Josh Poimboeuf 0d025d271e mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS ... There are three usercopy warnings which are currently being silenced for gcc 4.6 and newer: 1) "copy_from_user() buffer size is too small" compile warning/error This is a static warning which happens when object size and copy size are both const, and copy size > object size. I didn't see any false positives for this one. So the function warning attribute seems to be working fine here. Note this scenario is always a bug and so I think it should be changed to *always* be an error, regardless of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS. 2) "copy_from_user() buffer size is not provably correct" compile warning This is another static warning which happens when I enable __compiletime_object_size() for new compilers (and CONFIG_DEBUG_STRICT_USER_COPY_CHECKS). It happens when object size is const, but copy size is *not*. In this case there's no way to compare the two at build time, so it gives the warning. (Note the warning is a byproduct of the fact that gcc has no way of knowing whether the overflow function will be called, so the call isn't dead code and the warning attribute is activated.) So this warning seems to only indicate "this is an unusual pattern, maybe you should check it out" rather than "this is a bug". I get 102(!) of these warnings with allyesconfig and the __compiletime_object_size() gcc check removed. I don't know if there are any real bugs hiding in there, but from looking at a small sample, I didn't see any. According to Kees, it does sometimes find real bugs. But the false positive rate seems high. 3) "Buffer overflow detected" runtime warning This is a runtime warning where object size is const, and copy size > object size. All three warnings (both static and runtime) were completely disabled for gcc 4.6 with the following commit: 2fb0815c9e ("gcc4: disable __compiletime_object_size for GCC 4.6+") That commit mistakenly assumed that the false positives were caused by a gcc bug in __compiletime_object_size(). But in fact, __compiletime_object_size() seems to be working fine. The false positives were instead triggered by #2 above. (Though I don't have an explanation for why the warnings supposedly only started showing up in gcc 4.6.) So remove warning #2 to get rid of all the false positives, and re-enable warnings #1 and #3 by reverting the above commit. Furthermore, since #1 is a real bug which is detected at compile time, upgrade it to always be an error. Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer needed. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Nilay Vaish <nilayvaish@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-08-30 10:10:21 -07:00
..
842	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2016-03-17 21:38:27 -07:00
fonts	…
lz4	lib: lz4: cleanup unaligned access efficiency detection	2016-04-13 09:22:49 -07:00
lzo	…
mpi	lib/mpi: Fix SG miter leak	2016-07-29 18:30:16 +08:00
raid6	powerpc: Create disable_kernel_{fp,altivec,vsx,spe}()	2015-12-01 13:52:25 +11:00
reed_solomon	…
xz	…
zlib_deflate	zlib_deflate/deftree: remove bi_reverse()	2015-09-10 13:29:01 -07:00
zlib_inflate	…
.gitignore	…
Kconfig	raxix-tree: introduce CONFIG_RADIX_TREE_MULTIORDER	2016-05-20 17:58:30 -07:00
Kconfig.debug	mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS	2016-08-30 10:10:21 -07:00
Kconfig.kasan	mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB	2016-07-28 16:07:41 -07:00
Kconfig.kgdb	kgdb: depends on VT	2016-05-23 17:04:14 -07:00
Kconfig.kmemcheck	…
Kconfig.ubsan	ubsan: fix tree-wide -Wmaybe-uninitialized false positives	2016-03-22 15:36:02 -07:00
Makefile	mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS	2016-08-30 10:10:21 -07:00
