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2020-04-20docs: filesystems: fix renamed referencesMauro Carvalho Chehab2-2/+2
Some filesystem references got broken by a previous patch series I submitted. Address those. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Acked-by: David Sterba <dsterba@suse.com> # fs/affs/Kconfig Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-20Merge tag 'v5.7-rc2' into patchworkMauro Carvalho Chehab1-28/+19
Linux 5.7-rc2 * tag 'v5.7-rc2': (331 commits) Linux 5.7-rc2 mm: Fix MREMAP_DONTUNMAP accounting on VMA merge xattr.h: Replace zero-length array with flexible-array member uapi: linux: fiemap.h: Replace zero-length array with flexible-array member uapi: linux: dlm_device.h: Replace zero-length array with flexible-array member tpm_eventlog.h: Replace zero-length array with flexible-array member ti_wilink_st.h: Replace zero-length array with flexible-array member swap.h: Replace zero-length array with flexible-array member skbuff.h: Replace zero-length array with flexible-array member sched: topology.h: Replace zero-length array with flexible-array member rslib.h: Replace zero-length array with flexible-array member rio.h: Replace zero-length array with flexible-array member posix_acl.h: Replace zero-length array with flexible-array member platform_data: wilco-ec.h: Replace zero-length array with flexible-array member memcontrol.h: Replace zero-length array with flexible-array member list_lru.h: Replace zero-length array with flexible-array member lib: cpu_rmap: Replace zero-length array with flexible-array member irq.h: Replace zero-length array with flexible-array member ihex.h: Replace zero-length array with flexible-array member igmp.h: Replace zero-length array with flexible-array member ...
2020-04-20x86/speculation: Add SRBDS vulnerability and mitigation documentationMark Gross2-0/+149
Add documentation for the SRBDS vulnerability and its mitigation. [ bp: Massage. jpoimboe: sysfs table strings. ] Signed-off-by: Mark Gross <mgross@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
2020-04-20x86/speculation: Add Special Register Buffer Data Sampling (SRBDS) mitigationMark Gross1-0/+20
SRBDS is an MDS-like speculative side channel that can leak bits from the random number generator (RNG) across cores and threads. New microcode serializes the processor access during the execution of RDRAND and RDSEED. This ensures that the shared buffer is overwritten before it is released for reuse. While it is present on all affected CPU models, the microcode mitigation is not needed on models that enumerate ARCH_CAPABILITIES[MDS_NO] in the cases where TSX is not supported or has been disabled with TSX_CTRL. The mitigation is activated by default on affected processors and it increases latency for RDRAND and RDSEED instructions. Among other effects this will reduce throughput from /dev/urandom. * Enable administrator to configure the mitigation off when desired using either mitigations=off or srbds=off. * Export vulnerability status via sysfs * Rename file-scoped macros to apply for non-whitelist table initializations. [ bp: Massage, - s/VULNBL_INTEL_STEPPING/VULNBL_INTEL_STEPPINGS/g, - do not read arch cap MSR a second time in tsx_fused_off() - just pass it in, - flip check in cpu_set_bug_bits() to save an indentation level, - reflow comments. jpoimboe: s/Mitigated/Mitigation/ in user-visible strings tglx: Dropped the fused off magic for now ] Signed-off-by: Mark Gross <mgross@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
2020-04-17cpufreq: intel_pstate: Use passive mode by default without HWPRafael J. Wysocki1-13/+19
After recent changes allowing scale-invariant utilization to be used on x86, the schedutil governor on top of intel_pstate in the passive mode should be on par with (or better than) the active mode "powersave" algorithm of intel_pstate on systems in which hardware-managed P-states (HWP) are not used, so it should not be necessary to use the internal scaling algorithm in those cases. Accordingly, modify intel_pstate to start in the passive mode by default if the processor at hand does not support HWP of if the driver is requested to avoid using HWP through the kernel command line. Among other things, that will allow utilization clamps and the support for RT/DL tasks in the schedutil governor to be utilized on systems in which intel_pstate is used. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
2020-04-16doc/admin-guide: Update perf-security.rst with CAP_PERFMON informationAlexey Budankov1-24/+60
