From c6d308534aef6c99904bf5862066360ae067abc4 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Wed, 20 Jan 2016 15:00:55 -0800 Subject: 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 - 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 --- arch/x86/Kconfig | 1 + arch/x86/boot/Makefile | 1 + arch/x86/boot/compressed/Makefile | 1 + arch/x86/entry/vdso/Makefile | 1 + arch/x86/realmode/rm/Makefile | 1 + 5 files changed, 5 insertions(+) (limited to 'arch') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 4a10ba9e95da..92b2a73162ee 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -31,6 +31,7 @@ config X86 select ARCH_HAS_PMEM_API if X86_64 select ARCH_HAS_MMIO_FLUSH select ARCH_HAS_SG_CHAIN + select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_HAVE_NMI_SAFE_CMPXCHG select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI select ARCH_MIGHT_HAVE_PC_PARPORT diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 2ee62dba0373..bbe1a62efc02 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -60,6 +60,7 @@ clean-files += cpustr.h KBUILD_CFLAGS := $(USERINCLUDE) $(REALMODE_CFLAGS) -D_SETUP KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ GCOV_PROFILE := n +UBSAN_SANITIZE := n $(obj)/bzImage: asflags-y := $(SVGA_MODE) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 0a291cdfaf77..f9ce75d80101 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -33,6 +33,7 @@ KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ GCOV_PROFILE := n +UBSAN_SANITIZE :=n LDFLAGS := -m elf_$(UTS_MACHINE) LDFLAGS_vmlinux := -T diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 265c0ed68118..c854541d93ff 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -4,6 +4,7 @@ KBUILD_CFLAGS += $(DISABLE_LTO) KASAN_SANITIZE := n +UBSAN_SANITIZE := n VDSO64-$(CONFIG_X86_64) := y VDSOX32-$(CONFIG_X86_X32_ABI) := y diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index 2730d775ef9a..3e75fcf6b836 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -70,3 +70,4 @@ KBUILD_CFLAGS := $(LINUXINCLUDE) $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \ -I$(srctree)/arch/x86/boot KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ GCOV_PROFILE := n +UBSAN_SANITIZE := n -- cgit v1.2.3