argv_split.c	…
asn1_decoder.c	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2016-05-17 09:33:39 -07:00
assoc_array.c	assoc_array: don't call compare_object() on a node	2016-04-06 14:06:48 +01:00
atomic64.c	locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()	2016-06-16 10:48:32 +02:00
atomic64_test.c	locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()	2016-06-16 10:48:32 +02:00
audit.c	…
bcd.c	…
bch.c	…
bitmap.c	x86/uaccess: Move thread_info::addr_limit to thread_struct	2016-07-15 10:26:30 +02:00
bitrev.c	…
bsearch.c	…
btree.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
bug.c	lib/bug.c: use common WARN helper	2016-03-17 15:09:34 -07:00
build_OID_registry	…
bust_spinlocks.c	…
chacha20.c	random: replace non-blocking pool with a Chacha20-based CRNG	2016-07-03 00:57:23 -04:00
check_signature.c	…
checksum.c	ipv4: Update parameters for csum_tcpudp_magic to their original types	2016-03-13 23:55:13 -04:00
clz_ctz.c	…
clz_tab.c	…
cmdline.c	…
compat_audit.c	…
cordic.c	…
cpu-notifier-error-inject.c	…
cpu_rmap.c	sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask()	2015-05-27 15:22:15 +02:00
cpumask.c	cpumask: Export cpumask_any_but()	2016-02-29 09:35:20 +01:00
crc-ccitt.c	…
crc-itu-t.c	lib: crc-itu-t.[ch] fix 0x0x prefix in integer constants	2015-05-26 15:26:43 +02:00
crc-t10dif.c	lib: introduce crc_t10dif_update()	2015-05-30 22:42:24 -07:00
crc7.c	…
crc8.c	…
crc16.c	…
crc32.c	crc32: use ktime_get_ns() for measurement	2016-08-02 19:35:08 -04:00
crc32defs.h	…
ctype.c	…
debug_info.c	kbuild: include core debug info when DEBUG_INFO_REDUCED	2015-06-11 15:08:32 +02:00
debug_locks.c	…
debugobjects.c	debugobjects: insulate non-fixup logic related to static obj from fixup callbacks	2016-05-19 19:12:14 -07:00
dec_and_lock.c	…
decompress.c	lib/decompress: set the compressor name to NULL on error	2015-07-17 16:39:54 -07:00
decompress_bunzip2.c	lib/decompressors: use real out buf size for gunzip with kernel	2015-09-10 13:29:01 -07:00
decompress_inflate.c	lib/decompressors: use real out buf size for gunzip with kernel	2015-09-10 13:29:01 -07:00
decompress_unlz4.c	lib/decompressors: use real out buf size for gunzip with kernel	2015-09-10 13:29:01 -07:00
decompress_unlzma.c	lib/decompress_unlzma: Do a NULL check for pointer	2015-09-10 13:29:01 -07:00
decompress_unlzo.c	lib/decompressors: use real out buf size for gunzip with kernel	2015-09-10 13:29:01 -07:00
decompress_unxz.c	lib/decompressors: use real out buf size for gunzip with kernel	2015-09-10 13:29:01 -07:00
devres.c	devres: use to_pci_dev()	2016-02-07 23:17:59 -08:00
digsig.c	lib/digsig: digsig_verify_rsa(): return -EINVAL if modulo length is zero	2016-05-31 16:42:00 +08:00
div64.c	__div64_32(): make it overridable at compile time	2015-11-16 14:42:12 -05:00
dma-debug.c	dma-debug: track bucket lock state for static checkers	2016-07-26 16:19:19 -07:00
dma-noop.c	dma-mapping: use unsigned long for dma_attrs	2016-08-04 08:50:07 -04:00
dump_stack.c	dump_stack: avoid potential deadlocks	2016-02-05 18:10:40 -08:00
dynamic_debug.c	dynamic_debug: add jump label support	2016-08-04 08:50:07 -04:00
dynamic_queue_limits.c	lib/dynamic_queue_limits.c: simplify includes	2015-02-12 18:54:15 -08:00
earlycpio.c	lib/cpio: Make find_cpio_data()'s offset arg optional	2016-06-08 11:04:19 +02:00
extable.c	extable: add support for relative extables to search and sort routines	2016-02-24 14:57:26 +00:00
fault-inject.c	fault-inject: fix inverted interval/probability values in printk	2015-10-23 17:55:10 +09:00
fdt.c	…
fdt_empty_tree.c	…
fdt_ro.c	…
fdt_rw.c	…
fdt_strerror.c	…
fdt_sw.c	…
fdt_wip.c	…
find_bit.c	lib: rename lib/find_next_bit.c to lib/find_bit.c	2015-04-17 09:03:54 -04:00
