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2012-05-07powerpc/85xx: don't call of_platform_bus_probe() twiceTimur Tabi
commit 8a95bc8dfe06982fc2b8a0a2adda7baa2346a17b upstream. Commit 46d026ac ("powerpc/85xx: consolidate of_platform_bus_probe calls") replaced platform-specific of_device_id tables with a single function that probes the most of the busses in 85xx device trees. If a specific platform needed additional busses probed, then it could call of_platform_bus_probe() again. Typically, the additional platform-specific busses are children of existing busses that have already been probed. of_platform_bus_probe() does not handle those child busses automatically. Unfortunately, this doesn't actually work. The second (platform-specific) call to of_platform_bus_probe() never finds any of the busses it's asked to find. To remedy this, the platform-specific of_device_id tables are eliminated, and their entries are merged into mpc85xx_common_ids[], so that all busses are probed at once. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, efi: Add dedicated EFI stub entry pointMatt Fleming
commit b1994304fc399f5d3a5368c81111d713490c4799 upstream. The method used to work out whether we were booted by EFI firmware or via a boot loader is broken. Because efi_main() is always executed when booting from a boot loader we will dereference invalid pointers either on the stack (CONFIG_X86_32) or contained in %rdx (CONFIG_X86_64) when searching for an EFI System Table signature. Instead of dereferencing these invalid system table pointers, add a new entry point that is only used when booting from EFI firmware, when we know the pointer arguments will be valid. With this change legacy boot loaders will no longer execute efi_main(), but will instead skip EFI stub initialisation completely. [ hpa: Marking this for urgent/stable since it is a regression when the option is enabled; without the option the patch has no effect ] Signed-off-by: Matt Fleming <matt.hfleming@intel.com> Link: http://lkml.kernel.org/r/1334584744.26997.14.camel@mfleming-mobl1.ger.corp.intel.com Reported-by: Jordan Justen <jordan.l.justen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, boot: Correct CFLAGS for hostprogsH. Peter Anvin
commit 446e1c86d51d0823e003a43a2b85c430efce2733 upstream. This is a partial revert of commit: d40f833 "Restrict CFLAGS for hostprogs" The endian-manipulation macros in tools/include need <linux/types.h>, but the hostprogs in arch/x86/boot need several headers from the kernel build tree, which means we have to add the kernel headers to the include path. This picks up <linux/types.h> from the kernel tree, which gives a warning. Since this use of <linux/types.h> is intentional, add -D__EXPORTED_HEADERS__ to the command line to silence the warning. A better way to fix this would be to always install the exported kernel headers into $(objtree)/usr/include as a standard part of the kernel build, but that is a lot more involved. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1330436245-24875-5-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, efi: Fix endian issues and unaligned accessesMatt Fleming
commit 92f42c50f227ad228f815a8f4eec872524dae3a5 upstream. We may need to convert the endianness of the data we read from/write to 'buf', so let's use {get,put}_unaligned_le32() to do that. Failure to do so can result in accessing invalid memory, leading to a segfault. Stephen Rothwell noticed this bug while cross-building an x86_64 allmodconfig kernel on PowerPC. We need to read from and write to 'buf' a byte at a time otherwise it's possible we'll perform an unaligned access, which can lead to bus errors when cross-building an x86 kernel on risc architectures. Cc: H. Peter Anvin <hpa@zytor.com> Cc: Nick Bowler <nbowler@elliptictech.com> Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1330436245-24875-6-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, boot: Restrict CFLAGS for hostprogsMatt Fleming
commit d40f833630a1299fd377408dc8d8fac370d621b0 upstream. Currently tools/build has access to all the kernel headers in $(srctree). This is unnecessary and could potentially allow tools/build to erroneously include kernel headers when it should only be including userspace-exported headers. Unfortunately, mkcpustr still needs access to some of the asm kernel headers, so explicitly special case that hostprog. Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1330436245-24875-5-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, mkpiggy: Don't open code put_unaligned_le32()Matt Fleming
commit 12871c568305a0b20f116315479a18cd46882e9b upstream. Use the new headers in tools/include instead of rolling our own put_unaligned_le32() implementation. Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1330436245-24875-4-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, efi: Fix pointer math issue in handle_ramdisks()Dan Carpenter
commit c7b738351ba92f48b943ac59aff6b5b0f17f37c9 upstream. "filename" is a efi_char16_t string so this check for reaching the end of the array doesn't work. We need to cast the pointer to (u8 *) before doing the math. This patch changes the "filename" to "filename_16" to avoid confusion in the future. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: http://lkml.kernel.org/r/20120305180614.GA26880@elgon.mountain Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07MIPS: ath79: fix AR933X WMAC reset codeGabor Juhos
