WSL2-Linux-Kernel/kernel
Rik van Riel 2084140594 mm: fix TLB flush race between migration, and change_protection_range
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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-18 19:04:51 -08:00
..
cpu sched: Add NEED_RESCHED to the preempt_count 2013-09-25 14:07:49 +02:00
debug kdb: Add support for external NMI handler to call KGDB/KDB 2013-10-03 18:47:54 +02:00
events perf: Remove fragile swevent hlist optimization 2013-11-19 16:57:42 +01:00
gcov gcov: reuse kbasename helper 2013-11-13 12:09:34 +09:00
irq Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-12-02 10:15:39 -08:00
locking locking/lockdep: Mark __lockdep_count_forward_deps() as static 2013-11-13 13:50:17 +01:00
power Merge branch 'pm-sleep' 2013-11-19 01:07:08 +01:00
printk printk.c: comments should refer to /proc/vmcore instead of /proc/vmcoreinfo 2013-11-13 12:09:14 +09:00
rcu NOHZ: Check for nohz active instead of nohz enabled 2013-11-19 14:59:50 +01:00
sched sched: numa: skip inaccessible VMAs 2013-12-18 19:04:51 -08:00
time nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off 2013-11-29 12:23:03 +01:00
trace A regression showed up that there's a large delay when enabling 2013-12-06 08:34:16 -08:00
.gitignore Ignore generated file kernel/x509_certificate_list 2013-12-10 18:21:34 +00:00
Kconfig.freezer
Kconfig.hz kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS 2013-11-15 09:32:22 +09:00
Kconfig.locks
Kconfig.preempt
Makefile Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2013-11-21 19:46:00 -08:00
acct.c
async.c
audit.c Merge git://git.infradead.org/users/eparis/audit 2013-11-21 19:18:14 -08:00
audit.h audit: call audit_bprm() only once to add AUDIT_EXECVE information 2013-11-05 11:15:03 -05:00
audit_tree.c
audit_watch.c
auditfilter.c audit: do not reject all AUDIT_INODE filter types 2013-11-05 11:09:16 -05:00
auditsc.c audit: fix type of sessionid in audit_set_loginuid() 2013-11-06 11:47:24 -05:00
backtracetest.c
bounds.c kernel/bounds: avoid circular dependencies in generated headers 2013-11-19 14:20:12 -08:00
capability.c xfs: update for v3.12-rc1 2013-09-09 11:19:09 -07:00
cgroup.c cgroup: fix cgroup_subsys_state leak for seq_files 2013-11-27 18:16:21 -05:00
cgroup_freezer.c
compat.c
configs.c
context_tracking.c Linux 3.12-rc4 2013-10-09 12:36:13 +02:00
cpu.c Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-14 16:55:11 +09:00
cpu_pm.c
cpuset.c cpuset: Fix memory allocator deadlock 2013-11-27 13:52:47 -05:00
crash_dump.c
cred.c
delayacct.c kernel/delayacct.c: remove redundant checking in __delayacct_add_tsk() 2013-11-13 12:09:12 +09:00
dma.c
elfcore.c switch elf_core_write_extra_phdrs() to dump_emit() 2013-11-09 00:16:23 -05:00
exec_domain.c
exit.c
extable.c kernel/extable: fix address-checks for core_kernel and init areas 2013-11-28 09:49:41 -08:00
fork.c mm: fix TLB flush race between migration, and change_protection_range 2013-12-18 19:04:51 -08:00
freezer.c
futex.c futex: move user address verification up to common code 2013-12-12 09:53:51 -08:00
futex_compat.c
groups.c userns: Kill nsown_capable it makes the wrong thing easy 2013-08-30 23:44:11 -07:00
hrtimer.c
hung_task.c Here are the 3.13 KVM changes. There was a lot of work on the PPC 2013-11-15 13:51:36 +09:00
irq_work.c
itimer.c
jump_label.c static_key: WARN on usage before jump_label_init was called 2013-10-19 19:45:35 -04:00
kallsyms.c
kcmp.c
kexec.c kexec: migrate to reboot cpu 2013-12-18 19:04:50 -08:00
