- 17 Nov, 2020 7 commits
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Sean Christopherson authored
Kernel support for SGX is ultimately decided by the state of the launch control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the hardware supports SGX, but neglects to support flexible launch control, the kernel will not enable SGX. Enable SGX at feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all derivatives) if the kernel is not able to establish itself as the authority over SGX Launch Control. All checks are performed for each logical CPU (not just boot CPU) in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. All SGX code in this series expects the same configuration from all CPUs. This differs from VMX where X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load like which CPU doesn't support VMX. There’s not much the kernel or an administrator can do to fix the situation, so SGX neglects to convey additional details about these kinds of failures if they occur. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
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Sean Christopherson authored
The x86 architecture has a set of page fault error codes. These indicate things like whether the fault occurred from a write, or whether it originated in userspace. The SGX hardware architecture has its own per-page memory management metadata (EPCM) [*] and hardware which is separate from the normal x86 MMU. The architecture has a new page fault error code: PF_SGX. This new error code bit is set whenever a page fault occurs as the result of the SGX MMU. These faults occur for a variety of reasons. For instance, an access attempt to enclave memory from outside the enclave causes a PF_SGX fault. PF_SGX would also be set for permission conflicts, such as if a write to an enclave page occurs and the page is marked read-write in the x86 page tables but is read-only in the EPCM. These faults do not always indicate errors, though. SGX pages are encrypted with a key that is destroyed at hardware reset, including suspend. Throwing a SIGSEGV allows user space software to react and recover when these events occur. Include PF_SGX in the PF error codes list and throw SIGSEGV when it is encountered. [*] Intel SDM: 36.5.1 Enclave Page Cache Map (EPCM) [ bp: Add bit 15 to the comment above enum x86_pf_error_code too. ] Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-7-jarkko@kernel.org
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Sean Christopherson authored
Although carved out of normal DRAM, enclave memory is marked in the system memory map as reserved and is not managed by the core mm. There may be several regions spread across the system. Each contiguous region is called an Enclave Page Cache (EPC) section. EPC sections are enumerated via CPUID Enclave pages can only be accessed when they are mapped as part of an enclave, by a hardware thread running inside the enclave. Parse CPUID data, create metadata for EPC pages and populate a simple EPC page allocator. Although much smaller, ‘struct sgx_epc_page’ metadata is the SGX analog of the core mm ‘struct page’. Similar to how the core mm’s page->flags encode zone and NUMA information, embed the EPC section index to the first eight bits of sgx_epc_page->desc. This allows a quick reverse lookup from EPC page to EPC section. Existing client hardware supports only a single section, while upcoming server hardware will support at most eight sections. Thus, eight bits should be enough for long term needs. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Serge Ayoun <serge.ayoun@intel.com> Signed-off-by: Serge Ayoun <serge.ayoun@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-6-jarkko@kernel.org
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Sean Christopherson authored
The SGX Launch Control hardware helps restrict which enclaves the hardware will run. Launch control is intended to restrict what software can run with enclave protections, which helps protect the overall system from bad enclaves. For the kernel's purposes, there are effectively two modes in which the launch control hardware can operate: rigid and flexible. In its rigid mode, an entity other than the kernel has ultimate authority over which enclaves can be run (firmware, Intel, etc...). In its flexible mode, the kernel has ultimate authority over which enclaves can run. Enable X86_FEATURE_SGX_LC to enumerate when the CPU supports SGX Launch Control in general. Add MSR_IA32_SGXLEPUBKEYHASH{0, 1, 2, 3}, which when combined contain a SHA256 hash of a 3072-bit RSA public key. The hardware allows SGX enclaves signed with this public key to initialize and run [*]. Enclaves not signed with this key can not initialize and run. Add FEAT_CTL_SGX_LC_ENABLED, which informs whether the SGXLEPUBKEYHASH MSRs can be written by the kernel. If the MSRs do not exist or are read-only, the launch control hardware is operating in rigid mode. Linux does not and will not support creating enclaves when hardware is configured in rigid mode because it takes away the authority for launch decisions from the kernel. Note, this does not preclude KVM from virtualizing/exposing SGX to a KVM guest when launch control hardware is operating in rigid mode. [*] Intel SDM: 38.1.4 Intel SGX Launch Control Configuration Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-5-jarkko@kernel.org
