- 20 Aug, 2015 18 commits
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Juergen Gross authored
Some special pages containing interfaces to xen are being reserved implicitly only today. The memblock_reserve() call to reserve them is meant to reserve the p2m list supplied by xen. It is just reserving not only the p2m list itself, but some more pages up to the start of the xen built page tables. To be able to move the p2m list to another pfn range, which is needed for support of huge RAM, this memblock_reserve() must be split up to cover all affected reserved pages explicitly. The affected pages are: - start_info page - xenstore ring (might be missing, mfn is 0 in this case) - console ring (not for initial domain) Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
During early boot as Xen pv domain the kernel needs to map some page tables supplied by the hypervisor read only. This is needed to be able to relocate some data structures conflicting with the physical memory map especially on systems with huge RAM (above 512GB). Provide the function early_memremap_ro() to provide this read only mapping. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Check whether the initrd is placed at a location which is conflicting with the target E820 map. If this is the case relocate it to a new area unused up to now and compliant to the E820 map. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Check whether the page tables built by the domain builder are at memory addresses which are in conflict with the target memory map. If this is the case just panic instead of running into problems later. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Checks whether the pre-allocated memory of the loaded kernel is in conflict with the target memory map. If this is the case, just panic instead of run into problems later, as there is nothing we can do to repair this situation. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
For being able to relocate pre-allocated data areas like initrd or p2m list it is mandatory to find a contiguous memory area which is not yet in use and doesn't conflict with the memory map we want to be in effect. In case such an area is found reserve it at once as this will be required to be done in any case. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Provide a service routine to check a physical memory area against the E820 map. The routine will return false if the complete area is RAM according to the E820 map and true otherwise. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Memory pages in the initial memory setup done by the Xen hypervisor conflicting with the target E820 map are remapped. In order to do this those pages are counted and remapped in xen_set_identity_and_remap(). Split the counting from the remapping operation to be able to setup the needed memory sizes in time but doing the remap operation at a later time. This enables us to simplify the interface to xen_set_identity_and_remap() as the number of remapped and released pages is no longer needed here. Finally move the remapping further down to prepare relocating conflicting memory contents before the memory might be clobbered by xen_set_identity_and_remap(). This requires to not destroy the Xen E820 map when the one for the system is being constructed. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Instead of using a function local static e820 map in xen_memory_setup() and calling various functions in the same source with the map as a parameter use a map directly accessible by all functions in the source. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Direct Xen to place the initial P->M table outside of the initial mapping, as otherwise the 1G (implementation) / 2G (theoretical) restriction on the size of the initial mapping limits the amount of memory a domain can be handed initially. As the initial P->M table is copied rather early during boot to domain private memory and it's initial virtual mapping is dropped, the easiest way to avoid virtual address conflicts with other addresses in the kernel is to use a user address area for the virtual address of the initial P->M table. This allows us to just throw away the page tables of the initial mapping after the copy without having to care about address invalidation. It should be noted that this patch won't enable a pv-domain to USE more than 512 GB of RAM. It just enables it to be started with a P->M table covering more memory. This is especially important for being able to boot a Dom0 on a system with more than 512 GB memory. Signed-off-by: Juergen Gross <jgross@suse.com> Based-on-patch-by: Jan Beulich <jbeulich@suse.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
In case the Xen tools indicate they don't need the p2m 3 level tree as they support the virtual mapped linear p2m list, just omit building the tree. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
