Alexandre Courbot 1431574a1c lib/decompressors: fix "no limit" output buffer length ... When decompressing into memory, the output buffer length is set to some arbitrarily high value (0x7fffffff) to indicate the output is, virtually, unlimited in size. The problem with this is that some platforms have their physical memory at high physical addresses (0x80000000 or more), and that the output buffer address and its "unlimited" length cannot be added without overflowing. An example of this can be found in inflate_fast(): /* next_out is the output buffer address */ out = strm->next_out - OFF; /* avail_out is the output buffer size. end will overflow if the output * address is >= 0x80000104 */ end = out + (strm->avail_out - 257); This has huge consequences on the performance of kernel decompression, since the following exit condition of inflate_fast() will be always true: } while (in < last && out < end); Indeed, "end" has overflowed and is now always lower than "out". As a result, inflate_fast() will return after processing one single byte of input data, and will thus need to be called an unreasonably high number of times. This probably went unnoticed because kernel decompression is fast enough even with this issue. Nonetheless, adjusting the output buffer length in such a way that the above pointer arithmetic never overflows results in a kernel decompression that is about 3 times faster on affected machines. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Tested-by: Jon Medhurst <tixy@linaro.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2013-09-11 15:58:38 -07:00
..
fonts	lib: Move fonts from drivers/video/console/ to lib/fonts/	2013-06-28 10:28:22 +02:00
lz4	lib/lz4: correct the LZ4 license	2013-08-23 09:51:22 -07:00
lzo	lib/lzo: Update LZO compression to current upstream version	2013-02-20 19:36:01 +01:00
mpi	alpha: Modernize lib/mpi/longlong.h	2013-07-19 13:54:23 -07:00
raid6	md update for v3.12	2013-09-10 13:03:41 -07:00
reed_solomon
xz	decompressors: fix typo "POWERPC"	2013-03-13 15:21:48 -07:00
zlib_deflate
zlib_inflate
.gitignore
argv_split.c	argv_split(): teach it to handle mutable strings	2013-04-29 18:28:19 -07:00
asn1_decoder.c	Nothing all that exciting; a new module-from-fd syscall for those who want	2012-12-19 07:55:08 -08:00
atomic64_test.c
atomic64.c	lib: atomic64: Initialize locks statically to fix early users	2012-12-20 13:50:16 -08:00
audit.c
average.c
bcd.c
bch.c
bitmap.c	propagate name change to comments in kernel source	2012-12-06 10:39:54 +01:00
bitrev.c
bsearch.c
btree.c
bug.c	taint: add explicit flag to show whether lock dep is still OK.	2013-01-21 17:17:57 +10:30
build_OID_registry	X.509: do not emit any informational output	2013-06-19 17:54:06 +02:00
bust_spinlocks.c	printk: Provide a wake_up_klogd() off-case	2013-03-22 16:41:20 -07:00
check_signature.c
checksum.c	asm-generic headers: Allow yet more arch overrides in checksum.h	2013-02-11 20:00:33 +05:30
clz_ctz.c	lib: add weak clz/ctz functions	2013-07-09 10:33:30 -07:00
clz_tab.c
cmdline.c
cordic.c
cpu_rmap.c	lib: cpu_rmap: avoid flushing all workqueues	2013-01-11 14:54:54 -08:00
cpu-notifier-error-inject.c
cpumask.c	bootmem: fix wrong call parameter for free_bootmem()	2012-12-11 17:22:28 -08:00
crc7.c
crc8.c
crc16.c
crc32.c	lib/crc32: update the comments of crc32_{be,le}_generic()	2013-09-11 15:58:38 -07:00
crc32defs.h
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c	Reinstate "crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework"	2013-09-07 12:56:26 +10:00
ctype.c
debug_locks.c	mutex: Add support for wound/wait style locks	2013-06-26 12:10:56 +02:00
debugobjects.c	debugobjects: Make debug_object_activate() return status	2013-08-18 17:39:55 -07:00
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c	lib/decompressors: fix "no limit" output buffer length	2013-09-11 15:58:38 -07:00
decompress_unlz4.c	lib: add support for LZ4-compressed kernel	2013-07-09 10:33:30 -07:00
decompress_unlzma.c
decompress_unlzo.c	lib/lzo: Rename lzo1x_decompress.c to lzo1x_decompress_safe.c	2013-02-20 19:36:00 +01:00
decompress_unxz.c
decompress.c	lib: add support for LZ4-compressed kernel	2013-07-09 10:33:30 -07:00
devres.c	lib/devres.c: fix misplaced #endif	2013-02-27 19:10:09 -08:00
digsig.c	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2013-02-21 08:18:12 -08:00
div64.c	math64: New separate div64_u64_rem helper	2013-08-23 09:02:14 -04:00
dma-debug.c	dma-debug: update DMA debug API to better handle multiple mappings of a buffer	2013-03-22 16:41:20 -07:00
dump_stack.c	x86, asmlinkage: Make dump_stack visible	2013-08-06 14:21:01 -07:00
