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2014-09-19x86/mm: Update memory map description to list hypervisor-reserved areaDave Hansen1-1/+1
Peter Anvin says: > 0xffff880000000000 is the lowest usable address because we have > agreed to leave 0xffff800000000000-0xffff880000000000 for the > hypervisor or other non-OS uses. Let's call this out in the documentation. This came up during the kernel address sanitizer discussions where it was proposed to use this area for other kernel things. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Link: http://lkml.kernel.org/r/20140918195606.841389D2@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-30x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stackH. Peter Anvin1-0/+2
The IRET instruction, when returning to a 16-bit segment, only restores the bottom 16 bits of the user space stack pointer. This causes some 16-bit software to break, but it also leaks kernel state to user space. We have a software workaround for that ("espfix") for the 32-bit kernel, but it relies on a nonzero stack segment base which is not available in 64-bit mode. In checkin: b3b42ac2cbae x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels we "solved" this by forbidding 16-bit segments on 64-bit kernels, with the logic that 16-bit support is crippled on 64-bit kernels anyway (no V86 support), but it turns out that people are doing stuff like running old Win16 binaries under Wine and expect it to work. This works around this by creating percpu "ministacks", each of which is mapped 2^16 times 64K apart. When we detect that the return SS is on the LDT, we copy the IRET frame to the ministack and use the relevant alias to return to userspace. The ministacks are mapped readonly, so if IRET faults we promote #GP to #DF which is an IST vector and thus has its own stack; we then do the fixup in the #DF handler. (Making #GP an IST exception would make the msr_safe functions unsafe in NMI/MC context, and quite possibly have other effects.) Special thanks to: - Andy Lutomirski, for the suggestion of using very small stack slots and copy (as opposed to map) the IRET frame there, and for the suggestion to mark them readonly and let the fault promote to #DF. - Konrad Wilk for paravirt fixup and testing. - Borislav Petkov for testing help and useful comments. Reported-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andrew Lutomriski <amluto@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Dirk Hohndel <dirk@hohndel.org> Cc: Arjan van de Ven <arjan.van.de.ven@intel.com> Cc: comex <comexk@gmail.com> Cc: Alexander van Heukelum <heukelum@fastmail.fm> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: <stable@vger.kernel.org> # consider after upstream merge
2014-01-22Merge branch 'for-linus' of ↵Linus Torvalds1-23/+0
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "Usual rocket science stuff from trivial.git" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) neighbour.h: fix comment sched: Fix warning on make htmldocs caused by wait.h slab: struct kmem_cache is protected by slab_mutex doc: Fix typo in USB Gadget Documentation of/Kconfig: Spelling s/one/once/ mkregtable: Fix sscanf handling lp5523, lp8501: comment improvements thermal: rcar: comment spelling treewide: fix comments and printk msgs IXP4xx: remove '1 &&' from a condition check in ixp4xx_restart() Documentation: update /proc/uptime field description Documentation: Fix size parameter for snprintf arm: fix comment header and macro name asm-generic: uaccess: Spelling s/a ny/any/ mtd: onenand: fix comment header doc: driver-model/platform.txt: fix a typo drivers: fix typo in DEVTMPFS_MOUNT Kconfig help text doc: Fix typo (acces_process_vm -> access_process_vm) treewide: Fix typos in printk drivers/gpu/drm/qxl/Kconfig: reformat the help text ...