The virtual address of the linear p2m list should be stored in the shared info structure read by the Xen tools to be able to support 64 bit pv-domains larger than 512 GB. Additionally the linear p2m list interface includes a generation count which is changed prior to and after each mapping change of the p2m list. Reading the generation count the Xen tools can detect changes of the mappings and re-read the p2m list eventually. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Juergen Gross authored
Use the newest headers from the xen tree to get some new structure layouts. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Julien Grall authored
The commit 6f6c15ef "xen/pvhvm: Remove the xen_platform_pci int." makes the x86 version of xen_pci_platform_unplug static. Therefore we don't need anymore to define a dummy xen_pci_platform_unplug for ARM. Signed-off-by: Julien Grall <julien.grall@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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Julien Grall authored
Currently, the event channel rebind code is gated with the presence of the vector callback. The virtual interrupt controller on ARM has the concept of per-CPU interrupt (PPI) which allow us to support per-VCPU event channel. Therefore there is no need of vector callback for ARM. Xen is already using a free PPI to notify the guest VCPU of an event. Furthermore, the xen code initialization in Linux (see arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ. Introduce new helper xen_support_evtchn_rebind to allow architecture decide whether rebind an event is support or not. It will always return true on ARM and keep the same behavior on x86. This is also allow us to drop the usage of xen_have_vector_callback entirely in the ARM code. Signed-off-by: Julien Grall <julien.grall@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Bob Liu authored
Note: This patch is based on original work of Arianna's internship for GNOME's Outreach Program for Women. Only one hardware queue is used now, so there is no significant performance change The legacy non-mq code is deleted completely which is the same as other drivers like virtio, mtip, and nvme. Also dropped one unnecessary holding of info->io_lock when calling blk_mq_stop_hw_queues(). Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jens Axboe <axboe@fb.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Konstantin Khlebnikov authored
This code is used only when CONFIG_PREEMPT=n and only in non-atomic context: xen_in_preemptible_hcall is set only in privcmd_ioctl_hypercall(). Thus preempt_count is zero and should_resched() is equal to need_resched(). Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Colin Ian King authored
xen_has_pv_devices() has no parameters, so use the normal void parameter convention to make it match the prototype in the header file include/xen/platform_pci.h. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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- 16 Aug, 2015 8 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-socLinus Torvalds authored
Pull ARM SoC fixes from Olof Johansson: "A smallish batch of fixes, a little more than expected this late, but all fixes are contained to their platforms and seem reasonably low risk: - a somewhat large SMP fix for ux500 that still seemed warranted to include here - OMAP DT fixes for pbias regulator specification that broke due to some DT reshuffling - PCIe IRQ routing bugfix for i.MX - networking fixes for keystone - runtime PM for OMAP GPMC - a couple of error path bug fixes for exynos" * tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file ARM: dts: keystone: fix the clock node for mdio memory: omap-gpmc: Don't try to save uninitialized GPMC context ARM: imx6: correct i.MX6 PCIe interrupt routing ARM: ux500: add an SMP enablement type and move cpu nodes ARM: dts: dra7: Fix broken pbias device creation ARM: dts: OMAP5: Fix broken pbias device creation ARM: dts: OMAP4: Fix broken pbias device creation ARM: dts: omap243x: Fix broken pbias device creation ARM: EXYNOS: fix double of_node_put() on error path ARM: EXYNOS: Fix potentian kfree() of ro memory
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git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds authored
Pull MIPS bugfix from Ralf Baechle: "Only a single MIPS fix - the math when invoking syscall_trace_enter was wrong" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: Fix seccomp syscall argument for MIPS64
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Merge x86 fixes from Ingo Molnar: "Two followup fixes related to the previous LDT fix" Also applied a further FPU emulation fix from Andy Lutomirski to the branch before actually merging it. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip x86/ldt: Further fix FPU emulation x86/ldt: Correct FPU emulation access to LDT x86/ldt: Correct LDT access in single stepping logic
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Andy Lutomirski authored