Update perf-security.rst documentation file with the information related to usage of CAP_PERFMON capability to secure performance monitoring and observability operations in system. Committer notes: While testing 'perf top' under cap_perfmon I noticed that it needs some more capability and Alexey pointed out cap_ipc_lock, as needed by this kernel chunk: kernel/events/core.c: 6101 if ((locked > lock_limit) && perf_is_paranoid() && !capable(CAP_IPC_LOCK)) { ret = -EPERM; goto unlock; } So I added it to the documentation, and also mentioned that if the libcap version doesn't yet supports 'cap_perfmon', its numeric value can be used instead, i.e. if: # setcap "cap_perfmon,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf Fails, try: # setcap "38,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf I also added a paragraph stating that using an unpatched libcap will fail the check for CAP_PERFMON, as it checks the cap number against a maximum to see if it is valid, which makes it use as the default the 'cycles:u' event, even tho a cap_perfmon capable perf binary can get kernel samples, to workaround that just use, e.g.: # perf top -e cycles # perf record -e cycles And it will sample kernel and user modes. Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.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/17278551-9399-9ebe-d665-8827016a217d@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>
2020-04-15media: docs: add cros-references to the other media guidesMauro Carvalho Chehab1-0/+12
In order to make easier for people to navigate between the three media guides, add cross-references between them Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: move copyrights to the end and update themMauro Carvalho Chehab1-9/+16
The copyright info is not the most valuable information there. Move them to the end. While here, change the copyright to cover up to this year (2020). Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: get rid of obsoleted udev documentationMauro Carvalho Chehab3-66/+0
This file is very old, and doesn't match the current udev behavior. I wanted to preserve it, because we'll need some udev description some day about how to keep names unique, but there's nothing here to help with that... So, be it: let's just discard this document, as it doesn't provide anything useful anymore. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: zr364xx: update documentationMauro Carvalho Chehab1-18/+10
There aren't much to be done here... almost everything is still valid. The supported boards even reflect the current driver's state. Yet, some things changed, so let's keep this document updated. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: saa7134.rst: update the documentationMauro Carvalho Chehab1-15/+42
There are several things here that are outdated, because this document was written a long time ago. Update them to reflect the current status of the driver and the media subsystem. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: update Digital TV faq.rstMauro Carvalho Chehab1-96/+143
This file contains lots of obsoleted information. Update it to reflect the current status and tools used by Digital TV users and add pointers to the current locations and to LinuxTV wiki pages. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: cpia2.rst: do some cleanupsMauro Carvalho Chehab1-7/+3
Do some cleanups at the document in order to mark two literal blocks as such. While here, simplify two block markups, using the less verbose option (::). Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: add a cardlist for cx18 boardsMauro Carvalho Chehab2-0/+18
There aren't many boards supported by this driver. So, add a list for it manually generated. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: update bttv.rst informationMauro Carvalho Chehab1-178/+133
This document is... old. The bttv driver was one of the first drivers at the Kernel. So, the document became a little obsoleted. Update it to reflect some changes that happened along the time affecting this driver and the subsystem. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: bt8xx.rst: update document infoMauro Carvalho Chehab1-51/+85
This document is very outdated, and doesn't match the upstream current way. Update it, making some parts a little bit more generic. While the main focus of this document is digital TV cards, its content also may also help someone with just analog TV support. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: update avermedia.rst contentsMauro Carvalho Chehab1-5/+5
