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Jan Kara b5bd6a0e5f lib/flex_proportions.c: fix corruption of denominator in flexible proportions 
When racing with CPU hotplug, percpu_counter_sum() can return negative
values for the number of observed events.

This confuses fprop_new_period(), which uses unsigned type and as a
result number of events is set to big *positive* number.  From that
moment on, things go pear shaped and can result e.g.  in division by
zero as denominator is later truncated to 32-bits.

This bug causes a divide-by-zero oops in bdi_dirty_limit() in Borislav's
3.6.0-rc6 based kernel.

Fix the issue by using a signed type in fprop_new_period().  That makes
us bail out from the function without doing anything (mistakenly)
thinking there are no events to age.  That makes aging somewhat
inaccurate but getting accurate data would be rather hard.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Borislav Petkov <bp@amd64.org>
Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-25 08:59:21 -07:00
..
lzo
mpi Remove unused code from MPI library 2012-05-26 11:51:03 +10:00
raid6 lib/raid6: fix sparse warnings in recovery functions 2012-05-28 14:10:22 +10:00
reed_solomon
xz
zlib_deflate
zlib_inflate
.gitignore
argv_split.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
atomic64_test.c atomic64_test: simplify the #ifdef for atomic64_dec_if_positive() test 2012-07-30 17:25:16 -07:00
atomic64.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
audit.c
average.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
bcd.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
bch.c
bitmap.c lib/bitmap.c: fix documentation for scnprintf() functions 2012-05-29 16:22:32 -07:00
bitrev.c
bsearch.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
btree.c btree: catch NULL value before it does harm 2012-06-07 14:43:55 -07:00
bug.c bugs, x86: Fix printk levels for panic, softlockups and stack dumps 2012-01-26 21:28:45 +01:00
bust_spinlocks.c
check_signature.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
checksum.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
clz_tab.c lib: Fix multiple definitions of clz_tab 2012-02-02 10:34:23 +11:00
cmdline.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
cordic.c Docs: wording: functions -> algorithm 2011-10-29 21:20:22 +02:00
cpu_rmap.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
cpu-notifier-error-inject.c cpu: rewrite cpu-notifier-error-inject module 2012-07-30 17:25:22 -07:00
cpumask.c lib/cpumask.c: remove __any_online_cpu() 2012-03-28 17:14:35 -07:00
crc7.c
crc8.c
crc16.c
crc32.c lib/crc32.c: fix unused variables warnings 2012-07-30 17:25:17 -07:00
crc32defs.h crc32: select an algorithm via Kconfig 2012-03-23 16:58:38 -07:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
debug_locks.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
debugobjects.c debugobjects: Fill_pool() returns void now 2012-04-18 13:38:48 +02:00
dec_and_lock.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
decompress_bunzip2.c decompress_bunzip2: remove invalid vi modeline 2011-12-06 10:00:05 +01:00
decompress_inflate.c
decompress_unlzma.c treewide: Fix comment and string typo 'bufer' 2011-12-06 09:53:40 +01:00
decompress_unlzo.c unlzo: fix input buffer free 2012-01-12 20:13:13 -08:00
decompress_unxz.c
decompress.c
devres.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
digsig.c digsig: add hash size comparision on signature verification 2012-09-13 09:13:02 +08:00
div64.c lib: correct link to the original source for div64_u64 2012-06-28 11:51:39 +02:00
dma-debug.c dma-debug: debugfs_create_bool() takes a u32 pointer 2012-07-02 12:11:40 +02:00
dump_stack.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
dynamic_debug.c Revert "dynamic_debug: remove unneeded includes" 2012-05-07 16:47:32 -07:00
dynamic_queue_limits.c bql: Avoid possible inconsistent calculation. 2012-05-31 18:18:17 -04:00
extable.c
fault-inject.c fault-inject: avoid call to random32() if fault injection is disabled 2012-06-20 14:39:36 -07:00
fdt_ro.c of/lib: Allow scripts/dtc/libfdt to be used from kernel code 2012-07-23 13:54:52 +01:00
fdt_rw.c of/lib: Allow scripts/dtc/libfdt to be used from kernel code 2012-07-23 13:54:52 +01:00
fdt_strerror.c of/lib: Allow scripts/dtc/libfdt to be used from kernel code 2012-07-23 13:54:52 +01:00
fdt_sw.c of/lib: Allow scripts/dtc/libfdt to be used from kernel code 2012-07-23 13:54:52 +01:00
fdt_wip.c of/lib: Allow scripts/dtc/libfdt to be used from kernel code 2012-07-23 13:54:52 +01:00
fdt.c of/lib: Allow scripts/dtc/libfdt to be used from kernel code 2012-07-23 13:54:52 +01:00
find_last_bit.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
find_next_bit.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
flex_array.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
flex_proportions.c lib/flex_proportions.c: fix corruption of denominator in flexible proportions 2012-09-25 08:59:21 -07:00