commit de14ca6ae2c592d66db88f1e5596b26f7f011384 upstream. The current code puts the built-in WMAC device of the AR933X SoCs into reset instead of starting it. This causes a hard lock on AR933X based boards when the wireless driver tries to access the device. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3484/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating IRQsWill Deacon
commit 5e7371ded05adfcfcee44a8bc070bfc37979b8f2 upstream. When a CPU is hotplugged off, we migrate any IRQs currently affine to it away and onto another online CPU by calling the irq_set_affinity function of the relevant interrupt controller chip. This function returns either IRQ_SET_MASK_OK or IRQ_SET_MASK_OK_NOCOPY, to indicate whether irq_data.affinity was updated. If we are forcefully migrating an interrupt (because the affinity mask no longer identifies any online CPUs) then we should update the IRQ affinity mask to reflect the new CPU set. Failure to do so can potentially leave /proc/irq/n/smp_affinity identifying only offline CPUs, which may confuse userspace IRQ balancing daemons. This patch updates migrate_one_irq to copy the affinity mask when the interrupt chip returns IRQ_SET_MASK_OK after forcefully changing the affinity of an interrupt. Reported-by: Leif Lindholm <leif.lindholm@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07ARM: 7403/1: tls: remove covert channel via TPIDRURWWill Deacon
commit 6a1c53124aa161eb624ce7b1e40ade728186d34c upstream. TPIDRURW is a user read/write register forming part of the group of thread registers in more recent versions of the ARM architecture (~v6+). Currently, the kernel does not touch this register, which allows tasks to communicate covertly by reading and writing to the register without context-switching affecting its contents. This patch clears TPIDRURW when TPIDRURO is updated via the set_tls macro, which is called directly from __switch_to. Since the current behaviour makes the register useless to userspace as far as thread pointers are concerned, simply clearing the register (rather than saving and restoring it) will not cause any problems to userspace. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07ARM: 7396/1: errata: only handle ARM erratum #326103 on affected coresWill Deacon
commit f0c4b8d653f5ee091fb8d4d02ed7eaad397491bb upstream. Erratum #326103 ("FSR write bit incorrect on a SWP to read-only memory") only affects the ARM 1136 core prior to r1p0. The workaround disassembles the faulting instruction to determine whether it was a read or write access on all v6 cores. An issue has been reported on the ARM 11MPCore whereby loading the faulting instruction may happen in parallel with that page being unmapped, resulting in a deadlock due to the lack of TLB broadcasting in hardware: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-March/091561.html This patch limits the workaround so that it is only used on affected cores, which are known to be UP only. Other v6 cores can rely on the FSR to indicate the access type correctly. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07i387: ptrace breaks the lazy-fpu-restore logicOleg Nesterov
commit 089f9fba56faf33cc6dd2a6442b7ac92c58b8209 upstream. Starting from 7e16838d "i387: support lazy restore of FPU state" we assume that fpu_owner_task doesn't need restore_fpu_checking() on the context switch, its FPU state should match what we already have in the FPU on this CPU. However, debugger can change the tracee's FPU state, in this case we should reset fpu.last_cpu to ensure fpu_lazy_restore() can't return true. Change init_fpu() to do this, it is called by user_regset->set() methods. Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20120416204815.GB24884@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07xen/smp: Fix crash when booting with ACPI hotplug CPUs.Konrad Rzeszutek Wilk
commit cf405ae612b0f7e2358db7ff594c0e94846137aa upstream. When we boot on a machine that can hotplug CPUs and we are using 'dom0_max_vcpus=X' on the Xen hypervisor line to clip the amount of CPUs available to the initial domain, we get this: (XEN) Command line: com1=115200,8n1 dom0_mem=8G noreboot dom0_max_vcpus=8 sync_console mce_verbosity=verbose console=com1,vga loglvl=all guest_loglvl=all .. snip.. DMI: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.99.99.x032.072520111118 07/25/2011 .. snip. SMP: Allowing 64 CPUs, 32 hotplug CPUs installing Xen timer for CPU 7 cpu 7 spinlock event irq 361 NMI watchdog: disabled (cpu7): hardware events not enabled Brought up 8 CPUs .. snip.. [acpi processor finds the CPUs are not initialized and starts calling arch_register_cpu, which creates /sys/devices/system/cpu/cpu8/online] CPU 8 got hotplugged CPU 9 got hotplugged CPU 10 got hotplugged .. snip.. initcall 1_acpi_battery_init_async+0x0/0x1b returned 0 after 406 usecs calling erst_init+0x0/0x2bb @ 1 [and the scheduler sticks newly started tasks on the new CPUs, but said CPUs cannot be initialized b/c the hypervisor has limited the amount of vCPUS to 8 - as per the dom0_max_vcpus=8 flag. The spinlock tries to kick the other CPU, but the structure for that is not initialized and we crash.] BUG: unable to handle kernel paging request at fffffffffffffed8 IP: [<ffffffff81035289>] xen_spin_lock+0x29/0x60 PGD 180d067 PUD 180e067 PMD 0 Oops: 0002 [#1] SMP CPU 7 Modules linked in: Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc2upstream-00001-gf5154e8 #1 Intel Corporation S2600CP/S2600CP RIP: e030:[<ffffffff81035289>] [<ffffffff81035289>] xen_spin_lock+0x29/0x60 RSP: e02b:ffff8801fb9b3a70 EFLAGS: 00010282 With this patch, we cap the amount of vCPUS that the initial domain can run, to exactly what dom0_max_vcpus=X has specified. In the future, if there is a hypercall that will allow a running domain to expand past its initial set of vCPUS, this patch should be re-evaluated. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07xen: correctly check for pending events when restoring irq flagsDavid Vrabel