2013-12-02Documentation: Update x86_64/boot-options.txtRichard Weinberger1-23/+0
Removed obsolte parameters from boot-options.txt. Verified by grepping around in arch/x86/. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Rob Landley <rob@landley.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-11-26Merge tag 'efi-next' of ↵Ingo Molnar1-0/+7
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efi Pull EFI virtual mapping changes from Matt Fleming: * New static EFI runtime services virtual mapping layout which is groundwork for kexec support on EFI. (Borislav Petkov) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-02x86/efi: Runtime services virtual mappingBorislav Petkov1-0/+7
We map the EFI regions needed for runtime services non-contiguously, with preserved alignment on virtual addresses starting from -4G down for a total max space of 64G. This way, we provide for stable runtime services addresses across kernels so that a kexec'd kernel can still use them. Thus, they're mapped in a separate pagetable so that we don't pollute the kernel namespace. Add an efi= kernel command line parameter for passing miscellaneous options and chicken bits from the command line. While at it, add a chicken bit called "efi=old_map" which can be used as a fallback to the old runtime services mapping method in case there's some b0rkage with a particular EFI implementation (haha, it is hard to hold up the sarcasm here...). Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-07-08mce: acpi/apei: Add a boot option to disable ff mode for corrected errorsNaveen N. Rao1-0/+5
Add a boot option to disable firmware first mode for corrected errors. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Tony Luck <tony.luck@intel.com>
2013-04-30Merge branch 'x86-debug-for-linus' of ↵Linus Torvalds1-14/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 debug update from Ingo Molnar: "Two small changes: a documentation update and a constification" * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, early-printk: Update earlyprintk documentation (and kill x86 copy) x86: Constify a few items
2013-04-11x86, early-printk: Update earlyprintk documentation (and kill x86 copy)Dave Hansen1-14/+0
Documentation/kernel-parameters.txt and Documentation/x86/x86_64/boot-options.txt contain virtually identical text describing earlyprintk. This consolidates the two copies and updates the documentation a bit. No one ever documented the: earlyprintk=serial,0x1008,115200 syntax, nor mentioned that ARM is now a supported earlyprintk arch. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Rob Landley <rob@landley.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20130410210338.E2930E98@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-02x86-64, docs, mm: Add vsyscall range to virtual address space layoutBorislav Petkov1-1/+3
Add the end of the virtual address space to its layout documentation. Signed-off-by: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1362428180-8865-4-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-23time: x86: report_lost_ticks doesn't exist any moreJiri Kosina1-4/+0
'report_lost_ticks' parameter has been removed back in 2007 through 1489939f0ab ("time: x86_64: convert x86_64 to use GENERIC_TIME"). Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-09-27x86/mce: Provide boot argument to honour bios-set CMCI thresholdNaveen N. Rao1-0/+7
The ACPI spec doesn't provide for a way for the bios to pass down recommended thresholds to the OS on a _per-bank_ basis. This patch adds a new boot option, which if passed, tells Linux to use CMCI thresholds set by the bios. As fail-safe, we initialize threshold to 1 if some banks have not been initialized by the bios and warn the user. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2011-05-10x86, gart: Rename pci-gart_64.c to amd_gart_64.cJoerg Roedel1-1/+1
This file only contains code relevant for the northbridge gart in AMD processors. This patch renames the file to represent this fact in the filename. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-03-22move x86 specific oops=panic to generic codeOlaf Hering1-5/+0
The oops=panic cmdline option is not x86 specific, move it to generic code. Update documentation. Signed-off-by: Olaf Hering <olaf@aepfle.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-18x86: Fix misspelling and align paramsLucas De Marchi1-7/+7
Fix 'upto' misspelling and align parameters. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: trivial@kernel.org LKML-Reference: <1300389856-1099-2-git-send-email-lucas.demarchi@profusion.mobi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-29x86: Always use irq stacksChristoph Hellwig1-3/+3
IRQ stacks provide much better safety against unexpected stack use from interrupts, at the minimal downside of slightly higher memory usage. Enable irq stacks also for the default 8k stack on 32-bit kernels to minimize the problem of stack overflows through interrupt activity. This is what the 64-bit kernel and various other architectures already do. Signed-off-by: Christoph Hellwig <hch@lst.de> LKML-Reference: <20100628121554.GA6605@lst.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-15x86, numa: Remove configurable node size support for numa emulationDavid Rientjes1-13/+3
Now that numa=fake=<size>[MG] is implemented, it is possible to remove configurable node size support. The command-line parsing was already broken (numa=fake=*128, for example, would not work) and since fake nodes are now interleaved over physical nodes, this support is no longer required. Signed-off-by: David Rientjes <rientjes@google.com> LKML-Reference: <alpine.DEB.2.00.1002151343080.26927@chino.kir.corp.google.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-15x86, numa: Add fixed node size option for numa emulationDavid Rientjes1-0/+4