dynamic_debug.c	dynamic debug: line queries failing due to uninitialized local variable	2013-08-28 12:10:53 -07:00
dynamic_queue_limits.c
earlycpio.c	earlycpio.c: Fix the confusing comment of find_cpio_data().	2013-08-14 23:24:01 +02:00
extable.c
fault-inject.c	debugfs: add get/set for atomic types	2013-06-03 13:55:01 -07:00
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_last_bit.c
find_next_bit.c
flex_array.c
flex_proportions.c
gcd.c
gen_crc32table.c
genalloc.c	lib/genalloc.c: correct dev_get_gen_pool documentation	2013-09-11 15:58:38 -07:00
halfmd4.c
hexdump.c	dynamic_debug: dynamic hex dump	2013-01-17 12:19:09 -08:00
hweight.c
idr.c	idr: print a stack dump after ida_remove warning	2013-07-03 16:08:04 -07:00
inflate.c
int_sqrt.c	lib/int_sqrt.c: optimize square root algorithm	2013-04-29 18:28:19 -07:00
interval_tree_test_main.c	random32: rename random32 to prandom	2012-12-17 17:15:26 -08:00
interval_tree.c
iomap_copy.c
iomap.c
iommu-helper.c
ioremap.c
iovec.c	Hoist memcpy_fromiovec/memcpy_toiovec into lib/	2013-05-20 10:24:22 +09:30
irq_regs.c
is_single_threaded.c
jedec_ddr_data.c
kasprintf.c
Kconfig	Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2013-09-07 14:31:18 -07:00
Kconfig.debug	ARC changes for 3.12	2013-09-09 09:05:33 -07:00
Kconfig.kgdb	treewide: Fix typo in printk	2013-06-18 13:48:45 +02:00
Kconfig.kmemcheck
kfifo.c	kfifo: fix kfifo_alloc() and kfifo_init()	2013-02-27 19:10:23 -08:00
klist.c	klist: del waiter from klist_remove_waiters before wakeup waitting process	2013-05-21 10:16:39 -07:00
kobject_uevent.c
kobject.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
kstrtox.c	kstrto*: add documentation	2012-12-17 17:15:22 -08:00
kstrtox.h
lcm.c
libcrc32c.c
list_debug.c
list_sort.c	lib/: rename random32() to prandom_u32()	2013-04-29 18:28:42 -07:00
llist.c	llist: fix/simplify llist_add() and llist_add_batch()	2013-07-13 13:29:24 +04:00
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	mutex: Move ww_mutex definitions to ww_mutex.h	2013-07-12 12:07:46 +02:00
lockref.c	lockref: add ability to mark lockrefs "dead"	2013-09-07 15:49:18 -07:00
lru_cache.c	lru_cache: introduce lc_get_cumulative()	2013-03-22 22:17:36 -06:00
Makefile	lockref: uninline lockref helper functions	2013-09-02 11:58:20 -07:00
md5.c
memory-notifier-error-inject.c
memweight.c
net_utils.c	net: core: move mac_pton() to lib/net_utils.c	2013-06-05 12:00:27 -07:00
nlattr.c
notifier-error-inject.c	mode_t, whack-a-mole at 11...	2013-04-09 14:13:05 -04:00
notifier-error-inject.h
of-reconfig-notifier-error-inject.c	powerpc+of: Rename and fix OF reconfig notifier error inject module	2012-12-14 10:32:52 +11:00
oid_registry.c	Give the OID registry file module info to avoid kernel tainting	2013-05-05 14:38:00 -07:00
parser.c	lib/parser.c: fix up comments for valid return values from match_number	2013-02-21 17:22:25 -08:00
pci_iomap.c
percpu_counter.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
percpu-refcount.c	percpu-refcount: use RCU-sched insted of normal RCU	2013-06-16 16:12:26 -07:00
percpu-rwsem.c	percpu_rw_semaphore: add lockdep annotations	2012-12-17 17:15:18 -08:00
plist.c
pm-notifier-error-inject.c
prio_heap.c
proportions.c
radix-tree.c
random32.c	prandom: introduce prandom_bytes() and prandom_bytes_state()	2012-12-17 17:15:26 -08:00
ratelimit.c
rational.c
rbtree_test.c	rbtree_test: add __init/__exit annotations	2013-04-30 17:04:07 -07:00
rbtree.c	lib/rbtree.c: avoid the use of non-static __always_inline	2013-01-11 14:54:56 -08:00
reciprocal_div.c
rwsem-spinlock.c	rwsem: simplify __rwsem_do_wake	2013-05-07 07:20:16 -07:00
rwsem.c	rwsem: check counter to avoid cmpxchg calls	2013-05-07 16:11:51 -07:00
scatterlist.c	lib/scatterlist: error handling in __sg_alloc_table()	2013-07-09 10:33:31 -07:00
sha1.c
show_mem.c	mm, show_mem: suppress page counts in non-blockable contexts	2013-04-29 15:54:28 -07:00
smp_processor_id.c
sort.c
spinlock_debug.c
stmp_device.c
string_helpers.c	lib/string_helpers: introduce generic string_unescape	2013-04-30 17:04:03 -07:00
string.c
strncpy_from_user.c
strnlen_user.c
swiotlb.c	swiotlb: replace dma_length with sg_dma_len() macro	2013-08-09 11:28:42 -04:00
syscall.c
test-kstrtox.c
test-string_helpers.c	lib/string_helpers: introduce generic string_unescape	2013-04-30 17:04:03 -07:00
textsearch.c
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ucs2_string.c	Move utf16 functions to kernel core and rename	2013-04-15 21:23:03 +01:00
usercopy.c	Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS	2013-04-30 17:04:09 -07:00
uuid.c	uuid: use prandom_bytes()	2013-04-29 18:28:42 -07:00
vsprintf.c	add formats for dentry/file pathnames	2013-09-04 00:13:11 -04:00