flex_array.c	…
flex_proportions.c	lib+mm: fix few spelling mistakes	2016-02-15 11:18:23 +01:00
gcd.c	lib/GCD.c: use binary GCD algorithm instead of Euclidean	2016-05-20 17:58:30 -07:00
gen_crc32table.c	lib: crc32: constify crc32 lookup table	2015-02-13 21:21:35 -08:00
genalloc.c	CPM/QE: use genalloc to manage CPM/QE muram	2015-12-22 17:10:18 -06:00
glob.c	…
halfmd4.c	lib/halfmd4.c: use rol32 inline function in the ROUND macro	2015-11-06 17:50:42 -08:00
hexdump.c	lib/hexdump.c: truncate output in case of overflow	2015-11-06 17:50:42 -08:00
hweight.c	x86/hweight: Get rid of the special calling convention	2016-06-08 15:01:02 +02:00
idr.c	mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd	2015-11-06 17:50:42 -08:00
inflate.c	…
int_sqrt.c	…
interval_tree.c	lib/interval_tree.c: simplify includes	2015-02-12 18:54:15 -08:00
interval_tree_test.c	…
iomap.c	…
iomap_copy.c	lib/iomap_copy.c: add __ioread32_copy()	2016-01-20 17:09:18 -08:00
iommu-common.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc	2015-11-05 16:34:48 -08:00
iommu-helper.c	lib/iommu-helper: skip to next segment	2016-08-02 19:35:07 -04:00
ioremap.c	x86, mm: support huge KVA mappings on x86	2015-04-14 16:49:04 -07:00
iov_iter.c	mm: optimize copy_page_to/from_iter_iovec	2016-07-28 16:07:41 -07:00
irq_poll.c	irq_poll: Fix irq_poll_sched()	2016-01-19 15:26:55 -05:00
irq_regs.c	…
is_single_threaded.c	lib/is_single_threaded.c: change current_is_single_threaded() to use for_each_thread()	2015-11-06 17:50:42 -08:00
jedec_ddr_data.c	…
kasprintf.c	lib/kasprintf.c: add sanity check to kvasprintf	2016-01-16 11:17:27 -08:00
kfifo.c	…
klist.c	klist: fix starting point removed bug in klist iterators	2016-02-07 22:18:47 -08:00
kobject.c	kobject: export kset_find_obj() for module use	2016-02-09 17:36:34 -08:00
kobject_uevent.c	lib/kobject_uevent.c: remove redundant include	2015-02-12 18:54:15 -08:00
kstrtox.c	lib: add "on"/"off" support to kstrtobool	2016-03-17 15:09:34 -07:00
kstrtox.h	…
lcm.c	block: fix blk_stack_limits() regression due to lcm() change	2015-03-31 09:45:50 -06:00
libcrc32c.c	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2016-01-22 11:58:43 -08:00
list_debug.c	list: kill list_force_poison()	2016-03-09 15:43:42 -08:00
list_sort.c	lib/list_sort: use late_initcall to hook in self tests	2015-06-16 14:12:35 -04:00
llist.c	lib/llist.c: fix data race in llist_del_first	2015-11-06 17:50:42 -08:00
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	…
lockref.c	locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition	2015-08-12 11:59:04 +02:00
lru_cache.c	lru_cache: Converted lc_seq_printf_status to return void	2015-11-25 09:22:02 -07:00
md5.c	lib/md5.c: simplify include	2015-02-12 18:54:15 -08:00
memory-notifier-error-inject.c	…
memweight.c	…
net_utils.c	…
netdev-notifier-error-inject.c	net: Add support for CHANGEUPPER notifier error injection	2015-12-03 11:49:23 -05:00
nlattr.c	libnl: fix help of _64bit functions	2016-04-23 20:13:24 -04:00
nmi_backtrace.c	printk/nmi: generic solution for safe printk in NMI	2016-05-20 17:58:30 -07:00
nodemask.c	include/linux/nodemask.h: create next_node_in() helper	2016-05-19 19:12:14 -07:00
notifier-error-inject.c	…
notifier-error-inject.h	…
of-reconfig-notifier-error-inject.c	…
oid_registry.c	…
once.c	once: make helper generic for calling functions once	2015-10-08 05:26:36 -07:00
parser.c	…
pci_iomap.c	libnvdimm for 4.3:	2015-09-08 14:35:59 -07:00
percpu-refcount.c	lib+mm: fix few spelling mistakes	2016-02-15 11:18:23 +01:00
percpu_counter.c	percpu_counter: update debugobjects fixup callbacks return type	2016-05-19 19:12:14 -07:00
percpu_ida.c	mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM	2015-11-06 17:50:42 -08:00
