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>
This commit is contained in:
Andrey Ryabinin
Linus Torvalds
parent
68920c9732
commit
c6d308534a
17 changed files with 693 additions and 1 deletions
84
Documentation/ubsan.txt
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84
Documentation/ubsan.txt
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@ -0,0 +1,84 @@
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Undefined Behavior Sanitizer - UBSAN
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Overview
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--------
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UBSAN is a runtime undefined behaviour checker.
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UBSAN uses compile-time instrumentation to catch undefined behavior (UB).
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Compiler inserts code that perform certain kinds of checks before operations
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that may cause UB. If check fails (i.e. UB detected) __ubsan_handle_*
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function called to print error message.
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GCC has that feature since 4.9.x [1] (see -fsanitize=undefined option and
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its suboptions). GCC 5.x has more checkers implemented [2].
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Report example
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---------------
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================================================================================
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UBSAN: Undefined behaviour in ../include/linux/bitops.h:110:33
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shift exponent 32 is to large for 32-bit type 'unsigned int'
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CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.0-rc1+ #26
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0000000000000000 ffffffff82403cc8 ffffffff815e6cd6 0000000000000001
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ffffffff82403cf8 ffffffff82403ce0 ffffffff8163a5ed 0000000000000020
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ffffffff82403d78 ffffffff8163ac2b ffffffff815f0001 0000000000000002
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Call Trace:
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[<ffffffff815e6cd6>] dump_stack+0x45/0x5f
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[<ffffffff8163a5ed>] ubsan_epilogue+0xd/0x40
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[<ffffffff8163ac2b>] __ubsan_handle_shift_out_of_bounds+0xeb/0x130
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[<ffffffff815f0001>] ? radix_tree_gang_lookup_slot+0x51/0x150
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[<ffffffff8173c586>] _mix_pool_bytes+0x1e6/0x480
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[<ffffffff83105653>] ? dmi_walk_early+0x48/0x5c
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[<ffffffff8173c881>] add_device_randomness+0x61/0x130
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[<ffffffff83105b35>] ? dmi_save_one_device+0xaa/0xaa
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[<ffffffff83105653>] dmi_walk_early+0x48/0x5c
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[<ffffffff831066ae>] dmi_scan_machine+0x278/0x4b4
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[<ffffffff8111d58a>] ? vprintk_default+0x1a/0x20
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[<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
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[<ffffffff830b2240>] setup_arch+0x405/0xc2c
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[<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
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[<ffffffff830ae053>] start_kernel+0x83/0x49a
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[<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
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[<ffffffff830ad386>] x86_64_start_reservations+0x2a/0x2c
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[<ffffffff830ad4f3>] x86_64_start_kernel+0x16b/0x17a
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================================================================================
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Usage
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-----
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To enable UBSAN configure kernel with:
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CONFIG_UBSAN=y
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and to check the entire kernel:
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CONFIG_UBSAN_SANITIZE_ALL=y
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To enable instrumentation for specific files or directories, add a line
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similar to the following to the respective kernel Makefile:
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For a single file (e.g. main.o):
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UBSAN_SANITIZE_main.o := y
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For all files in one directory:
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UBSAN_SANITIZE := y
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To exclude files from being instrumented even if
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CONFIG_UBSAN_SANITIZE_ALL=y, use:
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UBSAN_SANITIZE_main.o := n
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and:
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UBSAN_SANITIZE := n
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Detection of unaligned accesses controlled through the separate option -
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CONFIG_UBSAN_ALIGNMENT. It's off by default on architectures that support
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unaligned accesses (CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y). One could
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still enable it in config, just note that it will produce a lot of UBSAN
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reports.
