summaryrefslogtreecommitdiff
path: root/Documentation/admin-guide/sysctl/kernel.rst
AgeCommit message (Collapse)AuthorFilesLines
2022-03-25Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+2
Merge more updates from Andrew Morton: "Various misc subsystems, before getting into the post-linux-next material. 41 patches. Subsystems affected by this patch series: procfs, misc, core-kernel, lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump, taskstats, panic, kcov, resource, and ubsan" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits) Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang" kernel/resource: fix kfree() of bootmem memory again kcov: properly handle subsequent mmap calls kcov: split ioctl handling into locked and unlocked parts panic: move panic_print before kmsg dumpers panic: add option to dump all CPUs backtraces in panic_print docs: sysctl/kernel: add missing bit to panic_print taskstats: remove unneeded dead assignment kasan: no need to unset panic_on_warn in end_report() ubsan: no need to unset panic_on_warn in ubsan_epilogue() panic: unset panic_on_warn inside panic() docs: kdump: add scp example to write out the dump file docs: kdump: update description about sysfs file system support arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible cgroup: use irqsave in cgroup_rstat_flush_locked(). fat: use pointer to simple type in put_user() minix: fix bug when opening a file with O_DIRECT ...
2022-03-24panic: add option to dump all CPUs backtraces in panic_printGuilherme G. Piccoli1-0/+1
Currently the "panic_print" parameter/sysctl allows some interesting debug information to be printed during a panic event. This is useful for example in cases the user cannot kdump due to resource limits, or if the user collects panic logs in a serial output (or pstore) and prefers a fast reboot instead of a kdump. Happens that currently there's no way to see all CPUs backtraces in a panic using "panic_print" on architectures that support that. We do have "oops_all_cpu_backtrace" sysctl, but although partially overlapping in the functionality, they are orthogonal in nature: "panic_print" is a panic tuning (and we have panics without oopses, like direct calls to panic() or maybe other paths that don't go through oops_enter() function), and the original purpose of "oops_all_cpu_backtrace" is to provide more information on oopses for cases in which the users desire to continue running the kernel even after an oops, i.e., used in non-panic scenarios. So, we hereby introduce an additional bit for "panic_print" to allow dumping the CPUs backtraces during a panic event. Link: https://lkml.kernel.org/r/20211109202848.610874-3-gpiccoli@igalia.com Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Reviewed-by: Feng Tang <feng.tang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-24docs: sysctl/kernel: add missing bit to panic_printGuilherme G. Piccoli1-0/+1
Patch series "Some improvements on panic_print". This is a mix of a documentation fix with some additions to the "panic_print" syscall / parameter. The goal here is being able to collect all CPUs backtraces during a panic event and also to enable "panic_print" in a kdump event - details of the reasoning and design choices in the patches. This patch (of 3): Commit de6da1e8bcf0 ("panic: add an option to replay all the printk message in buffer") added a new bit to the sysctl/kernel parameter "panic_print", but the documentation was added only in kernel-parameters.txt, not in the sysctl guide. Fix it here by adding bit 5 to sysctl admin-guide documentation. [rdunlap@infradead.org: fix table format warning] Link: https://lkml.kernel.org/r/20220109055635.6999-1-rdunlap@infradead.org Link: https://lkml.kernel.org/r/20211109202848.610874-1-gpiccoli@igalia.com Link: https://lkml.kernel.org/r/20211109202848.610874-2-gpiccoli@igalia.com Fixes: de6da1e8bcf0 ("panic: add an option to replay all the printk message in buffer") Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Reviewed-by: Feng Tang <feng.tang@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-9/+21
Merge updates from Andrew Morton: - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs - Most the MM patches which precede the patches in Willy's tree: kasan, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb, userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp, cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap, zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (227 commits) mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release() Docs/ABI/testing: add DAMON sysfs interface ABI document Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface selftests/damon: add a test for DAMON sysfs interface mm/damon/sysfs: support DAMOS stats mm/damon/sysfs: support DAMOS watermarks mm/damon/sysfs: support schemes prioritization mm/damon/sysfs: support DAMOS quotas mm/damon/sysfs: support DAMON-based Operation Schemes mm/damon/sysfs: support the physical address space monitoring mm/damon/sysfs: link DAMON for virtual address spaces monitoring mm/damon: implement a minimal stub for sysfs-based DAMON interface mm/damon/core: add number of each enum type values mm/damon/core: allow non-exclusive DAMON start/stop Docs/damon: update outdated term 'regions update interval' Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling Docs/vm/damon: call low level monitoring primitives the operations mm/damon: remove unnecessary CONFIG_DAMON option mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}() mm/damon/dbgfs-test: fix is_target_id() change ...
