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* Merge branch 'x86-trampoline-for-linus' of ↵Linus Torvalds2012-05-29
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 trampoline rework from H. Peter Anvin: "This code reworks all the "trampoline"/"realmode" code (various bits that need to live in the first megabyte of memory, most but not all of which runs in real mode at some point) in the kernel into a single object. The main reason for doing this is that it eliminates the last place in the kernel where we needed pages to be mapped RWX. This code separates all that code into proper R/RW/RX pages." Fix up conflicts in arch/x86/kernel/Makefile (mca removed next to reboot code), and arch/x86/kernel/reboot.c (reboot code moved around in one branch, modified in this one), and arch/x86/tools/relocs.c (mostly same code came in earlier due to working around the ld bugs just before the 3.4 release). Also remove stale x86-relocs entry from scripts/.gitignore as per Peter Anvin. * commit '61f5446169046c217a5479517edac3a890c3bee7': (36 commits) x86, realmode: Move end signature into header.S x86, relocs: When printing an error, say relative or absolute x86, relocs: More relocations which may end up as absolute x86, relocs: Workaround for binutils 2.22.52.0.1 section bug xen-acpi-processor: Add missing #include <xen/xen.h> acpi, bgrd: Add missing <linux/io.h> to drivers/acpi/bgrt.c x86, realmode: Change EFER to a single u64 field x86, realmode: Move kernel/realmode.c to realmode/init.c x86, realmode: Move not-common bits out of trampoline_common.S x86, realmode: Mask out EFER.LMA when saving trampoline EFER x86, realmode: Fix no cache bits test in reboot_32.S x86, realmode: Make sure all generated files are listed in targets x86, realmode: build fix: remove duplicate build x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline x86, realmode: fixes compilation issue in tboot.c x86, realmode: move relocs from scripts/ to arch/x86/tools x86, realmode: header for trampoline code x86, realmode: flattened rm hierachy x86, realmode: don't copy real_mode_header x86, realmode: fix 64-bit wakeup sequence ...
| * x86, realmode: Move kernel/realmode.c to realmode/init.cH. Peter Anvin2012-05-16
| | | | | | | | | | | | | | | | Keep all the realmode code together, including initialization (only the rm/ subdirectory is actually built as real-mode code, anyway.) Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
| * x86, realmode: Mask out EFER.LMA when saving trampoline EFERH. Peter Anvin2012-05-16
| | | | | | | | | | | | | | | | | | | | | | Some AMD processors apparently #GP(0) if EFER.LMA is set in WRMSR, rather than ignoring it. Thus, we need to mask it out. Reported-by: Ingo Molnar <mingo@kernel.org> Tested-by: Borislav Petkov <bp@alien8.de> Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-24-git-send-email-jarkko.sakkinen@intel.com
| * x86, realmode: read cr4 and EFER from kernel for 64-bit trampolineJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | This patch changes 64-bit trampoline so that CR4 and EFER are provided by the kernel instead of using fixed values. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-24-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: fixes compilation issue in tboot.cJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | Fixed include path of wakeup.h in tboot.c. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-23-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: header for trampoline codeJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | | | | | Added header for trampoline code that can be used to supply input data to it. This makes interface between real mode code and kernel cleaner and simpler. Replaced two confusing pointers to level4 pgt in trampoline_64.S with a single pointer to the beginning of the page table. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-21-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: flattened rm hierachyJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | | | Simplified hierarchy under rm directory to a flat directory because it is not anymore really justified to have own directory for wakeup code. It only adds more complexity. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-20-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: don't copy real_mode_headerJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | Replaced copying of real_mode_header with a pointer to beginning of RM memory. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-19-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: fix 64-bit wakeup sequenceJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There were number of issues in wakeup sequence: - Wakeup stack was placed in hardcoded address. - NX bit in EFER was not enabled. - Initialization incorrectly set physical address of secondary_startup_64. - Some alignment issues. This patch fixes these issues and in addition: - Unifies coding conventions in .S files. - Sets alignments of code and data right. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-18-git-send-email-jarkko.sakkinen@intel.com Originally-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <len.brown@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: Set permission for real mode pagesJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | Set proper permissions for rodata, text and data, removing the realmode trampoline area as a remaining RWX memory mapping in the kernel. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-8-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: Move ACPI wakeup to unified realmode codeJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | Migrated ACPI wakeup code to the real-mode blob. Code existing in .x86_trampoline can be completely removed. Static descriptor table in wakeup_asm.S is courtesy of H. Peter Anvin. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-7-git-send-email-jarkko.sakkinen@intel.com Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <len.brown@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: Move SMP trampoline to unified realmode codeJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Migrated SMP trampoline code to the real mode blob. SMP trampoline code is not yet removed from .x86_trampoline because it is needed by the wakeup code. [ hpa: always enable compiling startup_32_smp in head_32.S... it is only a few instructions which go into .init on UP builds, and it makes the rest of the code less #ifdef ugly. ] Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-6-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: Move reboot_32.S to unified realmode codeJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | Migrated reboot_32.S from x86_trampoline to the real-mode blob. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-5-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86, realmode: Relocator for realmode codeJarkko Sakkinen2012-05-08
| | | | | | | | | | | | | | | | | | | | | | Implements relocator for real mode code that is called as part of setup_arch(). Processes segment relocations and linear relocations. Real-mode code is relocated to a free hole below 1 MB. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-4-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | x86: print physical addresses consistently with other parts of kernelBjorn Helgaas2012-05-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Print physical address info in a style consistent with the %pR style used elsewhere in the kernel. For example: -found SMP MP-table at [ffff8800000fce90] fce90 +found SMP MP-table at [mem 0x000fce90-0x000fce9f] mapped at [ffff8800000fce90] -initial memory mapped : 0 - 20000000 +initial memory mapped: [mem 0x00000000-0x1fffffff] -Base memory trampoline at [ffff88000009c000] 9c000 size 8192 +Base memory trampoline [mem 0x0009c000-0x0009dfff] mapped at [ffff88000009c000] -SRAT: Node 0 PXM 0 0-80000000 +SRAT: Node 0 PXM 0 [mem 0x00000000-0x7fffffff] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | x86: print e820 physical addresses consistently with other parts of kernelBjorn Helgaas2012-05-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Print physical address info in a style consistent with the %pR style used elsewhere in the kernel. For example: -BIOS-provided physical RAM map: +e820: BIOS-provided physical RAM map: - BIOS-e820: 0000000000000100 - 000000000009e000 (usable) +BIOS-e820: [mem 0x0000000000000100-0x000000000009dfff] usable -Allocating PCI resources starting at 90000000 (gap: 90000000:6ed1c000) +e820: [mem 0x90000000-0xfed1bfff] available for PCI devices -reserve RAM buffer: 000000000009e000 - 000000000009ffff +e820: reserve RAM buffer [mem 0x0009e000-0x0009ffff] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'x86-mce-merge' of ↵Linus Torvalds2012-05-25
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras Pull x86/mce merge window patches from Tony Luck: "Including two that make error_context() checks less sucky" * tag 'x86-mce-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: x86/mce: Add instruction recovery signatures to mce-severity table x86/mce: Fix check for processor context when machine check was taken. MCE: Fix vm86 handling for 32bit mce handler x86/mce Add validation check before GHES error is recorded x86/mce: Avoid reading every machine check bank register twice.
| * | x86/mce: Add instruction recovery signatures to mce-severity tableTony Luck2012-05-23
| | | | | | | | | | | | | | | | | | | | | Instruction recovery cases are very similar to the data recovery one we already have. Just trade out for a new MCACOD value. Signed-off-by: Tony Luck <tony.luck@intel.com>
| * | x86/mce: Fix check for processor context when machine check was taken.Tony Luck2012-05-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus pointed out that there was no value is checking whether m->ip was zero - because zero is a legimate value. If we have a reliable (or faked in the VM86 case) "m->cs" we can use it to tell whether we were in user mode or kernelwhen the machine check hit. Reported-by: Linus Torvalds <torvalds@linuxfoundation.org> Cc: <stable@vger.kernel.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
| * | MCE: Fix vm86 handling for 32bit mce handlerAndi Kleen2012-05-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running on 32bit the mce handler could misinterpret vm86 mode as ring 0. This can affect whether it does recovery or not; it was possible to panic when recovery was actually possible. Fix this by always forcing vm86 to look like ring 3. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
| * | x86/mce Add validation check before GHES error is recordedChen Gong2012-04-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When GHES error record is logged into mcelog kernel buffer, a validation check for physical address is necessary, which prevents reporting an invalid physical address. [Since physical address is the only useful element in this error record, we drop generating the record completely if we don't have a valid address] Signed-off-by: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
| * | x86/mce: Avoid reading every machine check bank register twice.Tony Luck2012-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reading machine check bank registers is slow. There is a trend of increasing the number of banks, and the number of cores. The main section of do_machine_check() is a serialized section where each cpu in turn checks every bank. Even on a little two socket SandyBridge-EP system that multiplies out as: 2 sockets * 8 cores * 2 hyperthreads * 20 banks = 640 MSRs We already scan the banks in parallel in mce_no_way_out() to see if there is a fatal error anywhere in the system. If we build a cache of VALID bits during this scan, we can avoid uselessly re-reading banks that have no data. Note that this cache is only a hint. If the valid bit is set in a shared bank, all cpus that share that bank will see it during the parallel scan, but the first to find it in the sequential scan will (usually) clear the bank. Acked-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2012-05-25
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.linaro.org/people/mszyprowski/linux-dma-mapping Pull CMA and ARM DMA-mapping updates from Marek Szyprowski: "These patches contain two major updates for DMA mapping subsystem (mainly for ARM architecture). First one is Contiguous Memory Allocator (CMA) which makes it possible for device drivers to allocate big contiguous chunks of memory after the system has booted. The main difference from the similar frameworks is the fact that CMA allows to transparently reuse the memory region reserved for the big chunk allocation as a system memory, so no memory is wasted when no big chunk is allocated. Once the alloc request is issued, the framework migrates system pages to create space for the required big chunk of physically contiguous memory. For more information one can refer to nice LWN articles: - 'A reworked contiguous memory allocator': http://lwn.net/Articles/447405/ - 'CMA and ARM': http://lwn.net/Articles/450286/ - 'A deep dive into CMA': http://lwn.net/Articles/486301/ - and the following thread with the patches and links to all previous versions: https://lkml.org/lkml/2012/4/3/204 The main client for this new framework is ARM DMA-mapping subsystem. The second part provides a complete redesign in ARM DMA-mapping subsystem. The core implementation has been changed to use common struct dma_map_ops based infrastructure with the recent updates for new dma attributes merged in v3.4-rc2. This allows to use more than one implementation of dma-mapping calls and change/select them on the struct device basis. The first client of this new infractructure is dmabounce implementation which has been completely cut out of the core, common code. The last patch of this redesign update introduces a new, experimental implementation of dma-mapping calls on top of generic IOMMU framework. This lets ARM sub-platform to transparently use IOMMU for DMA-mapping calls if one provides required IOMMU hardware. For more information please refer to the following thread: http://www.spinics.net/lists/arm-kernel/msg175729.html The last patch merges changes from both updates and provides a resolution for the conflicts which cannot be avoided when patches have been applied on the same files (mainly arch/arm/mm/dma-mapping.c)." Acked by Andrew Morton <akpm@linux-foundation.org>: "Yup, this one please. It's had much work, plenty of review and I think even Russell is happy with it." * 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: (28 commits) ARM: dma-mapping: use PMD size for section unmap cma: fix migration mode ARM: integrate CMA with DMA-mapping subsystem X86: integrate CMA with DMA-mapping subsystem drivers: add Contiguous Memory Allocator mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks mm: extract reclaim code from __alloc_pages_direct_reclaim() mm: Serialize access to min_free_kbytes mm: page_isolation: MIGRATE_CMA isolation functions added mm: mmzone: MIGRATE_CMA migration type added mm: page_alloc: change fallbacks array handling mm: page_alloc: introduce alloc_contig_range() mm: compaction: export some of the functions mm: compaction: introduce isolate_freepages_range() mm: compaction: introduce map_pages() mm: compaction: introduce isolate_migratepages_range() mm: page_alloc: remove trailing whitespace ARM: dma-mapping: add support for IOMMU mapper ARM: dma-mapping: use alloc, mmap, free from dma_ops ARM: dma-mapping: remove redundant code and do the cleanup ... Conflicts: arch/x86/include/asm/dma-mapping.h
| * | | X86: integrate CMA with DMA-mapping subsystemMarek Szyprowski2012-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for CMA to dma-mapping subsystem for x86 architecture that uses common pci-dma/pci-nommu implementation. This allows to test CMA on KVM/QEMU and a lot of common x86 boxes. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> CC: Michal Nazarewicz <mina86@mina86.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
* | | | Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2012-05-24
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM changes from Avi Kivity: "Changes include additional instruction emulation, page-crossing MMIO, faster dirty logging, preventing the watchdog from killing a stopped guest, module autoload, a new MSI ABI, and some minor optimizations and fixes. Outside x86 we have a small s390 and a very large ppc update. Regarding the new (for kvm) rebaseless workflow, some of the patches that were merged before we switch trees had to be rebased, while others are true pulls. In either case the signoffs should be correct now." Fix up trivial conflicts in Documentation/feature-removal-schedule.txt arch/powerpc/kvm/book3s_segment.S and arch/x86/include/asm/kvm_para.h. I suspect the kvm_para.h resolution ends up doing the "do I have cpuid" check effectively twice (it was done differently in two different commits), but better safe than sorry ;) * 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (125 commits) KVM: make asm-generic/kvm_para.h have an ifdef __KERNEL__ block KVM: s390: onereg for timer related registers KVM: s390: epoch difference and TOD programmable field KVM: s390: KVM_GET/SET_ONEREG for s390 KVM: s390: add capability indicating COW support KVM: Fix mmu_reload() clash with nested vmx event injection KVM: MMU: Don't use RCU for lockless shadow walking KVM: VMX: Optimize %ds, %es reload KVM: VMX: Fix %ds/%es clobber KVM: x86 emulator: convert bsf/bsr instructions to emulate_2op_SrcV_nobyte() KVM: VMX: unlike vmcs on fail path KVM: PPC: Emulator: clean up SPR reads and writes KVM: PPC: Emulator: clean up instruction parsing kvm/powerpc: Add new ioctl to retreive server MMU infos kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM KVM: PPC: bookehv: Fix r8/r13 storing in level exception handler KVM: PPC: Book3S: Enable IRQs during exit handling KVM: PPC: Fix PR KVM on POWER7 bare metal KVM: PPC: Fix stbux emulation KVM: PPC: bookehv: Use lwz/stw instead of PPC_LL/PPC_STL for 32-bit fields ...
