kernel/linux.git/lib/ubsan.c, branch v4.14.223

ubsan: Fix nasty -Wbuiltin-declaration-mismatch GCC-9 warnings

2019-05-10T15:53:08+00:00

commit f0996bc2978e02d2ea898101462b960f6119b18f upstream. Building lib/ubsan.c with gcc-9 results in a ton of nasty warnings like this one: lib/ubsan.c warning: conflicting types for built-in function ‘__ubsan_handle_negate_overflow’; expected ‘void(void *, void *)’ [-Wbuiltin-declaration-mismatch] The kernel's declarations of __ubsan_handle_*() often uses 'unsigned long' types in parameters while GCC these parameters as 'void *' types, hence the mismatch. Fix this by using 'void *' to match GCC's declarations. Reported-by: Linus Torvalds Signed-off-by: Andrey Ryabinin Fixes: c6d308534aef ("UBSAN: run-time undefined behavior sanity checker") Cc: Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib/ubsan.c: don't mark __ubsan_handle_builtin_unreachable as noreturn

2018-11-21T08:24:15+00:00

commit 1c23b4108d716cc848b38532063a8aca4f86add8 upstream. gcc-8 complains about the prototype for this function: lib/ubsan.c:432:1: error: ignoring attribute 'noreturn' in declaration of a built-in function '__ubsan_handle_builtin_unreachable' because it conflicts with attribute 'const' [-Werror=attributes] This is actually a GCC's bug. In GCC internals __ubsan_handle_builtin_unreachable() declared with both 'noreturn' and 'const' attributes instead of only 'noreturn': https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84210 Workaround this by removing the noreturn attribute. [aryabinin: add information about GCC bug in changelog] Link: http://lkml.kernel.org/r/20181107144516.4587-1-aryabinin@virtuozzo.com Signed-off-by: Arnd Bergmann Signed-off-by: Andrey Ryabinin Acked-by: Olof Johansson Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib/ubsan: add type mismatch handler for new GCC/Clang

2018-02-16T19:23:09+00:00

commit 42440c1f9911b4b7b8ba3dc4e90c1197bc561211 upstream. UBSAN=y fails to build with new GCC/clang: arch/x86/kernel/head64.o: In function `sanitize_boot_params': arch/x86/include/asm/bootparam_utils.h:37: undefined reference to `__ubsan_handle_type_mismatch_v1' because Clang and GCC 8 slightly changed ABI for 'type mismatch' errors. Compiler now uses new __ubsan_handle_type_mismatch_v1() function with slightly modified 'struct type_mismatch_data'. Let's add new 'struct type_mismatch_data_common' which is independent from compiler's layout of 'struct type_mismatch_data'. And make __ubsan_handle_type_mismatch[_v1]() functions transform compiler-dependent type mismatch data to our internal representation. This way, we can support both old and new compilers with minimal amount of change. Link: http://lkml.kernel.org/r/20180119152853.16806-1-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin Reported-by: Sodagudi Prasad Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib/ubsan.c: s/missaligned/misaligned/

2018-02-16T19:23:09+00:00

commit b8fe1120b4ba342b4f156d24e952d6e686b20298 upstream. A vist from the spelling fairy. Cc: David Laight Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

UBSAN: fix typo in format string

2016-08-02T21:31:41+00:00

handle_object_size_mismatch() used %pk to format a kernel pointer with pr_err(). This seemed to be a misspelling for %pK, but using this to format a kernel pointer does not make much sence here. Therefore use %p instead, like in handle_missaligned_access(). Link: http://lkml.kernel.org/r/20160730083010.11569-1-nicolas.iooss_linux@m4x.org Signed-off-by: Nicolas Iooss Acked-by: Andrey Ryabinin Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

UBSAN: run-time undefined behavior sanity checker

2016-01-21T01:09:18+00:00

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 - 97840cb67ff5 ("netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind") undefined shifts: * d48458d4a768 ("jbd2: use a better hash function for the revoke table") * 10632008b9e1 ("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/ WONTFIX here because it should be fixed in bpf program, not in kernel. signed overflows: * 32a8df4e0b33f ("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/ * [NOTABUG] signed overflow in ktime_add_safe() - http://lkml.kernel.org/r/ [akpm@linux-foundation.org: fix unused local warning] [akpm@linux-foundation.org: fix __int128 build woes] Signed-off-by: Andrey Ryabinin Cc: Peter Zijlstra Cc: Sasha Levin Cc: Randy Dunlap Cc: Rasmus Villemoes Cc: Jonathan Corbet Cc: Michal Marek Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Yury Gribov Cc: Dmitry Vyukov Cc: Konstantin Khlebnikov Cc: Kostya Serebryany Cc: Johannes Berg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds