- 27 Nov, 2015 14 commits
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Gerald Schaefer authored
DMA addresses returned from map_page() are calculated by using an iommu bitmap plus a start_dma offset. The size of this bitmap is based on the main memory size. If we have more than (4 TB - start_dma) main memory, the DMA address calculation will also produce addresses > 4 TB. Such addresses cannot be inserted in the 3-level DMA page table, instead the entries modulo 4 TB will be overwritten. Fix this by restricting the iommu bitmap size to (4 TB - start_dma). Also set zdev->end_dma to the actual end address of the usable range, instead of the theoretical maximum as reported by the hardware, which fixes a sanity check in dma_map() and also the IOMMU API domain geometry aperture calculation. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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David Hildenbrand authored
Let's annotate it correctly, so we directly get a warning if we ever were to use it in atomic/preempt_disable/spinlock environment. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
The spinlock implementation calls the diagnose 0x9c / 0x44 immediately if the SIGP sense running reported the target CPU as not running. The diagnose 0x9c is a hint to the hypervisor to schedule the target CPU in preference to the source CPU that issued the diagnose. It can happen that on return from the diagnose the target CPU has not been scheduled yet, e.g. if the target logical CPU is on another physical CPU and the hypervisor did not want to migrate the logical CPU. Avoid the immediate repeat of the diagnose instruction, instead do the retry loop before the next invocation of diagnose 0x9c. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
Introduce save_area_alloc(), save_area_boot_cpu(), save_area_add_regs() and save_area_add_vxrs to deal with storing the CPU state in case of a system dump. Remove struct save_area and save_area_ext, and create a new struct save_area as a local definition to arch/s390/kernel/crash_dump.c. Copy each individual field from the hardware status area to the save area, storing the minimum of required data. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
To collect the CPU registers of the crashed system allocated a single page with memblock_alloc_base and use it as a copy buffer. Replace the stop-and-store-status sigp with a store-status-at-address sigp in smp_save_dump_cpus() and smp_store_status(). In both cases the target CPU is already stopped and store-status-at-address avoids the detour via the absolute zero page. For kexec simplify s390_reset_system and call store_status() before the prefix register of the boot CPU has been set to zero. Use STPX to store the prefix register and remove dump_prefix_page. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
Replace the SAVE_AREA_BASE offset calculations in reipl.S with the assembler constant for the location of each register status area. Use __LC_FPREGS_SAVE_AREA instead of SAVE_AREA_BASE in the three remaining code locations and remove the definition of SAVE_AREA_BASE. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
Replace the offsets based on the struct area_area with the offset constants from asm-offsets.c based on the struct _lowcore. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
Replace the three part copy logic int memcpy_hsa with a single loop around sclp_sdias_copy with appropriate offset and size calculations, and inline memcpy_hsa into memcpy_hsa_user and memcpy_hsa_kernel. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
Introduce two copy functions for the memory of the dumped system, copy_oldmem_kernel() to copy to the virtual kernel address space and copy_oldmem_user() to copy to user space. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
The s390 architecture can store the CPU registers of the crashed system after the kdump kernel has been started and this is the preferred way. Remove the remaining code fragments that deal with storing CPU registers while the crashed system is still active. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
New versions of the SCSI dumper use the /dev/vmcore interface instead of zcore mem. Remove the outdated interface. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
The /sys/kernel/debug/zcore/mem interface delivers the memory of the old system with the CPU registers stored to the assigned locations in each prefix page. For the vector registers the prefix page of each CPU has an address of a 1024 byte save area at 0x11b0. But the /sys/kernel/debug/zcore/mem interface fails copy the vector registers saved at boot of the zfcpdump kernel into the dump image. Copy the saved vector registers of a CPU to the outout buffer if the memory area that is read via /sys/kernel/debug/zcore/mem intersects with the vector register save area of this CPU. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
The extended save area for the boot CPU has been allocated by smp_save_dump_cpus() with memblock_alloc() and may not be freed with kfree(). Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Ingo Tuchscherer authored
When the AP queue depth of requests was reached additional requests have been ignored. These request are stuck in the request queue. The AP queue handling now push the next waiting request into the queue after fetching a previous serviced and finished reply. Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 25 Nov, 2015 5 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
Pull vfs fixes from Al Viro: "A couple of fixes for sendfile lockups caught by Dmitry + a fix for ancient sysvfs symlink breakage" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Avoid softlockups with sendfile(2) vfs: Make sendfile(2) killable even better fix sysvfs symlinks
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git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull more block layer fixes from Jens Axboe: "I wasn't going to send off a new pull before next week, but the blk flush fix from Jan from the other day introduced a regression. It's rare enough not to have hit during testing, since it requires both a device that rejects the first flush, and bad timing while it does that. But since someone did hit it, let's get the revert into 4.4-rc3 so we don't have a released rc with that known issue. Apart from that revert, three other fixes: - From Christoph, a fix for a missing unmap in NVMe request preparation. - An NVMe fix from Nishanth that fixes data corruption on powerpc. - Also from Christoph, fix a list_del() attempt on blk-mq that didn't have a matching list_add() at timer start" * 'for-linus' of git://git.kernel.dk/linux-block: Revert "blk-flush: Queue through IO scheduler when flush not required" block: fix blk_abort_request for blk-mq drivers nvme: add missing unmaps in nvme_queue_rq NVMe: default to 4k device page size
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Jens Axboe authored
This reverts commit 1b2ff19e. Jan writes: -- Thanks for report! After some investigation I found out we allocate elevator specific data in __get_request() only for non-flush requests. And this is actually required since the flush machinery uses the space in struct request for something else. Doh. So my patch is just wrong and not easy to fix since at the time __get_request() is called we are not sure whether the flush machinery will be used in the end. Jens, please revert 1b2ff19e. Thanks! I'm somewhat surprised that you can reliably hit the race where flushing gets disabled for the device just while the request is in flight. But I guess during boot it makes some sense. -- So let's just revert it, we can fix the queue run manually after the fact. This race is rare enough that it didn't trigger in testing, it requires the specific disable-while-in-flight scenario to trigger.
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull KVM fixes from Paolo Bonzini: "Bug fixes for all architectures. Nothing really stands out" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits) KVM: nVMX: remove incorrect vpid check in nested invvpid emulation arm64: kvm: report original PAR_EL1 upon panic arm64: kvm: avoid %p in __kvm_hyp_panic KVM: arm/arm64: vgic: Trust the LR state for HW IRQs KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active KVM: arm/arm64: Fix preemptible timer active state crazyness arm64: KVM: Add workaround for Cortex-A57 erratum 834220 arm64: KVM: Fix AArch32 to AArch64 register mapping ARM/arm64: KVM: test properly for a PTE's uncachedness KVM: s390: fix wrong lookup of VCPUs by array index KVM: s390: avoid memory overwrites on emergency signal injection KVM: Provide function for VCPU lookup by id KVM: s390: fix pfmf intercept handler KVM: s390: enable SIMD only when no VCPUs were created KVM: x86: request interrupt window when IRQ chip is split KVM: x86: set KVM_REQ_EVENT on local interrupt request from user space KVM: x86: split kvm_vcpu_ready_for_interrupt_injection out of dm_request_for_irq_injection KVM: x86: fix interrupt window handling in split IRQ chip case MIPS: KVM: Uninit VCPU in vcpu_create error path MIPS: KVM: Fix CACHE immediate offset sign extension ...