| * \ \ \ Merge branch 'linus' into queueMarcelo Tosatti2012-04-19
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: development work has dependency on kvm patches merged upstream. Conflicts: Documentation/feature-removal-schedule.txt Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| * | | | | kvmclock: remove unneeded EXPORT macroEric B Munson2012-04-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | check_and_clear_guest_paused does not need to be exported as it isn't used by any modules, remove the export. Signed-off-by: Eric B Munson <emunson@mgebm.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | | | kvmclock: Add functions to check if the host has stopped the vmEric B Munson2012-04-08
| | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a host stops or suspends a VM it will set a flag to show this. The watchdog will use these functions to determine if a softlockup is real, or the result of a suspended VM. Signed-off-by: Eric B Munson <emunson@mgebm.net> asm-generic changes Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | | | Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2012-05-24
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner. Various trivial conflict fixups in arch Kconfig due to addition of unrelated entries nearby. And one slightly more subtle one for sparc32 (new user of GENERIC_CLOCKEVENTS), fixed up as per Thomas. * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) timekeeping: Fix a few minor newline issues. time: remove obsolete declaration ntp: Fix a stale comment and a few stray newlines. ntp: Correct TAI offset during leap second timers: Fixup the Kconfig consolidation fallout x86: Use generic time config unicore32: Use generic time config um: Use generic time config tile: Use generic time config sparc: Use: generic time config sh: Use generic time config score: Use generic time config s390: Use generic time config openrisc: Use generic time config powerpc: Use generic time config mn10300: Use generic time config mips: Use generic time config microblaze: Use generic time config m68k: Use generic time config m32r: Use generic time config ...
| * | | | | x86: Allow multiple values to be specified with "hpet="Jan Beulich2012-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is particularly to be able to specify "hpet=force,verbose", as "force" ought to be a primary candidate for also wanting to use "verbose". Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F79D120020000780007C031@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86: Clear HPET configuration registers on startupJan Beulich2012-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While Linux itself has been calling hpet_disable() for quite a while, having e.g. a secondary (kexec) kernel depend on such behavior of the primary (crashed) environment is fragile. It particularly broke until very recently when the primary environment was Xen based, as that hypervisor did not clear any of the HPET settings it may have used. Rather than blindly (and incompletely) clearing certain HPET settings in hpet_disable(), latch the config register settings during boot and restore then here. (Note on the hpet_set_mode() change: Now that we're clearing the level bit upon initialization, there's no need anymore to do so here.) Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F79D0BB020000780007C02D@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | Merge branch 'perf-uprobes-for-linus' of ↵Linus Torvalds2012-05-24
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull user-space probe instrumentation from Ingo Molnar: "The uprobes code originates from SystemTap and has been used for years in Fedora and RHEL kernels. This version is much rewritten, reviews from PeterZ, Oleg and myself shaped the end result. This tree includes uprobes support in 'perf probe' - but SystemTap (and other tools) can take advantage of user probe points as well. Sample usage of uprobes via perf, for example to profile malloc() calls without modifying user-space binaries. First boot a new kernel with CONFIG_UPROBE_EVENT=y enabled. If you don't know which function you want to probe you can pick one from 'perf top' or can get a list all functions that can be probed within libc (binaries can be specified as well): $ perf probe -F -x /lib/libc.so.6 To probe libc's malloc(): $ perf probe -x /lib64/libc.so.6 malloc Added new event: probe_libc:malloc (on 0x7eac0) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc -aR sleep 1 Make use of it to create a call graph (as the flat profile is going to look very boring): $ perf record -e probe_libc:malloc -gR make [ perf record: Woken up 173 times to write data ] [ perf record: Captured and wrote 44.190 MB perf.data (~1930712 $ perf report | less 32.03% git libc-2.15.so [.] malloc | --- malloc 29.49% cc1 libc-2.15.so [.] malloc | --- malloc | |--0.95%-- 0x208eb1000000000 | |--0.63%-- htab_traverse_noresize 11.04% as libc-2.15.so [.] malloc | --- malloc | 7.15% ld libc-2.15.so [.] malloc | --- malloc | 5.07% sh libc-2.15.so [.] malloc | --- malloc | 4.99% python-config libc-2.15.so [.] malloc | --- malloc | 4.54% make libc-2.15.so [.] malloc | --- malloc | |--7.34%-- glob | | | |--93.18%-- 0x41588f | | | --6.82%-- glob | 0x41588f ... Or: $ perf report -g flat | less # Overhead Command Shared Object Symbol # ........ ............. ............. .......... # 32.03% git libc-2.15.so [.] malloc 27.19% malloc 29.49% cc1 libc-2.15.so [.] malloc 24.77% malloc 11.04% as libc-2.15.so [.] malloc 11.02% malloc 7.15% ld libc-2.15.so [.] malloc 6.57% malloc ... The core uprobes design is fairly straightforward: uprobes probe points register themselves at (inode:offset) addresses of libraries/binaries, after which all existing (or new) vmas that map that address will have a software breakpoint injected at that address. vmas are COW-ed to preserve original content. The probe points are kept in an rbtree. If user-space executes the probed inode:offset instruction address then an event is generated which can be recovered from the regular perf event channels and mmap-ed ring-buffer. Multiple probes at the same address are supported, they create a dynamic callback list of event consumers. The basic model is further complicated by the XOL speedup: the original instruction that is probed is copied (in an architecture specific fashion) and executed out of line when the probe triggers. The XOL area is a single vma per process, with a fixed number of entries (which limits probe execution parallelism). The API: uprobes are installed/removed via /sys/kernel/debug/tracing/uprobe_events, the API is integrated to align with the kprobes interface as much as possible, but is separate to it. Injecting a probe point is privileged operation, which can be relaxed by setting perf_paranoid to -1. You can use multiple probes as well and mix them with kprobes and regular PMU events or tracepoints, when instrumenting a task." Fix up trivial conflicts in mm/memory.c due to previous cleanup of unmap_single_vma(). * 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf probe: Detect probe target when m/x options are absent perf probe: Provide perf interface for uprobes tracing: Fix kconfig warning due to a typo tracing: Provide trace events interface for uprobes tracing: Extract out common code for kprobes/uprobes trace events tracing: Modify is_delete, is_return from int to bool uprobes/core: Decrement uprobe count before the pages are unmapped uprobes/core: Make background page replacement logic account for rss_stat counters uprobes/core: Optimize probe hits with the help of a counter uprobes/core: Allocate XOL slots for uprobes use uprobes/core: Handle breakpoint and singlestep exceptions uprobes/core: Rename bkpt to swbp uprobes/core: Make order of function parameters consistent across functions uprobes/core: Make macro names consistent uprobes: Update copyright notices uprobes/core: Move insn to arch specific structure uprobes/core: Remove uprobe_opcode_sz uprobes/core: Make instruction tables volatile uprobes: Move to kernel/events/ uprobes/core: Clean up, refactor and improve the code ...
| * \ \ \ \ \ Merge branch 'perf/uprobes' of ↵Ingo Molnar2012-05-14
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/uprobes
| * \ \ \ \ \ \ Merge branch 'perf/core' into perf/uprobesIngo Molnar2012-04-14
| |\ \ \ \ \ \ \ | | | |_|/ / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge in latest upstream (and the latest perf development tree), to prepare for tooling changes, and also to pick up v3.4 MM changes that the uprobes code needs to take care of. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | uprobes/core: Handle breakpoint and singlestep exceptionsSrikar Dronamraju2012-03-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Uprobes uses exception notifiers to get to know if a thread hit a breakpoint or a singlestep exception. When a thread hits a uprobe or is singlestepping post a uprobe hit, the uprobe exception notifier sets its TIF_UPROBE bit, which will then be checked on its return to userspace path (do_notify_resume() ->uprobe_notify_resume()), where the consumers handlers are run (in task context) based on the defined filters. Uprobe hits are thread specific and hence we need to maintain information about if a task hit a uprobe, what uprobe was hit, the slot where the original instruction was copied for xol so that it can be singlestepped with appropriate fixups. In some cases, special care is needed for instructions that are executed out of line (xol). These are architecture specific artefacts, such as handling RIP relative instructions on x86_64. Since the instruction at which the uprobe was inserted is executed out of line, architecture specific fixups are added so that the thread continues normal execution in the presence of a uprobe. Postpone the signals until we execute the probed insn. post_xol() path does a recalc_sigpending() before return to user-mode, this ensures the signal can't be lost. Uprobes relies on DIE_DEBUG notification to notify if a singlestep is complete. Adds x86 specific uprobe exception notifiers and appropriate hooks needed to determine a uprobe hit and subsequent post processing. Add requisite x86 fixups for xol for uprobes. Specific cases needing fixups include relative jumps (x86_64), calls, etc. Where possible, we check and skip singlestepping the breakpointed instructions. For now we skip single byte as well as few multibyte nop instructions. However this can be extended to other instructions too. Credits to Oleg Nesterov for suggestions/patches related to signal, breakpoint, singlestep handling code. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120313180011.29771.89027.sendpatchset@srdronam.in.ibm.com [ Performed various cleanliness edits ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | Merge branch 'x86/cleanups' into perf/uprobesIngo Molnar2012-03-13
