Rik van Riel d303cf4624 mm: fix TLB flush race between migration, and change_protection_range ... commit 2084140594 upstream. There are a few subtle races, between change_protection_range (used by mprotect and change_prot_numa) on one side, and NUMA page migration and compaction on the other side. The basic race is that there is a time window between when the PTE gets made non-present (PROT_NONE or NUMA), and the TLB is flushed. During that time, a CPU may continue writing to the page. This is fine most of the time, however compaction or the NUMA migration code may come in, and migrate the page away. When that happens, the CPU may continue writing, through the cached translation, to what is no longer the current memory location of the process. This only affects x86, which has a somewhat optimistic pte_accessible. All other architectures appear to be safe, and will either always flush, or flush whenever there is a valid mapping, even with no permissions (SPARC). The basic race looks like this: CPU A CPU B CPU C load TLB entry make entry PTE/PMD_NUMA fault on entry read/write old page start migrating page change PTE/PMD to new page read/write old page [*] flush TLB reload TLB from new entry read/write new page lose data [*] the old page may belong to a new user at this point! The obvious fix is to flush remote TLB entries, by making sure that pte_accessible aware of the fact that PROT_NONE and PROT_NUMA memory may still be accessible if there is a TLB flush pending for the mm. This should fix both NUMA migration and compaction. [mgorman@suse.de: fix build] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Alex Thorlton <athorlton@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-01-09 12:24:23 -08:00
..
bitops
4level-fixup.h
atomic-long.h
atomic.h	asm-generic: move cmpxchg*_local defs to cmpxchg.h	2013-03-13 06:11:05 +01:00
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	asm-generic headers: Allow yet more arch overrides in checksum.h	2013-02-11 20:00:33 +05:30
clkdev.h
cmpxchg-local.h	generic: Use raw local irq variant for generic cmpxchg	2013-02-19 08:43:37 +01:00
cmpxchg.h	asm-generic: move cmpxchg*_local defs to cmpxchg.h	2013-03-13 06:11:05 +01:00
cputime_jiffies.h	cputime: Move default nsecs_to_cputime() to jiffies based cputime file	2013-01-27 19:23:25 +01:00
cputime_nsecs.h	cputime_nsecs: use math64.h for nsec resolution conversion helpers	2013-04-26 18:58:12 +02:00
cputime.h	cputime: Generic on-demand virtual cputime accounting	2013-01-27 19:23:27 +01:00
current.h
delay.h
device.h
div64.h
dma-coherent.h
dma-contiguous.h
dma-mapping-broken.h	asm-generic/dma-mapping-broken.h: Provide dma_alloc_attrs()/dma_free_attrs()	2012-12-25 20:14:54 +01:00
dma-mapping-common.h
dma.h
emergency-restart.h
exec.h
fb.h
ftrace.h
futex.h
getorder.h
gpio.h	gpiolib: let gpio_chip reference its descriptors	2013-02-11 22:21:28 +00:00
hardirq.h
hugetlb.h	mm: Fix generic hugetlb pte check return type.	2013-10-13 16:08:33 -07:00
hw_irq.h
ide_iops.h
int-l64.h
int-ll64.h
io-64-nonatomic-hi-lo.h
io-64-nonatomic-lo-hi.h
io.h	kernel: Fix s390 absolute memory access for /dev/mem	2013-05-22 09:45:57 +02:00
ioctl.h
iomap.h
irq_regs.h
irq.h
irqflags.h
Kbuild.asm
kdebug.h
kmap_types.h
kvm_para.h	KVM: add kvm_para_available to asm-generic/kvm_para.h	2013-06-05 13:21:29 +03:00
libata-portmap.h
linkage.h
local.h
local64.h
memory_model.h
mm_hooks.h
mmu_context.h
mmu.h	asm-generic/mmu.h: Add support for FDPIC	2012-12-09 23:14:14 +01:00
module.h
mutex-dec.h
mutex-null.h
mutex-xchg.h
mutex.h
page.h
param.h
parport.h	include: remove __dev* attributes.	2013-01-03 15:57:16 -08:00
pci_iomap.h
pci-bridge.h
pci-dma-compat.h
pci.h
percpu.h
pgalloc.h
pgtable-nopmd.h
pgtable-nopud.h
pgtable.h	mm: fix TLB flush race between migration, and change_protection_range	2014-01-09 12:24:23 -08:00
ptrace.h
resource.h
rtc.h
rwsem.h
scatterlist.h
sections.h
segment.h
serial.h
siginfo.h
signal.h	unify default ptrace_signal_deliver	2012-11-29 00:01:23 -05:00
sizes.h
spinlock.h
statfs.h
string.h
switch_to.h
syscall.h
syscalls.h	burying unused conditionals	2013-02-14 09:21:15 -05:00
termios-base.h
termios.h
timex.h
tlb.h	Fix TLB gather virtual address range invalidation corner cases	2013-08-20 08:43:05 -07:00
tlbflush.h
topology.h
trace_clock.h	tracing,x86: Add a TSC trace_clock	2012-11-13 15:48:27 -05:00
uaccess-unaligned.h
uaccess.h	asm-generic: uaccess: Allow arches to over-ride __{get,put}_user_fn()	2013-02-11 20:00:32 +05:30
unaligned.h
unistd.h	We get rid of the general module prefix confusion with a binary config option,	2013-05-05 10:58:06 -07:00
user.h
vga.h
vmlinux.lds.h	CONFIG_SYMBOL_PREFIX: cleanup.	2013-03-15 15:09:43 +10:30
word-at-a-time.h
xor.h