Import Undefined Behavior SANitizer from Linux Kernel v4.18, as implemented by Andrey Ryabinin aryabinin@virtuozzo.com.
Roughly, the UBSAN development history in Linux kernel looks like:
v4.18 3ca17b1f3628 ("lib/ubsan: remove null-pointer checks") v4.17-rc1 317506009216 ("lib/test_ubsan.c: make test_ubsan_misaligned_access() static") v4.17-rc1 854686f4edf4 ("lib: add testing module for UBSAN") v4.16-rc1 bac7a1fff792 ("lib/ubsan: remove returns-nonnull-attribute checks") v4.16-rc1 42440c1f9911 ("lib/ubsan: add type mismatch handler for new GCC/Clang") v4.16-rc1 b8fe1120b4ba ("lib/ubsan.c: s/missaligned/misaligned/") v4.10-rc1 0462554707d6 ("Kconfig: lib/Kconfig.ubsan fix reference to ubsan documentation") v4.9-rc5 a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"") v4.9-rc1 725c4d22bbc4 ("ubsan: allow to disable the null sanitizer") v4.9-rc1 1ead009cd622 ("docs: sphinxify ubsan.txt and move it to dev-tools") v4.8-rc1 901d805c33fc ("UBSAN: fix typo in format string") v4.8-rc1 6e8d666e9253 ("Disable "maybe-uninitialized" warning globally") v4.6-rc1 dde5cf39d4d2 ("ubsan: fix tree-wide -Wmaybe-uninitialized false positives") v4.5-rc4 7707535ab95e ("ubsan: cosmetic fix to Kconfig text") v4.5-rc1 bf76f73c5f65 ("powerpc: enable UBSAN support") v4.5-rc1 c6d308534aef ("UBSAN: run-time undefined behavior sanity checker")
What's not interesting for U-Boot is: - 317506009216 ("lib/test_ubsan.c: make test_ubsan_misaligned_access() static") - 854686f4edf4 ("lib: add testing module for UBSAN") since they add a module-only test functionality. - any Documentation commits.
Since dump_stack() evaluates to NOOP in U-Boot, the UBSAN report retains only the header from the original kernel report.
As example, below is a UB found in U-Boot thanks to UBSAN:
==================================================================== UBSAN: Undefined behaviour in drivers/net/phy/phy.c:728:19 left shift of 1 by 31 places cannot be represented in type 'int' ====================================================================
For comparison, below is a full-fledged kernel UBSAN report, based on v4.17-rc4 Linux commit 0dfc0c792d69 ("iommu/vt-d: fix shift-out-of- bounds in bug checking"):
================================================================================ UBSAN: Undefined behaviour in drivers/iommu/dmar.c:1348:3 shift exponent 64 is too large for 32-bit type 'int' CPU: 2 PID: 0 Comm: swapper/2 Tainted: G U 4.17.0-rc1+ #89 Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016 Call Trace: <IRQ> dump_stack+0x90/0xfb ubsan_epilogue+0x9/0x40 __ubsan_handle_shift_out_of_bounds+0x10e/0x170 ? qi_flush_dev_iotlb+0x124/0x180 -----[snip]----- apic_timer_interrupt+0xf/0x20 </IRQ> RIP: 0010:poll_idle+0x60/0xe7 RSP: 0018:ffffb1b201943e30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000080200000 RBX: 000000000000008e RCX: 000000000000001f RDX: 0000000000000000 RSI: 000000002819aa06 RDI: 0000000000000000 RBP: ffff9e93c6b33280 R08: 00000010f717d567 R09: 000000000010d205 R10: ffffb1b201943df8 R11: 0000000000000001 R12: 00000000e01b169d R13: 0000000000000000 R14: ffffffffb12aa400 R15: 0000000000000000 cpuidle_enter_state+0xb4/0x470 do_idle+0x222/0x310 cpu_startup_entry+0x78/0x90 start_secondary+0x205/0x2e0 secondary_startup_64+0xa5/0xb0 ================================================================================
To enable UBSAN, two prerequisites must be met from Kconfig perspective: * ARCH has to select CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL * defconfig has to enable CONFIG_UBSAN
Enable CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL on below architectures (specify compiler, defconfig and phys/virt target used for testing): * SANDBOX: * gcc (Ubuntu 8.1.0-5ubuntu1~16.04) * sandbox*_defconfig * x86_64 Ubuntu machine * x86: * gcc (Ubuntu 8.1.0-5ubuntu1~16.04) * qemu-x86_defconfig * qemu-system-i386 * ARM: * arm-linux-gnueabihf-gcc (Linaro GCC 7.2-2017.11) * vexpress_ca9x4_defconfig * qemu-system-arm * ARM64: * aarch64-linux-gnu-gcc (Linaro GCC 7.2-2017.11) * r8a7795_salvator-x_defconfig * R-Car H3 ES2.0 Salvator-X board * PPC: * powerpc-linux-gnu-gcc (Ubuntu 5.4.0-6ubuntu1~16.04.9) * qemu-ppce500_defconfig * qemu-system-ppc
Any defconfig update (UBSAN=y) is expected to come separately. No functional change is intended, assuming CONFIG_UBSAN=n.
