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236dec0510
linux/lib
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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 fonts: Add 6x10 font 2014-10-09 11:35:48 +03:00
lz4 lib: lz4: cleanup unaligned access efficiency detection 2016-04-13 09:22:49 -07:00
lzo lzo: check for length overrun in variable length encoding. 2014-09-28 11:08:01 +02:00
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 lib/xz: enable all filters by default in Kconfig 2014-06-04 16:54:18 -07:00
zlib_deflate zlib_deflate/deftree: remove bi_reverse() 2015-09-10 13:29:01 -07:00
zlib_inflate zlib: clean up some dead code 2014-08-06 18:01:24 -07:00
.gitignore
argv_split.c argv_split(): teach it to handle mutable strings 2013-04-29 18:28:19 -07:00
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_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
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
audit.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
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 ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction 2014-12-22 16:43:06 +00:00
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 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
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 lib/clz_ctz.c: add prototype declarations in lib/clz_ctz.c 2014-04-03 16:21:12 -07:00
clz_tab.c
cmdline.c lib: Add a generic cmdline parse function parse_option_str 2014-10-03 18:40:58 +01:00
compat_audit.c audit: Add generic compat syscall support 2014-03-20 10:11:35 -04:00
cordic.c
cpu_rmap.c sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask() 2015-05-27 15:22:15 +02:00
cpu-notifier-error-inject.c
cpumask.c cpumask: Export cpumask_any_but() 2016-02-29 09:35:20 +01:00
crc7.c lib/crc7: Shift crc7() output left 1 bit 2014-05-16 14:26:52 -04:00
crc8.c
crc16.c
crc32.c crc32: use ktime_get_ns() for measurement 2016-08-02 19:35:08 -04:00
crc32defs.h
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
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 mutex: Add support for wound/wait style locks 2013-06-26 12:10:56 +02:00
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_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
decompress.c lib/decompress: set the compressor name to NULL on error 2015-07-17 16:39:54 -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_empty_tree.c lib: add fdt_empty_tree.c 2014-04-30 19:49:37 +01:00
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.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 reciprocal_divide: update/correction of the algorithm 2014-01-21 23:17:20 -08:00
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 lib/glob.c: add CONFIG_GLOB_SELFTEST 2014-08-06 18:01:25 -07:00
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 lib/int_sqrt.c: optimize square root algorithm 2013-04-29 18:28:19 -07:00
interval_tree_test.c lib: Export interval_tree 2014-05-05 09:09:14 +02:00
interval_tree.c lib/interval_tree.c: simplify includes 2015-02-12 18:54:15 -08:00
iomap_copy.c lib/iomap_copy.c: add __ioread32_copy() 2016-01-20 17:09:18 -08:00
iomap.c Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
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
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
kfifo.c kfifo: use BUG_ON 2014-08-08 15:57:25 -07:00
klist.c klist: fix starting point removed bug in klist iterators 2016-02-07 22:18:47 -08:00
kobject_uevent.c lib/kobject_uevent.c: remove redundant include 2015-02-12 18:54:15 -08:00
kobject.c kobject: export kset_find_obj() for module use 2016-02-09 17:36:34 -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 locking/lockdep: Revert qrwlock recusive stuff 2014-10-03 06:09:30 +02:00
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
Makefile mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -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 mac_pton: Use bool not int return 2014-06-25 17:45:43 -07:00
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 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
once.c once: make helper generic for calling functions once 2015-10-08 05:26:36 -07:00
parser.c lib/parser.c: put EXPORT_SYMBOLs in the conventional place 2014-01-23 16:36:55 -08:00
pci_iomap.c libnvdimm for 4.3: 2015-09-08 14:35:59 -07:00
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 percpu: add test module for various percpu operations 2013-11-13 12:09:11 +09:00
percpu-refcount.c lib+mm: fix few spelling mistakes 2016-02-15 11:18:23 +01:00
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_test.c rbtree/test: test rbtree_postorder_for_each_entry_safe() 2014-01-23 16:37:03 -08:00
rbtree.c Introduce rb_replace_node_rcu() 2016-07-06 10:51:14 +01:00
reciprocal_div.c reciprocal_divide: update/correction of the algorithm 2014-01-21 23:17:20 -08:00
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 percpu: add preemption checks to __this_cpu ops 2014-04-07 16:36:14 -07:00
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_helpers.c string_helpers: add kstrdup_quotable_file 2016-04-21 10:47:26 +10:00
string.c lib: move strtobool() to kstrtobool() 2016-03-17 15:09:34 -07:00
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 lib/syscall.c: unexport task_current_syscall() 2014-04-03 16:21:06 -07:00
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: add minimal module for verification testing 2014-01-23 16:36:57 -08:00
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: check copy_to/from_user boundary validation 2014-01-23 16:36:57 -08:00
test_uuid.c lib/uuid: add a test module 2016-05-30 15:26:57 -07:00
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
textsearch.c lib/textsearch.c: remove textsearch_put reference from comments 2014-10-14 02:18:14 +02:00
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