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2019-09-03dma-mapping: fix filename referencesAndy Shevchenko
After commit cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma") some of the files are referring to outdated information, i.e. old file names of DMA mapping sources. Fix it here. Note, the lines with "Glue code for..." have been removed completely. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-07-15docs: cgroup-v1: add it to the admin-guide bookMauro Carvalho Chehab
Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-09Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds
Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
2019-06-14docs: cgroup-v1: convert docs to ReST and rename to *.rstMauro Carvalho Chehab
Convert the cgroup-v1 files to ReST format, in order to allow a later addition to the admin-guide. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-08docs: fix broken documentation linksMauro Carvalho Chehab
Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-10Merge tag 'docs-5.2a' of git://git.lwn.net/linuxLinus Torvalds
Pull more documentation updates from Jonathan Corbet: "Some late arriving documentation changes. In particular, this contains the conversion of the x86 docs to RST, which has been in the works for some time but needed a couple of final tweaks" * tag 'docs-5.2a' of git://git.lwn.net/linux: (29 commits) Documentation: x86: convert x86_64/machinecheck to reST Documentation: x86: convert x86_64/cpu-hotplug-spec to reST Documentation: x86: convert x86_64/fake-numa-for-cpusets to reST Documentation: x86: convert x86_64/5level-paging.txt to reST Documentation: x86: convert x86_64/mm.txt to reST Documentation: x86: convert x86_64/uefi.txt to reST Documentation: x86: convert x86_64/boot-options.txt to reST Documentation: x86: convert i386/IO-APIC.txt to reST Documentation: x86: convert usb-legacy-support.txt to reST Documentation: x86: convert orc-unwinder.txt to reST Documentation: x86: convert resctrl_ui.txt to reST Documentation: x86: convert microcode.txt to reST Documentation: x86: convert pti.txt to reST Documentation: x86: convert amd-memory-encryption.txt to reST Documentation: x86: convert intel_mpx.txt to reST Documentation: x86: convert protection-keys.txt to reST Documentation: x86: convert pat.txt to reST Documentation: x86: convert mtrr.txt to reST Documentation: x86: convert tlb.txt to reST Documentation: x86: convert zero-page.txt to reST ...
2019-05-08Documentation: x86: convert x86_64/machinecheck to reSTChangbin Du
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08Documentation: x86: convert x86_64/cpu-hotplug-spec to reSTChangbin Du
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08Documentation: x86: convert x86_64/fake-numa-for-cpusets to reSTChangbin Du
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08Documentation: x86: convert x86_64/5level-paging.txt to reSTChangbin Du
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08Documentation: x86: convert x86_64/mm.txt to reSTChangbin Du
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08Documentation: x86: convert x86_64/uefi.txt to reSTChangbin Du
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08Documentation: x86: convert x86_64/boot-options.txt to reSTChangbin Du
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-16x86/mm: Fix the 56-bit addresses memory map in Documentation/x86/x86_64/mm.txtStephen Kitt
This fixes a PT typo, and the following 56-bit address-space addresses: * the hole extends from 0100000000000000 to feffffffffffffff * the KASAN shadow memory area stops at fffffbffffffffff (see kasan.h) Signed-off-by: Stephen Kitt <steve@sk2.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alex.popov@linux.com Cc: bhe@redhat.com Cc: corbet@lwn.net Cc: kirill.shutemov@linux.intel.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20190415150853.10354-1-steve@sk2.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-11x86/dma/amd-gart: Stop resizing dma_debug_entry poolRobin Murphy
dma-debug is now capable of adding new entries to its pool on-demand if the initial preallocation was insufficient, so the IOMMU_LEAK logic no longer needs to explicitly change the pool size. This does lose it the ability to save a couple of megabytes of RAM by reducing the pool size below its default, but it seems unlikely that that is a realistic concern these days (or indeed that anyone is actively debugging AGP drivers' DMA usage any more). Getting rid of dma_debug_resize_entries() will make room for further streamlining in the dma-debug code itself. Removing the call reveals quite a lot of cruft which has been useless for nearly a decade since commit 19c1a6f5764d ("x86 gart: reimplement IOMMU_LEAK feature by using DMA_API_DEBUG"), including the entire 'iommu=leak' parameter, which controlled nothing except whether dma_debug_resize_entries() was called or not. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-11-06x86/mm: Move LDT remap out of KASLR region on 5-level pagingKirill A. Shutemov