commit 7eb7ce4d2e8991aff4ecb71a81949a907ca755ac upstream. In xen_restore_fl_direct(), xen_force_evtchn_callback() was being called even if no events were pending. This resulted in (depending on workload) about a 100 times as many xen_version hypercalls as necessary. Fix this by correcting the sense of the conditional jump. This seems to give a significant performance benefit for some workloads. There is some subtle tricksy "..since the check here is trying to check both pending and masked in a single cmpw, but I think this is correct. It will call check_events now only when the combined mask+pending word is 0x0001 (aka unmasked, pending)." (Ian) Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86/platform: Remove incorrect error message in x86_default_fixup_cpu_id()Andreas Herrmann
commit 68894632afb2729a1d8785c877840953894c7283 upstream. It's only called from amd.c:srat_detect_node(). The introduced condition for calling the fixup code is true for all AMD multi-node processors, e.g. Magny-Cours and Interlagos. There we have 2 NUMA nodes on one socket. Thus there are cores having different numa-node-id but with equal phys_proc_id. There is no point to print error messages in such a situation. The confusing/misleading error message was introduced with commit 64be4c1c2428e148de6081af235e2418e6a66dda ("x86: Add x86_init platform override to fix up NUMA core numbering"). Remove the default fixup function (especially the error message) and replace it by a NULL pointer check, move the Numascale-specific condition for calling the fixup into the fixup-function itself and slightly adapt the comment. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Borislav Petkov <borislav.petkov@amd.com> Cc: <sp@numascale.com> Cc: <bp@amd64.org> Cc: <daniel@numascale-asia.com> Link: http://lkml.kernel.org/r/20120402160648.GR27684@alberich.amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, apic: APIC code touches invalid MSR on P5 class machinesBryan O'Donoghue
commit cbf2829b61c136edcba302a5e1b6b40e97d32c00 upstream. Current APIC code assumes MSR_IA32_APICBASE is present for all systems. Pentium Classic P5 and friends didn't have this MSR. MSR_IA32_APICBASE was introduced as an architectural MSR by Intel @ P6. Code paths that can touch this MSR invalidly are when vendor == Intel && cpu-family == 5 and APIC bit is set in CPUID - or when you simply pass lapic on the kernel command line, on a P5. The below patch stops Linux incorrectly interfering with the MSR_IA32_APICBASE for P5 class machines. Other code paths exist that touch the MSR - however those paths are not currently reachable for a conformant P5. Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linux.intel.com> Link: http://lkml.kernel.org/r/4F8EEDD3.1080404@linux.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, microcode: Ensure that module is only loaded on supported AMD CPUsAndreas Herrmann
commit 283c1f2558ef4a4411fe908364b15b73b6ab44cf upstream. Exit early when there's no support for a particular CPU family. Also, fixup the "no support for this CPU vendor" to be issued only when the driver is attempted to be loaded on an unsupported vendor. Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: http://lkml.kernel.org/r/20120411163849.GE4794@alberich.amd.com [Boris: add a commit msg because Andreas is lazy] Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, microcode: Fix sysfs warning during module unload on unsupported CPUsAndreas Herrmann
commit a956bd6f8583326b18348ab1452b4686778f785d upstream. Loading the microcode driver on an unsupported CPU and subsequently unloading the driver causes WARNING: at fs/sysfs/group.c:138 mc_device_remove+0x5f/0x70 [microcode]() Hardware name: 01972NG sysfs group ffffffffa00013d0 not found for kobject 'cpu0' Modules linked in: snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_intel btusb snd_hda_codec bluetooth thinkpad_acpi rfkill microcode(-) [last unloaded: cfg80211] Pid: 4560, comm: modprobe Not tainted 3.4.0-rc2-00002-g258f742 #5 Call Trace: [<ffffffff8103113b>] ? warn_slowpath_common+0x7b/0xc0 [<ffffffff81031235>] ? warn_slowpath_fmt+0x45/0x50 [<ffffffff81120e74>] ? sysfs_remove_group+0x34/0x120 [<ffffffffa00000ef>] ? mc_device_remove+0x5f/0x70 [microcode] [<ffffffff81331eb9>] ? subsys_interface_unregister+0x69/0xa0 [<ffffffff81563526>] ? mutex_lock+0x16/0x40 [<ffffffffa0000c3e>] ? microcode_exit+0x50/0x92 [microcode] [<ffffffff8107051d>] ? sys_delete_module+0x16d/0x260 [<ffffffff810a0065>] ? wait_iff_congested+0x45/0x110 [<ffffffff815656af>] ? page_fault+0x1f/0x30 [<ffffffff81565ba2>] ? system_call_fastpath+0x16/0x1b on recent kernels. This is due to commit 8a25a2fd126c ("cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem") which renders commit 6c53cbfced04 ("x86, microcode: Correct sysdev_add error path") useless. See http://marc.info/?l=linux-kernel&m=133416246406478 Avoid above warning by restoring the old driver behaviour before 6c53cbfced04 ("x86, microcode: Correct sysdev_add error path"). Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: http://lkml.kernel.org/r/20120411163849.GE4794@alberich.amd.com Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ARM: OMAP: serial: Fix the ocp smart idlemode handling bugSantosh Shilimkar
