linux_dsm_epyc7002/Documentation
Andrey Ryabinin c6d308534a UBSAN: run-time undefined behavior sanity checker
UBSAN uses compile-time instrumentation to catch undefined behavior
(UB).  Compiler inserts code that perform certain kinds of checks before
operations that could cause UB.  If check fails (i.e.  UB detected)
__ubsan_handle_* function called to print error message.

So the most of the work is done by compiler.  This patch just implements
ubsan handlers printing errors.

GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.

[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Issues which UBSAN has found thus far are:

Found bugs:

 * out-of-bounds access - 97840cb67f ("netfilter: nfnetlink: fix
   insufficient validation in nfnetlink_bind")

undefined shifts:

 * d48458d4a7 ("jbd2: use a better hash function for the revoke
   table")

 * 10632008b9 ("clockevents: Prevent shift out of bounds")

 * 'x << -1' shift in ext4 -
   http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com>

 * undefined rol32(0) -
   http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com>

 * undefined dirty_ratelimit calculation -
   http://lkml.kernel.org/r/<566594E2.3050306@odin.com>

 * undefined roundown_pow_of_two(0) -
   http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com>

 * [WONTFIX] undefined shift in __bpf_prog_run -
   http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com>

   WONTFIX here because it should be fixed in bpf program, not in kernel.

signed overflows:

 * 32a8df4e0b ("sched: Fix odd values in effective_load()
   calculations")

 * mul overflow in ntp -
   http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com>

 * incorrect conversion into rtc_time in rtc_time64_to_tm() -
   http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com>

 * unvalidated timespec in io_getevents() -
   http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com>

 * [NOTABUG] signed overflow in ktime_add_safe() -
   http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com>

