8645c430a5
[ Upstream commit c58f0bb77ed8bf93dfdde762b01cb67eebbdfc29 ] Patch series "Do not lose dirty bit on THP pages", v4. Vlastimil noted that pmdp_invalidate() is not atomic and we can lose dirty and access bits if CPU sets them after pmdp dereference, but before set_pmd_at(). The bug can lead to data loss, but the race window is tiny and I haven't seen any reports that suggested that it happens in reality. So I don't think it worth sending it to stable. Unfortunately, there's no way to address the issue in a generic way. We need to fix all architectures that support THP one-by-one. All architectures that have THP supported have to provide atomic pmdp_invalidate() that returns previous value. If generic implementation of pmdp_invalidate() is used, architecture needs to provide atomic pmdp_estabish(). pmdp_estabish() is not used out-side generic implementation of pmdp_invalidate() so far, but I think this can change in the future. This patch (of 12): This is an implementation of pmdp_establish() that is only suitable for an architecture that doesn't have hardware dirty/accessed bits. In this case we can't race with CPU which sets these bits and non-atomic approach is fine. Link: http://lkml.kernel.org/r/20171213105756.69879-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Nitin Gupta <nitin.m.gupta@oracle.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| .. | ||
| bitops | ||
| 4level-fixup.h | ||
| asm-offsets.h | ||
| asm-prototypes.h | ||
| atomic-long.h | ||
| atomic.h | ||
| atomic64.h | ||
| audit_change_attr.h | ||
| audit_dir_write.h | ||
| audit_read.h | ||
| audit_signal.h | ||
| audit_write.h | ||
| barrier.h | ||
| bitops.h | ||
| bitsperlong.h | ||
| bug.h | ||
| bugs.h | ||
| cache.h | ||
| cacheflush.h | ||
| checksum.h | ||
| clkdev.h | ||
| cmpxchg-local.h | ||
| cmpxchg.h | ||
| cputime_jiffies.h | ||
| cputime_nsecs.h | ||
| cputime.h | ||
| current.h | ||
| delay.h | ||
| device.h | ||
| div64.h | ||
| dma-coherent.h | ||
| dma-contiguous.h | ||
| dma-mapping-broken.h | ||
| dma-mapping-common.h | ||
| dma.h | ||
| early_ioremap.h | ||
| emergency-restart.h | ||
| exec.h | ||
| export.h | ||
| fb.h | ||
| fixmap.h | ||
| ftrace.h | ||
| futex.h | ||
| getorder.h | ||
| gpio.h | ||
| hardirq.h | ||
| hugetlb.h | ||
| hw_irq.h | ||
| ide_iops.h | ||
| int-ll64.h | ||
| io-64-nonatomic-hi-lo.h | ||
| io-64-nonatomic-lo-hi.h | ||
| io.h | ||
| ioctl.h | ||
| iomap.h | ||
| irq_regs.h | ||
| irq_work.h | ||
| irq.h | ||
| irqflags.h | ||
| Kbuild.asm | ||
| kdebug.h | ||
| kmap_types.h | ||
| kvm_para.h | ||
| libata-portmap.h | ||
| linkage.h | ||
| local.h | ||
| local64.h | ||
| mcs_spinlock.h | ||
| memory_model.h | ||
| mm_hooks.h | ||
| mm-arch-hooks.h | ||
| mmu_context.h | ||
| mmu.h | ||
| module.h | ||
| msi.h | ||
| mutex-dec.h | ||
| mutex-null.h | ||
| mutex-xchg.h | ||
| mutex.h | ||
| page.h | ||
| param.h | ||
| parport.h | ||
| pci_iomap.h | ||
| pci-bridge.h | ||
| pci-dma-compat.h | ||
| pci.h | ||
| percpu.h | ||
| pgalloc.h | ||
| pgtable-nopmd.h | ||
| pgtable-nopud.h | ||
| pgtable.h | ||
| preempt.h | ||
| ptrace.h | ||
| qrwlock_types.h | ||
| qrwlock.h | ||
| qspinlock_types.h | ||
| qspinlock.h | ||
| resource.h | ||
| rtc.h | ||
| rwsem.h | ||
| seccomp.h | ||
| sections.h | ||
| segment.h | ||
| serial.h | ||
| siginfo.h | ||
| signal.h | ||
| simd.h | ||
| sizes.h | ||
| spinlock.h | ||
| statfs.h | ||
| string.h | ||
| switch_to.h | ||
| syscall.h | ||
| syscalls.h | ||
| termios-base.h | ||
| termios.h | ||
| timex.h | ||
| tlb.h | ||
| tlbflush.h | ||
| topology.h | ||
| trace_clock.h | ||
| uaccess-unaligned.h | ||
| uaccess.h | ||
| unaligned.h | ||
| unistd.h | ||
| user.h | ||
| vga.h | ||
| vmlinux.lds.h | ||
| vtime.h | ||
| word-at-a-time.h | ||
| xor.h | ||