commit 5ae256dcd91bf308826a4ac19598b27ebb86a536 upstream. The current serial UART code, while fidling with ocp idlemode bits, forget about the smart idle wakeup bit even if it is supported by UART IP block. This will lead to missing the module wakeup on OMAP's where the smart idle wakeup is supported. This was the root cause of the console sluggishness issue, I have been observing on OMAP4 devices and also can be potential reason for some other UART wakeup issues. Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Acked-by: Govindraj.R <govindraj.raja@ti.com> Reviewed-by: Paul Walmsley <paul@pwsan.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ARM: OMAP1: DMTIMER: fix broken timer clock source selectionPaul Walmsley
commit 6aaec67da1e41a0752a2b903b989e73b9f02e182 upstream. DMTIMER source selection on OMAP1 is broken. omap1_dm_timer_set_src() tries to use __raw_{read,write}l() to read from and write to physical addresses, but those functions take virtual addresses. sparse caught this: arch/arm/mach-omap1/timer.c:50:13: warning: incorrect type in argument 1 (different base types) arch/arm/mach-omap1/timer.c:50:13: expected void const volatile [noderef] <asn:2>*<noident> arch/arm/mach-omap1/timer.c:50:13: got unsigned int arch/arm/mach-omap1/timer.c:52:9: warning: incorrect type in argument 1 (different base types) arch/arm/mach-omap1/timer.c:52:9: expected void const volatile [noderef] <asn:2>*<noident> arch/arm/mach-omap1/timer.c:52:9: got unsigned int Fix by using omap_{read,writel}(), just like the other users of the MOD_CONF_CTRL_1 register in the OMAP1 codebase. Of course, in the long term, removing omap_{read,write}l() is the appropriate thing to do; but this will take some work to do this cleanly. Looks like this was caused by 97933d6 (ARM: OMAP1: dmtimer: conversion to platform devices) that dangerously moved code and changed it in the same patch. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Tarun Kanti DebBarma <tarun.kanti@ti.com> [tony@atomide.com: updated comments to include the breaking commit] Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ARM: at91: fix at91sam9261ek Ethernet dm9000 irqJean-Christophe PLAGNIOL-VILLARD
commit ee9dd7631af6fb5c02964ed5b496217cd4ced059 upstream. You need to setup the dm9000 irq via gpio_to_irq() since d0fbda9add (ARM: at91/gpio: drop PIN_BASE). Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22fix tlb flushing for page table pagesMartin Schwidefsky
commit cd94154cc6a28dd9dc271042c1a59c08d26da886 upstream. Git commit 36409f6353fc2d7b6516e631415f938eadd92ffa "use generic RCU page-table freeing code" introduced a tlb flushing bug. Partially revert the above git commit and go back to s390 specific page table flush code. For s390 the TLB can contain three types of entries, "normal" TLB page-table entries, TLB combined region-and-segment-table (CRST) entries and real-space entries. Linux does not use real-space entries which leaves normal TLB entries and CRST entries. The CRST entries are intermediate steps in the page-table translation called translation paths. For example a 4K page access in a three-level page table setup will create two CRST TLB entries and one page-table TLB entry. The advantage of that approach is that a page access next to the previous one can reuse the CRST entries and needs just a single read from memory to create the page-table TLB entry. The disadvantage is that the TLB flushing rules are more complicated, before any page-table may be freed the TLB needs to be flushed. In short: the generic RCU page-table freeing code is incorrect for the CRST entries, in particular the check for mm_users < 2 is troublesome. This is applicable to 3.0+ kernels. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22x86: Use correct byte-sized register constraint in __add()H. Peter Anvin
commit 8c91c5325e107ec17e40a59a47c6517387d64eb7 upstream. Similar to: 2ca052a x86: Use correct byte-sized register constraint in __xchg_op() ... the __add() macro also needs to use a "q" constraint in the byte-sized case, lest we try to generate an illegal register. Link: http://lkml.kernel.org/r/4F7A3315.501@goop.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Leigh Scott <leigh123linux@googlemail.com> Cc: Thomas Reitmayr <treitmayr@devbase.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22x86: Use correct byte-sized register constraint in __xchg_op()Jeremy Fitzhardinge
commit 2ca052a3710fac208eee690faefdeb8bbd4586a1 upstream. x86-64 can access the low half of any register, but i386 can only do it with a subset of registers. 'r' causes compilation failures on i386, but 'q' expresses the constraint properly. Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Link: http://lkml.kernel.org/r/4F7A3315.501@goop.org Reported-by: Leigh Scott <leigh123linux@googlemail.com> Tested-by: Thomas Reitmayr <treitmayr@devbase.at> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22sparc64: Fix bootup crash on sun4v.David S. Miller
commit 9e0daff30fd7ecf698e5d20b0fa7f851e427cca5 upstream. The DS driver registers as a subsys_initcall() but this can be too early, in particular this risks registering before we've had a chance to allocate and setup module_kset in kernel/params.c which is performed also as a subsyts_initcall(). Register DS using device_initcall() insteal. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22sparc64: Eliminate obsolete __handle_softirq() functionPaul E. McKenney