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Haozhong Zhang authored
This patch removes the vpid check when emulating nested invvpid instruction of type all-contexts invalidation. The existing code is incorrect because: (1) According to Intel SDM Vol 3, Section "INVVPID - Invalidate Translations Based on VPID", invvpid instruction does not check vpid in the invvpid descriptor when its type is all-contexts invalidation. (2) According to the same document, invvpid of type all-contexts invalidation does not require there is an active VMCS, so/and get_vmcs12() in the existing code may result in a NULL-pointer dereference. In practice, it can crash both KVM itself and L1 hypervisors that use invvpid (e.g. Xen). Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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- 24 Nov, 2015 21 commits
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Christoph Hellwig authored
We only added the request to the request list for the !blk-mq case, so we should only delete it in that case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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Christoph Hellwig authored
When we fail various metadata related operations in nvme_queue_rq we need to unmap the data SGL. Cc: stable@vger.kernel.org Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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Nishanth Aravamudan authored
We received a bug report recently when DDW (64-bit direct DMA on Power) is not enabled for NVMe devices. In that case, we fall back to 32-bit DMA via the IOMMU, which is always done via 4K TCEs (Translation Control Entries). The NVMe device driver, though, assumes that the DMA alignment for the PRP entries will match the device's page size, and that the DMA aligment matches the kernel's page aligment. On Power, the the IOMMU page size, as mentioned above, can be 4K, while the device can have a page size of 8K, while the kernel has a page size of 64K. This eventually trips the BUG_ON in nvme_setup_prps(), as we have a 'dma_len' that is a multiple of 4K but not 8K (e.g., 0xF000). In this particular case of page sizes, we clearly want to use the IOMMU's page size in the driver. And generally, the NVMe driver in this function should be using the IOMMU's page size for the default device page size, rather than the kernel's page size. There is not currently an API to obtain the IOMMU's page size across all architectures and in the interest of a stop-gap fix to this functional issue, default the NVMe device page size to 4K, with the intent of adding such an API and implementation across all architectures in the next merge window. With the functionally equivalent v3 of this patch, our hardware test exerciser survives when using 32-bit DMA; without the patch, the kernel will BUG within a few minutes. Signed-off-by: Nishanth Aravamudan <nacc at linux.vnet.ibm.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dmLinus Torvalds authored
Pull device mapper fixes from Mike Snitzer: "Two fixes for 4.4-rc1's DM ioctl changes that introduced the potential for infinite recursion on ioctl (with DM multipath). And four stable fixes: - A DM thin-provisioning fix to restore 'error_if_no_space' setting when a thin-pool is made writable again (after having been out of space). - A DM thin-provisioning fix to properly advertise discard support for thin volumes that are stacked on a thin-pool whose underlying data device doesn't support discards. - A DM ioctl fix to allow ctrl-c to break out of an ioctl retry loop when DM multipath is configured to 'queue_if_no_path'. - A DM crypt fix for a possible hang on dm-crypt device removal" * tag 'dm-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm thin: fix regression in advertised discard limits dm crypt: fix a possible hang due to race condition on exit dm mpath: fix infinite recursion in ioctl when no paths and !queue_if_no_path dm: do not reuse dm_blk_ioctl block_device input as local variable dm: fix ioctl retry termination with signal dm thin: restore requested 'error_if_no_space' setting on OODS to WRITE transition
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Eric Dumazet authored
I got a crash during a "perf top" session that was caused by a race in __task_pid_nr_ns() : pid_nr_ns() was inlined, but apparently compiler chose to read task->pids[type].pid twice, and the pid->level dereference crashed because we got a NULL pointer at the second read : if (pid && ns->level <= pid->level) { // CRASH Just use RCU API properly to solve this race, and not worry about "perf top" crashing hosts :( get_task_pid() can benefit from same fix. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Paolo Bonzini authored
Merge tag 'kvm-arm-for-v4.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/ARM Fixes for v4.4-rc3. Includes some timer fixes, properly unmapping PTEs, an errata fix, and two tweaks to the EL2 panic code.
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git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull block layer fixes from Jens Axboe: "A round of fixes/updates for the current series. This looks a little bigger than it is, but that's mainly because we pushed the lightnvm enabled null_blk change out of the merge window so it could be updated a bit. The rest of the volume is also mostly lightnvm. In particular: - Lightnvm. Various fixes, additions, updates from Matias and Javier, as well as from Wenwei Tao. - NVMe: - Fix for potential arithmetic overflow from Keith. - Also from Keith, ensure that we reap pending completions from a completion queue before deleting it. Fixes kernel crashes when resetting a device with IO pending. - Various little lightnvm related tweaks from Matias. - Fixup flushes to go through the IO scheduler, for the cases where a flush is not required. Fixes a case in CFQ where we would be idling and not see this request, hence not break the idling. From Jan Kara. - Use list_{first,prev,next} in elevator.c for cleaner code. From Gelian Tang. - Fix for a warning trigger on btrfs and raid on single queue blk-mq devices, where we would flush plug callbacks with preemption disabled. From me. - A mac partition validation fix from Kees Cook. - Two merge fixes from Ming, marked stable. A third part is adding a new warning so we'll notice this quicker in the future, if we screw up the accounting. - Cleanup of thread name/creation in mtip32xx from Rasmus Villemoes" * 'for-linus' of git://git.kernel.dk/linux-block: (32 commits) blk-merge: warn if figured out segment number is bigger than nr_phys_segments blk-merge: fix blk_bio_segment_split block: fix segment split blk-mq: fix calling unplug callbacks with preempt disabled mac: validate mac_partition is within sector mtip32xx: use formatting capability of kthread_create_on_node NVMe: reap completion entries when deleting queue lightnvm: add free and bad lun info to show luns lightnvm: keep track of block counts nvme: lightnvm: use admin queues for admin cmds lightnvm: missing free on init error lightnvm: wrong return value and redundant free null_blk: do not del gendisk with lightnvm null_blk: use device addressing mode null_blk: use ppa_cache pool NVMe: Fix possible arithmetic overflow for max segments blk-flush: Queue through IO scheduler when flush not required null_blk: register as a LightNVM device elevator: use list_{first,prev,next}_entry lightnvm: cleanup queue before target removal ...