While this is old, now that we moved the intro part of it, its contents seem to be valid, if we mention that we're talking only about the BT878 support. Update the document title accordingly and remove the obsolete note from it. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: intro.rst actually contain DVB referencesMauro Carvalho Chehab3-28/+32
This document doesn't describe the DVB subsystem. Instead, it just contain references to some places. Better name it and improve its contents. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: dvb_intro.rst: update its contentsMauro Carvalho Chehab1-151/+565
The content there is somewhat outdated. Update to reflect the current status. While here, remove extra spaces, as we won't be preserving left margin alinment on this document. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: split avermedia.rst contents on two filesMauro Carvalho Chehab3-179/+204
Part of this document has nothing to do with the Avermedia driver. It is generic to the entire subsystem. So, split it on a separate file. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-15media: docs: update cardlistsMauro Carvalho Chehab3-1/+13
There were some changes at the drivers adding support for more cards. Update cardlists accordingly. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-14dm integrity: document allow_discard optionMilan Broz1-5/+8
Add decription of the allow_discard option added in commit 84597a44a9d86ac949900441cea7da0af0f2f473. Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-14media: ipu3.rst: add yuv-downscaling into pipeline diagramBingbu Cao1-8/+8
For ipu3 ImgU image processing, the frame data from TNR can feed into DDR by Output Formatting System or feed into YUV downscaler to do YUV downscaling for secondary output, which is usually used for display. current ImgU image pipeline diagram misses the YUV downscaling, this patch add it to aligh with actual hardware blocks. Signed-off-by: Bingbu Cao <bingbu.cao@intel.com> Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-14media: doc-rst: add yavta test example in ipu3 docsBingbu Cao1-0/+13
This patch add yavta test command in ipu3.rst as an example on how to run simple ImgU test using yavta. Signed-off-by: Bingbu Cao <bingbu.cao@intel.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-14media: imx.rst: Add example media graphsSteve Longerbeam3-7/+143
Add the media graph topologies for the i.MX6Q SabreSD and SabreAuto. This makes it easier to understand the topology and follow the entity descriptions in the following sections. Also clarify that the SabreSD and SabreLite media pipeline config examples are for the i.MX6Q boards. Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-14media: docs: move user-facing docs to the admin guideMauro Carvalho Chehab56-2/+12341
Most of the driver-specific documentation is meant to help users of the media subsystem. Move them to the admin-guide. It should be noticed, however, that several of those files are outdated and will require further work in order to make them useful again. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-12Merge tag 'timers-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+6
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
2020-04-10Merge branch 'akpm' (patches from Andrew)Linus Torvalds2-0/+29
Merge yet more updates from Andrew Morton: - Almost all of the rest of MM (memcg, slab-generic, slab, pagealloc, gup, hugetlb, pagemap, memremap) - Various other things (hfs, ocfs2, kmod, misc, seqfile) * akpm: (34 commits) ipc/util.c: sysvipc_find_ipc() should increase position index kernel/gcov/fs.c: gcov_seq_next() should increase position index fs/seq_file.c: seq_read(): add info message about buggy .next functions drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings change email address for Pali Rohár selftests: kmod: test disabling module autoloading selftests: kmod: fix handling test numbers above 9 docs: admin-guide: document the kernel.modprobe sysctl fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once() kmod: make request_module() return an error when autoloading is disabled mm/memremap: set caching mode for PCI P2PDMA memory to WC mm/memory_hotplug: add pgprot_t to mhp_params powerpc/mm: thread pgprot_t through create_section_mapping() x86/mm: introduce __set_memory_prot() x86/mm: thread pgprot_t through init_memory_mapping() mm/memory_hotplug: rename mhp_restrictions to mhp_params mm/memory_hotplug: drop the flags field from struct mhp_restrictions mm/special: create generic fallbacks for pte_special() and pte_mkspecial() mm/vma: introduce VM_ACCESS_FLAGS mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS ...