commit 3d3eeb2ef26112a200785e5fca58ec58dd33bf1e upstream. The invocation of softirq is now handled by irq_exit(), so there is no need for sparc64 to invoke it on the trap-return path. In fact, doing so is a bug because if the trap occurred in the idle loop, this invocation can result in lockdep-RCU failures. The problem is that RCU ignores idle CPUs, and the sparc64 trap-return path to the softirq handlers fails to tell RCU that the CPU must be considered non-idle while those handlers are executing. This means that RCU is ignoring any RCU read-side critical sections in those handlers, which in turn means that RCU-protected data can be yanked out from under those read-side critical sections. The shiny new lockdep-RCU ability to detect RCU read-side critical sections that RCU is ignoring located this problem. The fix is straightforward: Make sparc64 stop manually invoking the softirq handlers. Reported-by: Meelis Roos <mroos@linux.ee> Suggested-by: David Miller <davem@davemloft.net> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22ia64: fix futex_atomic_cmpxchg_inatomic()Luck, Tony
commit c76f39bddb84f93f70a5520d9253ec0317bec216 upstream. Michel Lespinasse cleaned up the futex calling conventions in commit 37a9d912b24f ("futex: Sanitize cmpxchg_futex_value_locked API"). But the ia64 implementation was subtly broken. Gcc does not know that register "r8" will be updated by the fault handler if the cmpxchg instruction takes an exception. So it feels safe in letting the initialization of r8 slide to after the cmpxchg. Result: we always return 0 whether the user address faulted or not. Fix by moving the initialization of r8 into the __asm__ code so gcc won't move it. Reported-by: <emeric.maschino@gmail.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42757 Tested-by: <emeric.maschino@gmail.com> Acked-by: Michel Lespinasse <walken@google.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22ARM: 7384/1: ThumbEE: Disable userspace TEEHBR access for !CONFIG_ARM_THUMBEEJonathan Austin
commit 078c04545ba56da21567728a909a496df5ff730d upstream. Currently when ThumbEE is not enabled (!CONFIG_ARM_THUMBEE) the ThumbEE register states are not saved/restored at context switch. The default state of the ThumbEE Ctrl register (TEECR) allows userspace accesses to the ThumbEE Base Handler register (TEEHBR). This can cause unexpected behaviour when people use ThumbEE on !CONFIG_ARM_THUMBEE kernels, as well as allowing covert communication - eg between userspace tasks running inside chroot jails. This patch sets up TEECR in order to prevent user-space access to TEEHBR when !CONFIG_ARM_THUMBEE. In this case, tasks are sent SIGILL if they try to access TEEHBR. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-22ARM: 7379/1: DT: fix atags_to_fdt() second call siteMarc Zyngier
commit 9c5fd9e85f574d9d0361b2b878f55732290afe5b upstream. atags_to_fdt() returns 1 when it fails to find a valid FDT signature. The CONFIG_ARM_ATAG_DTB_COMPAT code is supposed to retry with another location, but only does so when the initial call doesn't fail. Fix this by using the correct condition in the assembly code. Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13sched/x86: Fix overflow in cyc2ns_offsetSalman Qazi
commit 9993bc635d01a6ee7f6b833b4ee65ce7c06350b1 upstream. When a machine boots up, the TSC generally gets reset. However, when kexec is used to boot into a kernel, the TSC value would be carried over from the previous kernel. The computation of cycns_offset in set_cyc2ns_scale is prone to an overflow, if the machine has been up more than 208 days prior to the kexec. The overflow happens when we multiply *scale, even though there is enough room to store the final answer. We fix this issue by decomposing tsc_now into the quotient and remainder of division by CYC2NS_SCALE_FACTOR and then performing the multiplication separately on the two components. Refactor code to share the calculation with the previous fix in __cycles_2_ns(). Signed-off-by: Salman Qazi <sqazi@google.com> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Turner <pjt@google.com> Cc: john stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20120310004027.19291.88460.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13Revert "x86/ioapic: Add register level checks to detect bogus io-apic entries"Greg Kroah-Hartman
This reverts commit a998dc2fa76f496d2944f0602b920d1d10d7467d [73d63d038ee9f769f5e5b46792d227fe20e442c5 upstream] It causes problems, so needs to be reverted from 3.2-stable for now. Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jon Dufresne <jon@jondufresne.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: <yinghai@kernel.org> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Teck Choon Giam <giamteckchoon@gmail.com> Cc: Ben Guthro <ben@guthro.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13ARM: at91/USB host: specify and handle properly vbus_pin_active_lowNicolas Ferre
commit cca0355a09b1bfe9f8985285199a346e13cacf39 upstream. Due to an error while handling vbus_pin_active_low in ohci-at91 driver, the specification of this property was not good in devices/board files. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13x86,kgdb: Fix DEBUG_RODATA limitation using text_poke()Jason Wessel