numa=fake=N specifies the number of fake nodes, N, to partition the system into and then allocates them by interleaving over physical nodes. This requires knowledge of the system capacity when attempting to allocate nodes of a certain size: either very large nodes to benchmark scalability of code that operates on individual nodes, or very small nodes to find bugs in the VM. This patch introduces numa=fake=<size>[MG] so it is possible to specify the size of each node to allocate. When used, nodes of the size specified will be allocated and interleaved over the set of physical nodes. FAKE_NODE_MIN_SIZE was also moved to the more-appropriate include/asm/numa_64.h. Signed-off-by: David Rientjes <rientjes@google.com> LKML-Reference: <alpine.DEB.2.00.1002151342510.26927@chino.kir.corp.google.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-11Merge branch 'linus' into x86/mce3Ingo Molnar2-9/+5
Conflicts: arch/x86/kernel/cpu/mcheck/mce_64.c arch/x86/kernel/irq.c Merge reason: Resolve the conflicts above. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-11x86, mce: Add boot options for corrected errorsHidetoshi Seto1-6/+30
This patch introduces three boot options (no_cmci, dont_log_ce and ignore_ce) to control handling for corrected errors. The "mce=no_cmci" boot option disables the CMCI feature. Since CMCI is a new feature so having boot controls to disable it will be a help if the hardware is misbehaving. The "mce=dont_log_ce" boot option disables logging for corrected errors. All reported corrected errors will be cleared silently. This option will be useful if you never care about corrected errors. The "mce=ignore_ce" boot option disables features for corrected errors, i.e. polling timer and cmci. All corrected events are not cleared and kept in bank MSRs. Usually this disablement is not recommended, however it will be a help if there are some conflict with the BIOS or hardware monitoring applications etc., that clears corrected events in banks instead of OS. [ And trivial cleanup (space -> tab) for doc is included. ] Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> LKML-Reference: <4A30ACDF.5030408@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-03x86, mce: switch x86 machine check handler to Monarch election.Andi Kleen2-1/+9
On Intel platforms machine check exceptions are always broadcast to all CPUs. This patch makes the machine check handler synchronize all these machine checks, elect a Monarch to handle the event and collect the worst event from all CPUs and then process it first. This has some advantages: - When there is a truly data corrupting error the system panics as quickly as possible. This improves containment of corrupted data and makes sure the corrupted data never hits stable storage. - The panics are synchronized and do not reenter the panic code on multiple CPUs (which currently does not handle this well). - All the errors are reported. Currently it often happens that another CPU happens to do the panic first, but reports useless information (empty machine check) because the real error happened on another CPU which came in later. This is a big advantage on Nehalem where the 8 threads per CPU lead to often the wrong CPU winning the race and dumping useless information on a machine check. The problem also occurs in a less severe form on older CPUs. - The system can detect when no CPUs detected a machine check and shut down the system. This can happen when one CPU is so badly hung that that it cannot process a machine check anymore or when some external agent wants to stop the system by asserting the machine check pin. This follows Intel hardware recommendations. - This matches the recommended error model by the CPU designers. - The events can be output in true severity order - When a panic happens on another CPU it makes sure to be actually be able to process the stop IPI by enabling interrupts. The code is extremly careful to handle timeouts while waiting for other CPUs. It can't rely on the normal timing mechanisms (jiffies, ktime_get) because of its asynchronous/lockless nature, so it uses own timeouts using ndelay() and a "SPINUNIT" The timeout is configurable. By default it waits for upto one second for the other CPUs. This can be also disabled. From some informal testing AMD systems do not see to broadcast machine checks, so right now it's always disabled by default on non Intel CPUs or also on very old Intel systems. Includes fixes from Ying Huang Fixed a "ecception" in a comment (H.Seto) Moved global_nwo reset later based on suggestion from H.Seto v2: Avoid duplicate messages [ Impact: feature, fixes long standing problems. ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28x86, mce: improve documentationAndi Kleen2-1/+5
Document that check_interval set to 0 means no polling. Noticed by Hidetoshi Seto Also add a reference from boot options to the sysfs tunables Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-18mm, x86: remove MEMORY_HOTPLUG_RESERVE related codeYinghai Lu1-5/+0
after: | commit b263295dbffd33b0fbff670720fa178c30e3392a | Author: Christoph Lameter <clameter@sgi.com> | Date: Wed Jan 30 13:30:47 2008 +0100 | | x86: 64-bit, make sparsemem vmemmap the only memory model we don't have MEMORY_HOTPLUG_RESERVE anymore. Historically, x86-64 had an architecture-specific method for memory hotplug whereby it scanned the SRAT for physical memory ranges that could be potentially used for memory hot-add later. By reserving those ranges without physical memory, the memmap would be allocated and left dormant until needed. This depended on the DISCONTIG memory model which has been removed so the code implementing HOTPLUG_RESERVE is now dead. This patch removes the dead code used by MEMORY_HOTPLUG_RESERVE. (Changelog authored by Mel.) v2: updated changelog, and remove hotadd= in doc [ Impact: remove dead code ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Mel Gorman <mel@csn.ul.ie> Workflow-found-OK-by: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <4A0C4910.7090508@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-05x86: fix typo in address space documentationH. Peter Anvin1-1/+1