On 5-level paging the LDT remap area is placed in the middle of the KASLR randomization region and it can overlap with the direct mapping, the vmalloc or the vmap area. The LDT mapping is per mm, so it cannot be moved into the P4D page table next to the CPU_ENTRY_AREA without complicating PGD table allocation for 5-level paging. The 4 PGD slot gap just before the direct mapping is reserved for hypervisors, so it cannot be used. Move the direct mapping one slot deeper and use the resulting gap for the LDT remap area. The resulting layout is the same for 4 and 5 level paging. [ tglx: Massaged changelog ] Fixes: f55f0501cbf6 ("x86/pti: Put the LDT in its own PGD if PTI is on") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: bp@alien8.de Cc: hpa@zytor.com Cc: dave.hansen@linux.intel.com Cc: peterz@infradead.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: bhe@redhat.com Cc: willy@infradead.org Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181026122856.66224-2-kirill.shutemov@linux.intel.com
2018-11-01Merge tag 'stackleak-v4.20-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull stackleak gcc plugin from Kees Cook: "Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin was ported from grsecurity by Alexander Popov. It provides efficient stack content poisoning at syscall exit. This creates a defense against at least two classes of flaws: - Uninitialized stack usage. (We continue to work on improving the compiler to do this in other ways: e.g. unconditional zero init was proposed to GCC and Clang, and more plugin work has started too). - Stack content exposure. By greatly reducing the lifetime of valid stack contents, exposures via either direct read bugs or unknown cache side-channels become much more difficult to exploit. This complements the existing buddy and heap poisoning options, but provides the coverage for stacks. The x86 hooks are included in this series (which have been reviewed by Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already been merged through the arm64 tree (written by Laura Abbott and reviewed by Mark Rutland and Will Deacon). With VLAs having been removed this release, there is no need for alloca() protection, so it has been removed from the plugin" * tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: arm64: Drop unneeded stackleak_check_alloca() stackleak: Allow runtime disabling of kernel stack erasing doc: self-protection: Add information about STACKLEAK feature fs/proc: Show STACKLEAK metrics in the /proc file system lkdtm: Add a test for STACKLEAK gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
2018-10-24Merge tag 'docs-4.20' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "This is a fairly typical cycle for documentation. There's some welcome readability improvements for the formatted output, some LICENSES updates including the addition of the ISC license, the removal of the unloved and unmaintained 00-INDEX files, the deprecated APIs document from Kees, more MM docs from Mike Rapoport, and the usual pile of typo fixes and corrections" * tag 'docs-4.20' of git://git.lwn.net/linux: (41 commits) docs: Fix typos in histogram.rst docs: Introduce deprecated APIs list kernel-doc: fix declaration type determination doc: fix a typo in adding-syscalls.rst docs/admin-guide: memory-hotplug: remove table of contents doc: printk-formats: Remove bogus kobject references for device nodes Documentation: preempt-locking: Use better example dm flakey: Document "error_writes" feature docs/completion.txt: Fix a couple of punctuation nits LICENSES: Add ISC license text LICENSES: Add note to CDDL-1.0 license that it should not be used docs/core-api: memory-hotplug: add some details about locking internals docs/core-api: rename memory-hotplug-notifier to memory-hotplug docs: improve readability for people with poorer eyesight yama: clarify ptrace_scope=2 in Yama documentation docs/vm: split memory hotplug notifier description to Documentation/core-api docs: move memory hotplug description into admin-guide/mm doc: Fix acronym "FEKEK" in ecryptfs docs: fix some broken documentation references iommu: Fix passthrough option documentation ...
2018-10-06x86/mm/doc: Enhance the x86-64 virtual memory layout descriptionsIngo Molnar
After the cleanups from Baoquan He, make it even more readable: - Remove the 'bits' area size column: it's pretty pointless and was even wrong for some of the entries. Given that MB, GB, TB, PT are 10, 20, 30 and 40 bits, a "8 TB" size description makes it obvious that it's 43 bits. - Introduce an "offset" column: -------------------------------------------------------------------------------- start addr | offset | end addr | size | VM area description -----------------|------------|------------------|---------|-------------------- ... ffff880000000000 | -120 TB | ffffc7ffffffffff | 64 TB | direct mapping of all physical memory (page_offset_base), this is what limits max physical memory supported. The -120 TB notation makes it obvious where this particular virtual memory region starts: 120 TB down from the top of the 64-bit virtual memory space. Especially the layout of the kernel mappings is a *lot* more obvious when written this way, plus it's much easier to compare it with the size column and understand/check/validate and modify the kernel's layout in the future. - Mark the part from where the 47-bit and 56-bit kernel layouts are 100% identical, this starts at the -512 GB offset and the EFI region. - Re-shuffle the size desciptions to be continous blocks of sizes, instead of the often mixed size. I.e. write "0.5 TB" instead of "512 GB" if we are still in the TB-granular region of the map. - Make the 47-bit and 56-bit descriptions use the *exact* same layout and wording, and only differ where there's a material difference. This makes it easy to compare the two tables side by side by switching between two terminal tabs. - Plus enhance a lot of other stylistic/typographical details: make the tables explicitly tabular, add headers, enhance certain entries, etc. etc. Note that there are some apparent errors in the tables as well, but I'll fix them in a separate patch to make it easier to review/validate. Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-06x86/mm/doc: Clean up the x86-64 virtual memory layout descriptionsBaoquan He
In Documentation/x86/x86_64/mm.txt, the description of the x86-64 virtual memory layout has become a confusing hodgepodge of inconsistencies: - there's a hard to read mixture of 'TB' and 'bits' notation - the entries sometimes mention a size in the description and sometimes not - sometimes they list holes by address, sometimes only as an 'unused hole' line So make it all a coherent, readable, well organized description. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: thgarnie@google.com Link: http://lkml.kernel.org/r/20181006084327.27467-3-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-09Drop all 00-INDEX files from Documentation/Henrik Austad
This is a respin with a wider audience (all that get_maintainer returned) and I know this spams a *lot* of people. Not sure what would be the correct way, so my apologies for ruining your inbox. The 00-INDEX files are supposed to give a summary of all files present in a directory, but these files are horribly out of date and their usefulness is brought into question. Often a simple "ls" would reveal the same information as the filenames are generally quite descriptive as a short introduction to what the file covers (it should not surprise anyone what Documentation/sched/sched-design-CFS.txt covers) A few years back it was mentioned that these files were no longer really needed, and they have since then grown further out of date, so perhaps it is time to just throw them out. A short status yields the following _outdated_ 00-INDEX files, first counter is files listed in 00-INDEX but missing in the directory, last is files present but not listed in 00-INDEX. List of outdated 00-INDEX: Documentation: (4/10) Documentation/sysctl: (0/1) Documentation/timers: (1/0) Documentation/blockdev: (3/1) Documentation/w1/slaves: (0/1) Documentation/locking: (0/1) Documentation/devicetree: (0/5) Documentation/power: (1/1) Documentation/powerpc: (0/5) Documentation/arm: (1/0) Documentation/x86: (0/9) Documentation/x86/x86_64: (1/1) Documentation/scsi: (4/4) Documentation/filesystems: (2/9) Documentation/filesystems/nfs: (0/2) Documentation/cgroup-v1: (0/2) Documentation/kbuild: (0/4) Documentation/spi: (1/0) Documentation/virtual/kvm: (1/0) Documentation/scheduler: (0/2) Documentation/fb: (0/1) Documentation/block: (0/1) Documentation/networking: (6/37) Documentation/vm: (1/3) Then there are 364 subdirectories in Documentation/ with several files that are missing 00-INDEX alltogether (and another 120 with a single file and no 00-INDEX). I don't really have an opinion to whether or not we /should/ have 00-INDEX, but the above 00-INDEX should either be removed or be kept up to date. If we should keep the files, I can try to keep them updated, but I rather not if we just want to delete them anyway. As a starting point, remove all index-files and references to 00-INDEX and see where the discussion is going. Signed-off-by: Henrik Austad <henrik@austad.us> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Just-do-it-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: [Almost everybody else] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-09-04x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscallsAlexander Popov