percpu_test.c	…
plist.c	lib/plist.c: remove redundant include	2015-02-12 18:54:16 -08:00
pm-notifier-error-inject.c	…
radix-tree.c	radix-tree: account nodes to memcg only if explicitly requested	2016-08-02 17:31:41 -04:00
random32.c	timers: Remove set_timer_slack() leftovers	2016-07-07 10:35:09 +02:00
ratelimit.c	ratelimit: extend to print suppressed messages on release	2016-08-02 19:35:06 -04:00
rational.c	…
rbtree.c	Introduce rb_replace_node_rcu()	2016-07-06 10:51:14 +01:00
rbtree_test.c	…
reciprocal_div.c	…
rhashtable.c	rhashtable: fix a memory leak in alloc_bucket_locks()	2016-08-26 21:59:53 -07:00
scatterlist.c	scatterlist: fix a typo in comment block of sg_miter_stop()	2016-02-08 10:15:17 -08:00
seq_buf.c	tracing: Use seq_buf_used() in seq_buf_to_user() instead of len	2015-12-23 14:27:20 -05:00
sg_pool.c	lib: scatterlist: move SG pool code from SCSI driver to lib/sg_pool.c	2016-04-15 16:53:14 -04:00
sg_split.c	lib: scatterlist: add sg splitting function	2015-08-24 14:28:01 -06:00
sha1.c	lib: EXPORT_SYMBOL sha_init	2015-03-23 22:12:08 -04:00
show_mem.c	lib/show_mem.c: correct reserved memory calculation	2015-09-08 15:35:28 -07:00
smp_processor_id.c	…
sort.c	lib/sort: Add 64 bit swap function	2015-06-25 17:00:40 -07:00
stackdepot.c	lib/stackdepot.c: use __GFP_NOWARN for stack allocations	2016-07-28 16:07:41 -07:00
stmp_device.c	lib/stmp_device.c: replace module.h include	2015-02-12 18:54:16 -08:00
string.c	lib: move strtobool() to kstrtobool()	2016-03-17 15:09:34 -07:00
string_helpers.c	string_helpers: add kstrdup_quotable_file	2016-04-21 10:47:26 +10:00
strncpy_from_user.c	unsafe_[get|put]_user: change interface to use a error target label	2016-08-08 13:02:01 -07:00
strnlen_user.c	unsafe_[get|put]_user: change interface to use a error target label	2016-08-08 13:02:01 -07:00
swiotlb.c	dma-mapping: use unsigned long for dma_attrs	2016-08-04 08:50:07 -04:00
syscall.c	…
test-kstrtox.c	kstrto*: accept "-0" for signed conversion	2015-09-10 13:29:01 -07:00
test-string_helpers.c	lib/test-string_helpers.c: fix and improve string_get_size() tests	2016-02-03 08:28:43 -08:00
test_bitmap.c	test_bitmap: unit tests for lib/bitmap.c	2016-02-19 22:54:09 -05:00
test_bpf.c	bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apis	2016-05-16 13:49:32 -04:00
test_firmware.c	test: firmware_class: add asynchronous request trigger	2016-01-07 13:44:22 -07:00
test_hash.c	vfs: make the string hashes salt the hash	2016-06-10 20:21:46 -07:00
test_hexdump.c	test_hexdump: print statistics at the end	2016-01-20 17:09:18 -08:00
test_kasan.c	kasan/tests: add tests for user memory access functions	2016-05-20 17:58:30 -07:00
test_module.c	…
test_printf.c	mm, printk: introduce new format string for flags	2016-03-15 16:55:16 -07:00
test_rhashtable.c	rhashtable-test: Fix max_size parameter description	2016-08-08 12:52:42 -07:00
test_static_key_base.c	locking/static_keys: Provide a selftest	2015-08-03 11:51:12 +02:00
test_static_keys.c	locking/static_keys: Avoid nested functions	2016-02-09 10:27:29 +01:00
test_user_copy.c	…
test_uuid.c	lib/uuid: add a test module	2016-05-30 15:26:57 -07:00
textsearch.c	…
timerqueue.c	timerqueue: Let timerqueue_add/del return information	2015-04-22 17:06:49 +02:00
ts_bm.c	…
ts_fsm.c	…
ts_kmp.c	…
ubsan.c	UBSAN: fix typo in format string	2016-08-02 17:31:41 -04:00
ubsan.h	UBSAN: run-time undefined behavior sanity checker	2016-01-20 17:09:18 -08:00
ucs2_string.c	lib/ucs2_string: Correct ucs2 -> utf8 conversion	2016-02-16 12:49:05 +00:00
uuid.c	lib/uuid.c: use correct offset in uuid parser	2016-05-30 15:26:57 -07:00
vsprintf.c	lib/uuid.c: introduce a few more generic helpers	2016-05-20 17:58:30 -07:00