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Sean Christopherson authored
Populate X86_FEATURE_SGX feature from CPUID and tie it to the Kconfig option with disabled-features.h. IA32_FEATURE_CONTROL.SGX_ENABLE must be examined in addition to the CPUID bits to enable full SGX support. The BIOS must both set this bit and lock IA32_FEATURE_CONTROL for SGX to be supported (Intel SDM section 36.7.1). The setting or clearing of this bit has no impact on the CPUID bits above, which is why it needs to be detected separately. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-4-jarkko@kernel.org
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Jarkko Sakkinen authored
ENCLS is the userspace instruction which wraps virtually all unprivileged SGX functionality for managing enclaves. It is essentially the ioctl() of instructions with each function implementing different SGX-related functionality. Add macros to wrap the ENCLS functionality. There are two main groups, one for functions which do not return error codes and a “ret_” set for those that do. ENCLS functions are documented in Intel SDM section 36.6. Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-3-jarkko@kernel.org
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Jarkko Sakkinen authored
Define the SGX architectural data structures used by various SGX functions. This is not an exhaustive representation of all SGX data structures but only those needed by the kernel. The goal is to sequester hardware structures in "sgx/arch.h" and keep them separate from kernel-internal or uapi structures. The data structures are described in Intel SDM section 37.6. Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-2-jarkko@kernel.org
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- 16 Nov, 2020 1 commit
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Linus Torvalds authored
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- 15 Nov, 2020 11 commits
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git://anongit.freedesktop.org/drm/drmLinus Torvalds authored
Pull drm fixes from Dave Airlie: "Nouveau fixes: - atomic modesetting regression fix - ttm pre-nv50 fix - connector NULL ptr deref fix" * tag 'drm-fixes-2020-11-16' of git://anongit.freedesktop.org/drm/drm: drm/nouveau/kms/nv50-: Use atomic encoder callbacks everywhere drm/nouveau/ttm: avoid using nouveau_drm.ttm.type_vram prior to nv50 drm/nouveau/kms: Fix NULL pointer dereference in nouveau_connector_detect_depth
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git://github.com/skeggsb/linuxDave Airlie authored
- atomic modesetting regression fix - ttm pre-nv50 fix - connector NULL ptr deref fix Signed-off-by: Dave Airlie <airlied@redhat.com> From: Ben Skeggs <skeggsb@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/CACAvsv5D9p78MNN0OxVeRZxN8LDqcadJEGUEFCgWJQ6+_rjPuw@mail.gmail.com
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-miscLinus Torvalds authored
Pull char/misc driver fixes from Greg KH: "Here are some small char/misc/whatever driver fixes for 5.10-rc4. Nothing huge, lots of small fixes for reported issues: - habanalabs driver fixes - speakup driver fixes - uio driver fixes - virtio driver fix - other tiny driver fixes Full details are in the shortlog. All of these have been in linux-next for a full week with no reported issues" * tag 'char-misc-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: uio: Fix use-after-free in uio_unregister_device() firmware: xilinx: fix out-of-bounds access nitro_enclaves: Fixup type and simplify logic of the poll mask setup speakup ttyio: Do not schedule() in ttyio_in_nowait speakup: Fix clearing selection in safe context speakup: Fix var_id_t values and thus keymap virtio: virtio_console: fix DMA memory allocation for rproc serial habanalabs/gaudi: mask WDT error in QMAN habanalabs/gaudi: move coresight mmu config habanalabs: fix kernel pointer type mei: protect mei_cl_mtu from null dereference
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usbLinus Torvalds authored