[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yury Gribov <y.gribov@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
..
ABI Merge git://www.linux-watchdog.org/linux-watchdog 2016-01-17 12:15:38 -08:00
accounting Documentation-getdelays: Apply a recommendation from "checkpatch.pl" in main() 2015-12-24 07:22:32 -07:00
acpi
aoe
arm A relatively boring cycle in the docs tree. There's a few kernel-doc 2016-01-17 11:55:07 -08:00
arm64 arm64: Documentation: add list of software workarounds for errata 2015-12-11 17:33:21 +00:00
auxdisplay
backlight
blackfin
block A relatively boring cycle in the docs tree. There's a few kernel-doc 2016-01-17 11:55:07 -08:00
blockdev
bus-devices
cdrom
cgroup-v1 cgroup: rename cgroup documentations 2016-01-11 23:14:51 -05:00
cma
connector
console
cpu-freq Documentation: cpufreq: intel_pstate: enhance documentation 2016-01-05 13:47:37 +01:00
cpuidle
cris
crypto
development-process
device-mapper dm verity: add ignore_zero_blocks feature 2015-12-10 10:39:03 -05:00
devicetree dmaengine fixes for 4.5-rc1 2016-01-20 10:15:21 -08:00
dmaengine Merge branch 'topic/async' into for-linus 2016-01-06 15:17:47 +05:30
DocBook Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2016-01-17 13:40:25 -08:00
driver-model
dvb [media] use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:38:59 -02:00
early-userspace
EDID
extcon
fault-injection net: Add support for CHANGEUPPER notifier error injection 2015-12-03 11:49:23 -05:00
fb
features mm, thp: remove infrastructure for handling splitting PMDs 2016-01-15 17:56:32 -08:00
filesystems Documentation/filesystems/vfat.txt: update the limitation for fat fallocate 2016-01-20 17:09:18 -08:00
firmware_class
fmc
fpga
frv
gpio Doc: gpio: Fix typos in Documentation/gpio 2015-11-20 16:51:16 -07:00
hid
hwmon hwmon: (pmbus) Add client driver for LTC3815 2015-12-18 08:20:59 -08:00
i2c i2c: i801: add Intel Lewisburg device IDs 2015-11-20 16:22:21 +01:00
ia64
ide
iio iio: Documentation: Add IIO configfs documentation 2015-12-03 18:19:28 +00:00
infiniband
input
ioctl Doc: ioctl: Fix typos in Documentation/ioctl 2015-11-20 16:52:50 -07:00
isdn
ja_JP Documentation: translations: update linux cross reference link 2016-01-11 18:26:58 -07:00
kbuild
kdump
ko_KR Documentation: translations: update linux cross reference link 2016-01-11 18:26:58 -07:00
laptops
leds Documentation: leds: Add description of brightness setting API 2016-01-04 09:57:31 +01:00
locking
m68k
memory-devices
metag
mic
mips
misc-devices
mmc
mn10300
mtd Documentation: mtd: improve nand_ecc.txt for readability and correctness 2015-11-17 17:05:14 -08:00
namespaces
netlabel
networking A relatively boring cycle in the docs tree. There's a few kernel-doc 2016-01-17 11:55:07 -08:00
nfc
nios2
nvdimm libnvdimm: documentation clarifications 2015-11-12 09:55:23 -08:00
nvmem
parisc
PCI
pcmcia
phy
platform
power Merge branches 'pm-pci' and 'pm-core' 2016-01-12 01:10:52 +01:00
powerpc
pps
prctl
pti
ptp
rapidio
RCU documentation: Update RCU requirements based on expedited changes 2015-12-05 12:34:32 -08:00
s390 s390/zcore: remove /sys/kernel/debug/zcore/mem 2015-11-27 09:24:12 +01:00
scheduler
scsi st: allow debug output to be enabled or disabled via sysfs 2015-11-09 17:17:27 -08:00
security keys, trusted: seal with a TPM2 authorization policy 2015-12-20 15:27:13 +02:00
serial
sh
sound ASoC: img: Add documentation for SPDIF in controls 2015-11-16 10:06:58 +00:00
spi spi: tools: move spidev_test metadata 2015-11-30 12:14:12 +00:00
sysctl sysctl: enable strict writes 2016-01-20 17:09:18 -08:00
target
thermal thermal: add description for integral_cutoff unit 2016-01-14 13:29:08 -07:00
timers
tpm
trace x86, tracing, perf: Add trace point for MSR accesses 2015-12-06 12:56:10 +01:00
usb The chipidea changes for v4.5-rc1 2015-12-26 16:59:14 -08:00
vDSO
video4linux [media] media framework: rename pads init function to media_entity_pads_init() 2016-01-11 12:19:03 -02:00
virtual KVM: s390: fix mismatch between user and in-kernel guest limit 2015-12-15 17:08:21 +01:00
vm Merge branch 'akpm' (patches from Andrew) 2016-01-17 12:58:52 -08:00
w1
watchdog watchdog: Drop pointer to watchdog device from struct watchdog_device 2016-01-11 21:53:59 +01:00
wimax
x86
xtensa
zh_CN [media] media framework: rename pads init function to media_entity_pads_init() 2016-01-11 12:19:03 -02:00
00-INDEX
adding-syscalls.txt
applying-patches.txt
assoc_array.txt
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt
cgroup-v2.txt cgroup: rename cgroup documentations 2016-01-11 23:14:51 -05:00
Changes
circular-buffers.txt
clk.txt
coccinelle.txt
CodeOfConflict
CodingStyle Documentation: fix typo in CodingStyle 2016-01-11 18:18:16 -07:00
cpu-hotplug.txt Documentation: cpu-hotplug: Fix sysfs mount instructions 2015-12-10 11:35:30 -07:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
devices.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt DMA-API: fix confusing sentence in Documentation/DMA-API.txt 2016-01-11 18:29:00 -07:00
DMA-attributes.txt
dma-buf-sharing.txt
DMA-ISA-LPC.txt
dontdiff Documentation: dontdiff: remove media from dontdiff 2015-11-11 10:08:07 -07:00
dynamic-debug-howto.txt
edac.txt EDAC: Remove references to bluesmoke.sourceforge.net 2015-11-26 14:46:06 +01:00
efi-stub.txt
eisa.txt
email-clients.txt A few more documentation patches that wandered in and have no reason to 2015-11-13 09:19:05 -08:00
flexible-arrays.txt
futex-requeue-pi.txt
gcov.txt
gdb-kernel-debugging.txt
highuid.txt
HOWTO Documentation: HOWTO: update code cross reference link 2015-12-10 11:19:35 -07:00
hsi.txt
hw_random.txt
hwspinlock.txt
init.txt
initrd.txt
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt ipmi watchdog : add panic_wdt_timeout parameter 2015-11-16 06:28:43 -06:00
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kasan.txt
kernel-doc-nano-HOWTO.txt
kernel-docs.txt Documentation: translations: update linux cross reference link 2016-01-11 18:26:58 -07:00
kernel-parameters.txt A relatively boring cycle in the docs tree. There's a few kernel-doc 2016-01-17 11:55:07 -08:00
kernel-per-CPU-kthreads.txt
kmemcheck.txt
kmemleak.txt
kobject.txt
kprobes.txt
kref.txt
kselftest.txt
ldm.txt
local_ops.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lzo.txt
magic-number.txt
mailbox.txt
Makefile spi: Move spi code from Documentation to tools 2015-11-23 14:54:01 +00:00
ManagementStyle
md-cluster.txt md-cluster: update the documentation 2016-01-06 11:39:06 +11:00
md.txt
memory-barriers.txt virtio: barrier rework+fixes 2016-01-18 16:44:24 -08:00
memory-hotplug.txt
men-chameleon-bus.txt
module-signing.txt
mono.txt
nommu-mmap.txt
ntb.txt
numastat.txt
oops-tracing.txt
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pinctrl.txt
pnp.txt
preempt-locking.txt
printk-formats.txt printk-formats.txt: remove unimplemented %pT 2016-01-16 11:17:30 -08:00
pwm.txt
ramoops.txt
rbtree.txt
remoteproc.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
stable_api_nonsense.txt
stable_kernel_rules.txt stable_kernel_rules.txt: Remove extra space after Cc: 2015-11-20 16:54:57 -07:00
static-keys.txt
SubmitChecklist
SubmittingDrivers
SubmittingPatches A few more documentation patches that wandered in and have no reason to 2015-11-13 09:19:05 -08:00
svga.txt
sysfs-rules.txt
sysrq.txt
this_cpu_ops.txt
ubsan.txt UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt
volatile-considered-harmful.txt
workqueue.txt
xillybus.txt
xz.txt
zorro.txt