2020-04-10Merge tag 'docs-5.7-2' of git://git.lwn.net/linuxLinus Torvalds3-15/+19
Pull Documentation fixes from Jonathan Corbet: "A handful of late-arriving fixes for the documentation tree" * tag 'docs-5.7-2' of git://git.lwn.net/linux: Documentation: android: binderfs: add 'stats' mount option Documentation: driver-api/usb/writing_usb_driver.rst Updates documentation links docs: driver-api: address duplicate label warning Documentation: sysrq: fix RST formatting docs: kernel-parameters.txt: Fix broken references docs: kernel-parameters.txt: Remove nompx docs: filesystems: fix typo in qnx6.rst
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. [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>
2020-04-10mm: hugetlb: optionally allocate gigantic hugepages using cmaRoman Gushchin1-0/+8
Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime") has added the run-time allocation of gigantic pages. However it actually works only at early stages of the system loading, when the majority of memory is free. After some time the memory gets fragmented by non-movable pages, so the chances to find a contiguous 1GB block are getting close to zero. Even dropping caches manually doesn't help a lot. At large scale rebooting servers in order to allocate gigantic hugepages is quite expensive and complex. At the same time keeping some constant percentage of memory in reserved hugepages even if the workload isn't using it is a big waste: not all workloads can benefit from using 1 GB pages. The following solution can solve the problem: 1) On boot time a dedicated cma area* is reserved. The size is passed as a kernel argument. 2) Run-time allocations of gigantic hugepages are performed using the cma allocator and the dedicated cma area In this case gigantic hugepages can be allocated successfully with a high probability, however the memory isn't completely wasted if nobody is using 1GB hugepages: it can be used for pagecache, anon memory, THPs, etc. * On a multi-node machine a per-node cma area is allocated on each node. Following gigantic hugetlb allocation are using the first available numa node if the mask isn't specified by a user. Usage: 1) configure the kernel to allocate a cma area for hugetlb allocations: pass hugetlb_cma=10G as a kernel argument 2) allocate hugetlb pages as usual, e.g. echo 10 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages If the option isn't enabled or the allocation of the cma area failed, the current behavior of the system is preserved. x86 and arm-64 are covered by this patch, other architectures can be trivially added later. The patch contains clean-ups and fixes proposed and implemented by Aslan Bakirov and Randy Dunlap. It also contains ideas and suggestions proposed by Rik van Riel, Michal Hocko and Mike Kravetz. Thanks! Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Andreas Schaufler <andreas.schaufler@gmx.de> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Aslan Bakirov <aslan@fb.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Joonsoo Kim <js1304@gmail.com> Link: http://lkml.kernel.org/r/20200407163840.92263-3-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-10Documentation: android: binderfs: add 'stats' mount optionRandy Dunlap1-0/+6
Add documentation of the binderfs 'stats' mount option. Description taken from the commit message. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/baa0aa81-007d-af46-16a5-91fead0bd1b9@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-07Documentation: sysrq: fix RST formattingAlyssa Ross1-9/+11
"On x86" and "On SPARC" are now definition list terms, like "On PowerPC", "On other", and "On all". The Credits list is now a bulleted list, like lots of Credits lists in other files. This prevents the list from becoming a single long, unpunctuated sentence in the generated documentation. I also did a couple of other tiny readability improvements to the "How do I use the magic SysRq key?" section while I was there. Signed-off-by: Alyssa Ross <hi@alyssa.is> Link: https://lore.kernel.org/r/20200403170701.10852-1-hi@alyssa.is Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-07docs: kernel-parameters.txt: Fix broken referencesJimmy Assarsson1-2/+2