The previous fix confused a selector with a segment prefix. Fix it. Compile-tested only. Cc: stable@vger.kernel.org Cc: Juergen Gross <jgross@suse.com> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Fixes: 4809146b ("x86/ldt: Correct FPU emulation access to LDT") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jann Horn authored
fuse_dev_ioctl() performed fuse_get_dev() on a user-supplied fd, leading to a type confusion issue. Fix it by checking file->f_op. Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Olof Johansson authored
Merge tag 'keystone-dts-late-fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone into fixes ARM: Couple of Keysyone MDIO DTS fixes for 4.2-rc6+ These are necessary to get the NIC card working on all Keystone EVMs. Couple of boards are broken without these two fixes. * tag 'keystone-dts-late-fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone: ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file ARM: dts: keystone: fix the clock node for mdio Signed-off-by: Olof Johansson <olof@lixom.net>
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Markos Chandras authored
Commit 4c21b8fd ("MIPS: seccomp: Handle indirect system calls (o32)") fixed indirect system calls on O32 but it also introduced a bug for MIPS64 where it erroneously modified the v0 (syscall) register with the assumption that the sycall offset hasn't been taken into consideration. This breaks seccomp on MIPS64 n64 and n32 ABIs. We fix this by replacing the addition with a move instruction. Fixes: 4c21b8fd ("MIPS: seccomp: Handle indirect system calls (o32)") Cc: <stable@vger.kernel.org> # 3.15+ Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10951/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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- 15 Aug, 2015 3 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "This has two libfc fixes for bugs causing rare crashes, one iscsi fix for a potential hang on shutdown, and a fix for an I/O blocksize issue which caused a regression" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: sd: Fix maximum I/O size for BLOCK_PC requests libfc: Fix fc_fcp_cleanup_each_cmd() libfc: Fix fc_exch_recv_req() error path libiscsi: Fix host busy blocking during connection teardown
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull KVM fixes from Paolo Bonzini: "Just two very small & simple patches" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Use adjustment in guest cycles when handling MSR_IA32_TSC_ADJUST KVM: x86: zero IDT limit on entry to SMM
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Linus Torvalds authored
Merge fixes from Andrew Morton: "11 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: Update maintainers for DRM STI driver mm: cma: mark cma_bitmap_maxno() inline in header zram: fix pool name truncation memory-hotplug: fix wrong edge when hot add a new node .mailmap: Andrey Ryabinin has moved ipc/sem.c: update/correct memory barriers mm/hwpoison: fix panic due to split huge zero page ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem() ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held mm/hwpoison: fix page refcount of unknown non LRU page
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- 14 Aug, 2015 11 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/clk/linuxLinus Torvalds authored
Pull clock fix from Stephen Boyd: "A one-liner for a regression found in the PXA clock driver" * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: clk: pxa: pxa3xx: fix CKEN register access
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Benjamin Gaignard authored
Add Vincent Abriou and myself as maintainers. Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Cc: Vincent Abriou <vincent.abriou@st.com> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Gregory Fong authored
cma_bitmap_maxno() was marked as static and not static inline, which can cause warnings about this function not being used if this file is included in a file that does not call that function, and violates the conventions used elsewhere. The two options are to move the function implementation back to mm/cma.c or make it inline here, and it's simple enough for the latter to make sense. Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Sergey Senozhatsky authored
zram_meta_alloc() constructs a pool name for zs_create_pool() call as snprintf(pool_name, sizeof(pool_name), "zram%d", device_id); However, it defines pool name buffer to be only 8 bytes long (minus trailing zero), which means that we can have only 1000 pool names: zram0 -- zram999. With CONFIG_ZSMALLOC_STAT enabled an attempt to create a device zram1000 can fail if device zram100 already exists, because snprintf() will truncate new pool name to zram100 and pass it debugfs_create_dir(), causing: debugfs dir <zram100> creation failed zram: Error creating memory pool ... and so on. Fix it by passing zram->disk->disk_name to zram_meta_alloc() instead of divice_id. We construct zram%d name earlier and keep it as a ->disk_name, no need to snprintf() it again. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Xishi Qiu authored
