mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
687c85afa6
Drop CONFIG_KASAN_TAGS_IDENTIFY and related code to simplify making changes to the reporting code. The dropped functionality will be restored in the following patches in this series. Link: https://lkml.kernel.org/r/4c66ba98eb237e9ed9312c19d423bbcf4ecf88f8.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
201 lines
6.3 KiB
Text
201 lines
6.3 KiB
Text
# SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
# This config refers to the generic KASAN mode.
|
|
config HAVE_ARCH_KASAN
|
|
bool
|
|
|
|
config HAVE_ARCH_KASAN_SW_TAGS
|
|
bool
|
|
|
|
config HAVE_ARCH_KASAN_HW_TAGS
|
|
bool
|
|
|
|
config HAVE_ARCH_KASAN_VMALLOC
|
|
bool
|
|
|
|
config ARCH_DISABLE_KASAN_INLINE
|
|
bool
|
|
help
|
|
Disables both inline and stack instrumentation. Selected by
|
|
architectures that do not support these instrumentation types.
|
|
|
|
config CC_HAS_KASAN_GENERIC
|
|
def_bool $(cc-option, -fsanitize=kernel-address)
|
|
|
|
config CC_HAS_KASAN_SW_TAGS
|
|
def_bool $(cc-option, -fsanitize=kernel-hwaddress)
|
|
|
|
# This option is only required for software KASAN modes.
|
|
# Old GCC versions do not have proper support for no_sanitize_address.
|
|
# See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89124 for details.
|
|
config CC_HAS_WORKING_NOSANITIZE_ADDRESS
|
|
def_bool !CC_IS_GCC || GCC_VERSION >= 80300
|
|
|
|
menuconfig KASAN
|
|
bool "KASAN: dynamic memory safety error detector"
|
|
depends on (((HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC) || \
|
|
(HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS)) && \
|
|
CC_HAS_WORKING_NOSANITIZE_ADDRESS) || \
|
|
HAVE_ARCH_KASAN_HW_TAGS
|
|
depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB)
|
|
select STACKDEPOT_ALWAYS_INIT
|
|
help
|
|
Enables KASAN (Kernel Address Sanitizer) - a dynamic memory safety
|
|
error detector designed to find out-of-bounds and use-after-free bugs.
|
|
|
|
See Documentation/dev-tools/kasan.rst for details.
|
|
|
|
For better error reports, also enable CONFIG_STACKTRACE.
|
|
|
|
if KASAN
|
|
|
|
choice
|
|
prompt "KASAN mode"
|
|
default KASAN_GENERIC
|
|
help
|
|
KASAN has three modes:
|
|
|
|
1. Generic KASAN (supported by many architectures, enabled with
|
|
CONFIG_KASAN_GENERIC, similar to userspace ASan),
|
|
2. Software Tag-Based KASAN (arm64 only, based on software memory
|
|
tagging, enabled with CONFIG_KASAN_SW_TAGS, similar to userspace
|
|
HWASan), and
|
|
3. Hardware Tag-Based KASAN (arm64 only, based on hardware memory
|
|
tagging, enabled with CONFIG_KASAN_HW_TAGS).
|
|
|
|
See Documentation/dev-tools/kasan.rst for details about each mode.
|
|
|
|
config KASAN_GENERIC
|
|
bool "Generic KASAN"
|
|
depends on HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC
|
|
depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
|
|
select SLUB_DEBUG if SLUB
|
|
select CONSTRUCTORS
|
|
help
|
|
Enables Generic KASAN.
|
|
|
|
Requires GCC 8.3.0+ or Clang.
|
|
|
|
Consumes about 1/8th of available memory at kernel start and adds an
|
|
overhead of ~50% for dynamic allocations.
|
|
The performance slowdown is ~x3.
|
|
|
|
(Incompatible with CONFIG_DEBUG_SLAB: the kernel does not boot.)
|
|
|
|
config KASAN_SW_TAGS
|
|
bool "Software Tag-Based KASAN"
|
|
depends on HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS
|
|
depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
|
|
select SLUB_DEBUG if SLUB
|
|
select CONSTRUCTORS
|
|
help
|
|
Enables Software Tag-Based KASAN.
|
|
|
|
Requires GCC 11+ or Clang.
|
|
|
|
Supported only on arm64 CPUs and relies on Top Byte Ignore.
|
|
|
|
Consumes about 1/16th of available memory at kernel start and
|
|
add an overhead of ~20% for dynamic allocations.