commit 3751d3e85cf693e10e2c47c03c8caa65e171099b upstream. There has long been a limitation using software breakpoints with a kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For this particular patch, it will apply cleanly and has been tested all the way back to 2.6.36. The kprobes code uses the text_poke() function which accommodates writing a breakpoint into a read-only page. The x86 kgdb code can solve the problem similarly by overriding the default breakpoint set/remove routines and using text_poke() directly. The x86 kgdb code will first attempt to use the traditional probe_kernel_write(), and next try using a the text_poke() function. The break point install method is tracked such that the correct break point removal routine will get called later on. Cc: x86@kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Inspried-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13m68k/mac: Add missing platform check before registering platform devicesGeert Uytterhoeven
commit 6cfeba53911d6d2f17ebbd1246893557d5ff5aeb upstream. On multi-platform kernels, the Mac platform devices should be registered when running on Mac only. Else it may crash later. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13x86 bpf_jit: fix a bug in emitting the 16-bit immediate operand of ANDFeiran Zhuang
[ Upstream commit 1d24fb3684f347226747c6b11ea426b7b992694e ] When K >= 0xFFFF0000, AND needs the two least significant bytes of K as its operand, but EMIT2() gives it the least significant byte of K and 0x2. EMIT() should be used here to replace EMIT2(). Signed-off-by: Feiran Zhuang <zhuangfeiran@ict.ac.cn> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02ARM: tegra: Fix device tree AUXDATA for USB/EHCIStephen Warren
commit 8c3ec84102d171a24f050a086bfc546e9de93f9f upstream. Commit 4a53f4e "USB: ehci-tegra: add probing through device tree" added AUXDATA for Tegra's USB/EHCI controller. However, it pointed the platform data at a location containing the address of the intended platform data, rather than the platform data itself. This change fixes that. Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86, tls: Off by one limit checkDan Carpenter
commit 8f0750f19789cf352d7e24a6cc50f2ab1b4f1372 upstream. These are used as offsets into an array of GDT_ENTRY_TLS_ENTRIES members so GDT_ENTRY_TLS_ENTRIES is one past the end of the array. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: http://lkml.kernel.org/r/20120324075250.GA28258@elgon.mountain Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86, tsc: Skip refined tsc calibration on systems with reliable TSCAlok Kataria
commit 57779dc2b3b75bee05ef5d1ada47f615f7a13932 upstream. While running the latest Linux as guest under VMware in highly over-committed situations, we have seen cases when the refined TSC algorithm fails to get a valid tsc_start value in tsc_refine_calibration_work from multiple attempts. As a result the kernel keeps on scheduling the tsc_irqwork task for later. Subsequently after several attempts when it gets a valid start value it goes through the refined calibration and either bails out or uses the new results. Given that the kernel originally read the TSC frequency from the platform, which is the best it can get, I don't think there is much value in refining it. So for systems which get the TSC frequency from the platform we should skip the refined tsc algorithm. We can use the TSC_RELIABLE cpu cap flag to detect this, right now it is set only on VMware and for Moorestown Penwell both of which have there own TSC calibration methods. Signed-off-by: Alok N Kataria <akataria@vmware.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Dirk Brandewie <dirk.brandewie@gmail.com> Cc: Alan Cox <alan@linux.intel.com> [jstultz: Reworked to simply not schedule the refining work, rather then scheduling the work and bombing out later] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02net: bpf_jit: fix BPF_S_LDX_B_MSH compilationEric Dumazet
[ Upstream commit dc72d99dabb870ca5bd6d9fff674be853bb4a88d ] Matt Evans spotted that x86 bpf_jit was incorrectly handling negative constant offsets in BPF_S_LDX_B_MSH instruction. We need to abort JIT compilation like we do in common_load so that filter uses the interpreter code and can call __load_pointer() Reference: http://lists.openwall.net/netdev/2011/07/19/11 Thanks to Indan Zupancic to bring back this issue. Reported-by: Matt Evans <matt@ozlabs.org> Reported-by: Indan Zupancic <indan@nul.nu> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02ARM: tegra: select required CPU and L2 errata optionsStephen Warren
commit f35b431dde39fb40944d1024f08d88fbf04a3193 upstream. The ARM IP revisions in Tegra are: Tegra20: CPU r1p1, PL310 r2p0 Tegra30: CPU A01=r2p7/>=A02=r2p9, NEON r2p3-50, PL310 r3p1-50 Based on work by Olof Johansson, although the actual list of errata is somewhat different here, since I added a bunch more and removed one PL310 erratum that doesn't seem applicable. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02PM / shmobile: Make TMU driver use pm_genpd_dev_always_on()Rafael J. Wysocki
Commit 2ee619f9487c2acc1efdf2c78e68e2bd51b635fa upstream. Make the TMU clocksource driver mark its device as "always on" using pm_genpd_dev_always_on() to protect it from surprise power removals and make sh7372_add_standard_devices() add TMU devices on sh7372 to the A4R power domain so that their "always on" flags are taken into account as appropriate. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Simon Horman <horms@verge.net.au> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86-32: Fix endless loop when processing signals for kernel tasksDmitry Adamushko
