sysctl documentation to be checked against the kernel source code, to identify missing or obsolete entries. Running it against 5.5 shows for example that sysctl/kernel.rst has two obsolete entries and is missing 52 entries. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-25docs: sysctl/kernel: document acpi_video_flagsStephen Kitt1-2/+9
Based on the implementation in arch/x86/kernel/acpi/sleep.c, in particular the acpi_sleep_setup() function. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-19docs: sysctl/kernel: remove rtsig entriesStephen Kitt1-10/+0
These have no corresponding code in the kernel. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-19docs: document panic fully in sysctl/kernel.rstStephen Kitt1-3/+9
The description of panic doesn’t cover all the supported scenarios; this patch fixes that, describing the three possibilities (no reboot, immediate reboot, reboot after a delay). Based on the implementation in kernel/panic.c. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-19docs: document stop-a in sysctl/kernel.rstStephen Kitt1-0/+10
This describes the SPARC-specific stop-a sysctl entry, which was previously listed in kernel.rst but not documented. Base on the implementation in arch/sparc/kernel/setup_{32,64}.c and kernel/panic.c. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-19docs: add missing IPC documentation in sysctl/kernel.rstStephen Kitt1-0/+12
This adds short descriptions of msgmax, msgmnb, msgmni, and shmmni, which were previously listed in kernel.rst but not described. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-19docs: drop l2cr from sysctl/kernel.rstStephen Kitt1-7/+0
The l2cr sysctl entry was removed in commit c2f3dabefa73 ("sysctl: kill binary sysctl KERN_PPC_L2CR"), this removes the corresponding documentation. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-19docs: merge debugging-modules.txt into sysctl/kernel.rstStephen Kitt1-1/+13
This fits nicely in sysctl/kernel.rst, merge it (and rephrase it) instead of linking to it. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-19docs: pretty up sysctl/kernel.rstStephen Kitt1-495/+492
This updates sysctl/kernel.rst to use ReStructured Text more fully: * the list of files is now the table of contents (old entries with no corresponding sections are added as empty sections for now); * code references and commands are formatted as code, except for function names which end up linked to the appropriate documentation; * links are used to point to other documentation and other sections; * tables are used to make lists of values more readable (as already done for some sections); * in heavily-reworked paragraphs, sentences are wrapped individually, to make future diffs easier to read. The first mention of the kernel version is dropped. The second mention, saying that the document is accurate for 2.2, is preserved for now; I will update that once the document really is accurate for a current kernel release. Signed-off-by: Stephen Kitt <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2020-02-13docs: admin-guide: Add description of %c corename format[email protected]1-0/+1
There is somehow no description of %c corename format specifier for /proc/sys/kernel/core_pattern. The %c corename format specifier is used by user-space application such as systemd-coredump, so it should be documented. To find where %c is handled in the kernel source code, look at function format_corename() in fs/coredump.c. Signed-off-by: HATAYAMA Daisuke <[email protected]> Link: https://lore.kernel.org/r/TYAPR01MB4014714BB2ACE425BB6EC6B7951A0@TYAPR01MB4014.jpnprd01.prod.outlook.com Signed-off-by: Jonathan Corbet <[email protected]>
2019-11-07docs: admin-guide: Remove threads-max auto-tuningMasanari Iida1-4/+0
Since following path was merged in 5.4-rc3, auto-tuning feature in threads-max does not exist any more. Fix the admin-guide document as is. kernel/sysctl.c: do not override max_threads provided by userspace b0f53dbc4bc4c371f38b14c391095a3bb8a0bb40 Fixes: b0f53dbc4bc4 ("kernel/sysctl.c: do not override max_threads provided by userspace") Signed-off-by: Masanari Iida <[email protected]> Acked-by: Michal Hocko <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2019-11-07docs: admin-guide: Fix min value of threads-max in kernel.rstMasanari Iida1-1/+1
Since following patch was merged 5.4-rc3, minimum value for threads-max changed to 1. kernel/sysctl.c: do not override max_threads provided by userspace b0f53dbc4bc4c371f38b14c391095a3bb8a0bb40 Fixes: b0f53dbc4bc4 ("kernel/sysctl.c: do not override max_threads provided by userspace") Signed-off-by: Masanari Iida <[email protected]> Acked-by: Michal Hocko <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2019-10-10docs: admin-guide: fix printk_ratelimit explanationOleksandr Natalenko1-2/+4
The printk_ratelimit value accepts seconds, not jiffies (though it is converted into jiffies internally). Update documentation to reflect this. Also, remove the statement about allowing 1 message in 5 seconds since bursts up to 10 messages are allowed by default. Finally, while we are here, mention default value for printk_ratelimit_burst too. Signed-off-by: Oleksandr Natalenko <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2019-08-08docs: admin-guide: remove references to IPX and token-ringStephen Hemminger1-28/+1
Both IPX and TR have not been supported for a while now. Remove them from the /proc/sys/net documentation. Signed-off-by: Stephen Hemminger <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2019-07-15docs: admin-guide: add a series of orphaned documentsMauro Carvalho Chehab1-1/+1
There are lots of documents that belong to the admin-guide but are on random places (most under Documentation root dir). Move them to the admin guide. Signed-off-by: Mauro Carvalho Chehab <[email protected]> Acked-by: Alexandre Belloni <[email protected]> Acked-by: Bartlomiej Zolnierkiewicz <[email protected]>
2019-07-15docs: admin-guide: add laptops documentationMauro Carvalho Chehab1-2/+2
The docs under Documentation/laptops contain users specific information. Signed-off-by: Mauro Carvalho Chehab <[email protected]> Acked-by: Andy Shevchenko <[email protected]>
2019-07-15docs: admin-guide: move sysctl directory to itMauro Carvalho Chehab8-0/+3254
The stuff under sysctl describes /sys interface from userspace point of view. So, add it to the admin-guide and remove the :orphan: from its index file. Signed-off-by: Mauro Carvalho Chehab <[email protected]>