gcd.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
gen_crc32table.c crc32: bolt on crc32c 2012-03-23 16:58:38 -07:00
genalloc.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
halfmd4.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
hexdump.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
hweight.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
idr.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
inflate.c
int_sqrt.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
iomap_copy.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
iomap.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
iommu-helper.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
ioremap.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
irq_regs.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
is_single_threaded.c
jedec_ddr_data.c ddr: add LPDDR2 data from JESD209-2 2012-05-02 00:04:06 -07:00
kasprintf.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
Kconfig Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-30 17:25:34 -07:00
Kconfig.debug powerpc: pSeries reconfig notifier error injection module 2012-07-30 17:25:22 -07:00
Kconfig.kgdb
Kconfig.kmemcheck
klist.c Revert "driver core: check start node in klist_iter_init_node" 2012-04-19 19:17:30 -07:00
kobject_uevent.c netlink: add netlink_kernel_cfg parameter to netlink_kernel_create 2012-06-29 16:46:02 -07:00
kobject.c kobject: fix the uncorrect comment 2012-05-07 16:51:19 -07:00
kstrtox.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
kstrtox.h lib/kstrtox: common code between kstrto*() and simple_strto*() functions 2011-10-31 17:30:56 -07:00
lcm.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
libcrc32c.c
list_debug.c rcu: Fix broken strings in RCU's source code. 2012-07-06 06:01:49 -07:00
list_sort.c
llist.c Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
lru_cache.c
Makefile Use time based periods to age the writeback proportions, 2012-07-30 22:14:04 -07:00
md5.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
memory-notifier-error-inject.c memory: memory notifier error injection module 2012-07-30 17:25:22 -07:00
memweight.c string: introduce memweight() 2012-07-30 17:25:16 -07:00
nlattr.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
notifier-error-inject.c fault-injection: notifier error injection 2012-07-30 17:25:22 -07:00
notifier-error-inject.h fault-injection: notifier error injection 2012-07-30 17:25:22 -07:00
parser.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
pci_iomap.c lib: add NO_GENERIC_PCI_IOPORT_MAP 2012-01-31 23:19:47 +02:00
percpu_counter.c switch the protection of percpu_counter list to spinlock 2012-07-31 09:28:31 +04:00
plist.c bug.h: add include of it to various implicit C users 2012-02-29 17:15:08 -05:00
pm-notifier-error-inject.c PM: PM notifier error injection module 2012-07-30 17:25:22 -07:00
prio_heap.c
prio_tree.c prio_tree: introduce prio_set_parent() 2012-03-23 16:58:36 -07:00
proportions.c
pSeries-reconfig-notifier-error-inject.c powerpc: pSeries reconfig notifier error injection module 2012-07-30 17:25:22 -07:00
radix-tree.c radix-tree: fix contiguous iterator 2012-06-05 10:46:40 -07:00
random32.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
ratelimit.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
rational.c lib: Change mail address of Oskar Schirmer 2012-05-17 15:18:37 +02:00
rbtree.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
reciprocal_div.c sch_red: Adaptative RED AQM 2011-12-08 19:52:43 -05:00
rwsem-spinlock.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
rwsem.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
scatterlist.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-30 17:25:34 -07:00
sha1.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
show_mem.c
smp_processor_id.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
sort.c
spinlock_debug.c spinlock_debug: print offset in addition to symbol name 2012-07-30 17:25:16 -07:00
stmp_device.c lib: add support for stmp-style devices 2012-04-20 23:27:08 +02:00
string_helpers.c lib/string_helpers.c: make arrays static 2012-05-29 16:22:32 -07:00
string.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
strncpy_from_user.c word-at-a-time: make the interfaces truly generic 2012-05-26 11:33:40 -07:00
strnlen_user.c lib: Fix generic strnlen_user for 32-bit big-endian machines 2012-05-27 20:59:46 -07:00
swiotlb.c swiotlb: print physical addresses consistently with other parts of kernel 2012-05-29 16:22:21 -07:00
syscall.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
test-kstrtox.c lib/test-kstrtox.c: mark const init data with __initconst instead of __initdata 2012-05-29 16:22:32 -07:00
textsearch.c
timerqueue.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
ts_bm.c
ts_fsm.c
ts_kmp.c
uuid.c lib: reduce the use of module.h wherever possible 2012-03-07 15:04:04 -05:00
vsprintf.c vsprintf: add support of '%*ph[CDN]' 2012-07-30 17:25:14 -07:00