The STACKLEAK feature (initially developed by PaX Team) has the following benefits: 1. Reduces the information that can be revealed through kernel stack leak bugs. The idea of erasing the thread stack at the end of syscalls is similar to CONFIG_PAGE_POISONING and memzero_explicit() in kernel crypto, which all comply with FDP_RIP.2 (Full Residual Information Protection) of the Common Criteria standard. 2. Blocks some uninitialized stack variable attacks (e.g. CVE-2017-17712, CVE-2010-2963). That kind of bugs should be killed by improving C compilers in future, which might take a long time. This commit introduces the code filling the used part of the kernel stack with a poison value before returning to userspace. Full STACKLEAK feature also contains the gcc plugin which comes in a separate commit. The STACKLEAK feature is ported from grsecurity/PaX. More information at: https://grsecurity.net/ https://pax.grsecurity.net/ This code is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on our understanding of the code. Changes or omissions from the original code are ours and don't reflect the original grsecurity/PaX code. Performance impact: Hardware: Intel Core i7-4770, 16 GB RAM Test #1: building the Linux kernel on a single core 0.91% slowdown Test #2: hackbench -s 4096 -l 2000 -g 15 -f 25 -P 4.2% slowdown So the STACKLEAK description in Kconfig includes: "The tradeoff is the performance impact: on a single CPU system kernel compilation sees a 1% slowdown, other systems and workloads may vary and you are advised to test this feature on your expected workload before deploying it". Signed-off-by: Alexander Popov <alex.popov@linux.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-08-13Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 timer updates from Thomas Gleixner: "Early TSC based time stamping to allow better boot time analysis. This comes with a general cleanup of the TSC calibration code which grew warts and duct taping over the years and removes 250 lines of code. Initiated and mostly implemented by Pavel with help from various folks" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/kvmclock: Mark kvm_get_preset_lpj() as __init x86/tsc: Consolidate init code sched/clock: Disable interrupts when calling generic_sched_clock_init() timekeeping: Prevent false warning when persistent clock is not available sched/clock: Close a hole in sched_clock_init() x86/tsc: Make use of tsc_calibrate_cpu_early() x86/tsc: Split native_calibrate_cpu() into early and late parts sched/clock: Use static key for sched_clock_running sched/clock: Enable sched clock early sched/clock: Move sched clock initialization and merge with generic clock x86/tsc: Use TSC as sched clock early x86/tsc: Initialize cyc2ns when tsc frequency is determined x86/tsc: Calibrate tsc only once ARM/time: Remove read_boot_clock64() s390/time: Remove read_boot_clock64() timekeeping: Default boot time offset to local_clock() timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset() s390/time: Add read_persistent_wall_and_boot_offset() x86/xen/time: Output xen sched_clock time from 0 x86/xen/time: Initialize pv xen time in init_hypervisor_platform() ...
2018-07-20x86/tsc: Redefine notsc to behave as tsc=unstablePavel Tatashin
Currently, the notsc kernel parameter disables the use of the TSC by sched_clock(). However, this parameter does not prevent the kernel from accessing tsc in other places. The only rationale to boot with notsc is to avoid timing discrepancies on multi-socket systems where TSC are not properly synchronized, and thus exclude TSC from being used for time keeping. But that prevents using TSC as sched_clock() as well, which is not necessary as the core sched_clock() implementation can handle non synchronized TSC based sched clocks just fine. However, there is another method to solve the above problem: booting with tsc=unstable parameter. This parameter allows sched_clock() to use TSC and just excludes it from timekeeping. So there is no real reason to keep notsc, but for compatibility reasons the parameter has to stay. Make it behave like 'tsc=unstable' instead. [ tglx: Massaged changelog ] Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-12-pasha.tatashin@oracle.com
2018-07-06x86/numa_emulation: Introduce uniform split capabilityDan Williams