commit 29a2e2836ff9ea65a603c89df217f4198973a74f upstream. The problem occurs on !CONFIG_VM86 kernels [1] when a kernel-mode task returns from a system call with a pending signal. A real-life scenario is a child of 'khelper' returning from a failed kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ]. kernel_execve() fails due to a pending SIGKILL, which is the result of "kill -9 -1" (at least, busybox's init does it upon reboot). The loop is as follows: * syscall_exit_work: - work_pending: // start_of_the_loop - work_notify_sig: - do_notify_resume() - do_signal() - if (!user_mode(regs)) return; - resume_userspace // TIF_SIGPENDING is still set - work_pending // so we call work_pending => goto // start_of_the_loop More information can be found in another LKML thread: http://www.serverphorums.com/read.php?12,457826 [1] the problem was also seen on MIPS. Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Link: http://lkml.kernel.org/r/1332448765.2299.68.camel@dimm Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86-32: Fix typo for mq_getsetattr in syscall tableThierry Reding
commit 13354dc412c36fe554f9904a92f1268c74af7e87 upstream. Syscall 282 was mistakenly named mq_getsetaddr instead of mq_getsetattr. When building uClibc against the Linux kernel this would result in a shared library that doesn't provide the mq_getattr() and mq_setattr() functions. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Link: http://lkml.kernel.org/r/1332366608-2695-2-git-send-email-thierry.reding@avionic-design.de Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read modeAndrea Arcangeli
commit 1a5a9906d4e8d1976b701f889d8f35d54b928f25 upstream. In some cases it may happen that pmd_none_or_clear_bad() is called with the mmap_sem hold in read mode. In those cases the huge page faults can allocate hugepmds under pmd_none_or_clear_bad() and that can trigger a false positive from pmd_bad() that will not like to see a pmd materializing as trans huge. It's not khugepaged causing the problem, khugepaged holds the mmap_sem in write mode (and all those sites must hold the mmap_sem in read mode to prevent pagetables to go away from under them, during code review it seems vm86 mode on 32bit kernels requires that too unless it's restricted to 1 thread per process or UP builds). The race is only with the huge pagefaults that can convert a pmd_none() into a pmd_trans_huge(). Effectively all these pmd_none_or_clear_bad() sites running with mmap_sem in read mode are somewhat speculative with the page faults, and the result is always undefined when they run simultaneously. This is probably why it wasn't common to run into this. For example if the madvise(MADV_DONTNEED) runs zap_page_range() shortly before the page fault, the hugepage will not be zapped, if the page fault runs first it will be zapped. Altering pmd_bad() not to error out if it finds hugepmds won't be enough to fix this, because zap_pmd_range would then proceed to call zap_pte_range (which would be incorrect if the pmd become a pmd_trans_huge()). The simplest way to fix this is to read the pmd in the local stack (regardless of what we read, no need of actual CPU barriers, only compiler barrier needed), and be sure it is not changing under the code that computes its value. Even if the real pmd is changing under the value we hold on the stack, we don't care. If we actually end up in zap_pte_range it means the pmd was not none already and it was not huge, and it can't become huge from under us (khugepaged locking explained above). All we need is to enforce that there is no way anymore that in a code path like below, pmd_trans_huge can be false, but pmd_none_or_clear_bad can run into a hugepmd. The overhead of a barrier() is just a compiler tweak and should not be measurable (I only added it for THP builds). I don't exclude different compiler versions may have prevented the race too by caching the value of *pmd on the stack (that hasn't been verified, but it wouldn't be impossible considering pmd_none_or_clear_bad, pmd_bad, pmd_trans_huge, pmd_none are all inlines and there's no external function called in between pmd_trans_huge and pmd_none_or_clear_bad). if (pmd_trans_huge(*pmd)) { if (next-addr != HPAGE_PMD_SIZE) { VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem)); split_huge_page_pmd(vma->vm_mm, pmd); } else if (zap_huge_pmd(tlb, vma, pmd, addr)) continue; /* fall through */ } if (pmd_none_or_clear_bad(pmd)) Because this race condition could be exercised without special privileges this was reported in CVE-2012-1179. The race was identified and fully explained by Ulrich who debugged it. I'm quoting his accurate explanation below, for reference. ====== start quote ======= mapcount 0 page_mapcount 1 kernel BUG at mm/huge_memory.c:1384! At some point prior to the panic, a "bad pmd ..." message similar to the following is logged on the console: mm/memory.c:145: bad pmd ffff8800376e1f98(80000000314000e7). The "bad pmd ..." message is logged by pmd_clear_bad() before it clears the page's PMD table entry. 143 void pmd_clear_bad(pmd_t *pmd) 144 { -> 145 pmd_ERROR(*pmd); 146 pmd_clear(pmd); 147 } After the PMD table entry has been cleared, there is an inconsistency between the actual number of PMD table entries that are mapping the page and the page's map count (_mapcount field in struct page). When the page is subsequently reclaimed, __split_huge_page() detects this inconsistency. 1381 if (mapcount != page_mapcount(page)) 1382 printk(KERN_ERR "mapcount %d page_mapcount %d\n", 1383 mapcount, page_mapcount(page)); -> 1384 BUG_ON(mapcount != page_mapcount(page)); The root cause of the problem is a race of two threads in a multithreaded process. Thread B incurs a page fault on a virtual address that has never been accessed (PMD entry is zero) while Thread A is executing an madvise() system call on a virtual address within the same 2 MB (huge page) range. virtual address space .