| |\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: We want to merge a dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | uprobes/core: Make order of function parameters consistent across functionsSrikar Dronamraju2012-03-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a function takes struct uprobe or struct arch_uprobe, then it is passed as the first parameter. This is pure cleanup, no functional change intended. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120312092530.5379.18394.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | uprobes/core: Make macro names consistentSrikar Dronamraju2012-03-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename macros that refer to individual uprobe to start with UPROBE_ instead of UPROBES_. This is pure cleanup, no functional change intended. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120312092514.5379.36595.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | uprobes/core: Move insn to arch specific structureSrikar Dronamraju2012-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Few cleanups suggested by Ingo Molnar. - Rename struct uprobe_arch_info to struct arch_uprobe. - Move insn from struct uprobe to struct arch_uprobe. - Make arch specific uprobe functions to accept struct arch_uprobe instead of struct uprobe. - Move struct uprobe to kernel/uprobes.c from include/linux/uprobes.h Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Anton Arapov <anton@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Stone <jistone@redhat.com> Link: http://lkml.kernel.org/r/20120222091602.15880.40249.sendpatchset@srdronam.in.ibm.com [ Made various small improvements ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | uprobes/core: Make instruction tables volatileSrikar Dronamraju2012-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some versions of gcc spits a warning about the asm operand for test_bit and also causes the first long of the instruction table to be output. Fix is similar to 7115e3fc on arch/x86/kernel/kprobes.c Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Anton Arapov <anton@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Stone <jistone@redhat.com> Link: http://lkml.kernel.org/r/20120222091535.15880.12502.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | uprobes/core: Clean up, refactor and improve the codeIngo Molnar2012-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the uprobes code readable to me: - improve the Kconfig text so that a mere mortal gets some idea what CONFIG_UPROBES=y is really about - do trivial renames to standardize around the uprobes_*() namespace - clean up and simplify various code flow details - separate basic blocks of functionality - line break artifact and white space related removal - use standard local varible definition blocks - use vertical spacing to make things more readable - remove unnecessary volatile - restructure comment blocks to make them more uniform and more readable in general Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Link: http://lkml.kernel.org/n/tip-ewbwhb8o6navvllsauu7k07p@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | uprobes, mm, x86: Add the ability to install and remove uprobes breakpointsSrikar Dronamraju2012-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add uprobes support to the core kernel, with x86 support. This commit adds the kernel facilities, the actual uprobes user-space ABI and perf probe support comes in later commits. General design: Uprobes are maintained in an rb-tree indexed by inode and offset (the offset here is from the start of the mapping). For a unique (inode, offset) tuple, there can be at most one uprobe in the rb-tree. Since the (inode, offset) tuple identifies a unique uprobe, more than one user may be interested in the same uprobe. This provides the ability to connect multiple 'consumers' to the same uprobe. Each consumer defines a handler and a filter (optional). The 'handler' is run every time the uprobe is hit, if it matches the 'filter' criteria. The first consumer of a uprobe causes the breakpoint to be inserted at the specified address and subsequent consumers are appended to this list. On subsequent probes, the consumer gets appended to the existing list of consumers. The breakpoint is removed when the last consumer unregisters. For all other unregisterations, the consumer is removed from the list of consumers. Given a inode, we get a list of the mms that have mapped the inode. Do the actual registration if mm maps the page where a probe needs to be inserted/removed. We use a temporary list to walk through the vmas that map the inode. - The number of maps that map the inode, is not known before we walk the rmap and keeps changing. - extending vm_area_struct wasn't recommended, it's a size-critical data structure. - There can be more than one maps of the inode in the same mm. We add callbacks to the mmap methods to keep an eye on text vmas that are of interest to uprobes. When a vma of interest is mapped, we insert the breakpoint at the right address. Uprobe works by replacing the instruction at the address defined by (inode, offset) with the arch specific breakpoint instruction. We save a copy of the original instruction at the uprobed address. This is needed for: a. executing the instruction out-of-line (xol). b. instruction analysis for any subsequent fixups. c. restoring the instruction back when the uprobe is unregistered. We insert or delete