Signed-off-by: Eugeniu Rosca erosca@de.adit-jv.com ---
Changes in v2: - [Tom Rini] Relocate the ELF/BIN size measurements to the commit updating the sandbox defconfig, to avoid confusion. - [York Sun] Fix SPL build with UBSAN=y. - Enable CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL on x86, ARM and PPC, in addition to SANDBOX and ARM64 (all build and runtime tested with at least one defconfig as described in the commit description). --- Makefile | 3 +- arch/Kconfig | 4 ++ arch/arm/Kconfig | 1 + examples/standalone/Makefile | 2 + include/linux/compat.h | 3 + lib/Kconfig | 1 + lib/Kconfig.ubsan | 29 +++++++++ lib/Makefile | 2 + lib/linux_compat.c | 3 + lib/ubsan.c | 461 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ lib/ubsan.h | 94 +++++++++++++++++++++++++++++ scripts/Makefile.lib | 6 ++ scripts/Makefile.ubsan | 20 +++++++ 13 files changed, 628 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile index b5bf8abc1f88..d1eeaa9dbcd2 100644 --- a/Makefile +++ b/Makefile @@ -391,7 +391,7 @@ export MAKE LEX YACC AWK PERL PYTHON PYTHON2 PYTHON3 export HOSTCXX HOSTCXXFLAGS CHECK CHECKFLAGS DTC DTC_FLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS UBOOTINCLUDE OBJCOPYFLAGS LDFLAGS -export KBUILD_CFLAGS KBUILD_AFLAGS +export KBUILD_CFLAGS KBUILD_AFLAGS CFLAGS_UBSAN
# When compiling out-of-tree modules, put MODVERDIR in the module # tree rather than in the kernel tree. The kernel tree might @@ -648,6 +648,7 @@ endif KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
include scripts/Makefile.extrawarn +include scripts/Makefile.ubsan
# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments KBUILD_CPPFLAGS += $(KCPPFLAGS) diff --git a/arch/Kconfig b/arch/Kconfig index bf1b4a9afac6..ebb8ee5979e0 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -19,6 +19,7 @@ config ARC
config ARM bool "ARM architecture" + select ARCH_HAS_UBSAN_SANITIZE_ALL select CREATE_ARCH_SYMLINK select HAVE_PRIVATE_LIBGCC if !ARM64 select SUPPORT_OF_CONTROL @@ -54,6 +55,7 @@ config NIOS2
config PPC bool "PowerPC architecture" + select ARCH_HAS_UBSAN_SANITIZE_ALL select HAVE_PRIVATE_LIBGCC select SUPPORT_OF_CONTROL select SYS_BOOT_GET_CMDLINE @@ -65,6 +67,7 @@ config RISCV
config SANDBOX bool "Sandbox" + select ARCH_HAS_UBSAN_SANITIZE_ALL select BOARD_LATE_INIT select DM select DM_GPIO @@ -98,6 +101,7 @@ config SH
config X86 bool "x86 architecture" + select ARCH_HAS_UBSAN_SANITIZE_ALL select CREATE_ARCH_SYMLINK select DM select DM_PCI diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 9f5eaf8591b6..0905ebce7004 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -6,6 +6,7 @@ config SYS_ARCH
config ARM64 bool + select ARCH_HAS_UBSAN_SANITIZE_ALL select PHYS_64BIT select SYS_CACHE_SHIFT_6
diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile index 09364d84a0ad..66716d37465a 100644 --- a/examples/standalone/Makefile +++ b/examples/standalone/Makefile @@ -3,6 +3,8 @@ # (C) Copyright 2000-2006 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+UBSAN_SANITIZE := n + extra-y := hello_world extra-$(CONFIG_SMC91111) += smc91111_eeprom extra-$(CONFIG_SMC911X) += smc911x_eeprom diff --git a/include/linux/compat.h b/include/linux/compat.h index 6e3feb64d2d5..e851b2982d76 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -11,6 +11,9 @@ typedef struct unused unused_t;
struct p_current{ int pid; +#ifdef CONFIG_UBSAN + unsigned int in_ubsan; +#endif };
extern struct p_current *current; diff --git a/lib/Kconfig b/lib/Kconfig index 622f3c26c331..251903af9e6b 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -375,6 +375,7 @@ endmenu
source lib/efi/Kconfig source lib/efi_loader/Kconfig +source lib/Kconfig.ubsan source lib/optee/Kconfig