Fix remaining broken references in kernel-parameters.txt. Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Jimmy Assarsson <jimmyassarsson@gmail.com> Link: https://lore.kernel.org/r/20200402172614.3020-2-jimmyassarsson@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-07docs: kernel-parameters.txt: Remove nompxJimmy Assarsson1-4/+0
x86/mpx was removed in commit 45fc24e89b7c ("x86/mpx: remove MPX from arch/x86"), this removes the documentation of parameter nompx. Fixes: 45fc24e89b7c ("x86/mpx: remove MPX from arch/x86") Signed-off-by: Jimmy Assarsson <jimmyassarsson@gmail.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/r/20200402172614.3020-1-jimmyassarsson@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-07mm/memory_hotplug.c: only respect mem= parameter during boot stageBaoquan He1-2/+11
In commit 357b4da50a62 ("x86: respect memory size limiting via mem= parameter") a global varialbe max_mem_size is added to store the value parsed from 'mem= ', then checked when memory region is added. This truly stops those DIMMs from being added into system memory during boot-time. However, it also limits the later memory hotplug functionality. Any DIMM can't be hotplugged any more if its region is beyond the max_mem_size. We will get errors like: [ 216.387164] acpi PNP0C80:02: add_memory failed [ 216.389301] acpi PNP0C80:02: acpi_memory_enable_device() error [ 216.392187] acpi PNP0C80:02: Enumeration failure This will cause issue in a known use case where 'mem=' is added to the hypervisor. The memory that lies after 'mem=' boundary will be assigned to KVM guests. After commit 357b4da50a62 merged, memory can't be extended dynamically if system memory on hypervisor is not sufficient. So fix it by also checking if it's during boot-time restricting to add memory. Otherwise, skip the restriction. And also add this use case to document of 'mem=' kernel parameter. Fixes: 357b4da50a62 ("x86: respect memory size limiting via mem= parameter") Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: William Kucharski <william.kucharski@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Link: http://lkml.kernel.org/r/20200204050643.20925-1-bhe@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07userfaultfd: wp: UFFDIO_REGISTER_MODE_WP documentation updateMartin Cracauer1-0/+51
Add documentation about the write protection support. [peterx@redhat.com: rewrite in rst format; fixups here and there] Signed-off-by: Martin Cracauer <cracauer@cons.org> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Bobby Powers <bobbypowers@gmail.com> Cc: Brian Geffon <bgeffon@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Denis Plotnikov <dplotnikov@virtuozzo.com> Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Marty McFadden <mcfadden8@llnl.gov> Cc: Maya Gokhale <gokhale2@llnl.gov> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@fb.com> Link: http://lkml.kernel.org/r/20200220163112.11409-17-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07mm, thp: track fallbacks due to failed memcg charges separatelyDavid Rientjes1-0/+10
The thp_fault_fallback and thp_file_fallback vmstats are incremented if either the hugepage allocation fails through the page allocator or the hugepage charge fails through mem cgroup. This patch leaves this field untouched but adds two new fields, thp_{fault,file}_fallback_charge, which is incremented only when the mem cgroup charge fails. This distinguishes between attempted hugepage allocations that fail due to fragmentation (or low memory conditions) and those that fail due to mem cgroup limits. That can be used to determine the impact of fragmentation on the system by excluding faults that failed due to memcg usage. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Jeremy Cline <jcline@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2003061422070.7412@chino.kir.corp.google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07mm, shmem: add vmstat for hugepage fallbackDavid Rientjes1-0/+4