kmod.c kernel/kmod.c: check for NULL in call_usermodehelper_exec() 2013-09-30 14:31:02 -07:00
kprobes.c kprobes: use KSYM_NAME_LEN to size identifier buffers 2013-11-13 12:09:26 +09:00
ksysfs.c kernel: replace strict_strto*() with kstrto*() 2013-09-12 15:38:03 -07:00
kthread.c kthread: make kthread_create() killable 2013-11-13 12:08:59 +09:00
latencytop.c
module-internal.h KEYS: Separate the kernel signature checking keyring from module signing 2013-09-25 17:17:01 +01:00
module.c Mainly boring here, too. rmmod --wait finally removed, though. 2013-11-15 13:27:50 +09:00
module_signing.c keys: change asymmetric keys to use common hash definitions 2013-10-25 17:15:18 -04:00
notifier.c
nsproxy.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-09-07 14:35:32 -07:00
padata.c padata: make the sequence counter an atomic_t 2013-10-30 12:02:58 +08:00
panic.c kernel/panic.c: reduce 1 byte usage for print tainted buffer 2013-11-13 12:09:35 +09:00
params.c kernel/params: fix handling of signed integer types 2013-09-28 12:35:52 -07:00
pid.c pidns: fix free_pid() to handle the first fork failure 2013-09-30 14:31:03 -07:00
pid_namespace.c pid_namespace: make freeing struct pid_namespace rcu-delayed 2013-10-24 23:43:29 -04:00
posix-cpu-timers.c
posix-timers.c
profile.c
ptrace.c exec/ptrace: fix get_dumpable() incorrect tests 2013-11-13 12:09:33 +09:00
range.c
reboot.c kexec: migrate to reboot cpu 2013-12-18 19:04:50 -08:00
relay.c
res_counter.c memcg: reduce function dereference 2013-09-12 15:38:02 -07:00
resource.c
seccomp.c
signal.c constify copy_siginfo_to_user{,32}() 2013-11-09 00:16:29 -05:00
smp.c kernel: fix generic_exec_single indentation 2013-11-15 09:32:22 +09:00
smpboot.c
smpboot.h
softirq.c revert "softirq: Add support for triggering softirq work on softirqs" 2013-11-15 09:32:22 +09:00
stacktrace.c
stop_machine.c stop_machine: Fix race between stop_two_cpus() and stop_cpus() 2013-11-11 12:43:38 +01:00
sys.c kernel/sys.c: remove obsolete #include <linux/kexec.h> 2013-11-13 12:09:13 +09:00
sys_ni.c
sysctl.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-14 16:30:30 +09:00
sysctl_binary.c kernel/sysctl_binary.c: use scnprintf() instead of snprintf() 2013-11-13 12:09:33 +09:00
system_certificates.S KEYS: correct alignment of system_certificate_list content in assembly file 2013-12-10 18:25:28 +00:00
system_keyring.c KEYS: correct alignment of system_certificate_list content in assembly file 2013-12-10 18:25:28 +00:00
task_work.c task_work: documentation 2013-09-11 15:58:27 -07:00
taskstats.c genetlink: only pass array to genl_register_family_with_ops() 2013-11-19 16:39:05 -05:00
test_kprobes.c
time.c
timeconst.bc
timer.c timer: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...) 2013-11-19 14:59:50 +01:00
tracepoint.c
tsacct.c
uid16.c userns: Kill nsown_capable it makes the wrong thing easy 2013-08-30 23:44:11 -07:00
up.c kernel: provide a __smp_call_function_single stub for !CONFIG_SMP 2013-11-15 09:32:22 +09:00
user-return-notifier.c
user.c KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches 2013-09-24 10:35:19 +01:00
user_namespace.c KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches 2013-09-24 10:35:19 +01:00
utsname.c userns: Kill nsown_capable it makes the wrong thing easy 2013-08-30 23:44:11 -07:00
utsname_sysctl.c
watchdog.c watchdog: update watchdog_thresh properly 2013-09-24 17:00:25 -07:00
workqueue.c PCI updates for v3.13: 2013-12-15 11:45:27 -08:00
workqueue_internal.h