Fix a trivial typo in Documentation/x86/x86_64/mm.txt. [ Impact: documentation only ] Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Rik van Riel <riel@redhat.com>
2009-05-05x86: 46 bit physical address support on 64 bitsRik van Riel1-4/+5
Extend the maximum addressable memory on x86-64 from 2^44 to 2^46 bytes. This requires some shuffling around of the vmalloc and virtual memmap memory areas, to keep them away from the direct mapping of up to 64TB of physical memory. This patch also introduces a guard hole between the vmalloc area and the virtual memory map space. There's really no good reason why we wouldn't have a guard hole there. [ Impact: future hardware enablement ] Signed-off-by: Rik van Riel <riel@redhat.com> LKML-Reference: <20090505172856.6820db22@cuia.bos.redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-30trivial: fix where cgroup documentation is not correctly referred toThadeu Lima de Souza Cascardo1-2/+3
cgroup documentation was moved to Documentation/cgroups/. There are some places that still refer to Documentation/controllers/, Documentation/cgroups.txt and Documentation/cpusets.txt. Fix those. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2008-12-23Merge branches 'x86/apic', 'x86/cleanups', 'x86/cpufeature', ↵Ingo Molnar2-12/+1
'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/detect-hyper', 'x86/doc', 'x86/dumpstack', 'x86/early-printk', 'x86/fpu', 'x86/idle', 'x86/io', 'x86/memory-corruption-check', 'x86/microcode', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/pat2', 'x86/pci-ioapic-boot-irq-quirks', 'x86/ptrace', 'x86/quirks', 'x86/reboot', 'x86/setup-memory', 'x86/signal', 'x86/sparse-fixes', 'x86/time', 'x86/uv' and 'x86/xen' into x86/core
2008-12-16Merge commit 'v2.6.28-rc8' into x86/docIngo Molnar2-3/+3
2008-11-11x86, 64-bit: update address space documentationJiri Slaby1-1/+1
Impact: documentation update Commit a6523748bddd38bcec11431f57502090b6014a96 (paravirt/x86, 64-bit: move __PAGE_OFFSET to leave a space for hypervisor) changed address space without changing the documentation. Change it according to the code change -- direct mapping start: ffff810000000000 => ffff880000000000 which gives 57 TiB, something between 45 and 46 bits. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-03x86: nmi - nmi_watchdog boot param docs cleanupCyrill Gorcunov1-11/+0
Impact: documentation update 1) nmi_watchdog boot parameter is common to 32/64 bit modes. So move it from Documentation/x86/x86_64/boot-options.txt to Documentation/kernel-parameters.txt and integrate with. 2) Also fix [panic] keyword placement -- it ought to be at first position otherwise it will not be recognized. 3) Document lapic and ioapic keywords. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-28doc/x86: fix doc subdirsUwe Hermann2-3/+3
The Documentation/i386 and Documentation/x86_64 directories and their contents have been moved into Documentation/x86. Fix references to those files accordingly. Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28x86: remove 8254 timer texts from DocumentationLuiz Fernando N. Capitulino1-4/+0
Commit ecd29476ae0143b1c3641edfa76c0fc3e9ad3021 removed the "disable_8254_timer" and "enable_8254_timer" kernel parameters from the kernel but did not remove the references to them from two files in the Documentation directory: kernel-parameters.txt and x86/x86_64/boot-options.txt. This change completes the removal. Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br> Acked-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86 boot: only pick up additional EFI memmap if add_efi_memmap flagPaul Jackson1-0/+4
Applies on top of the previous patch: x86 boot: add code to add BIOS provided EFI memory entries to kernel Instead of always adding EFI memory map entries (if present) to the memory map after initially finding either E820 BIOS memory map entries and/or kernel command line memmap entries, -instead- only add such additional EFI memory map entries if the kernel boot option: add_efi_memmap is specified. Requiring this 'add_efi_memmap' option is backward compatible with kernels that didn't load such additional EFI memory map entries in the first place, and it doesn't override a configuration that tries to replace all E820 or EFI BIOS memory map entries with ones given entirely on the kernel command line. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: "Yinghai Lu" <yhlu.kernel@gmail.com> Cc: "Jack Steiner" <steiner@sgi.com> Cc: "Mike Travis" <travis@sgi.com> Cc: "Huang Cc: Ying" <ying.huang@intel.com> Cc: "Andi Kleen" <andi@firstfloor.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08Merge branch 'x86/setup' into x86/develIngo Molnar8-0/+659
2008-05-30x86: move x86-specific documentation into Documentation/x86H. Peter Anvin8-0/+660
The current organization of the x86 documentation makes it appear as if the "i386" documentation doesn't apply to x86-64, which is does. Thus, move that documentation into Documentation/x86, and move the x86-64-specific stuff into Documentation/x86/x86_64 with the eventual goal to move stuff that isn't actually 64-bit specific back into Documentation/x86. Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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