When we add a new node, the edge of memory may be wrong. e.g. system has 4 nodes, and node3 is movable, node3 mem:[24G-32G], 1. hotremove the node3, 2. then hotadd node3 with a part of memory, mem:[26G-30G], 3. call hotadd_new_pgdat() free_area_init_node() get_pfn_range_for_nid() 4. it will return wrong start_pfn and end_pfn, because we have not update the memblock. This patch also fixes a BUG_ON during hot-addition, please see http://marc.info/?l=linux-kernel&m=142961156129456&w=2Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andrey Ryabinin authored
Update my email address. Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Manfred Spraul authored
sem_lock() did not properly pair memory barriers: !spin_is_locked() and spin_unlock_wait() are both only control barriers. The code needs an acquire barrier, otherwise the cpu might perform read operations before the lock test. As no primitive exists inside <include/spinlock.h> and since it seems noone wants another primitive, the code creates a local primitive within ipc/sem.c. With regards to -stable: The change of sem_wait_array() is a bugfix, the change to sem_lock() is a nop (just a preprocessor redefinition to improve the readability). The bugfix is necessary for all kernels that use sem_wait_array() (i.e.: starting from 3.10). Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Wanpeng Li authored
Bug: ------------[ cut here ]------------ kernel BUG at mm/huge_memory.c:1957! invalid opcode: 0000 [#1] SMP Modules linked in: snd_hda_codec_hdmi i915 rpcsec_gss_krb5 snd_hda_codec_realtek snd_hda_codec_generic nfsv4 dns_re CPU: 2 PID: 2576 Comm: test_huge Not tainted 4.2.0-rc5-mm1+ #27 Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015 task: ffff880204e3d600 ti: ffff8800db16c000 task.ti: ffff8800db16c000 RIP: split_huge_page_to_list+0xdb/0x120 Call Trace: memory_failure+0x32e/0x7c0 madvise_hwpoison+0x8b/0x160 SyS_madvise+0x40/0x240 ? do_page_fault+0x37/0x90 entry_SYSCALL_64_fastpath+0x12/0x71 Code: ff f0 41 ff 4c 24 30 74 0d 31 c0 48 83 c4 08 5b 41 5c 41 5d c9 c3 4c 89 e7 e8 e2 58 fd ff 48 83 c4 08 31 c0 RIP split_huge_page_to_list+0xdb/0x120 RSP <ffff8800db16fde8> ---[ end trace aee7ce0df8e44076 ]--- Testcase: #define _GNU_SOURCE #include <stdlib.h> #include <stdio.h> #include <sys/mman.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <errno.h> #include <string.h> #define MB 1024*1024 int main(void) { char *mem; posix_memalign((void **)&mem, 2 * MB, 200 * MB); madvise(mem, 200 * MB, MADV_HWPOISON); free(mem); return 0; } Huge zero page is allocated if page fault w/o FAULT_FLAG_WRITE flag. The get_user_pages_fast() which called in madvise_hwpoison() will get huge zero page if the page is not allocated before. Huge zero page is a tranparent huge page, however, it is not an anonymous page. memory_failure will split the huge zero page and trigger BUG_ON(is_huge_zero_page(page)); After commit 98ed2b00 ("mm/memory-failure: give up error handling for non-tail-refcounted thp"), memory_failure will not catch non anon thp from madvise_hwpoison path and this bug occur. Fix it by catching non anon thp in memory_failure in order to not split huge zero page in madvise_hwpoison path. After this patch: Injecting memory failure for page 0x202800 at 0x7fd8ae800000 MCE: 0x202800: non anonymous thp [...] [akpm@linux-foundation.org: remove second split, per Wanpeng] Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Herton R. Krzesinski authored
After we acquire the sma->sem_perm lock in exit_sem(), we are protected against a racing IPC_RMID operation. Also at that point, we are the last user of sem_undo_list. Therefore it isn't required that we acquire or use ulp->lock. Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Acked-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Rafael Aquini <aquini@redhat.com> CC: Aristeu Rozanski <aris@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Herton R. Krzesinski authored
The current semaphore code allows a potential use after free: in exit_sem we may free the task's sem_undo_list while there is still another task looping through the same semaphore set and cleaning the sem_undo list at freeary function (the task called IPC_RMID for the same semaphore set). For example, with a test program [1] running which keeps forking a lot of processes (which then do a semop call with SEM_UNDO flag), and with the parent right after removing the semaphore set with IPC_RMID, and a kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and CONFIG_DEBUG_SPINLOCK, you can easily see something like the following in the kernel log: Slab corruption (Not tainted): kmalloc-64 start=ffff88003b45c1c0, len=64 000: 6b 6b 6b 6b 6b 6b 6b 6b 00 6b 6b 6b 6b 6b 6b 6b kkkkkkkk.kkkkkkk 010: ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ Prev obj: start=ffff88003b45c180, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff c0 fb 01 37 00 88 ff ff ...........7.... Next obj: start=ffff88003b45c200, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff 68 29 a7 3c 00 88 ff ff ........h).