The current NUMA emulation capabilities for splitting System RAM by a fixed size or by a set number of nodes may result in some nodes being larger than others. The implementation prioritizes establishing a minimum usable memory size over satisfying the requested number of NUMA nodes. Introduce a uniform split capability that evenly partitions each physical NUMA node into N emulated nodes. For example numa=fake=3U creates 6 emulated nodes total on a system that has 2 physical nodes. This capability is useful for debugging and evaluating platform memory-side-cache capabilities as described by the ACPI HMAT (see 5.2.27.5 Memory Side Cache Information Structure in ACPI 6.2a) Compare numa=fake=6 that results in only 5 nodes being created against numa=fake=3U which takes the 2 physical nodes and evenly divides them. numa=fake=6 available: 5 nodes (0-4) node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 0 size: 2648 MB node 0 free: 2443 MB node 1 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 1 size: 2672 MB node 1 free: 2442 MB node 2 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 2 size: 5291 MB node 2 free: 5278 MB node 3 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 3 size: 2677 MB node 3 free: 2665 MB node 4 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 4 size: 2676 MB node 4 free: 2663 MB node distances: node 0 1 2 3 4 0: 10 20 10 20 20 1: 20 10 20 10 10 2: 10 20 10 20 20 3: 20 10 20 10 10 4: 20 10 20 10 10 numa=fake=3U available: 6 nodes (0-5) node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 0 size: 2900 MB node 0 free: 2637 MB node 1 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 1 size: 3023 MB node 1 free: 3012 MB node 2 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 2 size: 2015 MB node 2 free: 2004 MB node 3 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 3 size: 2704 MB node 3 free: 2522 MB node 4 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 4 size: 2709 MB node 4 free: 2698 MB node 5 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 5 size: 2612 MB node 5 free: 2601 MB node distances: node 0 1 2 3 4 5 0: 10 10 10 20 20 20 1: 10 10 10 20 20 20 2: 10 10 10 20 20 20 3: 20 20 20 10 10 10 4: 20 20 20 10 10 10 5: 20 20 20 10 10 10 Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/153089328617.27680.14930758266174305832.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-28x86/pci-dma: remove the explicit nodac and allowdac optionChristoph Hellwig
This is something drivers should decide (modulo chipset quirks like for VIA), which as far as I can tell is how things have been handled for the last 15 years. Note that we keep the usedac option for now, as it is used in the wild to override the too generic VIA quirk. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-28x86/pci-dma: remove the experimental forcesac boot optionChristoph Hellwig
Limiting the dma mask to avoid PCI (pre-PCIe) DAC cycles while paying the huge overhead of an IOMMU is rather pointless, and this seriously gets in the way of dma mapping work. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-28Documentation/x86: remove a stray reference to pci-nommu.cChristoph Hellwig
This is just the minimal workaround. The file is mostly either stale and/or duplicative of Documentation/admin-guide/kernel-parameters.txt, but that is much more work than I'm willing to do right now. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2018-04-12Merge branch 'WIP.x86/asm' into x86/urgent, because the topic is readyIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-03x86/mm: Fix documentation of module mapping range with 4-level pagingKirill A. Shutemov
Commit: f5a40711fa58 ("x86/mm: Set MODULES_END to 0xffffffffff000000") changed MODULES_END back to a fixed value, but didn't update the documentation of memory layout for 4-level paging. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: f5a40711fa58 ("x86/mm: Set MODULES_END to 0xffffffffff000000") Link: http://lkml.kernel.org/r/20180402121025.10244-1-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-16x86/mm: Allow to boot without LA57 if CONFIG_X86_5LEVEL=yKirill A. Shutemov
All pieces of the puzzle are in place and we can now allow to boot with CONFIG_X86_5LEVEL=y on a machine without LA57 support. Kernel will detect that LA57 is missing and fold p4d at runtime. Update the documentation and the Kconfig option description to reflect the change. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214182542.69302-10-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-05x86/kaslr: Fix the vaddr_end messThomas Gleixner
vaddr_end for KASLR is only documented in the KASLR code itself and is adjusted depending on config options. So it's not surprising that a change of the memory layout causes KASLR to have the wrong vaddr_end. This can map arbitrary stuff into other areas causing hard to understand problems. Remove the whole ifdef magic and define the start of the cpu_entry_area to be the end of the KASLR vaddr range. Add documentation to that effect. Fixes: 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap") Reported-by: Benjamin Gilbert <benjamin.gilbert@coreos.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Benjamin Gilbert <benjamin.gilbert@coreos.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Garnier <thgarnie@google.com>, Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801041320360.1771@nanos