The existing thp_fault_fallback indicates when thp attempts to allocate a hugepage but fails, or if the hugepage cannot be charged to the mem cgroup hierarchy. Extend this to shmem as well. Adds a new thp_file_fallback to complement thp_file_alloc that gets incremented when a hugepage is attempted to be allocated but fails, or if it cannot be charged to the mem cgroup hierarchy. Additionally, remove the check for CONFIG_TRANSPARENT_HUGE_PAGECACHE from shmem_alloc_hugepage() since it is only called with this configuration option. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Jeremy Cline <jcline@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2003061421240.7412@chino.kir.corp.google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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) <mtk.manpages@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andrei Vagin <avagin@gmail.com> Acked-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: stable@kernel.org Link: https://lkml.kernel.org/r/20200406171342.128733-1-dima@arista.com
2020-04-06Merge tag 'acpi-5.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds1-3/+5
Pull more ACPI updates from Rafael Wysocki: "Additional ACPI updates. These update the ACPICA code in the kernel to the 20200326 upstream revision, fix an ACPI-related CPU hotplug deadlock on x86, update Intel Tiger Lake device IDs in some places, add a new ACPI backlight blacklist entry, update the "acpi_backlight" kernel command line switch documentation and clean up a CPPC library routine. Specifics: - Update the ACPICA code in the kernel to upstream revision 20200326 including: * Fix for a typo in a comment field (Bob Moore) * acpiExec namespace init file fixes (Bob Moore) * Addition of NHLT to the known tables list (Cezary Rojewski) * Conversion of PlatformCommChannel ASL keyword to PCC (Erik Kaneda) * acpiexec cleanup (Erik Kaneda) * WSMT-related typo fix (Erik Kaneda) * sprintf() utility function fix (John Levon) * IVRS IVHD type 11h parsing implementation (Michał Żygowski) * IVRS IVHD type 10h reserved field name fix (Michał Żygowski) - Fix ACPI-related CPU hotplug deadlock on x86 (Qian Cai) - Fix Intel Tiger Lake ACPI device IDs in several places (Gayatri Kammela) - Add ACPI backlight blacklist entry for Acer Aspire 5783z (Hans de Goede) - Fix documentation of the "acpi_backlight" kernel command line switch (Randy Dunlap) - Clean up the acpi_get_psd_map() CPPC library routine (Liguang Zhang)" * tag 'acpi-5.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: x86: ACPI: fix CPU hotplug deadlock thermal: int340x_thermal: fix: Update Tiger Lake ACPI device IDs platform/x86: intel-hid: fix: Update Tiger Lake ACPI device ID ACPI: Update Tiger Lake ACPI device IDs ACPI: video: Use native backlight on Acer Aspire 5783z ACPI: video: Docs update for "acpi_backlight" kernel parameter options ACPICA: Update version 20200326 ACPICA: Fixes for acpiExec namespace init file ACPICA: Add NHLT table signature ACPICA: WSMT: Fix typo, no functional change ACPICA: utilities: fix sprintf() ACPICA: acpiexec: remove redeclaration of acpi_gbl_db_opt_no_region_support ACPICA: Change PlatformCommChannel ASL keyword to PCC ACPICA: Fix IVRS IVHD type 10h reserved field name ACPICA: Implement IVRS IVHD type 11h parsing ACPICA: Fix a typo in a comment field ACPI: CPPC: clean up acpi_get_psd_map()
2020-04-06Merge tag 'pm-5.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds3-0/+274
Pull more power management updates from Rafael Wysocki: "Additional power management updates. These fix a corner-case suspend-to-idle wakeup issue on systems where the ACPI SCI is shared with another wakeup source, add a kernel command line option to set pm_debug_messages via the kernel command line, add a document desctibing system-wide suspend and resume code flows, modify cpufreq Kconfig to choose schedutil as the preferred governor by default in a couple of cases and do some assorted cleanups. Specifics: - Fix corner-case suspend-to-idle wakeup issue on systems where the ACPI SCI is shared with another wakeup source (Hans de Goede). - Add document describing system-wide suspend and resume code flows to the admin guide (Rafael Wysocki). - Add kernel command line option to set pm_debug_messages (Chen Yu). - Choose schedutil as the preferred scaling governor by default on ARM big.LITTLE systems and on x86 systems using the intel_pstate driver in the passive mode (Linus Walleij, Rafael Wysocki). - Drop racy and redundant checks from the PM core's device_prepare() routine (Rafael Wysocki). - Make resume from hibernation take the hibernation_restore() return value into account (Dexuan Cui)" * tag 'pm-5.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: platform/x86: intel_int0002_vgpio: Use acpi_register_wakeup_handler() ACPI: PM: Add acpi_[un]register_wakeup_handler() Documentation: PM: sleep: Document system-wide suspend code flows cpufreq: Select schedutil when using big.LITTLE PM: sleep: Add pm_debug_messages kernel command line option PM: sleep: core: Drop racy and redundant checks from device_prepare() PM: hibernate: Propagate the return value of hibernation_restore() cpufreq: intel_pstate: Select schedutil as the default governor