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Mark Rutland authored
If we call __kvm_hyp_panic while a guest context is active, we call __restore_sysregs before acquiring the system register values for the panic, in the process throwing away the PAR_EL1 value at the point of the panic. This patch modifies __kvm_hyp_panic to stash the PAR_EL1 value prior to restoring host register values, enabling us to report the original values at the point of the panic. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Mark Rutland authored
Currently __kvm_hyp_panic uses %p for values which are not pointers, such as the ESR value. This can confusingly lead to "(null)" being printed for the value. Use %x instead, and only use %p for host pointers. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Christoffer Dall authored
We were probing the physial distributor state for the active state of a HW virtual IRQ, because we had seen evidence that the LR state was not cleared when the guest deactivated a virtual interrupted. However, this issue turned out to be a software bug in the GIC, which was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29 (KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active, 2015-11-24) Therefore, get rid of the complexities and just look at the LR. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Christoffer Dall authored
We were incorrectly removing the active state from the physical distributor on the timer interrupt when the timer output level was deasserted. We shouldn't be doing this without considering the virtual interrupt's active state, because the architecture requires that when an LR has the HW bit set and the pending or active bits set, then the physical interrupt must also have the corresponding bits set. This addresses an issue where we have been observing an inconsistency between the LR state and the physical distributor state where the LR state was active and the physical distributor was not active, which shouldn't happen. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Christoffer Dall authored
We were setting the physical active state on the GIC distributor in a preemptible section, which could cause us to set the active state on different physical CPU from the one we were actually going to run on, hacoc ensues. Since we are no longer descheduling/scheduling soft timers in the flush/sync timer functions, simply moving the timer flush into a non-preemptible section. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Marc Zyngier authored
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults when a Stage 1 permission fault or device alignment fault should have been reported. This patch implements the workaround (which is to validate that the Stage-1 translation actually succeeds) by using code patching. Cc: stable@vger.kernel.org Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Marc Zyngier authored
When running a 32bit guest under a 64bit hypervisor, the ARMv8 architecture defines a mapping of the 32bit registers in the 64bit space. This includes banked registers that are being demultiplexed over the 64bit ones. On exceptions caused by an operation involving a 32bit register, the HW exposes the register number in the ESR_EL2 register. It was so far understood that SW had to distinguish between AArch32 and AArch64 accesses (based on the current AArch32 mode and register number). It turns out that I misinterpreted the ARM ARM, and the clue is in D1.20.1: "For some exceptions, the exception syndrome given in the ESR_ELx identifies one or more register numbers from the issued instruction that generated the exception. Where the exception is taken from an Exception level using AArch32 these register numbers give the AArch64 view of the register." Which means that the HW is already giving us the translated version, and that we shouldn't try to interpret it at all (for example, doing an MMIO operation from the IRQ mode using the LR register leads to very unexpected behaviours). The fix is thus not to perform a call to vcpu_reg32() at all from vcpu_reg(), and use whatever register number is supplied directly. The only case we need to find out about the mapping is when we actively generate a register access, which only occurs when injecting a fault in a guest. Cc: stable@vger.kernel.org Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Ard Biesheuvel authored