|
|
|
|
May potentially introduce problems related to pointer casting and
|
|
comparison, as it embeds a tag into the top byte of each pointer.
|
|
|
|
(Incompatible with CONFIG_DEBUG_SLAB: the kernel does not boot.)
|
|
|
|
config KASAN_HW_TAGS
|
|
bool "Hardware Tag-Based KASAN"
|
|
depends on HAVE_ARCH_KASAN_HW_TAGS
|
|
depends on SLUB
|
|
help
|
|
Enables Hardware Tag-Based KASAN.
|
|
|
|
Requires GCC 10+ or Clang 12+.
|
|
|
|
Supported only on arm64 CPUs starting from ARMv8.5 and relies on
|
|
Memory Tagging Extension and Top Byte Ignore.
|
|
|
|
Consumes about 1/32nd of available memory.
|
|
|
|
May potentially introduce problems related to pointer casting and
|
|
comparison, as it embeds a tag into the top byte of each pointer.
|
|
|
|
endchoice
|
|
|
|
choice
|
|
prompt "Instrumentation type"
|
|
depends on KASAN_GENERIC || KASAN_SW_TAGS
|
|
default KASAN_OUTLINE
|
|
|
|
config KASAN_OUTLINE
|
|
bool "Outline instrumentation"
|
|
help
|
|
Makes the compiler insert function calls that check whether the memory
|
|
is accessible before each memory access. Slower than KASAN_INLINE, but
|
|
does not bloat the size of the kernel's .text section so much.
|
|
|
|
config KASAN_INLINE
|
|
bool "Inline instrumentation"
|
|
depends on !ARCH_DISABLE_KASAN_INLINE
|
|
help
|
|
Makes the compiler directly insert memory accessibility checks before
|
|
each memory access. Faster than KASAN_OUTLINE (gives ~x2 boost for
|
|
some workloads), but makes the kernel's .text size much bigger.
|
|
|
|
endchoice
|
|
|
|
config KASAN_STACK
|
|
bool "Stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST
|
|
depends on KASAN_GENERIC || KASAN_SW_TAGS
|
|
depends on !ARCH_DISABLE_KASAN_INLINE
|
|
default y if CC_IS_GCC
|
|
help
|
|
Disables stack instrumentation and thus KASAN's ability to detect
|
|
out-of-bounds bugs in stack variables.
|
|
|
|
With Clang, stack instrumentation has a problem that causes excessive
|
|
stack usage, see https://bugs.llvm.org/show_bug.cgi?id=38809. Thus,
|
|
with Clang, this option is deemed unsafe.
|
|
|
|
This option is always disabled when compile-testing with Clang to
|
|
avoid cluttering the log with stack overflow warnings.
|
|
|
|
With GCC, enabling stack instrumentation is assumed to be safe.
|
|
|
|
If the architecture disables inline instrumentation via
|
|
ARCH_DISABLE_KASAN_INLINE, stack instrumentation gets disabled
|
|
as well, as it adds inline-style instrumentation that is run
|
|
unconditionally.
|
|
|
|
config KASAN_VMALLOC
|
|
bool "Check accesses to vmalloc allocations"
|
|
depends on HAVE_ARCH_KASAN_VMALLOC
|
|
help
|
|
Makes KASAN check the validity of accesses to vmalloc allocations.
|
|
|
|
With software KASAN modes, all types vmalloc allocations are
|
|
checked. Enabling this option leads to higher memory usage.
|
|
|
|
With Hardware Tag-Based KASAN, only non-executable VM_ALLOC mappings
|
|
are checked. There is no additional memory usage.
|
|
|
|
config KASAN_KUNIT_TEST
|
|
tristate "KUnit-compatible tests of KASAN bug detection capabilities" if !KUNIT_ALL_TESTS
|
|
depends on KASAN && KUNIT
|
|
default KUNIT_ALL_TESTS
|
|
help
|
|
A KUnit-based KASAN test suite. Triggers different kinds of
|
|
out-of-bounds and use-after-free accesses. Useful for testing whether
|
|
KASAN can detect certain bug types.
|
|
|
|
For more information on KUnit and unit tests in general, please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
config KASAN_MODULE_TEST
|
|
tristate "KUnit-incompatible tests of KASAN bug detection capabilities"
|
|
depends on m && KASAN && !KASAN_HW_TAGS
|
|
help
|
|
A part of the KASAN test suite that is not integrated with KUnit.
|
|
Incompatible with Hardware Tag-Based KASAN.
|
|
|
|
endif # KASAN
|