2020-04-03Merge tag 'char-misc-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-miscLinus Torvalds1-0/+3
Pull char/misc driver updates from Greg KH: "Here is the big set of char/misc/other driver patches for 5.7-rc1. Lots of things in here, and it's later than expected due to some reverts to resolve some reported issues. All is now clean with no reported problems in linux-next. Included in here is: - interconnect updates - mei driver updates - uio updates - nvmem driver updates - soundwire updates - binderfs updates - coresight updates - habanalabs updates - mhi new bus type and core - extcon driver updates - some Kconfig cleanups - other small misc driver cleanups and updates As mentioned, all have been in linux-next for a while, and with the last two reverts, all is calm and good" * tag 'char-misc-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (174 commits) Revert "driver core: platform: Initialize dma_parms for platform devices" Revert "amba: Initialize dma_parms for amba devices" amba: Initialize dma_parms for amba devices driver core: platform: Initialize dma_parms for platform devices bus: mhi: core: Drop the references to mhi_dev in mhi_destroy_device() bus: mhi: core: Initialize bhie field in mhi_cntrl for RDDM capture bus: mhi: core: Add support for reading MHI info from device misc: rtsx: set correct pcr_ops for rts522A speakup: misc: Use dynamic minor numbers for speakup devices mei: me: add cedar fork device ids coresight: do not use the BIT() macro in the UAPI header Documentation: provide IBM contacts for embargoed hardware nvmem: core: remove nvmem_sysfs_get_groups() nvmem: core: use is_bin_visible for permissions nvmem: core: use device_register and device_unregister nvmem: core: add root_only member to nvmem device struct extcon: axp288: Add wakeup support extcon: Mark extcon_get_edev_name() function as exported symbol extcon: palmas: Hide error messages if gpio returns -EPROBE_DEFER dt-bindings: extcon: usbc-cros-ec: convert extcon-usbc-cros-ec.txt to yaml format ...
2020-04-03Merge branch 'for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds1-0/+11
Pull cgroup updates from Tejun Heo: - Christian extended clone3 so that processes can be spawned into cgroups directly. This is not only neat in terms of semantics but also avoids grabbing the global cgroup_threadgroup_rwsem for migration. - Daniel added !root xattr support to cgroupfs. Userland already uses xattrs on cgroupfs for bookkeeping. This will allow delegated cgroups to support such usages. - Prateek tried to make cpuset hotplug handling synchronous but that led to possible deadlock scenarios. Reverted. - Other minor changes including release_agent_path handling cleanup. * 'for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1: Document the cpuset_v2_mode mount option Revert "cpuset: Make cpuset hotplug synchronous" cgroupfs: Support user xattrs kernfs: Add option to enable user xattrs kernfs: Add removed_size out param for simple_xattr_set kernfs: kvmalloc xattr value instead of kmalloc cgroup: Restructure release_agent_path handling selftests/cgroup: add tests for cloning into cgroups clone3: allow spawning processes into cgroups cgroup: add cgroup_may_write() helper cgroup: refactor fork helpers cgroup: add cgroup_get_from_file() helper cgroup: unify attach permission checking cpuset: Make cpuset hotplug synchronous cgroup.c: Use built-in RCU list checking kselftest/cgroup: add cgroup destruction test cgroup: Clean up css_set task traversal
2020-04-03docs: cgroup-v1: Document the cpuset_v2_mode mount optionWaiman Long1-0/+11
The cpuset in cgroup v1 accepts a special "cpuset_v2_mode" mount option that make cpuset.cpus and cpuset.mems behave more like those in cgroup v2. Document it to make other people more aware of this feature that can be useful in some circumstances. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2020-04-03Documentation: PM: sleep: Document system-wide suspend code flowsRafael J. Wysocki2-0/+271