2022-03-23NUMA balancing: optimize page placement for memory tiering systemHuang Ying1-9/+20
With the advent of various new memory types, some machines will have multiple types of memory, e.g. DRAM and PMEM (persistent memory). The memory subsystem of these machines can be called memory tiering system, because the performance of the different types of memory are usually different. In such system, because of the memory accessing pattern changing etc, some pages in the slow memory may become hot globally. So in this patch, the NUMA balancing mechanism is enhanced to optimize the page placement among the different memory types according to hot/cold dynamically. In a typical memory tiering system, there are CPUs, fast memory and slow memory in each physical NUMA node. The CPUs and the fast memory will be put in one logical node (called fast memory node), while the slow memory will be put in another (faked) logical node (called slow memory node). That is, the fast memory is regarded as local while the slow memory is regarded as remote. So it's possible for the recently accessed pages in the slow memory node to be promoted to the fast memory node via the existing NUMA balancing mechanism. The original NUMA balancing mechanism will stop to migrate pages if the free memory of the target node becomes below the high watermark. This is a reasonable policy if there's only one memory type. But this makes the original NUMA balancing mechanism almost do not work to optimize page placement among different memory types. Details are as follows. It's the common cases that the working-set size of the workload is larger than the size of the fast memory nodes. Otherwise, it's unnecessary to use the slow memory at all. So, there are almost always no enough free pages in the fast memory nodes, so that the globally hot pages in the slow memory node cannot be promoted to the fast memory node. To solve the issue, we have 2 choices as follows, a. Ignore the free pages watermark checking when promoting hot pages from the slow memory node to the fast memory node. This will create some memory pressure in the fast memory node, thus trigger the memory reclaiming. So that, the cold pages in the fast memory node will be demoted to the slow memory node. b. Define a new watermark called wmark_promo which is higher than wmark_high, and have kswapd reclaiming pages until free pages reach such watermark. The scenario is as follows: when we want to promote hot-pages from a slow memory to a fast memory, but fast memory's free pages would go lower than high watermark with such promotion, we wake up kswapd with wmark_promo watermark in order to demote cold pages and free us up some space. So, next time we want to promote hot-pages we might have a chance of doing so. The choice "a" may create high memory pressure in the fast memory node. If the memory pressure of the workload is high, the memory pressure may become so high that the memory allocation latency of the workload is influenced, e.g. the direct reclaiming may be triggered. The choice "b" works much better at this aspect. If the memory pressure of the workload is high, the hot pages promotion will stop earlier because its allocation watermark is higher than that of the normal memory allocation. So in this patch, choice "b" is implemented. A new zone watermark (WMARK_PROMO) is added. Which is larger than the high watermark and can be controlled via watermark_scale_factor. In addition to the original page placement optimization among sockets, the NUMA balancing mechanism is extended to be used to optimize page placement according to hot/cold among different memory types. So the sysctl user space interface (numa_balancing) is extended in a backward compatible way as follow, so that the users can enable/disable these functionality individually. The sysctl is converted from a Boolean value to a bits field. The definition of the flags is, - 0: NUMA_BALANCING_DISABLED - 1: NUMA_BALANCING_NORMAL - 2: NUMA_BALANCING_MEMORY_TIERING We have tested the patch with the pmbench memory accessing benchmark with the 80:20 read/write ratio and the Gauss access address distribution on a 2 socket Intel server with Optane DC Persistent Memory Model. The test results shows that the pmbench score can improve up to 95.9%. Thanks Andrew Morton to help fix the document format error. Link: https://lkml.kernel.org/r/20220221084529.1052339-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@surriel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Wei Xu <weixugc@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: zhongjiang-ali <zhongjiang-ali@linux.alibaba.