2018-01-04x86/mm: Map cpu_entry_area at the same place on 4/5 levelThomas Gleixner
There is no reason for 4 and 5 level pagetables to have a different layout. It just makes determining vaddr_end for KASLR harder than necessary. Fixes: 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Gilbert <benjamin.gilbert@coreos.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Garnier <thgarnie@google.com>, Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801041320360.1771@nanos
2018-01-04x86/mm: Set MODULES_END to 0xffffffffff000000Andrey Ryabinin
Since f06bdd4001c2 ("x86/mm: Adapt MODULES_END based on fixmap section size") kasan_mem_to_shadow(MODULES_END) could be not aligned to a page boundary. So passing page unaligned address to kasan_populate_zero_shadow() have two possible effects: 1) It may leave one page hole in supposed to be populated area. After commit 21506525fb8d ("x86/kasan/64: Teach KASAN about the cpu_entry_area") that hole happens to be in the shadow covering fixmap area and leads to crash: BUG: unable to handle kernel paging request at fffffbffffe8ee04 RIP: 0010:check_memory_region+0x5c/0x190 Call Trace: <NMI> memcpy+0x1f/0x50 ghes_copy_tofrom_phys+0xab/0x180 ghes_read_estatus+0xfb/0x280 ghes_notify_nmi+0x2b2/0x410 nmi_handle+0x115/0x2c0 default_do_nmi+0x57/0x110 do_nmi+0xf8/0x150 end_repeat_nmi+0x1a/0x1e Note, the crash likely disappeared after commit 92a0f81d8957, which changed kasan_populate_zero_shadow() call the way it was before commit 21506525fb8d. 2) Attempt to load module near MODULES_END will fail, because __vmalloc_node_range() called from kasan_module_alloc() will hit the WARN_ON(!pte_none(*pte)) in the vmap_pte_range() and bail out with error. To fix this we need to make kasan_mem_to_shadow(MODULES_END) page aligned which means that MODULES_END should be 8*PAGE_SIZE aligned. The whole point of commit f06bdd4001c2 was to move MODULES_END down if NR_CPUS is big, so the cpu_entry_area takes a lot of space. But since 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap") the cpu_entry_area is no longer in fixmap, so we could just set MODULES_END to a fixed 8*PAGE_SIZE aligned address. Fixes: f06bdd4001c2 ("x86/mm: Adapt MODULES_END based on fixmap section size") Reported-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Garnier <thgarnie@google.com> Link: https://lkml.kernel.org/r/20171228160620.23818-1-aryabinin@virtuozzo.com
2017-12-23x86/pti: Put the LDT in its own PGD if PTI is onAndy Lutomirski
With PTI enabled, the LDT must be mapped in the usermode tables somewhere. The LDT is per process, i.e. per mm. An earlier approach mapped the LDT on context switch into a fixmap area, but that's a big overhead and exhausted the fixmap space when NR_CPUS got big. Take advantage of the fact that there is an address space hole which provides a completely unused pgd. Use this pgd to manage per-mm LDT mappings. This has a down side: the LDT isn't (currently) randomized, and an attack that can write the LDT is instant root due to call gates (thanks, AMD, for leaving call gates in AMD64 but designing them wrong so they're only useful for exploits). This can be mitigated by making the LDT read-only or randomizing the mapping, either of which is strightforward on top of this patch. This will significantly slow down LDT users, but that shouldn't matter for important workloads -- the LDT is only used by DOSEMU(2), Wine, and very old libc implementations. [ tglx: Cleaned it up. ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/mm/64: Make a full PGD-entry size hole in the memory mapAndy Lutomirski
Shrink vmalloc space from 16384TiB to 12800TiB to enlarge the hole starting at 0xff90000000000000 to be a full PGD entry. A subsequent patch will use this hole for the pagetable isolation LDT alias. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/cpu_entry_area: Move it out of the fixmapThomas Gleixner
Put the cpu_entry_area into a separate P4D entry. The fixmap gets too big and 0-day already hit a case where the fixmap PTEs were cleared by cleanup_highmap(). Aside of that the fixmap API is a pain as it's all backwards. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/doc: Remove obvious weirdnesses from the x86 MM layout documentationPeter Zijlstra
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/mm/64: Improve the memory map documentationAndy Lutomirski
The old docs had the vsyscall range wrong and were missing the fixmap. Fix both. There used to be 8 MB reserved for future vsyscalls, but that's long gone. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-20x86/kasan: Use the same shadow offset for 4- and 5-level pagingAndrey Ryabinin