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References
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----------
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[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
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[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
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3
Makefile
3
Makefile
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@ -411,7 +411,7 @@ export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
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export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
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export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
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export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KASAN
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export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KASAN CFLAGS_UBSAN
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export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
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export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
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export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
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@ -784,6 +784,7 @@ endif
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include scripts/Makefile.kasan
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include scripts/Makefile.extrawarn
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include scripts/Makefile.ubsan
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# Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
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# last assignments
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@ -31,6 +31,7 @@ config X86
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select ARCH_HAS_PMEM_API if X86_64
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select ARCH_HAS_MMIO_FLUSH
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select ARCH_HAS_SG_CHAIN
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select ARCH_HAS_UBSAN_SANITIZE_ALL
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select ARCH_HAVE_NMI_SAFE_CMPXCHG
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select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
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select ARCH_MIGHT_HAVE_PC_PARPORT
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@ -60,6 +60,7 @@ clean-files += cpustr.h
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KBUILD_CFLAGS := $(USERINCLUDE) $(REALMODE_CFLAGS) -D_SETUP
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KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
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GCOV_PROFILE := n
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UBSAN_SANITIZE := n
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$(obj)/bzImage: asflags-y := $(SVGA_MODE)
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@ -33,6 +33,7 @@ KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
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KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
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GCOV_PROFILE := n
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UBSAN_SANITIZE :=n
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LDFLAGS := -m elf_$(UTS_MACHINE)
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LDFLAGS_vmlinux := -T
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@ -4,6 +4,7 @@
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KBUILD_CFLAGS += $(DISABLE_LTO)
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KASAN_SANITIZE := n
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UBSAN_SANITIZE := n
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VDSO64-$(CONFIG_X86_64) := y
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VDSOX32-$(CONFIG_X86_X32_ABI) := y
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@ -70,3 +70,4 @@ KBUILD_CFLAGS := $(LINUXINCLUDE) $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \
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-I$(srctree)/arch/x86/boot
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KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
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GCOV_PROFILE := n
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UBSAN_SANITIZE := n
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@ -22,6 +22,7 @@ KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
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GCOV_PROFILE := n
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KASAN_SANITIZE := n
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UBSAN_SANITIZE := n
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lib-y := efi-stub-helper.o
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@ -1643,6 +1643,9 @@ struct task_struct {
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struct held_lock held_locks[MAX_LOCK_DEPTH];
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gfp_t lockdep_reclaim_gfp;
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#endif
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#ifdef CONFIG_UBSAN
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unsigned int in_ubsan;
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#endif
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/* journalling filesystem info */
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void *journal_info;
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@ -1893,6 +1893,8 @@ source "samples/Kconfig"
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source "lib/Kconfig.kgdb"
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source "lib/Kconfig.ubsan"
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config ARCH_HAS_DEVMEM_IS_ALLOWED
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bool
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29
lib/Kconfig.ubsan
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29
lib/Kconfig.ubsan
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@ -0,0 +1,29 @@
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config ARCH_HAS_UBSAN_SANITIZE_ALL
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bool
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config UBSAN
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bool "Undefined behaviour sanity checker"
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help
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This option enables undefined behaviour sanity checker
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Compile-time instrumentation is used to detect various undefined
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behaviours in runtime. Various types of checks may be enabled
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via boot parameter ubsan_handle (see: Documentation/ubsan.txt).
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config UBSAN_SANITIZE_ALL
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bool "Enable instrumentation for the entire kernel"
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depends on UBSAN
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depends on ARCH_HAS_UBSAN_SANITIZE_ALL
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default y
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help
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This option activates instrumentation for the entire kernel.
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If you don't enable this option, you have to explicitly specify
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UBSAN_SANITIZE := y for the files/directories you want to check for UB.
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config UBSAN_ALIGNMENT
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bool "Enable checking of pointers alignment"
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depends on UBSAN
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default y if !HAVE_EFFICIENT_UNALIGNED_ACCESS
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help
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This option enables detection of unaligned memory accesses.
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Enabling this option on architectures that support unalligned
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accesses may produce a lot of false positives.
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@ -209,3 +209,6 @@ quiet_cmd_build_OID_registry = GEN $@
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clean-files += oid_registry_data.c
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obj-$(CONFIG_UCS2_STRING) += ucs2_string.o
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obj-$(CONFIG_UBSAN) += ubsan.o
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UBSAN_SANITIZE_ubsan.o := n
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456
lib/ubsan.c
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456
lib/ubsan.c
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/*
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* UBSAN error reporting functions
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*
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* Copyright (c) 2014 Samsung Electronics Co., Ltd.