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23Merge tag 'sched-core-2022-03-22' of ↵Linus Torvalds1-45/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Cleanups for SCHED_DEADLINE - Tracing updates/fixes - CPU Accounting fixes - First wave of changes to optimize the overhead of the scheduler build, from the fast-headers tree - including placeholder *_api.h headers for later header split-ups. - Preempt-dynamic using static_branch() for ARM64 - Isolation housekeeping mask rework; preperatory for further changes - NUMA-balancing: deal with CPU-less nodes - NUMA-balancing: tune systems that have multiple LLC cache domains per node (eg. AMD) - Updates to RSEQ UAPI in preparation for glibc usage - Lots of RSEQ/selftests, for same - Add Suren as PSI co-maintainer * tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits) sched/headers: ARM needs asm/paravirt_api_clock.h too sched/numa: Fix boot crash on arm64 systems headers/prep: Fix header to build standalone: <linux/psi.h> sched/headers: Only include <linux/entry-common.h> when CONFIG_GENERIC_ENTRY=y cgroup: Fix suspicious rcu_dereference_check() usage warning sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity() sched/deadline,rt: Remove unused functions for !CONFIG_SMP sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistently sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy() sched/deadline: Move bandwidth mgmt and reclaim functions into sched class source file sched/deadline: Remove unused def_dl_bandwidth sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE sched/tracing: Don't re-read p->state when emitting sched_switch event sched/rt: Plug rt_mutex_setprio() vs push_rt_task() race sched/cpuacct: Remove redundant RCU read lock sched/cpuacct: Optimize away RCU read lock sched/cpuacct: Fix charge percpu cpuusage sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies ...
2022-02-21random: remove ifdef'd out interrupt benchJason A. Donenfeld1-9/+0
With tools like kbench9000 giving more finegrained responses, and this basically never having been used ever since it was initially added, let's just get rid of this. There *is* still work to be done on the interrupt handler, but this really isn't the way it's being developed. Cc: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21random: always wake up entropy writers after extractionJason A. Donenfeld1-2/+5
Now that POOL_BITS == POOL_MIN_BITS, we must unconditionally wake up entropy writers after every extraction. Therefore there's no point of write_wakeup_threshold, so we can move it to the dustbin of unused compatibility sysctls. While we're at it, we can fix a small comparison where we were waking up after <= min rather than < min. Cc: Theodore Ts'o <tytso@mit.edu> Suggested-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-12sched/numa-balancing: Move some document to make it consistent with the codeHuang Ying1-45/+1
After commit 8a99b6833c88 ("sched: Move SCHED_DEBUG sysctl to debugfs"), some NUMA balancing sysctls enclosed with SCHED_DEBUG has been moved to debugfs. This patch move the document for these sysctls from Documentation/admin-guide/sysctl/kernel.rst to Documentation/scheduler/sched-debug.rst to make the document consistent with the code. Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lkml.kernel.org/r/20220210052514.3038279-1-ying.huang@intel.com
2021-12-14arm64: perf: Add userspace counter access disable switchRob Herring1-0/+11
Like x86, some users may want to disable userspace PMU counter altogether. Add a sysctl 'perf_user_access' file to control userspace counter access. The default is '0' which is disabled. Writing '1' enables access. Note that x86 supports globally enabling user access by writing '2' to /sys/bus/event_source/devices/cpu/rdpmc. As there's not existing userspace support to worry about, this shouldn't be necessary for Arm. It could be added later if the need arises. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-perf-users@vger.kernel.org Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-4-robh@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-11-17docs: accounting: update delay-accounting.rst referenceMauro Carvalho Chehab1-1/+1
