Linus Torvalds 1bd4403d86 unsafe_[get|put]_user: change interface to use a error target label ... When I initially added the unsafe_[get|put]_user() helpers in commit 5b24a7a2aa ("Add 'unsafe' user access functions for batched accesses"), I made the mistake of modeling the interface on our traditional __[get|put]_user() functions, which return zero on success, or -EFAULT on failure. That interface is fairly easy to use, but it's actually fairly nasty for good code generation, since it essentially forces the caller to check the error value for each access. In particular, since the error handling is already internally implemented with an exception handler, and we already use "asm goto" for various other things, we could fairly easily make the error cases just jump directly to an error label instead, and avoid the need for explicit checking after each operation. So switch the interface to pass in an error label, rather than checking the error value in the caller. Best do it now before we start growing more users (the signal handling code in particular would be a good place to use the new interface). So rather than if (unsafe_get_user(x, ptr)) ... handle error .. the interface is now unsafe_get_user(x, ptr, label); where an error during the user mode fetch will now just cause a jump to 'label' in the caller. Right now the actual _implementation_ of this all still ends up being a "if (err) goto label", and does not take advantage of any exception label tricks, but for "unsafe_put_user()" in particular it should be fairly straightforward to convert to using the exception table model. Note that "unsafe_get_user()" is much harder to convert to a clever exception table model, because current versions of gcc do not allow the use of "asm goto" (for the exception) with output values (for the actual value to be fetched). But that is hopefully not a limitation in the long term. [ Also note that it might be a good idea to switch unsafe_get_user() to actually _return_ the value it fetches from user space, but this commit only changes the error handling semantics ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-08-08 13:02:01 -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
reed_solomon
xz
zlib_deflate
zlib_inflate
.gitignore
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_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
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
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_rmap.c
cpu-notifier-error-inject.c
cpumask.c	cpumask: Export cpumask_any_but()	2016-02-29 09:35:20 +01:00
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
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c
debug_info.c
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_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c
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
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
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
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit.c
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
genalloc.c
glob.c
halfmd4.c
hexdump.c
hweight.c	x86/hweight: Get rid of the special calling convention	2016-06-08 15:01:02 +02:00
idr.c
inflate.c
int_sqrt.c
interval_tree_test.c
interval_tree.c
iomap_copy.c	lib/iomap_copy.c: add __ioread32_copy()	2016-01-20 17:09:18 -08:00
iomap.c
iommu-common.c
iommu-helper.c	lib/iommu-helper: skip to next segment	2016-08-02 19:35:07 -04:00
ioremap.c
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
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	Merge branch 'akpm' (patches from Andrew)	2016-08-02 21:08:07 -04:00
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
klist.c	klist: fix starting point removed bug in klist iterators	2016-02-07 22:18:47 -08:00
kobject_uevent.c
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
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
llist.c
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
lru_cache.c
Makefile	A number of improvements for the /dev/random driver; the most	2016-07-27 15:11:55 -07:00
md5.c
memory-notifier-error-inject.c
memweight.c
net_utils.c
netdev-notifier-error-inject.c
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
parser.c
pci_iomap.c
percpu_counter.c	percpu_counter: update debugobjects fixup callbacks return type	2016-05-19 19:12:14 -07:00
percpu_ida.c
percpu_test.c
percpu-refcount.c	lib+mm: fix few spelling mistakes	2016-02-15 11:18:23 +01:00
plist.c
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.c	Introduce rb_replace_node_rcu()	2016-07-06 10:51:14 +01:00
reciprocal_div.c
rhashtable.c	rhashtable: accept GFP flags in rhashtable_walk_init	2016-04-05 10:56:32 +02:00
scatterlist.c	scatterlist: fix a typo in comment block of sg_miter_stop()	2016-02-08 10:15:17 -08:00
seq_buf.c
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
sha1.c
show_mem.c
smp_processor_id.c
sort.c
stackdepot.c	lib/stackdepot.c: use __GFP_NOWARN for stack allocations	2016-07-28 16:07:41 -07:00
stmp_device.c
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
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: accept GFP flags in rhashtable_walk_init	2016-04-05 10:56:32 +02:00
test_static_key_base.c
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
test-kstrtox.c
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
timerqueue.c
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
usercopy.c
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