The open coded tests for checking whether a PTE maps a page as uncached use a flawed '(pte_val(xxx) & CONST) != CONST' pattern, which is not guaranteed to work since the type of a mapping is not a set of mutually exclusive bits For HYP mappings, the type is an index into the MAIR table (i.e, the index itself does not contain any information whatsoever about the type of the mapping), and for stage-2 mappings it is a bit field where normal memory and device types are defined as follows: #define MT_S2_NORMAL 0xf #define MT_S2_DEVICE_nGnRE 0x1 I.e., masking *and* comparing with the latter matches on the former, and we have been getting lucky merely because the S2 device mappings also have the PTE_UXN bit set, or we would misidentify memory mappings as device mappings. Since the unmap_range() code path (which contains one instance of the flawed test) is used both for HYP mappings and stage-2 mappings, and considering the difference between the two, it is non-trivial to fix this by rewriting the tests in place, as it would involve passing down the type of mapping through all the functions. However, since HYP mappings and stage-2 mappings both deal with host physical addresses, we can simply check whether the mapping is backed by memory that is managed by the host kernel, and only perform the D-cache maintenance if this is the case. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Pavel Fedin <p.fedin@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Ming Lei authored
We had seen lots of reports of this kind issue, so add one warnning in blk-merge, then it can be triggered easily and avoid to depend on warning/bug from drivers. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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Ming Lei authored
Commit bdced438(block: setup bi_phys_segments after splitting) introduces function of computing bio->bi_phys_segments during bio splitting. Unfortunately both bio->bi_seg_front_size and bio->bi_seg_back_size arn't computed, so too many physical segments may be obtained for one request since both the two are used to check if one segment across two bios can be possible. This patch fixes the issue by computing the two variables in blk_bio_segment_split(). Fixes: bdced438(block: setup bi_phys_segments after splitting) Reported-by: Michael Ellerman <mpe@ellerman.id.au> Reported-by: Mark Salter <msalter@redhat.com> Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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Ming Lei authored
Inside blk_bio_segment_split(), previous bvec pointer(bvprvp) always points to the iterator local variable, which is obviously wrong, so fix it by pointing to the local variable of 'bvprv'. Fixes: 5014c311(block: fix bogus compiler warnings in blk-merge.c) Cc: stable@kernel.org #4.3 Reported-by: Michael Ellerman <mpe@ellerman.id.au> Reported-by: Mark Salter <msalter@redhat.com> Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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Jan Kara authored
The following test program from Dmitry can cause softlockups or RCU stalls as it copies 1GB from tmpfs into eventfd and we don't have any scheduling point at that path in sendfile(2) implementation: int r1 = eventfd(0, 0); int r2 = memfd_create("", 0); unsigned long n = 1<<30; fallocate(r2, 0, 0, n); sendfile(r1, r2, 0, n); Add cond_resched() into __splice_from_pipe() to fix the problem. CC: Dmitry Vyukov <dvyukov@google.com> CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Jan Kara authored
Commit 296291cd (mm: make sendfile(2) killable) fixed an issue where sendfile(2) was doing a lot of tiny writes into a filesystem and thus was unkillable for a long time. However sendfile(2) can be (mis)used to issue lots of writes into arbitrary file descriptor such as evenfd or similar special file descriptors which never hit the standard filesystem write path and thus are still unkillable. E.g. the following example from Dmitry burns CPU for ~16s on my test system without possibility to be killed: int r1 = eventfd(0, 0); int r2 = memfd_create("", 0); unsigned long n = 1<<30; fallocate(r2, 0, 0, n); sendfile(r1, r2, 0, n); There are actually quite a few tests for pending signals in sendfile code however we data to write is always available none of them seems to trigger. So fix the problem by adding a test for pending signal into splice_from_pipe_next() also before the loop waiting for pipe buffers to be available. This should fix all the lockup issues with sendfile of the do-ton-of-tiny-writes nature. CC: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
The thing got broken back in 2002 - sysvfs does *not* have inline symlinks; even short ones have bodies stored in the first block of file. sysv_symlink() handles that correctly; unfortunately, attempting to look an existing symlink up will end up confusing them for inline symlinks, and interpret the block number containing the body as the body itself. Nobody has noticed until now, which says something about the level of testing sysvfs gets ;-/ Cc: stable@vger.kernel.org # all of them, not that anyone cared Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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