a breakpoint instruction, and this breakpoint instruction is assumed to be the smallest instruction available on the platform. For fixed size instruction platforms this is trivially true, for variable size instruction platforms the breakpoint instruction is typically the smallest (often a single byte). Writing the instruction is done by COWing the page and changing the instruction during the copy, this even though most platforms allow atomic writes of the breakpoint instruction. This also mirrors the behaviour of a ptrace() memory write to a PRIVATE file map. The core worker is derived from KSM's replace_page() logic. In essence, similar to KSM: a. allocate a new page and copy over contents of the page that has the uprobed vaddr b. modify the copy and insert the breakpoint at the required address c. switch the original page with the copy containing the breakpoint d. flush page tables. replace_page() is being replicated here because of some minor changes in the type of pages and also because Hugh Dickins had plans to improve replace_page() for KSM specific work. Instruction analysis on x86 is based on instruction decoder and determines if an instruction can be probed and determines the necessary fixups after singlestep. Instruction analysis is done at probe insertion time so that we avoid having to repeat the same analysis every time a probe is hit. A lot of code here is due to the improvement/suggestions/inputs from Peter Zijlstra. Changelog: (v10): - Add code to clear REX.B prefix as suggested by Denys Vlasenko and Masami Hiramatsu. (v9): - Use insn_offset_modrm as suggested by Masami Hiramatsu. (v7): Handle comments from Peter Zijlstra: - Dont take reference to inode. (expect inode to uprobe_register to be sane). - Use PTR_ERR to set the return value. - No need to take reference to inode. - use PTR_ERR to return error value. - register and uprobe_unregister share code. (v5): - Modified del_consumer as per comments from Peter. - Drop reference to inode before dropping reference to uprobe. - Use i_size_read(inode) instead of inode->i_size. - Ensure uprobe->consumers is NULL, before __uprobe_unregister() is called. - Includes errno.h as recommended by Stephen Rothwell to fix a build issue on sparc defconfig - Remove restrictions while unregistering. - Earlier code leaked inode references under some conditions while registering/unregistering. - Continue the vma-rmap walk even if the intermediate vma doesnt meet the requirements. - Validate the vma found by find_vma before inserting/removing the breakpoint - Call del_consumer under mutex_lock. - Use hash locks. - Handle mremap. - Introduce find_least_offset_node() instead of close match logic in find_uprobe - Uprobes no more depends on MM_OWNER; No reference to task_structs while inserting/removing a probe. - Uses read_mapping_page instead of grab_cache_page so that the pages have valid content. - pass NULL to get_user_pages for the task parameter. - call SetPageUptodate on the new page allocated in write_opcode. - fix leaking a reference to the new page under certain conditions. - Include Instruction Decoder if Uprobes gets defined. - Remove const attributes for instruction prefix arrays. - Uses mm_context to know if the application is 32 bit. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Also-written-by: Jim Keniston <jkenisto@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Roland McGrath <roland@hack.frob.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/20120209092642.GE16600@linux.vnet.ibm.com [ Made various small edits to the commit log ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | | | Merge branch 'for-linus' of ↵Linus Torvalds2012-05-23
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull first series of signal handling cleanups from Al Viro: "This is just the first part of the queue (about a half of it); assorted fixes all over the place in signal handling. This one ends with all sigsuspend() implementations switched to generic one (->saved_sigmask-based). With this, a bunch of assorted old buglets are fixed and most of the missing bits of NOTIFY_RESUME hookup are in place. Two more fixes sit in arm and um trees respectively, and there's a couple of broken ones that need obvious fixes - parisc and avr32 check TIF_NOTIFY_RESUME only on one of two codepaths; fixes for that will happen in the next series" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (55 commits) unicore32: if there's no handler we need to restore sigmask, syscall or no syscall xtensa: add handling of TIF_NOTIFY_RESUME microblaze: drop 'oldset' argument of do_notify_resume() microblaze: handle TIF_NOTIFY_RESUME score: add handling of NOTIFY_RESUME to do_notify_resume() m68k: add TIF_NOTIFY_RESUME and handle it. sparc: kill ancient comment in sparc_sigaction() h8300: missing checks of __get_user()/__put_user() return values frv: missing checks of __get_user()/__put_user() return values cris: missing checks of __get_user()/__put_user() return values powerpc: missing checks of __get_user()/__put_user() return values sh: missing checks of __get_user()/__put_user() return values sparc: missing checks of __get_user()/__put_user() return values avr32: struct old_sigaction is never used m32r: struct old_sigaction is never used xtensa: xtensa_sigaction doesn't exist alpha: tidy signal delivery up score: don't open-code force_sigsegv() cris: don't open-code force_sigsegv() blackfin: don't open-code force_sigsegv() ...