The file name: accounting/delay-accounting.rst should be, instead: Documentation/accounting/delay-accounting.rst. Also, there's no need to use doc:`foo`, as automarkup.py will automatically handle plain text mentions to Documentation/ files. So, update its cross-reference accordingly. Fixes: fcb501704554 ("delayacct: Document task_delayacct sysctl") Fixes: c3123552aad3 ("docs: accounting: convert to ReST") Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-30Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-5/+5
Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
2021-06-29doc: watchdog: modify the doc related to "watchdog/%u"Wang Qing1-5/+5
"watchdog/%u" threads has be replaced by cpu_stop_work. The current description is extremely misleading. Link: https://lkml.kernel.org/r/1619687073-24686-5-git-send-email-wangqing@vivo.com Signed-off-by: Wang Qing <wangqing@vivo.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: "Guilherme G. Piccoli" <gpiccoli@canonical.com> Cc: Joe Perches <joe@perches.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Qais Yousef <qais.yousef@arm.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Santosh Sivaraj <santosh@fossix.org> Cc: Stephen Kitt <steve@sk2.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29Merge tag 'docs-5.14' of git://git.lwn.net/linuxLinus Torvalds1-18/+26
Pull documentation updates from Jonathan Corbet: "This was a reasonably active cycle for documentation; this includes: - Some kernel-doc cleanups. That script is still regex onslaught from hell, but it has gotten a little better. - Improvements to the checkpatch docs, which are also used by the tool itself. - A major update to the pathname lookup documentation. - Elimination of :doc: markup, since our automarkup magic can create references from filenames without all the extra noise. - The flurry of Chinese translation activity continues. Plus, of course, the usual collection of updates, typo fixes, and warning fixes" * tag 'docs-5.14' of git://git.lwn.net/linux: (115 commits) docs: path-lookup: use bare function() rather than literals docs: path-lookup: update symlink description docs: path-lookup: update get_link() ->follow_link description docs: path-lookup: update WALK_GET, WALK_PUT desc docs: path-lookup: no get_link() docs: path-lookup: update i_op->put_link and cookie description docs: path-lookup: i_op->follow_link replaced with i_op->get_link docs: path-lookup: Add macro name to symlink limit description docs: path-lookup: remove filename_mountpoint docs: path-lookup: update do_last() part docs: path-lookup: update path_mountpoint() part docs: path-lookup: update path_to_nameidata() part docs: path-lookup: update follow_managed() part docs: Makefile: Use CONFIG_SHELL not SHELL docs: Take a little noise out of the build process docs: x86: avoid using ReST :doc:`foo` markup docs: virt: kvm: s390-pv-boot.rst: avoid using ReST :doc:`foo` markup docs: userspace-api: landlock.rst: avoid using ReST :doc:`foo` markup docs: trace: ftrace.rst: avoid using ReST :doc:`foo` markup docs: trace: coresight: coresight.rst: avoid using ReST :doc:`foo` markup ...
2021-06-17docs: admin-guide: sysctl: avoid using ReST :doc:`foo` markupMauro Carvalho Chehab1-17/+20
The :doc:`foo` tag is auto-generated via automarkup.py. So, use the filename at the sources, instead of :doc:`foo`. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/12abd2290c7ebc05c89178d2556bea740bd70fac.1623824363.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-03Merge branch 'sched/urgent' into sched/core, to pick up fixesIngo Molnar1-7/+19
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-05-27Merge tag 'net-5.13-rc4' of ↵Linus Torvalds1-3/+14
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Networking fixes for 5.13-rc4, including fixes from bpf, netfilter, can and wireless trees. Notably including fixes for the recently announced "FragAttacks" WiFi vulnerabilities. Rather large batch, touching some core parts of the stack, too, but nothing hair-raising. Current release - regressions: - tipc: make node link identity publish thread safe - dsa: felix: re-enable TAS guard band mode - stmmac: correct clocks enabled in stmmac_vlan_rx_kill_vid() - stmmac: fix system hang if change mac address after interface ifdown Current release - new code bugs: - mptcp: avoid OOB access in setsockopt() - bpf: Fix nested bpf_bprintf_prepare with more per-cpu buffers - ethtool: stats: fix a copy-paste error - init correct array size Previous releases - regressions: - sched: fix packet stuck problem for lockless qdisc - net: really orphan skbs tied to closing sk - mlx4: fix EEPROM dump support - bpf: fix alu32 const subreg bound tracking on bitwise operations - bpf: fix mask direction swap upon off reg sign change - bpf, offload: reorder offload callback 'prepare' in verifier - stmmac: Fix MAC WoL not working if PHY does not support WoL - packetmmap: fix only tx timestamp on request - tipc: skb_linearize the head skb when reassembling msgs Previous releases - always broken: - mac80211: address recent "FragAttacks" vulnerabilities - mac80211: do not accept/forward invalid EAPOL frames - mptcp: avoid potential error message floods - bpf, ringbuf: deny reserve of buffers larger than ringbuf to prevent out of buffer writes - bpf: forbid trampoline attach for functions with variable arguments - bpf: add deny list of functions to prevent inf recursion of tracing programs - tls splice: check SPLICE_F_NONBLOCK instead of MSG_DONTWAIT - can: isotp: prevent race between isotp_bind() and isotp_setsockopt() - netfilter: nft_set_pipapo_avx2: Add irq_fpu_usable() check, fallback to non-AVX2 version Misc: - bpf: add kconfig knob for disabling unpriv bpf by default" * tag 'net-5.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (172 commits) net: phy: Document phydev::dev_flags bits allocation mptcp: validate 'id' when stopping the ADD_ADDR retransmit timer mptcp: avoid error message on infinite mapping mptcp: drop unconditional pr_warn on bad opt mptcp: avoid OOB access in setsockopt() nfp: update maintainer and mailing list addresses net: mvpp2: add buffer header handling in RX bnx2x: Fix missing error code in bnx2x_iov_init_one() net: zero-initialize tc skb extension on allocation net: hns: Fix kernel-doc sctp: fix the proc_handler for sysctl encap_port sctp: add the missing setting for asoc encap_port bpf, selftests: Adjust few selftest result_unpriv outcomes bpf: No need to simulate speculative domain for immediates bpf: Fix mask direction swap upon off reg sign change bpf: Wrap aux data inside bpf_sanitize_info container bpf: Fix BPF_LSM kconfig symbol dependency selftests/bpf: Add test for l3 use of bpf_redirect_peer bpftool: Add sock_release help info for cgroup attach/prog load command net: dsa: microchip: enable phy errata workaround on 9567 ...
2021-05-18delayacct: Document task_delayacct sysctlMel Gorman1-0/+7
Update sysctl/kernel.rst. Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210512114035.GH3672@suse.de
2021-05-15docs: admin-guide: update description for kernel.modprobe sysctlRasmus Villemoes1-4/+5
When I added CONFIG_MODPROBE_PATH, I neglected to update Documentation/. It's still true that this defaults to /sbin/modprobe, but now via a level of indirection. So document that the kernel might have been built with something other than /sbin/modprobe as the initial value. Link: https://lkml.kernel.org/r/20210420125324.1246826-1-linux@rasmusvillemoes.dk Fixes: 17652f4240f7a ("modules: add CONFIG_MODPROBE_PATH") Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-13docs: admin-guide: update description for kernel.hotplug sysctlRasmus Villemoes1-1/+6
It's been a few releases since this defaulted to /sbin/hotplug. Update the text, and include pointers to the two CONFIG_UEVENT_HELPER{,_PATH} config knobs whose help text could provide more info, but also hint that the user probably doesn't need to care at all. Fixes: 7934779a69f1 ("Driver-Core: disable /sbin/hotplug by default") Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Link: https://lore.kernel.org/r/20210420120638.1104016-1-linux@rasmusvillemoes.dk Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-05-11bpf: Add kconfig knob for disabling unpriv bpf by defaultDaniel Borkmann1-3/+14
Add a kconfig knob which allows for unprivileged bpf to be disabled by default. If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2. This still allows a transition of 2 -> {0,1} through an admin. Similarly, this also still keeps 1 -> {1} behavior intact, so that once set to permanently disabled, it cannot be undone aside from a reboot. We've also added extra2 with max of 2 for the procfs handler, so that an admin still has a chance to toggle between 0 <-> 2. Either way, as an additional alternative, applications can make use of CAP_BPF that we added a while ago. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net