<.... BUG: spinlock wrong CPU on CPU#2, test/18028 general protection fault: 0000 [#1] SMP Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 2 PID: 18028 Comm: test Not tainted 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: spin_dump+0x53/0xc0 Call Trace: spin_bug+0x30/0x40 do_raw_spin_unlock+0x71/0xa0 _raw_spin_unlock+0xe/0x10 freeary+0x82/0x2a0 ? _raw_spin_lock+0xe/0x10 semctl_down.clone.0+0xce/0x160 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 SyS_semctl+0x236/0x2c0 ? syscall_trace_leave+0xde/0x130 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 8b 80 88 03 00 00 48 8d 88 60 05 00 00 48 c7 c7 a0 2c a4 81 31 c0 65 8b 15 eb 40 f3 7e e8 08 31 68 00 4d 85 e4 44 8b 4b 08 74 5e <45> 8b 84 24 88 03 00 00 49 8d 8c 24 60 05 00 00 8b 53 04 48 89 RIP [<ffffffff810d6053>] spin_dump+0x53/0xc0 RSP <ffff88003750fd68> ---[ end trace 783ebb76612867a0 ]--- NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [test:18053] Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 3 PID: 18053 Comm: test Tainted: G D 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: native_read_tsc+0x0/0x20 Call Trace: ? delay_tsc+0x40/0x70 __delay+0xf/0x20 do_raw_spin_lock+0x96/0x140 _raw_spin_lock+0xe/0x10 sem_lock_and_putref+0x11/0x70 SYSC_semtimedop+0x7bf/0x960 ? handle_mm_fault+0xbf6/0x1880 ? dequeue_task_fair+0x79/0x4a0 ? __do_page_fault+0x19a/0x430 ? kfree_debugcheck+0x16/0x40 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 ? do_audit_syscall_entry+0x66/0x70 ? syscall_trace_enter_phase1+0x139/0x160 SyS_semtimedop+0xe/0x10 SyS_semop+0x10/0x20 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 47 10 83 e8 01 85 c0 89 47 10 75 08 65 48 89 3d 1f 74 ff 7e c9 c3 0f 1f 44 00 00 55 48 89 e5 e8 87 17 04 00 66 90 c9 c3 0f 1f 00 <55> 48 89 e5 0f 31 89 c1 48 89 d0 48 c1 e0 20 89 c9 48 09 c8 c9 Kernel panic - not syncing: softlockup: hung tasks I wasn't able to trigger any badness on a recent kernel without the proper config debugs enabled, however I have softlockup reports on some kernel versions, in the semaphore code, which are similar as above (the scenario is seen on some servers running IBM DB2 which uses semaphore syscalls). The patch here fixes the race against freeary, by acquiring or waiting on the sem_undo_list lock as necessary (exit_sem can race with freeary, while freeary sets un->semid to -1 and removes the same sem_undo from list_proc or when it removes the last sem_undo). After the patch I'm unable to reproduce the problem using the test case [1]. [1] Test case used below: #include <stdio.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h> #include <sys/wait.h> #include <stdlib.h> #include <time.h> #include <unistd.h> #include <errno.h> #define NSEM 1 #define NSET 5 int sid[NSET]; void thread() { struct sembuf op; int s; uid_t pid = getuid(); s = rand() % NSET; op.sem_num = pid % NSEM; op.sem_op = 1; op.sem_flg = SEM_UNDO; semop(sid[s], &op, 1); exit(EXIT_SUCCESS); } void create_set() { int i, j; pid_t p; union { int val; struct semid_ds *buf; unsigned short int *array; struct seminfo *__buf; } un; /* Create and initialize semaphore set */ for (i = 0; i < NSET; i++) { sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT); if (sid[i] < 0) { perror("semget"); exit(EXIT_FAILURE); } } un.val = 0; for (i = 0; i < NSET; i++) { for (j = 0; j < NSEM; j++) { if (semctl(sid[i], j, SETVAL, un) < 0) perror("semctl"); } } /* Launch threads that operate on semaphore set */ for (i = 0; i < NSEM * NSET * NSET; i++) { p = fork(); if (p < 0) perror("fork"); if (p == 0) thread(); } /* Free semaphore set */ for (i = 0; i < NSET; i++) { if (semctl(sid[i], NSEM, IPC_RMID)) perror("IPC_RMID"); } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } int main(int argc, char **argv) { pid_t p; srand(time(NULL)); while (1) { p = fork(); if (p < 0) { perror("fork"); exit(EXIT_FAILURE); } if (p == 0) { create_set(); goto end; } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } end: return 0; } [akpm@linux-foundation.org: use normal comment layout] Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Acked-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Rafael Aquini <aquini@redhat.com> CC: Aristeu Rozanski <aris@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Wanpeng Li authored
Hugetlbfs pages will get a refcount in get_any_page() or madvise_hwpoison() if soft offlining through madvise. The refcount which is held by the soft offline path should be released if we fail to isolate hugetlbfs pages. Fix it by reducing the refcount for both isolation success and failure. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: <stable@vger.kernel.org> [3.9+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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