endmenu diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan new file mode 100644 index 000000000000..dbbfe974221d --- /dev/null +++ b/lib/Kconfig.ubsan @@ -0,0 +1,29 @@ +config ARCH_HAS_UBSAN_SANITIZE_ALL + bool + +config UBSAN + bool "Undefined behaviour sanity checker" + help + This option enables undefined behaviour sanity checker + Compile-time instrumentation is used to detect various undefined + behaviours in runtime. + +config UBSAN_SANITIZE_ALL + bool "Enable instrumentation for the entire kernel" + depends on UBSAN + depends on ARCH_HAS_UBSAN_SANITIZE_ALL + default y + help + This option activates instrumentation for the entire kernel. + If you don't enable this option, you have to explicitly specify + UBSAN_SANITIZE := y for the files/directories you want to check for UB. + Enabling this option will get kernel image size increased + significantly. + +config UBSAN_ALIGNMENT + bool "Enable checking of pointers alignment" + depends on UBSAN + help + This option enables detection of unaligned memory accesses. + Enabling this option on architectures that support unaligned + accesses may produce a lot of false positives. diff --git a/lib/Makefile b/lib/Makefile index 5f583aed37d9..0ae2c121cacf 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -51,6 +51,8 @@ endif obj-$(CONFIG_RSA) += rsa/ obj-$(CONFIG_SHA1) += sha1.o obj-$(CONFIG_SHA256) += sha256.o +obj-$(CONFIG_UBSAN) += ubsan.o +UBSAN_SANITIZE_ubsan.o := n
obj-$(CONFIG_$(SPL_)ZLIB) += zlib/ obj-$(CONFIG_$(SPL_)GZIP) += gunzip.o diff --git a/lib/linux_compat.c b/lib/linux_compat.c index a936a7eac214..4dd89b50e924 100644 --- a/lib/linux_compat.c +++ b/lib/linux_compat.c @@ -4,6 +4,9 @@
struct p_current cur = { .pid = 1, +#ifdef CONFIG_UBSAN + .in_ubsan = 0, +#endif }; __maybe_unused struct p_current *current = &cur;
diff --git a/lib/ubsan.c b/lib/ubsan.c new file mode 100644 index 000000000000..642ef9f02c00 --- /dev/null +++ b/lib/ubsan.c @@ -0,0 +1,461 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * UBSAN error reporting functions + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin ryabinin.a.a@gmail.com + */ + +#include <linux/bitops.h> +#include <linux/bug.h> +#include <linux/ctype.h> +#include <linux/kernel.h> +#include <linux/types.h> + +#ifdef __UBOOT__ +#include <linux/compat.h> +#include <common.h> +#endif + +#include "ubsan.h" + +const char *type_check_kinds[] = { + "load of", + "store to", + "reference binding to", + "member access within", + "member call on", + "constructor call on", + "downcast of", + "downcast of" +}; + +#define REPORTED_BIT 31 + +#if (BITS_PER_LONG == 64) && defined(__BIG_ENDIAN) +#define COLUMN_MASK (~(1U << REPORTED_BIT)) +#define LINE_MASK (~0U) +#else +#define COLUMN_MASK (~0U) +#define LINE_MASK (~(1U << REPORTED_BIT)) +#endif + +#define VALUE_LENGTH 40 + +static bool was_reported(struct source_location *location) +{ + return test_and_set_bit(REPORTED_BIT, &location->reported); +} + +static void print_source_location(const char *prefix, + struct source_location *loc) +{ + pr_err("%s %s:%d:%d\n", prefix, loc->file_name, + loc->line & LINE_MASK, loc->column & COLUMN_MASK); +} + +static bool suppress_report(struct source_location *loc) +{ + return current->in_ubsan || was_reported(loc); +} + +static bool type_is_int(struct type_descriptor *type) +{ + return type->type_kind == type_kind_int; +} + +static bool type_is_signed(struct type_descriptor *type) +{ + WARN_ON(!type_is_int(type)); + return type->type_info & 1; +} + +static unsigned type_bit_width(struct type_descriptor *type) +{ + return 1 << (type->type_info >> 1); +} + +static bool is_inline_int(struct type_descriptor *type) +{ + unsigned inline_bits = sizeof(unsigned long)*8; + unsigned bits = type_bit_width(type); + + WARN_ON(!type_is_int(type)); + + return bits <= inline_bits; +} + +static s_max get_signed_val(struct type_descriptor *type, unsigned long val) +{ + if (is_inline_int(type)) { + unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type); + return ((s_max)val) << extra_bits >> extra_bits; + } + + if (type_bit_width(type) == 64) + return *(s64 *)val; + + return *(s_max *)val; +} + +static bool val_is_negative(struct type_descriptor *type, unsigned long val) +{ + return type_is_signed(type) && get_signed_val(type, val) < 0; +} + +static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val) +{ + if (is_inline_int(type)) + return val; + + if (type_bit_width(type) == 64) + return *(u64 *)val; + + return *(u_max *)val; +} + +static