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* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/bitops.h>
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#include <linux/bug.h>
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#include <linux/ctype.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/sched.h>
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#include "ubsan.h"
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const char *type_check_kinds[] = {
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"load of",
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"store to",
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"reference binding to",
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"member access within",
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"member call on",
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"constructor call on",
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"downcast of",
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"downcast of"
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};
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#define REPORTED_BIT 31
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#if (BITS_PER_LONG == 64) && defined(__BIG_ENDIAN)
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#define COLUMN_MASK (~(1U << REPORTED_BIT))
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#define LINE_MASK (~0U)
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#else
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#define COLUMN_MASK (~0U)
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#define LINE_MASK (~(1U << REPORTED_BIT))
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#endif
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#define VALUE_LENGTH 40
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static bool was_reported(struct source_location *location)
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{
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return test_and_set_bit(REPORTED_BIT, &location->reported);
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}
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static void print_source_location(const char *prefix,
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struct source_location *loc)
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{
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pr_err("%s %s:%d:%d\n", prefix, loc->file_name,
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loc->line & LINE_MASK, loc->column & COLUMN_MASK);
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}
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static bool suppress_report(struct source_location *loc)
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{
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return current->in_ubsan || was_reported(loc);
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}
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static bool type_is_int(struct type_descriptor *type)
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{
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return type->type_kind == type_kind_int;
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}
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static bool type_is_signed(struct type_descriptor *type)
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{
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WARN_ON(!type_is_int(type));
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return type->type_info & 1;
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}
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static unsigned type_bit_width(struct type_descriptor *type)
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{
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return 1 << (type->type_info >> 1);
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}
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static bool is_inline_int(struct type_descriptor *type)
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{
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unsigned inline_bits = sizeof(unsigned long)*8;
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unsigned bits = type_bit_width(type);
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WARN_ON(!type_is_int(type));
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return bits <= inline_bits;
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}
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static s_max get_signed_val(struct type_descriptor *type, unsigned long val)
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{
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if (is_inline_int(type)) {
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unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
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return ((s_max)val) << extra_bits >> extra_bits;
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}
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if (type_bit_width(type) == 64)
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return *(s64 *)val;
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return *(s_max *)val;
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}
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static bool val_is_negative(struct type_descriptor *type, unsigned long val)
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{
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return type_is_signed(type) && get_signed_val(type, val) < 0;
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}
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static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val)
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{
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if (is_inline_int(type))
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return val;
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if (type_bit_width(type) == 64)
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return *(u64 *)val;
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return *(u_max *)val;
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}
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static void val_to_string(char *str, size_t size, struct type_descriptor *type,
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unsigned long value)
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{
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if (type_is_int(type)) {
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if (type_bit_width(type) == 128) {
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#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
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u_max val = get_unsigned_val(type, value);
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scnprintf(str, size, "0x%08x%08x%08x%08x",
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(u32)(val >> 96),
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(u32)(val >> 64),
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(u32)(val >> 32),
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(u32)(val));
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#else
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WARN_ON(1);
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#endif
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} else if (type_is_signed(type)) {
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scnprintf(str, size, "%lld",
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(s64)get_signed_val(type, value));
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} else {
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scnprintf(str, size, "%llu",
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(u64)get_unsigned_val(type, value));
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}
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}
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}
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static bool location_is_valid(struct source_location *loc)
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{
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return loc->file_name != NULL;
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}
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static DEFINE_SPINLOCK(report_lock);
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static void ubsan_prologue(struct source_location *location,
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unsigned long *flags)
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{
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current->in_ubsan++;
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spin_lock_irqsave(&report_lock, *flags);
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pr_err("========================================"
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"========================================\n");
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print_source_location("UBSAN: Undefined behaviour in", location);
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}
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static void ubsan_epilogue(unsigned long *flags)
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{
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||||
dump_stack();
|
||||
pr_err("========================================"
|
||||
"========================================\n");
|
||||
spin_unlock_irqrestore(&report_lock, *flags);
|
||||
current->in_ubsan--;
|
||||
}
|
||||
|
||||
static void handle_overflow(struct overflow_data *data, unsigned long lhs,
|
||||
unsigned long rhs, char op)
|
||||
{
|
||||
|
||||
struct type_descriptor *type = data->type;
|
||||
unsigned long flags;
|
||||
char lhs_val_str[VALUE_LENGTH];
|
||||
char rhs_val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
|
||||
val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
|
||||
pr_err("%s integer overflow:\n",
|
||||
type_is_signed(type) ? "signed" : "unsigned");
|
||||
pr_err("%s %c %s cannot be represented in type %s\n",
|
||||
lhs_val_str,
|
||||
op,
|
||||
rhs_val_str,
|
||||
type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
void __ubsan_handle_add_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
|
||||
handle_overflow(data, lhs, rhs, '+');
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_add_overflow);
|
||||
|
||||
void __ubsan_handle_sub_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
handle_overflow(data, lhs, rhs, '-');
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_sub_overflow);
|
||||
|
||||
void __ubsan_handle_mul_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
handle_overflow(data, lhs, rhs, '*');
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
|
||||
|
||||
void __ubsan_handle_negate_overflow(struct overflow_data *data,
|
||||
unsigned long old_val)
|
||||
{
|
||||
unsigned long flags;
|
||||
char old_val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
|
||||
|
||||
pr_err("negation of %s cannot be represented in type %s:\n",
|
||||
old_val_str, data->type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
|
||||
|
||||
|
||||
void __ubsan_handle_divrem_overflow(struct overflow_data *data,
|
||||
unsigned long lhs,
|
||||
unsigned long rhs)
|
||||
{
|
||||
unsigned long flags;
|
||||
char rhs_val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
|
||||
|
||||
if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1)
|
||||
pr_err("division of %s by -1 cannot be represented in type %s\n",
|
||||
rhs_val_str, data->type->type_name);
|
||||
else
|
||||
pr_err("division by zero\n");
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
|
||||
|
||||
static void handle_null_ptr_deref(struct type_mismatch_data *data)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
pr_err("%s null pointer of type %s\n",
|
||||
type_check_kinds[data->type_check_kind],
|
||||
data->type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
static void handle_missaligned_access(struct type_mismatch_data *data,
|
||||
unsigned long ptr)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
pr_err("%s misaligned address %p for type %s\n",
|
||||
type_check_kinds[data->type_check_kind],
|
||||
(void *)ptr, data->type->type_name);
|
||||
pr_err("which requires %ld byte alignment\n", data->alignment);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
static void handle_object_size_mismatch(struct type_mismatch_data *data,
|
||||
unsigned long ptr)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
pr_err("%s address %pk with insufficient space\n",
|
||||
type_check_kinds[data->type_check_kind],
|
||||
(void *) ptr);
|
||||
pr_err("for an object of type %s\n", data->type->type_name);
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
|
||||
void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
|
||||
unsigned long ptr)
|
||||
{
|
||||
|
||||
if (!ptr)
|
||||
handle_null_ptr_deref(data);
|
||||
else if (data->alignment && !IS_ALIGNED(ptr, data->alignment))
|
||||