Add a document describing high-level system-wide suspend code flows in Linux. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-04-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+5
Pull kvm updates from Paolo Bonzini: "ARM: - GICv4.1 support - 32bit host removal PPC: - secure (encrypted) using under the Protected Execution Framework ultravisor s390: - allow disabling GISA (hardware interrupt injection) and protected VMs/ultravisor support. x86: - New dirty bitmap flag that sets all bits in the bitmap when dirty page logging is enabled; this is faster because it doesn't require bulk modification of the page tables. - Initial work on making nested SVM event injection more similar to VMX, and less buggy. - Various cleanups to MMU code (though the big ones and related optimizations were delayed to 5.8). Instead of using cr3 in function names which occasionally means eptp, KVM too has standardized on "pgd". - A large refactoring of CPUID features, which now use an array that parallels the core x86_features. - Some removal of pointer chasing from kvm_x86_ops, which will also be switched to static calls as soon as they are available. - New Tigerlake CPUID features. - More bugfixes, optimizations and cleanups. Generic: - selftests: cleanups, new MMU notifier stress test, steal-time test - CSV output for kvm_stat" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (277 commits) x86/kvm: fix a missing-prototypes "vmread_error" KVM: x86: Fix BUILD_BUG() in __cpuid_entry_get_reg() w/ CONFIG_UBSAN=y KVM: VMX: Add a trampoline to fix VMREAD error handling KVM: SVM: Annotate svm_x86_ops as __initdata KVM: VMX: Annotate vmx_x86_ops as __initdata KVM: x86: Drop __exit from kvm_x86_ops' hardware_unsetup() KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection KVM: x86: Set kvm_x86_ops only after ->hardware_setup() completes KVM: VMX: Configure runtime hooks using vmx_x86_ops KVM: VMX: Move hardware_setup() definition below vmx_x86_ops KVM: x86: Move init-only kvm_x86_ops to separate struct KVM: Pass kvm_init()'s opaque param to additional arch funcs s390/gmap: return proper error code on ksm unsharing KVM: selftests: Fix cosmetic copy-paste error in vm_mem_region_move() KVM: Fix out of range accesses to memslots KVM: X86: Micro-optimize IPI fastpath delay KVM: X86: Delay read msr data iff writes ICR MSR KVM: PPC: Book3S HV: Add a capability for enabling secure guests KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs KVM: arm64: GICv4.1: Allow non-trapping WFI when using HW SGIs ...
2020-04-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds3-11/+106
Merge updates from Andrew Morton: "A large amount of MM, plenty more to come. Subsystems affected by this patch series: - tools - kthread - kbuild - scripts - ocfs2 - vfs - mm: slub, kmemleak, pagecache, gup, swap, memcg, pagemap, mremap, sparsemem, kasan, pagealloc, vmscan, compaction, mempolicy, hugetlbfs, hugetlb" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (155 commits) include/linux/huge_mm.h: check PageTail in hpage_nr_pages even when !THP mm/hugetlb: fix build failure with HUGETLB_PAGE but not HUGEBTLBFS selftests/vm: fix map_hugetlb length used for testing read and write mm/hugetlb: remove unnecessary memory fetch in PageHeadHuge() mm/hugetlb.c: clean code by removing unnecessary initialization hugetlb_cgroup: add hugetlb_cgroup reservation docs hugetlb_cgroup: add hugetlb_cgroup reservation tests hugetlb: support file_region coalescing again hugetlb_cgroup: support noreserve mappings hugetlb_cgroup: add accounting for shared mappings hugetlb: disable region_add file_region coalescing hugetlb_cgroup: add reservation accounting for private mappings mm/hugetlb_cgroup: fix hugetlb_cgroup migration hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations hugetlb_cgroup: add hugetlb_cgroup reservation counter hugetlbfs: Use i_mmap_rwsem to address page fault/truncate race hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization mm/memblock.c: remove redundant assignment to variable max_addr mm: mempolicy: require at least one nodeid for MPOL_PREFERRED mm: mempolicy: use VM_BUG_ON_VMA in queue_pages_test_walk() ...