| * | | | | | | | | new helper: sigsuspend()Al Viro2012-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes kernel sigset_t *. Open-coded instances replaced with calling it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | | | | | Merge branch 'delete-mca' of ↵Linus Torvalds2012-05-23
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull the MCA deletion branch from Paul Gortmaker: "It was good that we could support MCA machines back in the day, but realistically, nobody is using them anymore. They were mostly limited to 386-sx 16MHz CPU and some 486 class machines and never more than 64MB of RAM. Even the enthusiast hobbyist community seems to have dried up close to ten years ago, based on what you can find searching various websites dedicated to the relatively short lived hardware. So lets remove the support relating to CONFIG_MCA. There is no point carrying this forward, wasting cycles doing routine maintenance on it; wasting allyesconfig build time on validating it, wasting I/O on git grep'ping over it, and so on." Let's see if anybody screams. It generally has compiled, and James Bottomley pointed out that there was a MCA extension from NCR that allowed for up to 4GB of memory and PPro-class machines. So in *theory* there may be users out there. But even James (technically listed as a maintainer) doesn't actually have a system, and while Alan Cox claims to have a machine in his cellar that he offered to anybody who wants to take it off his hands, he didn't argue for keeping MCA support either. So we could bring it back. But somebody had better speak up and talk about how they have actually been using said MCA hardware with modern kernels for us to do that. And David already took the patch to delete all the networking driver code (commit a5e371f61ad3: "drivers/net: delete all code/drivers depending on CONFIG_MCA"). * 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: MCA: delete all remaining traces of microchannel bus support. scsi: delete the MCA specific drivers and driver code serial: delete the MCA specific 8250 support. arm: remove ability to select CONFIG_MCA
| * | | | | | | | | | MCA: delete all remaining traces of microchannel bus support.Paul Gortmaker2012-05-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hardware with MCA bus is limited to 386 and 486 class machines that are now 20+ years old and typically with less than 32MB of memory. A quick search on the internet, and you see that even the MCA hobbyist/enthusiast community has lost interest in the early 2000 era and never really even moved ahead from the 2.4 kernels to the 2.6 series. This deletes anything remaining related to CONFIG_MCA from core kernel code and from the x86 architecture. There is no point in carrying this any further into the future. One complication to watch for is inadvertently scooping up stuff relating to machine check, since there is overlap in the TLA name space (e.g. arch/x86/boot/mca.c). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: James Bottomley <JBottomley@Parallels.com> Cc: x86@kernel.org Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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*-. \ \ \ \ \ \ \ \ \ \ Merge branches 'perf-urgent-for-linus' and 'perf-core-for-linus' of ↵Linus Torvalds2012-05-23
|\ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: - Leftover AMD PMU driver fix fix from the end of the v3.4 stabilization cycle. - Late tools/perf/ changes that missed the first round: * endianness fixes * event parsing improvements * libtraceevent fixes factored out from trace-cmd * perl scripting engine fixes related to libtraceevent, * testcase improvements * perf inject / pipe mode fixes * plus a kernel side fix * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Update event scheduling constraints for AMD family 15h models * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "sched, perf: Use a single callback into the scheduler" perf evlist: Show event attribute details perf tools: Bump default sample freq to 4 kHz perf buildid-list: Work better with pipe mode perf tools: Fix piped mode read code perf inject: Fix broken perf inject -b perf tools: rename HEADER_TRACE_INFO to HEADER_TRACING_DATA perf tools: Add union u64_swap type for swapping u64 data perf tools: Carry perf_event_attr bitfield throught different endians perf record: Fix documentation for branch stack sampling perf target: Add cpu flag to sample_type if target has cpu perf tools: Always try to build libtraceevent perf tools: Rename libparsevent to libtraceevent in Makefile perf script: Rename struct event to struct event_format in perl engine perf script: Explicitly handle known default print arg type perf tools: Add hardcoded name term for pmu events perf tools: Separate 'mem:' event scanner bits perf tools: Use allocated list for each parsed event perf tools: Add support for displaying event parser debug info perf test: Move parse event automated tests to separated object
| * | | | | | | | | | | | perf/x86: Update event scheduling constraints for AMD family 15h modelsRobert Richter2012-05-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This update is for newer family 15h cpu models from 0x02 to 0x1f. Signed-off-by: Robert Richter <robert.richter@amd.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: stable@vger.kernel.org # v2.6.39+ Link: http://lkml.kernel.org/r/1337337642-1621-1-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | | | | | Merge branch 'x86-reboot-for-linus' of ↵Linus Torvalds2012-05-23
|\ \ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 reboot changes from Ingo Molnar: "The biggest change is a gentler method of rebooting/stopping via IRQs first and then via NMIs. There are several cleanups in the tree as well." * 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/reboot: Update nonmi_ipi parameter x86/reboot: Use NMI to assist in shutting down if IRQ fails Revert "x86, reboot: Use NMI instead of REBOOT_VECTOR to stop cpus" x86/reboot: Clean up coding style x86/reboot: Reduce to a single DMI table for reboot quirks
| * | | | | | | | | | | | | x86/reboot: Update nonmi_ipi parameterDon Zickus2012-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the nonmi_ipi parameter to reflect the simple change instead of the previous complicated one. There should be less of a need to use it but there may still be corner cases on older hardware that stumble into NMI issues. Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1336761675-24296-4-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>