---------------------. | | | | .-|---------------------| | | | | | |<-- B(fault) | | | 2 MB | |/////////////////////|-. huge < |/////////////////////| > A(range) page | |/////////////////////|-' | | | | | | '-|---------------------| | | | | '---------------------' - Thread A is executing an madvise(..., MADV_DONTNEED) system call on the virtual address range "A(range)" shown in the picture. sys_madvise // Acquire the semaphore in shared mode. down_read(&current->mm->mmap_sem) ... madvise_vma switch (behavior) case MADV_DONTNEED: madvise_dontneed zap_page_range unmap_vmas unmap_page_range zap_pud_range zap_pmd_range // // Assume that this huge page has never been accessed. // I.e. content of the PMD entry is zero (not mapped). // if (pmd_trans_huge(*pmd)) { // We don't get here due to the above assumption. } // // Assume that Thread B incurred a page fault and .---------> // sneaks in here as shown below. | // | if (pmd_none_or_clear_bad(pmd)) | { | if (unlikely(pmd_bad(*pmd))) | pmd_clear_bad | { | pmd_ERROR | // Log "bad pmd ..." message here. | pmd_clear | // Clear the page's PMD entry. | // Thread B incremented the map count | // in page_add_new_anon_rmap(), but | // now the page is no longer mapped | // by a PMD entry (-> inconsistency). | } | } | v - Thread B is handling a page fault on virtual address "B(fault)" shown in the picture. ... do_page_fault __do_page_fault // Acquire the semaphore in shared mode. down_read_trylock(&mm->mmap_sem) ... handle_mm_fault if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) // We get here due to the above assumption (PMD entry is zero). do_huge_pmd_anonymous_page alloc_hugepage_vma // Allocate a new transparent huge page here. ... __do_huge_pmd_anonymous_page ... spin_lock(&mm->page_table_lock) ... page_add_new_anon_rmap // Here we increment the page's map count (starts at -1). atomic_set(&page->_mapcount, 0) set_pmd_at // Here we set the page's PMD entry which will be cleared // when Thread A calls pmd_clear_bad(). ... spin_unlock(&mm->page_table_lock) The mmap_sem does not prevent the race because both threads are acquiring it in shared mode (down_read). Thread B holds the page_table_lock while the page's map count and PMD table entry are updated. However, Thread A does not synchronize on that lock. ====== end quote ======= [akpm@linux-foundation.org: checkpatch fixes] Reported-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Jones <davej@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86/ioapic: Add register level checks to detect bogus io-apic entriesSuresh Siddha
commit 73d63d038ee9f769f5e5b46792d227fe20e442c5 upstream. With the recent changes to clear_IO_APIC_pin() which tries to clear remoteIRR bit explicitly, some of the users started to see "Unable to reset IRR for apic .." messages. Close look shows that these are related to bogus IO-APIC entries which return's all 1's for their io-apic registers. And the above mentioned error messages are benign. But kernel should have ignored such io-apic's in the first place. Check if register 0, 1, 2 of the listed io-apic are all 1's and ignore such io-apic. Reported-by: Álvaro Castillo <midgoon@gmail.com> Tested-by: Jon Dufresne <jon@jondufresne.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: yinghai@kernel.org Cc: kernel-team@fedoraproject.org Cc: Josh Boyer <jwboyer@redhat.com> Link: http://lkml.kernel.org/r/1331577393.31585.94.camel@sbsiddha-desk.sc.intel.com [ Performed minor cleanup of affected code. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-16Merge tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreamingLinus Torvalds
Pull c6x bugfix from Mark Salter: "Remove dead code from entry.S which causes a build failure when using a newer assembler (v2.22 complains about it, v2.20 ignores it)." * tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming: C6X: remove dead code from entry.S
2012-03-16C6X: remove dead code from entry.SMark Salter
The ENDPROC() on sys_fadvise64_c6x() in arch/c6x/kernel/entry.S is outside of the conditional block with the matching ENTRY() macro. This leads a newer (v2.22 vs. v2.20) assembler to complain: /tmp/ccGZBaPT.s: Assembler messages: /tmp/ccGZBaPT.s: Error: .size expression for sys_fadvise64_c6x does not evaluate to a constant The conditional block became dead code when c6x switched to generic unistd.h and should be removed along with the offending ENDPROC(). Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: David Howells <dhowells@redhat.com>
2012-03-14Merge branch 'stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile Pull arch/tile update to run "make minconfig" on the tile defconfigs from Chris Metcalf. This removes almost three thousand lines of inane defconfig chatter. * 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: arch/tile/configs: convert to minimal configs via "make savedefconfig"
2012-03-14arch/tile/configs: convert to minimal configs via "make savedefconfig"Chris Metcalf
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-03-13sparc32: Add -Av8 to assembler command line.David S. Miller
Newer version of binutils are more strict about specifying the correct options to enable certain classes of instructions. The sparc32 build is done for v7 in order to support sun4c systems which lack hardware integer multiply and divide instructions. So we have to pass -Av8 when building the assembler routines that use these instructions and get patched into the kernel when we find out that we have a v8 capable cpu. Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>