Pull USB and Thunderbolt fixes from Greg KH: "Here are some small Thunderbolt and USB driver fixes for 5.10-rc4 to solve some reported issues. Nothing huge in here, just small things: - thunderbolt memory leaks fixed and new device ids added - revert of problem patch for the musb driver - new quirks added for USB devices - typec power supply fixes to resolve much reported problems about charging notifications not working anymore All except the cdc-acm driver quirk addition have been in linux-next with no reported issues (the quirk patch was applied on Friday, and is self-contained)" * tag 'usb-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: usb: cdc-acm: Add DISABLE_ECHO for Renesas USB Download mode MAINTAINERS: add usb raw gadget entry usb: typec: ucsi: Report power supply changes xhci: hisilicon: fix refercence leak in xhci_histb_probe Revert "usb: musb: convert to devm_platform_ioremap_resource_byname" thunderbolt: Add support for Intel Tiger Lake-H thunderbolt: Only configure USB4 wake for lane 0 adapters thunderbolt: Add uaccess dependency to debugfs interface thunderbolt: Fix memory leak if ida_simple_get() fails in enumerate_services() thunderbolt: Add the missed ida_simple_remove() in ring_request_msix()
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull kvm fixes from Paolo Bonzini: "Fixes for ARM and x86, the latter especially for old processors without two-dimensional paging (EPT/NPT)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: mmu: fix is_tdp_mmu_check when the TDP MMU is not in use KVM: SVM: Update cr3_lm_rsvd_bits for AMD SEV guests KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_arch KVM: x86: clflushopt should be treated as a no-op by emulation KVM: arm64: Handle SCXTNUM_ELx traps KVM: arm64: Unify trap handlers injecting an UNDEF KVM: arm64: Allow setting of ID_AA64PFR0_EL1.CSV2 from userspace
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: "A small set of fixes for x86: - Cure the fallout from the MSI irqdomain overhaul which missed that the Intel IOMMU does not register virtual function devices and therefore never reaches the point where the MSI interrupt domain is assigned. This made the VF devices use the non-remapped MSI domain which is trapped by the IOMMU/remap unit - Remove an extra space in the SGI_UV architecture type procfs output for UV5 - Remove a unused function which was missed when removing the UV BAU TLB shootdown handler" * tag 'x86-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: iommu/vt-d: Cure VF irqdomain hickup x86/platform/uv: Fix copied UV5 output archtype x86/platform/uv: Drop last traces of uv_flush_tlb_others
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf fixes from Thomas Gleixner: "A set of fixes for perf: - A set of commits which reduce the stack usage of various perf event handling functions which allocated large data structs on stack causing stack overflows in the worst case - Use the proper mechanism for detecting soft interrupts in the recursion protection - Make the resursion protection simpler and more robust - Simplify the scheduling of event groups to make the code more robust and prepare for fixing the issues vs. scheduling of exclusive event groups - Prevent event multiplexing and rotation for exclusive event groups - Correct the perf event attribute exclusive semantics to take pinned events, e.g. the PMU watchdog, into account - Make the anythread filtering conditional for Intel's generic PMU counters as it is not longer guaranteed to be supported on newer CPUs. Check the corresponding CPUID leaf to make sure - Fixup a duplicate initialization in an array which was probably caused by the usual 'copy & paste - forgot to edit' mishap" * tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Fix Add BW copypasta perf/x86/intel: Make anythread filter support conditional perf: Tweak perf_event_attr::exclusive semantics perf: Fix event multiplexing for exclusive groups perf: Simplify group_sched_in() perf: Simplify group_sched_out() perf/x86: Make dummy_iregs static perf/arch: Remove perf_sample_data::regs_user_copy perf: Optimize get_recursion_context() perf: Fix get_recursion_context() perf/x86: Reduce stack usage for x86_pmu::drain_pebs() perf: Reduce stack usage of perf_output_begin()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler fixes from Thomas Gleixner: "A set of scheduler fixes: - Address a load balancer regression by making the load balancer use the same logic as the wakeup path to spread tasks in the LLC domain - Prefer the CPU on which a task run last over the local CPU in the fast wakeup path for asymmetric CPU capacity systems to align with the symmetric case. This ensures more locality and prevents massive migration overhead on those asymetric systems - Fix a memory corruption bug in the scheduler debug code caused by handing a modified buffer pointer to kfree()" * tag 'sched-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/debug: Fix memory corruption caused by multiple small reads of flags sched/fair: Prefer prev cpu in asymmetric wakeup path sched/fair: Ensure tasks spreading in LLC during LB
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull locking fixes from Thomas Gleixner: "Two fixes for the locking subsystem: - Prevent an unconditional interrupt enable in a futex helper function which can be called from contexts which expect interrupts to stay disabled across the call - Don't modify lockdep chain keys in the validation process as that causes chain inconsistency" * tag 'locking-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Avoid to modify chain keys in validate_chain() futex: Don't enable IRQs unconditionally in put_pi_state()
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git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpuLinus Torvalds authored
Pull percpu fix and cleanup from Dennis Zhou: "A fix for a Wshadow warning in the asm-generic percpu macros came in and then I tacked on the removal of flexible array initializers in the percpu allocator" * 'for-5.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu: percpu: convert flexible array initializers to use struct_size() asm-generic: percpu: avoid Wshadow warning
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Paolo Bonzini authored
In some cases where shadow paging is in use, the root page will be either mmu->pae_root or vcpu->arch.mmu->lm_root. Then it will not have an associated struct kvm_mmu_page, because it is allocated with alloc_page instead of kvm_mmu_alloc_page. Just return false quickly from is_tdp_mmu_root if the TDP MMU is not in use, which also includes the case where shadow paging is enabled. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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- 14 Nov, 2020 21 commits
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Linus Torvalds authored
Merge fixes from Andrew Morton: "14 patches. Subsystems affected by this patch series: mm (migration, vmscan, slub, gup, memcg, hugetlbfs), mailmap, kbuild, reboot, watchdog, panic, and ocfs2" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: ocfs2: initialize ip_next_orphan panic: don't dump stack twice on warn hugetlbfs: fix anon huge page migration race mm: memcontrol: fix missing wakeup polling thread kernel/watchdog: fix watchdog_allowed_mask not used warning reboot: fix overflow parsing reboot cpu number Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint" compiler.h: fix barrier_data() on clang mm/gup: use unpin_user_pages() in __gup_longterm_locked() mm/slub: fix panic in slab_alloc_node() mailmap: fix entry for Dmitry Baryshkov/Eremin-Solenikov mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit mm/compaction: stop isolation if too many pages are isolated and we have pages to migrate mm/compaction: count pages and stop correctly during page isolation
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git://git.kernel.org/pub/scm/linux/kernel/git/clk/linuxLinus Torvalds authored
Pull clk fixes from Stephen Boyd: "Two small clk driver fixes: - Make to_clk_regmap() inline to avoid compiler annoyance - Fix critical clks on i.MX imx8m SoCs" * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: clk: imx8m: fix bus critical clk registration clk: define to_clk_regmap() as inline function
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Linus Torvalds authored
Merge tag 'hwmon-for-v5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging Pull hwmon fixes from Guenter Roeck: - Fix potential bufer overflow in pmbus/max20730 driver - Fix locking issue in pmbus core - Fix regression causing timeouts in applesmc driver - Fix RPM calculation in pwm-fan driver - Restrict counter visibility in amd_energy driver * tag 'hwmon-for-v5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: hwmon: (amd_energy) modify the visibility of the counters hwmon: (applesmc) Re-work SMC comms hwmon: (pwm-fan) Fix RPM calculation hwmon: (pmbus) Add mutex locking for sysfs reads hwmon: (pmbus/max20730) use scnprintf() instead of snprintf()
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Three small fixes, all in the embedded ufs driver subsystem" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: ufshcd: Fix missing destroy_workqueue() scsi: ufs: Try to save power mode change and UIC cmd completion timeout scsi: ufs: Fix unbalanced scsi_block_reqs_cnt caused by ufshcd_hold()
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds authored
Pull selinux fix from Paul Moore: "One small SELinux patch to make sure we return an error code when an allocation fails. It passes all of our tests, but given the nature of the patch that isn't surprising" * tag 'selinux-pr-20201113' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: Fix error return code in sel_ib_pkey_sid_slow()
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git://git.kernel.org/pub/scm/linux/kernel/git/rw/umlLinus Torvalds authored
Pull uml fix from Richard Weinberger: "Call PMD destructor in __pmd_free_tlb()" * tag 'for-linus-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: Call pgtable_pmd_page_dtor() in __pmd_free_tlb()
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David Howells authored
When afs_write_end() is called with copied == 0, it tries to set the dirty region, but there's no way to actually encode a 0-length region in the encoding in page->private. "0,0", for example, indicates a 1-byte region at offset 0. The maths miscalculates this and sets it incorrectly. Fix it to just do nothing but unlock and put the page in this case. We don't actually need to mark the page dirty as nothing presumably changed. Fixes: 65dd2d60 ("afs: Alter dirty range encoding in page->private") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Wengang Wang authored
Though problem if found on a lower 4.1.12 kernel, I think upstream has same issue. In one node in the cluster, there is the following callback trace: # cat /proc/21473/stack __ocfs2_cluster_lock.isra.36+0x336/0x9e0 [ocfs2] ocfs2_inode_lock_full_nested+0x121/0x520 [ocfs2] ocfs2_evict_inode+0x152/0x820 [ocfs2] evict+0xae/0x1a0 iput+0x1c6/0x230 ocfs2_orphan_filldir+0x5d/0x100 [ocfs2] ocfs2_dir_foreach_blk+0x490/0x4f0 [ocfs2] ocfs2_dir_foreach+0x29/0x30 [ocfs2] ocfs2_recover_orphans+0x1b6/0x9a0 [ocfs2] ocfs2_complete_recovery+0x1de/0x5c0 [ocfs2] process_one_work+0x169/0x4a0 worker_thread+0x5b/0x560 kthread+0xcb/0xf0 ret_from_fork+0x61/0x90 The above stack is not reasonable, the final iput shouldn't happen in ocfs2_orphan_filldir() function. Looking at the code, 2067 /* Skip inodes which are already added to recover list, since dio may 2068 * happen concurrently with unlink/rename */ 2069 if (OCFS2_I(iter)->ip_next_orphan) { 2070 iput(iter); 2071 return 0; 2072 } 2073 The logic thinks the inode is already in recover list on seeing ip_next_orphan is non-NULL, so it skip this inode after dropping a reference which incremented in ocfs2_iget(). While, if the inode is already in recover list, it should have another reference and the iput() at line 2070 should not be the final iput (dropping the last reference). So I don't think the inode is really in the recover list (no vmcore to confirm). Note that ocfs2_queue_orphans(), though not shown up in the call back trace, is holding cluster lock on the orphan directory when looking up for unlinked inodes. The on disk inode eviction could involve a lot of IOs which may need long time to finish. That means this node could hold the cluster lock for very long time, that can lead to the lock requests (from other nodes) to the orhpan directory hang for long time. Looking at more on ip_next_orphan, I found it's not initialized when allocating a new ocfs2_inode_info structure. This causes te reflink operations from some nodes hang for very long time waiting for the cluster lock on the orphan directory. Fix: initialize ip_next_orphan as NULL. Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201109171746.27884-1-wen.gang.wang@oracle.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Christophe Leroy authored
Before commit 3f388f28 ("panic: dump registers on panic_on_warn"), __warn() was calling show_regs() when regs was not NULL, and show_stack() otherwise. After that commit, show_stack() is called regardless of whether show_regs() has been called or not, leading to duplicated Call Trace: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/nohash/8xx.c:186 mmu_mark_initmem_nx+0x24/0x94 CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092 NIP: c00128b4 LR: c0010228 CTR: 00000000 REGS: c9023e40 TRAP: 0700 Not tainted (5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24000424 XER: 00000000 GPR00: c0010228 c9023ef8 c2100000 0074c000 ffffffff 00000000 c2151000 c07b3880 GPR08: ff000900 0074c000 c8000000 c33b53a8 24000822 00000000 c0003a20 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00800000 NIP [c00128b4] mmu_mark_initmem_nx+0x24/0x94 LR [c0010228] free_initmem+0x20/0x58 Call Trace: free_initmem+0x20/0x58 kernel_init+0x1c/0x114 ret_from_kernel_thread+0x14/0x1c Instruction dump: 7d291850 7d234b78 4e800020 9421ffe0 7c0802a6 bfc10018 3fe0c060 3bff0000 3fff4080 3bffffff 90010024 57ff0010 <0fe00000> 392001cd 7c3e0b78 953e0008 CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092 Call Trace: __warn+0x8c/0xd8 (unreliable) report_bug+0x11c/0x154 program_check_exception+0x1dc/0x6e0 ret_from_except_full+0x0/0x4 --- interrupt: 700 at mmu_mark_initmem_nx+0x24/0x94 LR = free_initmem+0x20/0x58 free_initmem+0x20/0x58 kernel_init+0x1c/0x114 ret_from_kernel_thread+0x14/0x1c ---[ end trace 31702cd2a9570752 ]--- Only call show_stack() when regs is NULL. Fixes: 3f388f28 ("panic: dump registers on panic_on_warn") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Link: https://lkml.kernel.org/r/e8c055458b080707f1bc1a98ff8bea79d0cec445.1604748361.git.christophe.leroy@csgroup.euSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mike Kravetz authored
Qian Cai reported the following BUG in [1] LTP: starting move_pages12 BUG: unable to handle page fault for address: ffffffffffffffe0 ... RIP: 0010:anon_vma_interval_tree_iter_first+0xa2/0x170 avc_start_pgoff at mm/interval_tree.c:63 Call Trace: rmap_walk_anon+0x141/0xa30 rmap_walk_anon at mm/rmap.c:1864 try_to_unmap+0x209/0x2d0 try_to_unmap at mm/rmap.c:1763 migrate_pages+0x1005/0x1fb0 move_pages_and_store_status.isra.47+0xd7/0x1a0 __x64_sys_move_pages+0xa5c/0x1100 do_syscall_64+0x5f/0x310 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Hugh Dickins diagnosed this as a migration bug caused by code introduced to use i_mmap_rwsem for pmd sharing synchronization. Specifically, the routine unmap_and_move_huge_page() is always passing the TTU_RMAP_LOCKED flag to try_to_unmap() while holding i_mmap_rwsem. This is wrong for anon pages as the anon_vma_lock should be held in this case. Further analysis suggested that i_mmap_rwsem was not required to he held at all when calling try_to_unmap for anon pages as an anon page could never be part of a shared pmd mapping. Discussion also revealed that the hack in hugetlb_page_mapping_lock_write to drop page lock and acquire i_mmap_rwsem is wrong. There is no way to keep mapping valid while dropping page lock. This patch does the following: - Do not take i_mmap_rwsem and set TTU_RMAP_LOCKED for anon pages when calling try_to_unmap. - Remove the hacky code in hugetlb_page_mapping_lock_write. The routine will now simply do a 'trylock' while still holding the page lock. If the trylock fails, it will return NULL. This could impact the callers: - migration calling code will receive -EAGAIN and retry up to the hard coded limit (10). - memory error code will treat the page as BUSY. This will force killing (SIGKILL) instead of SIGBUS any mapping tasks. Do note that this change in behavior only happens when there is a race. None of the standard kernel testing suites actually hit this race, but it is possible. [1] https://lore.kernel.org/lkml/20200708012044.GC992@lca.pw/ [2] https://lore.kernel.org/linux-mm/alpine.LSU.2.11.2010071833100.2214@eggly.anvils/ Fixes: c0d0381a ("hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization") Reported-by: Qian Cai <cai@lca.pw> Suggested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201105195058.78401-1-mike.kravetz@oracle.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Muchun Song authored
When we poll the swap.events, we can miss being woken up when the swap event occurs. Because we didn't notify. Fixes: f3a53a3a ("mm, memcontrol: implement memory.swap.events") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Yafang Shao <laoar.shao@gmail.com> Cc: Chris Down <chris@chrisdown.name> Cc: Tejun Heo <tj@kernel.org> Link: https://lkml.kernel.org/r/20201105161936.98312-1-songmuchun@bytedance.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Santosh Sivaraj authored
Define watchdog_allowed_mask only when SOFTLOCKUP_DETECTOR is enabled. Fixes: 7feeb9cd ("watchdog/sysctl: Clean up sysctl variable name space") Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20201106015025.1281561-1-santosh@fossix.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matteo Croce authored
Limit the CPU number to num_possible_cpus(), because setting it to a value lower than INT_MAX but higher than NR_CPUS produces the following error on reboot and shutdown: BUG: unable to handle page fault for address: ffffffff90ab1bb0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0 Oops: 0000 [#1] SMP CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_sys_reboot.cold+0x34/0x5b do_syscall_64+0x2d/0x40 Fixes: 1b3a5d02 ("reboot: move arch/x86 reboot= handling to generic kernel") Signed-off-by: Matteo Croce <mcroce@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fabian Frederick <fabf@skynet.be> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201103214025.116799-3-mcroce@linux.microsoft.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matteo Croce authored
Patch series "fix parsing of reboot= cmdline", v3. The parsing of the reboot= cmdline has two major errors: - a missing bound check can crash the system on reboot - parsing of the cpu number only works if specified last Fix both. This patch (of 2): This reverts commit 616feab7. kstrtoint() and simple_strtoul() have a subtle difference which makes them non interchangeable: if a non digit character is found amid the parsing, the former will return an error, while the latter will just stop parsing, e.g. simple_strtoul("123xyx") = 123. The kernel cmdline reboot= argument allows to specify the CPU used for rebooting, with the syntax `s####` among the other flags, e.g. "reboot=warm,s31,force", so if this flag is not the last given, it's silently ignored as well as the subsequent ones. Fixes: 616feab7 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") Signed-off-by: Matteo Croce <mcroce@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Petr Mladek <pmladek@suse.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mike Rapoport <rppt@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201103214025.116799-2-mcroce@linux.microsoft.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Arvind Sankar authored