handle_missaligned_access(data, ptr);
|
||||
else
|
||||
handle_object_size_mismatch(data, ptr);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_type_mismatch);
|
||||
|
||||
void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
pr_err("null pointer returned from function declared to never return null\n");
|
||||
|
||||
if (location_is_valid(&data->attr_location))
|
||||
print_source_location("returns_nonnull attribute specified in",
|
||||
&data->attr_location);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_nonnull_return);
|
||||
|
||||
void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
|
||||
unsigned long bound)
|
||||
{
|
||||
unsigned long flags;
|
||||
char bound_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(bound_str, sizeof(bound_str), data->type, bound);
|
||||
pr_err("variable length array bound value %s <= 0\n", bound_str);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);
|
||||
|
||||
void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data,
|
||||
unsigned long index)
|
||||
{
|
||||
unsigned long flags;
|
||||
char index_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(index_str, sizeof(index_str), data->index_type, index);
|
||||
pr_err("index %s is out of range for type %s\n", index_str,
|
||||
data->array_type->type_name);
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
|
||||
|
||||
void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
|
||||
unsigned long lhs, unsigned long rhs)
|
||||
{
|
||||
unsigned long flags;
|
||||
struct type_descriptor *rhs_type = data->rhs_type;
|
||||
struct type_descriptor *lhs_type = data->lhs_type;
|
||||
char rhs_str[VALUE_LENGTH];
|
||||
char lhs_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
|
||||
val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
|
||||
|
||||
if (val_is_negative(rhs_type, rhs))
|
||||
pr_err("shift exponent %s is negative\n", rhs_str);
|
||||
|
||||
else if (get_unsigned_val(rhs_type, rhs) >=
|
||||
type_bit_width(lhs_type))
|
||||
pr_err("shift exponent %s is too large for %u-bit type %s\n",
|
||||
rhs_str,
|
||||
type_bit_width(lhs_type),
|
||||
lhs_type->type_name);
|
||||
else if (val_is_negative(lhs_type, lhs))
|
||||
pr_err("left shift of negative value %s\n",
|
||||
lhs_str);
|
||||
else
|
||||
pr_err("left shift of %s by %s places cannot be"
|
||||
" represented in type %s\n",
|
||||
lhs_str, rhs_str,
|
||||
lhs_type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
|
||||
|
||||
|
||||
void __noreturn
|
||||
__ubsan_handle_builtin_unreachable(struct unreachable_data *data)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
pr_err("calling __builtin_unreachable()\n");
|
||||
ubsan_epilogue(&flags);
|
||||
panic("can't return from __builtin_unreachable()");
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
|
||||
|
||||
void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
|
||||
unsigned long val)
|
||||
{
|
||||
unsigned long flags;
|
||||
char val_str[VALUE_LENGTH];
|
||||
|
||||
if (suppress_report(&data->location))
|
||||
return;
|
||||
|
||||
ubsan_prologue(&data->location, &flags);
|
||||
|
||||
val_to_string(val_str, sizeof(val_str), data->type, val);
|
||||
|
||||
pr_err("load of value %s is not a valid value for type %s\n",
|
||||
val_str, data->type->type_name);
|
||||
|
||||
ubsan_epilogue(&flags);
|
||||
}
|
||||
EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
|
||||
84
lib/ubsan.h
Normal file
84
lib/ubsan.h
Normal file
|
|
@ -0,0 +1,84 @@
|
|||
#ifndef _LIB_UBSAN_H
|
||||
#define _LIB_UBSAN_H
|
||||
|
||||
enum {
|
||||
type_kind_int = 0,
|
||||
type_kind_float = 1,
|
||||
type_unknown = 0xffff
|
||||
};
|
||||
|
||||
struct type_descriptor {
|
||||
u16 type_kind;
|
||||
u16 type_info;
|
||||
char type_name[1];
|
||||
};
|
||||
|
||||
struct source_location {
|
||||
const char *file_name;
|
||||
union {
|
||||
unsigned long reported;
|
||||
struct {
|
||||
u32 line;
|
||||
u32 column;
|
||||
};
|
||||
};
|
||||
};
|
||||
|
||||
struct overflow_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
};
|
||||
|
||||
struct type_mismatch_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
unsigned long alignment;
|
||||
unsigned char type_check_kind;
|
||||
};
|
||||
|
||||
struct nonnull_arg_data {
|
||||
struct source_location location;
|
||||
struct source_location attr_location;
|
||||
int arg_index;
|
||||
};
|
||||
|
||||
struct nonnull_return_data {
|
||||
struct source_location location;
|
||||
struct source_location attr_location;
|
||||
};
|
||||
|
||||
struct vla_bound_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
};
|
||||
|
||||
struct out_of_bounds_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *array_type;
|
||||
struct type_descriptor *index_type;
|
||||
};
|
||||
|
||||
struct shift_out_of_bounds_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *lhs_type;
|
||||
struct type_descriptor *rhs_type;
|
||||
};
|
||||
|
||||
struct unreachable_data {
|
||||
struct source_location location;
|
||||
};
|
||||
|
||||
struct invalid_value_data {
|
||||
struct source_location location;
|
||||
struct type_descriptor *type;
|
||||
};
|
||||
|
||||
#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
|
||||
typedef __int128 s_max;
|
||||
typedef unsigned __int128 u_max;
|
||||
#else
|
||||
typedef s64 s_max;
|
||||
typedef u64 u_max;
|
||||
#endif
|
||||
|
||||
#endif
|
||||
|
|
@ -1,4 +1,5 @@
|
|||
KASAN_SANITIZE := n
|
||||
UBSAN_SANITIZE_kasan.o := n
|
||||
|
||||
CFLAGS_REMOVE_kasan.o = -pg
|
||||
# Function splitter causes unnecessary splits in __asan_load1/__asan_store1
|
||||
|
|
|
|||
|
|
@ -130,6 +130,12 @@ _c_flags += $(if $(patsubst n%,, \
|
|||
$(CFLAGS_KASAN))
|
||||
endif
|
||||
|
||||
ifeq ($(CONFIG_UBSAN),y)
|
||||
_c_flags += $(if $(patsubst n%,, \
|
||||
$(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
|
||||
$(CFLAGS_UBSAN))
|
||||
endif
|
||||
|
||||
# If building the kernel in a separate objtree expand all occurrences
|
||||
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
|
||||
|
||||
|
|
|
|||
17
scripts/Makefile.ubsan
Normal file
17
scripts/Makefile.ubsan
Normal file
|
|
@ -0,0 +1,17 @@
|
|||
ifdef CONFIG_UBSAN
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=vla-bound)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=null)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=returns-nonnull-attribute)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool)
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum)
|
||||
|
||||
ifdef CONFIG_UBSAN_ALIGNMENT
|
||||
CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
|
||||
endif
|
||||
endif
|
||||
Loading…
Reference in a new issue