We are going to support boot-time switching between 4- and 5-level paging. For KASAN it means we cannot have different KASAN_SHADOW_OFFSET for different paging modes: the constant is passed to gcc to generate code and cannot be changed at runtime. This patch changes KASAN code to use 0xdffffc0000000000 as shadow offset for both 4- and 5-level paging. For 5-level paging it means that shadow memory region is not aligned to PGD boundary anymore and we have to handle unaligned parts of the region properly. In addition, we have to exclude paravirt code from KASAN instrumentation as we now use set_pgd() before KASAN is fully ready. [kirill.shutemov@linux.intel.com: clenaup, changelog message] Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@suse.de> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170929140821.37654-4-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-21x86: Enable 5-level paging support via CONFIG_X86_5LEVEL=yKirill A. Shutemov
Most of things are in place and we can enable support for 5-level paging. The patch makes XEN_PV and XEN_PVH dependent on !X86_5LEVEL. Both are not ready to work with 5-level paging. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170716225954.74185-9-kirill.shutemov@linux.intel.com [ Minor readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce: Update bootlog description to reflect behavior on AMDYazen Ghannam
The bootlog option is only disabled by default on AMD Fam10h and older systems. Update bootlog description to say this. Change the family value to hex to avoid confusion. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/20170613162835.30750-9-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-04x86/mm: Define virtual memory map for 5-level pagingKirill A. Shutemov
The first part of memory map (up to %esp fixup) simply scales existing map for 4-level paging by factor of 9 -- number of bits addressed by the additional page table level. The rest of the map is unchanged. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170330080731.65421-4-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16x86/mm: Adapt MODULES_END based on fixmap section sizeThomas Garnier
This patch aligns MODULES_END to the beginning of the fixmap section. It optimizes the space available for both sections. The address is pre-computed based on the number of pages required by the fixmap section. It will allow GDT remapping in the fixmap section. The current MODULES_END static address does not provide enough space for the kernel to support a large number of processors. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@suse.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Luis R . Rodriguez <mcgrof@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rafael J . Wysocki <rjw@rjwysocki.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: kasan-dev@googlegroups.com Cc: kernel-hardening@lists.openwall.com Cc: kvm@vger.kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: zijun_hu <zijun_hu@htc.com> Link: http://lkml.kernel.org/r/20170314170508.100882-1-thgarnie@google.com [ Small build fix. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25x86/dumpstack: Remove raw stack dumpJosh Poimboeuf
For mostly historical reasons, the x86 oops dump shows the raw stack values: ... [registers] Stack: ffff880079af7350 ffff880079905400 0000000000000000 ffffc900008f3ae0 ffffffffa0196610 0000000000000001 00010000ffffffff 0000000087654321 0000000000000002 0000000000000000 0000000000000000 0000000000000000 Call Trace: ... This seems to be an artifact from long ago, and probably isn't needed anymore. It generally just adds noise to the dump, and it can be actively harmful because it leaks kernel addresses. Linus says: "The stack dump actually goes back to forever, and it used to be useful back in 1992 or so. But it used to be useful mainly because stacks were simpler and we didn't have very good call traces anyway. I definitely remember having used them - I just do not remember having used them in the last ten+ years. Of course, it's still true that if you can trigger an oops, you've likely already lost the security game, but since the stack dump is so useless, let's aim to just remove it and make games like the above harder." This also removes the related 'kstack=' cmdline option and the 'kstack_depth_to_print' sysctl. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e83bd50df52d8fe88e94d2566426ae40d813bf8f.1477405374.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-06x86: fix memory ranges in mm documentationLorenzo Stoakes
This is a trivial fix to correct upper bound addresses to always be inclusive. Previously, the majority of ranges specified were inclusive with a small minority specifying an exclusive upper bound. This patch fixes this inconsistency. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-08-07Merge tag 'doc-4.8-fixes' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation fixes from Jonathan Corbet: "Three fixes for the docs build, including removing an annoying warning on 'make help' if sphinx isn't present" * tag 'doc-4.8-fixes' of git://git.lwn.net/linux: DocBook: use DOCBOOKS="" to ignore DocBooks instead of IGNORE_DOCBOOKS=1 Documenation: update cgroup's document path Documentation/sphinx: do not warn about missing tools in 'make help'
2016-08-03Documenation: update cgroup's document pathseokhoon.yoon
cgroup's document path is changed to "cgroup-v1". update it. Signed-off-by: seokhoon.yoon <iamyooon@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-07-25Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "The main changes: - add initial commits to randomize kernel memory section virtual addresses, enabled via a new kernel option: RANDOMIZE_MEMORY (Thomas Garnier, Kees Cook, Baoquan He, Yinghai Lu) - enhance KASLR (RANDOMIZE_BASE) physical memory randomization (Kees Cook) - EBDA/BIOS region boot quirk cleanups (Andy Lutomirski, Ingo Molnar) - misc cleanups/fixes" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Simplify EBDA-vs-BIOS reservation logic x86/boot: Clarify what x86_legacy_features.reserve_bios_regions does x86/boot: Reorganize and clean up the BIOS area reservation code x86/mm: Do not reference phys addr beyond kernel x86/mm: Add memory hotplug support for KASLR memory randomization x86/mm: Enable KASLR for vmalloc memory regions x86/mm: Enable KASLR for physical mapping memory regions x86/mm: Implement ASLR for kernel memory regions x86/mm: Separate variable for trampoline PGD x86/mm: Add PUD VA support for physical mapping x86/mm: Update physical mapping variable names x86/mm: Refactor KASLR entropy functions x86/KASLR: Fix boot crash with certain memory configurations x86/boot/64: Add forgotten end of function marker x86/KASLR: Allow randomization below the load address x86/KASLR: Extend kernel image physical address randomization to addresses larger than 4G x86/KASLR: Randomize virtual address separately x86/KASLR: Clarify identity map interface x86/boot: Refuse to build with data relocations x86/KASLR, x86/power: Remove x86 hibernation restrictions
2016-07-08x86/mm: Implement ASLR for kernel memory regionsThomas Garnier
Randomizes the virtual address space of kernel memory regions for x86_64. This first patch adds the infrastructure and does not randomize any region. The following patches will randomize the physical memory mapping, vmalloc and vmemmap regions. This security feature mitigates exploits relying on predictable kernel addresses. These addresses can be used to disclose the kernel modules base addresses or corrupt specific structures to elevate privileges bypassing the current implementation of KASLR. This feature can be enabled with the CONFIG_RANDOMIZE_MEMORY option. The order of each memory region is not changed. The feature looks at the available space for the regions based on different configuration options and randomizes the base and space between each. The size of the physical memory mapping is the available physical memory. No performance impact was detected while testing the feature. Entropy is generated using the KASLR early boot functions now shared in the lib directory (originally written by Kees Cook). Randomization is done on PGD & PUD page table levels to increase possible addresses. The physical memory mapping code was adapted to support PUD level virtual addresses. This implementation on the best configuration provides 30,000 possible virtual addresses in average for each memory region. An additional low memory page is used to ensure each CPU can start with a PGD aligned virtual address (for realmode). x86/dump_pagetable was updated to correctly display each region. Updated documentation on x86_64 memory layout accordingly. Performance data, after all patches in the series: Kernbench shows almost no difference (-+ less than 1%): Before: Average Optimal load -j 12 Run (std deviation): Elapsed Time 102.63 (1.2695) User Time 1034.89 (1.18115) System Time 87.056 (0.456416) Percent CPU 1092.9 (13.892) Context Switches 199805 (3455.33) Sleeps 97907.8 (900.636) After: Average Optimal load -j 12 Run (std deviation): Elapsed Time 102.489 (1.10636) User Time 1034.86 (1.36053) System Time 87.764 (0.49345) Percent CPU 1095 (12.7715) Context Switches 199036 (4298.1) Sleeps 97681.6 (1031.11) Hackbench shows 0% difference on average (hackbench 90 repeated 10 times): attemp,before,after 1,0.076,0.069 2,0.072,0.069 3,0.066,0.066 4,0.066,0.068 5,0.066,0.067 6,0.066,0.069 7,0.067,0.066 8,0.063,0.067 9,0.067,0.065 10,0.068,0.071 average,0.0677,0.0677 Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Alexander Popov <alpopov@ptsecurity.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Baoquan He <bhe@redhat.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/1466556426-32664-6-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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