kernel/git/stable/linux.git/arch/x86/include, branch linux-3.5.y

mm: thp: fix pmd_present for split_huge_page and PROT_NONE with THP

2012-10-12T20:47:12+00:00

commit 027ef6c87853b0a9df53175063028edb4950d476 upstream. In many places !pmd_present has been converted to pmd_none. For pmds that's equivalent and pmd_none is quicker so using pmd_none is better. However (unless we delete pmd_present) we should provide an accurate pmd_present too. This will avoid the risk of code thinking the pmd is non present because it's under __split_huge_page_map, see the pmd_mknotpresent there and the comment above it. If the page has been mprotected as PROT_NONE, it would also lead to a pmd_present false negative in the same way as the race with split_huge_page. Because the PSE bit stays on at all times (both during split_huge_page and when the _PAGE_PROTNONE bit get set), we could only check for the PSE bit, but checking the PROTNONE bit too is still good to remember pmd_present must always keep PROT_NONE into account. This explains a not reproducible BUG_ON that was seldom reported on the lists. The same issue is in pmd_large, it would go wrong with both PROT_NONE and if it races with split_huge_page. Signed-off-by: Andrea Arcangeli Acked-by: Rik van Riel Cc: Johannes Weiner Cc: Hugh Dickins Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

xen/m2p: do not reuse kmap_op->dev_bus_addr

2012-10-02T17:39:12+00:00

commit 2fc136eecd0c647a6b13fcd00d0c41a1a28f35a5 upstream. If the caller passes a valid kmap_op to m2p_add_override, we use kmap_op->dev_bus_addr to store the original mfn, but dev_bus_addr is part of the interface with Xen and if we are batching the hypercalls it might not have been written by the hypervisor yet. That means that later on Xen will write to it and we'll think that the original mfn is actually what Xen has written to it. Rather than "stealing" struct members from kmap_op, keep using page->index to store the original mfn and add another parameter to m2p_remove_override to get the corresponding kmap_op instead. It is now responsibility of the caller to keep track of which kmap_op corresponds to a particular page in the m2p_override (gntdev, the only user of this interface that passes a valid kmap_op, is already doing that). Reported-and-Tested-By: Sander Eikelenboom Signed-off-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-06-29T17:29:54+00:00

Pull x86 fixes from Ingo Molnar. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, cpufeature: Remove stray %s, add -w to mkcapflags.pl x86, cpufeature: Catch duplicate CPU feature strings x86, cpufeature: Rename X86_FEATURE_DTS to X86_FEATURE_DTHERM x86: Fix kernel-doc warnings x86, compat: Use test_thread_flag(TIF_IA32) in compat signal delivery

x86, cpufeature: Rename X86_FEATURE_DTS to X86_FEATURE_DTHERM

2012-06-25T16:01:15+00:00

It makes sense to label "Digital Thermal Sensor" as "DTS", but unfortunately the string "dts" was already used for "Debug Store", and /proc/cpuinfo is a user space ABI. Therefore, rename this to "dtherm". This conflict went into mainline via the hwmon tree without any x86 maintainer ack, and without any kind of hint in the subject. a4659053 x86/hwmon: fix initialization of coretemp Reported-by: Jean Delvare Link: http://lkml.kernel.org/r/4FE34BCB.5050305@linux.intel.com Cc: Jan Beulich Cc: v2.6.36..v3.4 Signed-off-by: H. Peter Anvin

thp: avoid atomic64_read in pmd_read_atomic for 32bit PAE

2012-06-20T21:39:35+00:00

In the x86 32bit PAE CONFIG_TRANSPARENT_HUGEPAGE=y case while holding the mmap_sem for reading, cmpxchg8b cannot be used to read pmd contents under Xen. So instead of dealing only with "consistent" pmdvals in pmd_none_or_trans_huge_or_clear_bad() (which would be conceptually simpler) we let pmd_none_or_trans_huge_or_clear_bad() deal with pmdvals where the low 32bit and high 32bit could be inconsistent (to avoid having to use cmpxchg8b). The only guarantee we get from pmd_read_atomic is that if the low part of the pmd was found null, the high part will be null too (so the pmd will be considered unstable). And if the low part of the pmd is found "stable" later, then it means the whole pmd was read atomically (because after a pmd is stable, neither MADV_DONTNEED nor page faults can alter it anymore, and we read the high part after the low part). In the 32bit PAE x86 case, it is enough to read the low part of the pmdval atomically to declare the pmd as "stable" and that's true for THP and no THP, furthermore in the THP case we also have a barrier() that will prevent any inconsistent pmdvals to be cached by a later re-read of the *pmd. Signed-off-by: Andrea Arcangeli Cc: Jonathan Nieder Cc: Ulrich Obergfell Cc: Mel Gorman Cc: Hugh Dickins Cc: Larry Woodman Cc: Petr Matousek Cc: Rik van Riel Cc: Jan Beulich Cc: KOSAKI Motohiro Tested-by: Andrew Jones Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-06-08T16:26:55+00:00