Commit 815f0ddb ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") neglected to copy barrier_data() from compiler-gcc.h into compiler-clang.h. The definition in compiler-gcc.h was really to work around clang's more aggressive optimization, so this broke barrier_data() on clang, and consequently memzero_explicit() as well. For example, this results in at least the memzero_explicit() call in lib/crypto/sha256.c:sha256_transform() being optimized away by clang. Fix this by moving the definition of barrier_data() into compiler.h. Also move the gcc/clang definition of barrier() into compiler.h, __memory_barrier() is icc-specific (and barrier() is already defined using it in compiler-intel.h) and doesn't belong in compiler.h. [rdunlap@infradead.org: fix ALPHA builds when SMP is not enabled] Link: https://lkml.kernel.org/r/20201101231835.4589-1-rdunlap@infradead.org Fixes: 815f0ddb ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201014212631.207844-1-nivedita@alum.mit.eduSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jason Gunthorpe authored
When FOLL_PIN is passed to __get_user_pages() the page list must be put back using unpin_user_pages() otherwise the page pin reference persists in a corrupted state. There are two places in the unwind of __gup_longterm_locked() that put the pages back without checking. Normally on error this function would return the partial page list making this the caller's responsibility, but in these two cases the caller is not allowed to see these pages at all. Fixes: 3faa52c0 ("mm/gup: track FOLL_PIN pages") Reported-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/0-v2-3ae7d9d162e2+2a7-gup_cma_fix_jgg@nvidia.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Laurent Dufour authored
While doing memory hot-unplug operation on a PowerPC VM running 1024 CPUs with 11TB of ram, I hit the following panic: BUG: Kernel NULL pointer dereference on read at 0x00000007 Faulting instruction address: 0xc000000000456048 Oops: Kernel access of bad area, sig: 11 [#2] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS= 2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp CPU: 160 PID: 1 Comm: systemd Tainted: G D 5.9.0 #1 NIP: c000000000456048 LR: c000000000455fd4 CTR: c00000000047b350 REGS: c00006028d1b77a0 TRAP: 0300 Tainted: G D (5.9.0) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24004228 XER: 00000000 CFAR: c00000000000f1b0 DAR: 0000000000000007 DSISR: 40000000 IRQMASK: 0 GPR00: c000000000455fd4 c00006028d1b7a30 c000000001bec800 0000000000000000 GPR04: 0000000000000dc0 0000000000000000 00000000000374ef c00007c53df99320 GPR08: 000007c53c980000 0000000000000000 000007c53c980000 0000000000000000 GPR12: 0000000000004400 c00000001e8e4400 0000000000000000 0000000000000f6a GPR16: 0000000000000000 c000000001c25930 c000000001d62528 00000000000000c1 GPR20: c000000001d62538 c00006be469e9000 0000000fffffffe0 c0000000003c0ff8 GPR24: 0000000000000018 0000000000000000 0000000000000dc0 0000000000000000 GPR28: c00007c513755700 c000000001c236a4 c00007bc4001f800 0000000000000001 NIP [c000000000456048] __kmalloc_node+0x108/0x790 LR [c000000000455fd4] __kmalloc_node+0x94/0x790 Call Trace: kvmalloc_node+0x58/0x110 mem_cgroup_css_online+0x10c/0x270 online_css+0x48/0xd0 cgroup_apply_control_enable+0x2c4/0x470 cgroup_mkdir+0x408/0x5f0 kernfs_iop_mkdir+0x90/0x100 vfs_mkdir+0x138/0x250 do_mkdirat+0x154/0x1c0 system_call_exception+0xf8/0x200 system_call_common+0xf0/0x27c Instruction dump: e93e0000 e90d0030 39290008 7cc9402a e94d0030 e93e0000 7ce95214 7f89502a 2fbc0000 419e0018 41920230 e9270010 <89290007> 7f994800 419e0220 7ee6bb78 This pointing to the following code: mm/slub.c:2851 if (unlikely(!object || !node_match(page, node))) { c000000000456038: 00 00 bc 2f cmpdi cr7,r28,0 c00000000045603c: 18 00 9e 41 beq cr7,c000000000456054 <__kmalloc_node+0x114> node_match(): mm/slub.c:2491 if (node != NUMA_NO_NODE && page_to_nid(page) != node) c000000000456040: 30 02 92 41 beq cr4,c000000000456270 <__kmalloc_node+0x330> page_to_nid(): include/linux/mm.h:1294 c000000000456044: 10 00 27 e9 ld r9,16(r7) c000000000456048: 07 00 29 89 lbz r9,7(r9) <<<< r9 = NULL node_match(): mm/slub.c:2491 c00000000045604c: 00 48 99 7f cmpw cr7,r25,r9 c000000000456050: 20 02 9e 41 beq cr7,c000000000456270 <__kmalloc_node+0x330> The panic occurred in slab_alloc_node() when checking for the page's node: object = c->freelist; page = c->page; if (unlikely(!object || !node_match(page, node))) { object = __slab_alloc(s, gfpflags, node, addr, c); stat(s, ALLOC_SLOWPATH); The issue is that object is not NULL while page is NULL which is odd but may happen if the cache flush happened after loading object but before loading page. Thus checking for the page pointer is required too. The cache flush is done through an inter processor interrupt when a piece