2020-12-08docs: Update documentation to reflect what TAINT_CPU_OUT_OF_SPEC meansMathieu Chouquet-Stringer1-1/+1
Here's a patch updating the meaning of TAINT_CPU_OUT_OF_SPEC after Borislav introduced changes in a7e1f67ed29f and upcoming patches in tip. TAINT_CPU_OUT_OF_SPEC now means a bit more what it implies as the flag isn't set just because of a CPU misconfiguration or mismatch. Historically it was for SMP kernel oops on an officially SMP incapable processor but now it also covers CPUs whose MSRs have been incorrectly poked at from userspace, drivers being used on non supported architectures, broken firmware, mismatched CPUs, ... Update documentation and script to reflect that. Signed-off-by: Mathieu Chouquet-Stringer <me@mathieu.digital> Link: https://lore.kernel.org/r/20201202153244.709752-1-me@mathieu.digital Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-08Documentation: fix multiple typos found in the admin-guide subdirectoryAndrew Klychkov1-1/+1
Fix thirty five typos in dm-integrity.rst, dm-raid.rst, dm-zoned.rst, verity.rst, writecache.rst, tsx_async_abort.rst, md.rst, bttv.rst, dvb_references.rst, frontend-cardlist.rst, gspca-cardlist.rst, ipu3.rst, remote-controller.rst, mm/index.rst, numaperf.rst, userfaultfd.rst, module-signing.rst, imx-ddr.rst, intel-speed-select.rst, intel_pstate.rst, ramoops.rst, abi.rst, kernel.rst, vm.rst Signed-off-by: Andrew Klychkov <andrew.a.klychkov@gmail.com> Link: https://lore.kernel.org/r/20201204072848.GA49895@spblnx124.lan Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-08docs: clean up sysctl/kernel: titles, versionStephen Kitt1-7/+7
This cleans up a few titles with extra colons, and removes the reference to kernel 2.2. The docs don't yet cover *all* of 5.10 or 5.11, but I think they're close enough. Most entries are documented, and have been checked against current kernels. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20201208074922.30359-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-08-12coredump: add %f for executable filenameLepton Wu1-1/+2
The document reads "%e" should be "executable filename" while actually it could be changed by things like pr_ctl PR_SET_NAME. People who uses "%e" in core_pattern get surprised when they find out they get thread name instead of executable filename. This is either a bug of document or a bug of code. Since the behavior of "%e" is there for long time, it could bring another surprise for users if we "fix" the code. So we just "fix" the document. And more, for users who really need the "executable filename" in core_pattern, we introduce a new "%f" for the real executable filename. We already have "%E" for executable path in kernel, so just reuse most of its code for the new added "%f" format. Signed-off-by: Lepton Wu <ytht.net@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200701031432.2978761-1-ytht.net@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-05Merge tag 'docs-5.9' of git://git.lwn.net/linuxLinus Torvalds1-5/+37
Pull documentation updates from Jonathan Corbet: "It's been a busy cycle for documentation - hopefully the busiest for a while to come. Changes include: - Some new Chinese translations - Progress on the battle against double words words and non-HTTPS URLs - Some block-mq documentation - More RST conversions from Mauro. At this point, that task is essentially complete, so we shouldn't see this kind of churn again for a while. Unless we decide to switch to asciidoc or something...:) - Lots of typo fixes, warning fixes, and more" * tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits) scripts/kernel-doc: optionally treat warnings as errors docs: ia64: correct typo mailmap: add entry for <alobakin@marvell.com> doc/zh_CN: add cpu-load Chinese version Documentation/admin-guide: tainted-kernels: fix spelling mistake MAINTAINERS: adjust kprobes.rst entry to new location devices.txt: document rfkill allocation PCI: correct flag name docs: filesystems: vfs: correct flag name docs: filesystems: vfs: correct sync_mode flag names docs: path-lookup: markup fixes for emphasis docs: path-lookup: more markup fixes docs: path-lookup: fix HTML entity mojibake CREDITS: Replace HTTP links with HTTPS ones docs: process: Add an example for creating a fixes tag doc/zh_CN: add Chinese translation prefer section doc/zh_CN: add clearing-warn-once Chinese version doc/zh_CN: add admin-guide index doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label futex: MAINTAINERS: Re-add selftests directory ...
