Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 189 insertions, 0 deletions

diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
new file mode 100644
index 000000000..542a9c183
--- /dev/null
+++ b/lib/Kconfig.kasan
@@ -0,0 +1,189 @@
+# 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_VMALLOC
+	bool
+
+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)
+
+config CC_HAS_WORKING_NOSANITIZE_ADDRESS
+	def_bool !CC_IS_GCC || GCC_VERSION >= 80300
+
+menuconfig KASAN
+	bool "KASAN: runtime memory debugger"
+	depends on (HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC) || \
+		   (HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS)
+	depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB)
+	depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
+	help
+	  Enables KASAN (KernelAddressSANitizer) - runtime memory debugger,
+	  designed to find out-of-bounds accesses and use-after-free bugs.
+	  See Documentation/dev-tools/kasan.rst for details.
+
+if KASAN
+
+choice
+	prompt "KASAN mode"
+	default KASAN_GENERIC
+	help
+	  KASAN has two modes: generic KASAN (similar to userspace ASan,
+	  x86_64/arm64/xtensa, enabled with CONFIG_KASAN_GENERIC) and
+	  software tag-based KASAN (a version based on software memory
+	  tagging, arm64 only, similar to userspace HWASan, enabled with
+	  CONFIG_KASAN_SW_TAGS).
+
+	  Both generic and tag-based KASAN are strictly debugging features.
+
+config KASAN_GENERIC
+	bool "Generic mode"
+	depends on HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC
+	depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB)
+	select SLUB_DEBUG if SLUB
+	select CONSTRUCTORS
+	select STACKDEPOT
+	help
+	  Enables generic KASAN mode.
+
+	  This mode is supported in both GCC and Clang. With GCC it requires
+	  version 8.3.0 or later. Any supported Clang version is compatible,
+	  but detection of out-of-bounds accesses for global variables is
+	  supported only since Clang 11.
+
+	  This mode consumes about 1/8th of available memory at kernel start
+	  and introduces an overhead of ~x1.5 for the rest of the allocations.
+	  The performance slowdown is ~x3.
+
+	  For better error detection enable CONFIG_STACKTRACE.
+
+	  Currently CONFIG_KASAN_GENERIC doesn't work with CONFIG_DEBUG_SLAB
+	  (the resulting kernel does not boot).
+
+config KASAN_SW_TAGS
+	bool "Software tag-based mode"
+	depends on HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS
+	depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB)
+	select SLUB_DEBUG if SLUB
+	select CONSTRUCTORS
+	select STACKDEPOT
+	help
+	  Enables software tag-based KASAN mode.
+
+	  This mode requires Top Byte Ignore support by the CPU and therefore
+	  is only supported for arm64. This mode requires Clang.
+
+	  This mode consumes about 1/16th of available memory at kernel start
+	  and introduces an overhead of ~20% for the rest of the allocations.
+	  This mode may potentially introduce problems relating to pointer
+	  casting and comparison, as it embeds tags into the top byte of each
+	  pointer.
+
+	  For better error detection enable CONFIG_STACKTRACE.
+
+	  Currently CONFIG_KASAN_SW_TAGS doesn't work with CONFIG_DEBUG_SLAB
+	  (the resulting kernel does not boot).
+
+endchoice
+
+choice
+	prompt "Instrumentation type"
+	default KASAN_OUTLINE
+
+config KASAN_OUTLINE
+	bool "Outline instrumentation"
+	help
+	  Before every memory access compiler insert function call
+	  __asan_load*/__asan_store*. These functions performs check
+	  of shadow memory. This is slower than inline instrumentation,
+	  however it doesn't bloat size of kernel's .text section so
+	  much as inline does.
+
+config KASAN_INLINE
+	bool "Inline instrumentation"
+	help
+	  Compiler directly inserts code checking shadow memory before
+	  memory accesses. This is faster than outline (in some workloads
+	  it gives about x2 boost over outline instrumentation), but
+	  make kernel's .text size much bigger.
+
+endchoice
+
+config KASAN_STACK_ENABLE
+	bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST
+	help
+	  The LLVM stack address sanitizer has a know problem that
+	  causes excessive stack usage in a lot of functions, see
+	  https://bugs.llvm.org/show_bug.cgi?id=38809
+	  Disabling asan-stack makes it safe to run kernels build
+	  with clang-8 with KASAN enabled, though it loses some of
+	  the functionality.
+	  This feature is always disabled when compile-testing with clang
+	  to avoid cluttering the output in stack overflow warnings,
+	  but clang users can still enable it for builds without
+	  CONFIG_COMPILE_TEST.	On gcc it is assumed to always be safe
+	  to use and enabled by default.
+
+config KASAN_STACK
+	int
+	default 1 if KASAN_STACK_ENABLE || CC_IS_GCC
+	default 0
+
+config KASAN_S390_4_LEVEL_PAGING
+	bool "KASan: use 4-level paging"
+	depends on S390
+	help
+	  Compiling the kernel with KASan disables automatic 3-level vs
+	  4-level paging selection. 3-level paging is used by default (up
+	  to 3TB of RAM with KASan enabled). This options allows to force
+	  4-level paging instead.
+
+config KASAN_SW_TAGS_IDENTIFY
+	bool "Enable memory corruption identification"
+	depends on KASAN_SW_TAGS
+	help
+	  This option enables best-effort identification of bug type
+	  (use-after-free or out-of-bounds) at the cost of increased
+	  memory consumption.
+
+config KASAN_VMALLOC
+	bool "Back mappings in vmalloc space with real shadow memory"
+	depends on HAVE_ARCH_KASAN_VMALLOC
+	help
+	  By default, the shadow region for vmalloc space is the read-only
+	  zero page. This means that KASAN cannot detect errors involving
+	  vmalloc space.
+
+	  Enabling this option will hook in to vmap/vmalloc and back those
+	  mappings with real shadow memory allocated on demand. This allows
+	  for KASAN to detect more sorts of errors (and to support vmapped
+	  stacks), but at the cost of higher 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
+	  This is a KUnit test suite doing various nasty things like
+	  out of bounds and use after free accesses. It is useful for testing
+	  kernel debugging features like KASAN.
+
+	  For more information on KUnit and unit tests in general, please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit
+
+config TEST_KASAN_MODULE
+	tristate "KUnit-incompatible tests of KASAN bug detection capabilities"
+	depends on m && KASAN
+	help
+	  This is a part of the KASAN test suite that is incompatible with
+	  KUnit. Currently includes tests that do bad copy_from/to_user
+	  accesses.
+
+endif # KASAN