Pull x86 fixes from Ingo Molnar. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/nmi: Fix section mismatch warnings on 32-bit x86/uv: Fix UV2 BAU legacy mode x86/mm: Only add extra pages count for the first memory range during pre-allocation early page table space x86, efi stub: Add .reloc section back into image x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs x86/reboot: Fix a warning message triggered by stop_other_cpus() x86/intel/moorestown: Change intel_scu_devices_create() to __devinit x86/numa: Set numa_nodes_parsed at acpi_numa_memory_affinity_init() x86/gart: Fix kmemleak warning x86: mce: Add the dropped timer interval init back x86/mce: Fix the MCE poll timer logic

x86/nmi: Fix section mismatch warnings on 32-bit

2012-06-08T10:19:27+00:00

It was reported that compiling for 32-bit caused a bunch of section mismatch warnings: VDSOSYM arch/x86/vdso/vdso32-syms.lds LD arch/x86/vdso/built-in.o LD arch/x86/built-in.o WARNING: arch/x86/built-in.o(.data+0x5af0): Section mismatch in reference from the variable test_nmi_ipi_callback_na.10451 to the function .init.text:test_nmi_ipi_callback() [...] WARNING: arch/x86/built-in.o(.data+0x5b04): Section mismatch in reference from the variable nmi_unk_cb_na.10399 to the function .init.text:nmi_unk_cb() The variable nmi_unk_cb_na.10399 references the function __init nmi_unk_cb() [...] Both of these are attributed to the internal representation of the nmiaction struct created during register_nmi_handler. The reason for this is that those structs are not defined in the init section whereas the rest of the code in nmi_selftest.c is. To resolve this, I created a new #define, register_nmi_handler_initonly, that tags the struct as __initdata to resolve the mismatch. This #define should only be used in rare situations where the register/unregister is called during init of the kernel. Big thanks to Jan Beulich for decoding this for me as I didn't have a clue what was going on. Reported-by: Witold Baryluk Tested-by: Witold Baryluk Cc: Jan Beulich Signed-off-by: Don Zickus Link: http://lkml.kernel.org/r/1338991542-23000-1-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar

x86/uv: Fix UV2 BAU legacy mode

2012-06-08T09:48:28+00:00

The SGI Altix UV2 BAU (Broadcast Assist Unit) as used for tlb-shootdown (selective broadcast mode) always uses UV2 broadcast descriptor format. There is no need to clear the 'legacy' (UV1) mode, because the hardware always uses UV2 mode for selective broadcast. But the BIOS uses general broadcast and legacy mode, and the hardware pays attention to the legacy mode bit for general broadcast. So the kernel must not clear that mode bit. Signed-off-by: Cliff Wickman Cc: Link: http://lkml.kernel.org/r/E1SccoO-0002Lh-Cb@eag09.americas.sgi.com Signed-off-by: Ingo Molnar

perf/x86: Check if user fp is valid

2012-06-06T15:08:01+00:00

Signed-off-by: Arun Sharma Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1334961696-19580-4-git-send-email-asharma@fb.com Signed-off-by: Ingo Molnar

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-06-02T23:17:03+00:00

Pull straggler x86 fixes from Peter Anvin: "Three groups of patches: - EFI boot stub documentation and the ability to print error messages; - Removal for PTRACE_ARCH_PRCTL for x32 (obsolete interface which should never have been ported, and the port is broken and potentially dangerous.) - ftrace stack corruption fixes. I'm not super-happy about the technical implementation, but it is probably the least invasive in the short term. In the future I would like a single method for nesting the debug stack, however." * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, x32, ptrace: Remove PTRACE_ARCH_PRCTL for x32 x86, efi: Add EFI boot stub documentation x86, efi; Add EFI boot stub console support x86, efi: Only close open files in error path ftrace/x86: Do not change stacks in DEBUG when calling lockdep x86: Allow nesting of the debug stack IDT setting x86: Reset the debug_stack update counter ftrace: Use breakpoint method to update ftrace caller ftrace: Synchronize variable setting with breakpoints