void val_to_string(char *str, size_t size, struct type_descriptor *type, + unsigned long value) +{ + if (type_is_int(type)) { + if (type_bit_width(type) == 128) { +#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__) + u_max val = get_unsigned_val(type, value); + + scnprintf(str, size, "0x%08x%08x%08x%08x", + (u32)(val >> 96), + (u32)(val >> 64), + (u32)(val >> 32), + (u32)(val)); +#else + WARN_ON(1); +#endif + } else if (type_is_signed(type)) { + scnprintf(str, size, "%lld", + (s64)get_signed_val(type, value)); + } else { + scnprintf(str, size, "%llu", + (u64)get_unsigned_val(type, value)); + } + } +} + +#ifndef __UBOOT__ +static DEFINE_SPINLOCK(report_lock); +#endif + +static void ubsan_prologue(struct source_location *location, + unsigned long *flags) +{ + current->in_ubsan++; + spin_lock_irqsave(&report_lock, *flags); + + pr_err("========================================" + "========================================\n"); + print_source_location("UBSAN: Undefined behaviour in", location); +} + +static void ubsan_epilogue(unsigned long *flags) +{ + 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_common *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_misaligned_access(struct type_mismatch_data_common *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_common *data, + unsigned long ptr) +{ + unsigned long flags; + + if (suppress_report(data->location)) + return; + + ubsan_prologue(data->location, &flags); + pr_err("%s address %p 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); +} + +static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data, + unsigned long ptr) +{ + + if (!ptr) + handle_null_ptr_deref(data); + else if (data->alignment && !IS_ALIGNED(ptr, data->alignment)) + handle_misaligned_access(data, ptr); + else + handle_object_size_mismatch(data, ptr); +} + +void __ubsan_handle_type_mismatch(struct type_mismatch_data *data, + unsigned long ptr) +{ + struct type_mismatch_data_common common_data = { + .location = &data->location, + .type = data->type, + .alignment = data->alignment, + .type_check_kind = data->type_check_kind + }; + + ubsan_type_mismatch_common(&common_data, ptr); +} +EXPORT_SYMBOL(__ubsan_handle_type_mismatch); + +void __ubsan_handle_type_mismatch_v1(struct type_mismatch_data_v1 *data, + unsigned long ptr) +{ + + struct type_mismatch_data_common common_data = { + .location = &data->location, + .type = data->type, + .alignment = 1UL << data->log_alignment, + .type_check_kind = data->type_check_kind + }; + + ubsan_type_mismatch_common(&common_data, ptr); +} +EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1); + +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); diff --git a/lib/ubsan.h b/lib/ubsan.h new file mode 100644 index 000000000000..01efea6bae11 --- /dev/null +++ b/lib/ubsan.h @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0 +#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 type_mismatch_data_v1 { + struct source_location location; + struct type_descriptor *type; + unsigned char log_alignment; + unsigned char type_check_kind; +}; + +struct type_mismatch_data_common { + 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 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 diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index f8c3fff1d151..ccf683265fcb 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -131,6 +131,12 @@ _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 '/').
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan new file mode 100644 index 000000000000..38b2b4818e8e --- /dev/null +++ b/scripts/Makefile.ubsan @@ -0,0 +1,20 @@ +# SPDX-License-Identifier: GPL-2.0 +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=signed-integer-overflow) + CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds) + CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size) + 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 + + # -fsanitize=* options makes GCC less smart than usual and + # increase number of 'maybe-uninitialized false-positives + CFLAGS_UBSAN += $(call cc-option, -Wno-maybe-uninitialized) +endif