2020-07-29Documentation/sysctl: Document uclamp sysctl knobsQais Yousef1-0/+54
Uclamp exposes 3 sysctl knobs: * sched_util_clamp_min * sched_util_clamp_max * sched_util_clamp_min_rt_default Document them in sysctl/kernel.rst. Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200716110347.19553-3-qais.yousef@arm.com
2020-07-05Documentation/admin-guide: sysctl/kernel: drop doubled wordRandy Dunlap1-1/+1
Drop the doubled word "set". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-12-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-26docs: sysctl/kernel: document randomStephen Kitt1-0/+32
This documents the random directory, based on the behaviour seen in drivers/char/random.c. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20200623112514.10650-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-19Documentation: fix sysctl/kernel.rst heading format warningsRandy Dunlap1-4/+4
Fix heading format warnings in admin-guide/sysctl/kernel.rst: Documentation/admin-guide/sysctl/kernel.rst:339: WARNING: Title underline too short. hung_task_all_cpu_backtrace: ================ Documentation/admin-guide/sysctl/kernel.rst:650: WARNING: Title underline too short. oops_all_cpu_backtrace: ================ Fixes: 0ec9dc9bcba0 ("kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected") Fixes: 60c958d8df9c ("panic: add sysctl to dump all CPUs backtraces on oops event") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/8af1cb77-4b5a-64b9-da5d-f6a95e537f99@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-08panic: add sysctl to dump all CPUs backtraces on oops eventGuilherme G. Piccoli1-0/+16
Usually when the kernel reaches an oops condition, it's a point of no return; in case not enough debug information is available in the kernel splat, one of the last resorts would be to collect a kernel crash dump and analyze it. The problem with this approach is that in order to collect the dump, a panic is required (to kexec-load the crash kernel). When in an environment of multiple virtual machines, users may prefer to try living with the oops, at least until being able to properly shutdown their VMs / finish their important tasks. This patch implements a way to collect a bit more debug details when an oops event is reached, by printing all the CPUs backtraces through the usage of NMIs (on architectures that support that). The sysctl added (and documented) here was called "oops_all_cpu_backtrace", and when set will (as the name suggests) dump all CPUs backtraces. Far from ideal, this may be the last option though for users that for some reason cannot panic on oops. Most of times oopses are clear enough to indicate the kernel portion that must be investigated, but in virtual environments it's possible to observe hypervisor/KVM issues that could lead to oopses shown in other guests CPUs (like virtual APIC crashes). This patch hence aims to help debug such complex issues without resorting to kdump. Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200327224116.21030-1-gpiccoli@canonical.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08kernel/hung_task.c: introduce sysctl to print all traces when a hung task is ↵Guilherme G. Piccoli1-0/+14
detected Commit 401c636a0eeb ("kernel/hung_task.c: show all hung tasks before panic") introduced a change in that we started to show all CPUs backtraces when a hung task is detected _and_ the sysctl/kernel parameter "hung_task_panic" is set. The idea is good, because usually when observing deadlocks (that may lead to hung tasks), the culprit is another task holding a lock and not necessarily the task detected as hung. The problem with this approach is that dumping backtraces is a slightly expensive task, specially printing that on console (and specially in many CPU machines, as servers commonly found nowadays). So, users that plan to collect a kdump to investigate the hung tasks and narrow down the deadlock definitely don't need the CPUs backtrace on dmesg/console, which will delay the panic and pollute the log (crash tool would easily grab all CPUs traces with 'bt -a' command). Also, there's the reciprocal scenario: some users may be interested in seeing the CPUs backtraces but not have the system panic when a hung task is detected. The current approach hence is almost as embedding a policy in the kernel, by forcing the CPUs backtraces' dump (only) on hung_task_panic. This patch decouples the panic event on hung task from the CPUs backtraces dump, by creating (and documenting) a new sysctl called "hung_task_all_cpu_backtrace", analog to the approach taken on soft/hard lockups, that have both a panic and an "all_cpu_backtrace" sysctl to allow individual control. The new mechanism for dumping the CPUs backtraces on hung task detection respects "hung_task_warnings" by not dumping the traces in case there's no warnings left. Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: http://lkml.kernel.org/r/20200327223646.20779-1-gpiccoli@canonical.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08kernel: add panic_on_taintRafael Aquini1-0/+7
Analogously to the introduction of panic_on_warn, this patch introduces a kernel option named panic_on_taint in order to provide a simple and generic way to stop execution and catch a coredump when the kernel gets tainted by any given flag. This is useful for debugging sessions as it avoids having to rebuild the kernel to explicitly add calls to panic() into the code sites that introduce the taint flags of interest. For instance, if one is interested in proceeding with a post-mortem analysis at the point a given code path is hitting a bad page (i.e. unaccount_page_cache_page(), or slab_bug()), a coredump can be collected by rebooting the kernel with 'panic_on_taint=0x20' amended to the command line. Another, perhaps less frequent, use for this option would be as a means for assuring a security policy case where only a subset of taints, or no single taint (in paranoid mode), is allowed for the running system. The optional switch 'nousertaint' is handy in this particular scenario, as it will avoid userspace induced crashes by writes to sysctl interface /proc/sys/kernel/tainted causing false positive hits for such policies. [akpm@linux-foundation.org: tweak kernel-parameters.txt wording] Suggested-by: Qian Cai <cai@lca.pw> Signed-off-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Bunk <bunk@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Takashi Iwai <tiwai@suse.de> Link: http://lkml.kernel.org/r/20200515175502.146720-1-aquini@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02Merge tag 'docs-5.8' of git://git.lwn.net/linuxLinus Torvalds1-1/+156
Pull documentation updates from Jonathan Corbet: "A fair amount of stuff this time around, dominated by yet another massive set from Mauro toward the completion of the RST conversion. I *really* hope we are getting close to the end of this. Meanwhile, those patches reach pretty far afield to update document references around the tree; there should be no actual code changes there. There will be, alas, more of the usual trivial merge conflicts. Beyond that we have more translations, improvements to the sphinx scripting, a number of additions to the sysctl documentation, and lots of fixes" * tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits) Documentation: fixes to the maintainer-entry-profile template zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst tracing: Fix events.rst section numbering docs: acpi: fix old http link and improve document format docs: filesystems: add info about efivars content Documentation: LSM: Correct the basic LSM description mailmap: change email for Ricardo Ribalda docs: sysctl/kernel: document unaligned controls Documentation: admin-guide: update bug-hunting.rst docs: sysctl/kernel: document ngroups_max nvdimm: fixes to maintainter-entry-profile Documentation/features: Correct RISC-V kprobes support entry Documentation/features: Refresh the arch support status files Revert "docs: sysctl/kernel: document ngroups_max" docs: move locking-specific documents to locking/ docs: move digsig docs to the security book docs: move the kref doc into the core-api book docs: add IRQ documentation at the core-api book docs: debugging-via-ohci1394.txt: add it to the core-api book docs: fix references for ipmi.rst file ...
2020-05-26docs: sysctl/kernel: document unaligned controlsStephen Kitt1-0/+51
This documents ignore-unaligned-usertrap, unaligned-dump-stack, and unaligned-trap, based on arch/arc/kernel/unaligned.c, arch/ia64/kernel/unaligned.c, and arch/parisc/kernel/unaligned.c. While we're at it, integrate unaligned-memory-access.txt into the docs tree. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20200515212443.5012-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-05-26docs: sysctl/kernel: document ngroups_maxStephen Kitt1-0/+9
This is a read-only export of NGROUPS_MAX. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20200518145836.15816-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-05-18Revert "docs: sysctl/kernel: document ngroups_max"Jonathan Corbet1-9/+0
This reverts commit 2f4c33063ad713e3a5b63002cf8362846e78bd71. The changes here were fine, but there's a non-documentation change to sysctl.c that makes messes elsewhere; those changes should have been done independently. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <steve@sk2.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200515160222.7994-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <steve@sk2.org> Link: https://lore.kernel.org/r/20200429205757.8677-2-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <steve@sk2.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20200429205757.8677-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/4ac8f3a7edd4d817acf0d173ead7ef74fe010c6c.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <steve@sk2.org> Link: https://lore.kernel.org/r/20200423183651.15365-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-21docs: 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 <steve@sk2.org> Link: https://lore.kernel.org/r/20200315122648.20558-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <alexey.budankov@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Igor Lubashev <ilubashe@akamai.com> Cc: James Morris <jmorris@namei.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Serge Hallyn <serge@hallyn.com> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/84c32383-14a2-fa35-16b6-f9e59bd37240@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 <ebiggers@google.com> Reviewed-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20200414172430.230293-1-ebiggers@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-11docs: 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. [ebiggers@google.com: v5] Link: http://lkml.kernel.org/r/20200318230515.171692-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: NeilBrown <neilb@suse.com> Link: http://lkml.kernel.org/r/20200312202552.241885-4-ebiggers@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <keescook@chromium.org> Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Link: https://lore.kernel.org/r/20200310183649.23163-1-gpiccoli@canonical.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>