linux/scripts
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
..
basic fixdep: constify strrcmp arguments 2015-12-07 12:42:55 +01:00
coccinelle coccinelle: tests: unsigned value cannot be lesser than zero 2016-01-12 17:47:47 +01:00
dtc
gdb
genksyms genksyms: Handle string literals with spaces in reference files 2015-12-09 15:19:23 +01:00
kconfig kconfig: fix qconf segfault by deleting heap objects 2016-01-11 09:45:08 +01:00
ksymoops
mod modpost: don't add a trailing wildcard for OF module aliases 2016-01-14 16:00:49 -08:00
package package Makefile: fix perf-tar targets when outdir is set 2015-11-24 17:49:42 +01:00
selinux
tracing
.gitignore
analyze_suspend.py
asn1_compiler.c
bloat-o-meter scripts/bloat-o-meter: fix python3 syntax error 2016-01-14 16:00:49 -08:00
bootgraph.pl
check_extable.sh
check-lc_ctype.c
checkincludes.pl
checkkconfigsymbols.py checkkconfigsymbols.py: find similar symbols 2015-12-14 10:54:23 -08:00
checkpatch.pl checkpatch: fix a number of COMPLEX_MACRO false positives 2016-01-20 17:09:18 -08:00
checkstack.pl
checksyscalls.sh
checkversion.pl
cleanfile
cleanpatch
coccicheck
config
conmakehash.c
decode_stacktrace.sh
decodecode
depmod.sh
diffconfig
docproc.c
export_report.pl
extract-cert.c
extract-ikconfig
extract-module-sig.pl
extract-sys-certs.pl
extract-vmlinux
gcc-goto.sh
gcc-ld
gcc-version.sh
gcc-x86_32-has-stack-protector.sh
gcc-x86_64-has-stack-protector.sh
gen_initramfs_list.sh
get_maintainer.pl scripts/get_maintainer.pl: handle file names beginning with ./ 2016-01-20 17:09:18 -08:00
gfp-translate
headerdep.pl
headers_check.pl
headers_install.sh
headers.sh
kallsyms.c
Kbuild.include
kernel-doc A relatively boring cycle in the docs tree. There's a few kernel-doc 2016-01-17 11:55:07 -08:00
kernel-doc-xml-ref
ld-version.sh ld-version: Fix it on Fedora 2016-01-08 16:34:27 +01:00
Lindent
link-vmlinux.sh um: link with -lpthread 2016-01-10 21:49:48 +01:00
Makefile
Makefile.asm-generic
Makefile.build kbuild: Allow to specify composite modules with modname-m 2015-11-25 11:23:25 +01:00
Makefile.clean
Makefile.dtbinst
Makefile.extrawarn kbuild: Demote 'sign-compare' warning to W=2 2016-01-12 16:07:03 +01:00
Makefile.fwinst
Makefile.headersinst
Makefile.help
Makefile.host
Makefile.kasan
Makefile.lib UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
Makefile.modbuiltin
Makefile.modinst
Makefile.modpost
Makefile.modsign
Makefile.ubsan UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
makelst
markup_oops.pl
mkcompile_h
mkmakefile
mksysmap
mkuboot.sh
mkversion
module-common.lds
namespace.pl
objdiff
patch-kernel
pnmtologo.c
profile2linkerlist.pl
recordmcount.c ftrace/scripts: Fix incorrect use of sprintf in recordmcount 2016-01-04 11:13:16 -05:00
recordmcount.h
recordmcount.pl scripts/recordmcount.pl: support data in text section on powerpc 2016-01-13 12:35:41 +11:00
setlocalversion
show_delta
sign-file.c
sortextable.c
sortextable.h
spelling.txt
stackdelta
stackusage
tags.sh Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-01-20 10:10:23 -08:00
unifdef.c
ver_linux
xen-hypercalls.sh
xz_wrap.sh