of memory is off-lined. That interrupt is triggered when a memory hot-unplug operation is initiated and offline_pages() is calling the slub's MEM_GOING_OFFLINE callback slab_mem_going_offline_callback() which is calling flush_cpu_slab(). If that interrupt is caught between the reading of c->freelist and the reading of c->page, this could lead to such a situation. That situation is expected and the later call to this_cpu_cmpxchg_double() will detect the change to c->freelist and redo the whole operation. In commit 6159d0f5 ("mm/slub.c: page is always non-NULL in node_match()") check on the page pointer has been removed assuming that page is always valid when it is called. It happens that this is not true in that particular case, so check for page before calling node_match() here. Fixes: 6159d0f5 ("mm/slub.c: page is always non-NULL in node_match()") Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Christoph Lameter <cl@linux.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201027190406.33283-1-ldufour@linux.ibm.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dmitry Baryshkov authored
Change back surname to new (old) one. Dmitry Baryshkov -> Dmitry Eremin-Solenikov -> Dmitry Baryshkov. Map several odd entries to main identity. Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20201103005158.1181426-1-dmitry.baryshkov@linaro.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nicholas Piggin authored
Previously the negated unsigned long would be cast back to signed long which would have the correct negative value. After commit 730ec8c0 ("mm/vmscan.c: change prototype for shrink_page_list"), the large unsigned int converts to a large positive signed long. Symptoms include CMA allocations hanging forever holding the cma_mutex due to alloc_contig_range->...->isolate_migratepages_block waiting forever in "while (unlikely(too_many_isolated(pgdat)))". [akpm@linux-foundation.org: fix -stat.nr_lazyfree_fail as well, per Michal] Fixes: 730ec8c0 ("mm/vmscan.c: change prototype for shrink_page_list") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vaneet Narang <v.narang@samsung.com> Cc: Maninder Singh <maninder1.s@samsung.com> Cc: Amit Sahrawat <a.sahrawat@samsung.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201029032320.1448441-1-npiggin@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Zi Yan authored
In isolate_migratepages_block, if we have too many isolated pages and nr_migratepages is not zero, we should try to migrate what we have without wasting time on isolating. In theory it's possible that multiple parallel compactions will cause too_many_isolated() to become true even if each has isolated less than COMPACT_CLUSTER_MAX, and loop forever in the while loop. Bailing immediately prevents that. [vbabka@suse.cz: changelog addition] Fixes: 1da2f328 (“mm,thp,compaction,cma: allow THP migration for CMA allocations”) Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Yang Shi <shy828301@gmail.com> Link: https://lkml.kernel.org/r/20201030183809.3616803-2-zi.yan@sent.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Zi Yan authored
In isolate_migratepages_block, when cc->alloc_contig is true, we are able to isolate compound pages. But nr_migratepages and nr_isolated did not count compound pages correctly, causing us to isolate more pages than we thought. So count compound pages as the number of base pages they contain. Otherwise, we might be trapped in too_many_isolated while loop, since the actual isolated pages can go up to COMPACT_CLUSTER_MAX*512=16384, where COMPACT_CLUSTER_MAX is 32, since we stop isolation after cc->nr_migratepages reaches to COMPACT_CLUSTER_MAX. In addition, after we fix the issue above, cc->nr_migratepages could never be equal to COMPACT_CLUSTER_MAX if compound pages are isolated, thus page isolation could not stop as we intended. Change the isolation stop condition to '>='. The issue can be triggered as follows: In a system with 16GB memory and an 8GB CMA region reserved by hugetlb_cma, if we first allocate 10GB THPs and mlock them (so some THPs are allocated in the CMA region and mlocked), reserving 6 1GB hugetlb pages via /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages will get stuck (looping in too_many_isolated function) until we kill either task. With the patch applied, oom will kill the application with 10GB THPs and let hugetlb page reservation finish. [ziy@nvidia.com: v3] Link: https://lkml.kernel.org/r/20201030183809.3616803-1-zi.yan@sent.com Fixes: 1da2f328 ("cmm,thp,compaction,cma: allow THP migration for CMA allocations") Signed-off-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Yang Shi <shy828301@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@surriel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201029200435.3386066-1-zi.yan@sent.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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