+ kasan-introduce-config_kasan_hw_tags.patch added to -mm tree

* + kasan-introduce-config_kasan_hw_tags.patch added to -mm tree
@ 2020-11-10 22:56 akpm
  0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2020-11-10 22:56 UTC (permalink / raw)
  To: andreyknvl, aryabinin, Branislav.Rankov, catalin.marinas,
	dvyukov, elver, eugenis, glider, gor, kevin.brodsky, mm-commits,
	vincenzo.frascino, will.deacon


The patch titled
     Subject: kasan: introduce CONFIG_KASAN_HW_TAGS
has been added to the -mm tree.  Its filename is
     kasan-introduce-config_kasan_hw_tags.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/kasan-introduce-config_kasan_hw_tags.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kasan-introduce-config_kasan_hw_tags.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Andrey Konovalov <andreyknvl@google.com>
Subject: kasan: introduce CONFIG_KASAN_HW_TAGS

This patch adds a configuration option for a new KASAN mode called
hardware tag-based KASAN. This mode uses the memory tagging approach
like the software tag-based mode, but relies on arm64 Memory Tagging
Extension feature for tag management and access checking.

Link: https://lkml.kernel.org/r/55d90be0a5815917f0e1bd468ea0a257f72e7e46.1605046192.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/Kconfig.kasan |   58 +++++++++++++++++++++++++++++++-------------
 1 file changed, 41 insertions(+), 17 deletions(-)

--- a/lib/Kconfig.kasan~kasan-introduce-config_kasan_hw_tags
+++ a/lib/Kconfig.kasan
@@ -6,7 +6,10 @@ config HAVE_ARCH_KASAN
 config HAVE_ARCH_KASAN_SW_TAGS
 	bool
 
-config	HAVE_ARCH_KASAN_VMALLOC
+config HAVE_ARCH_KASAN_HW_TAGS
+	bool
+
+config HAVE_ARCH_KASAN_VMALLOC
 	bool
 
 config CC_HAS_KASAN_GENERIC
@@ -20,11 +23,11 @@ config CC_HAS_WORKING_NOSANITIZE_ADDRESS
 
 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 (((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)
-	depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
-	select CONSTRUCTORS
 	select STACKDEPOT
 	help
 	  Enables KASAN (KernelAddressSANitizer) - runtime memory debugger,
@@ -37,18 +40,24 @@ 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).
+	  KASAN has three modes:
+	  1. generic KASAN (similar to userspace ASan,
+	     x86_64/arm64/xtensa, enabled with CONFIG_KASAN_GENERIC),
+	  2. software tag-based KASAN (arm64 only, based on software
+	     memory tagging (similar to userspace HWASan), enabled with
+	     CONFIG_KASAN_SW_TAGS), and
+	  3. hardware tag-based KASAN (arm64 only, based on hardware
+	     memory tagging, enabled with CONFIG_KASAN_HW_TAGS).
+
+	  All KASAN modes are strictly debugging features.
 
-	  Both generic and tag-based KASAN are strictly debugging features.
+	  For better error reports enable CONFIG_STACKTRACE.
 
 config KASAN_GENERIC
 	bool "Generic mode"
 	depends on HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC
 	select SLUB_DEBUG if SLUB
+	select CONSTRUCTORS
 	help
 	  Enables generic KASAN mode.
 
@@ -61,8 +70,6 @@ config KASAN_GENERIC
 	  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).
 
@@ -70,11 +77,15 @@ config KASAN_SW_TAGS
 	bool "Software tag-based mode"
 	depends on HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS
 	select SLUB_DEBUG if SLUB
+	select CONSTRUCTORS
 	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 require software memory tagging support in the form of
+	  HWASan-like compiler instrumentation.
+
+	  Currently this mode is only implemented for arm64 CPUs and relies on
+	  Top Byte Ignore. 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.
@@ -82,15 +93,27 @@ config KASAN_SW_TAGS
 	  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).
 
+config KASAN_HW_TAGS
+	bool "Hardware tag-based mode"
+	depends on HAVE_ARCH_KASAN_HW_TAGS
+	depends on SLUB
+	help
+	  Enables hardware tag-based KASAN mode.
+
+	  This mode requires hardware memory tagging support, and can be used
+	  by any architecture that provides it.
+
+	  Currently this mode is only implemented for arm64 CPUs starting from
+	  ARMv8.5 and relies on Memory Tagging Extension and Top Byte Ignore.
+
 endchoice
 
 choice
 	prompt "Instrumentation type"
+	depends on KASAN_GENERIC || KASAN_SW_TAGS
 	default KASAN_OUTLINE
 
 config KASAN_OUTLINE
@@ -114,6 +137,7 @@ endchoice
 
 config KASAN_STACK_ENABLE
 	bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST
+	depends on KASAN_GENERIC || KASAN_SW_TAGS
 	help
 	  The LLVM stack address sanitizer has a know problem that
 	  causes excessive stack usage in a lot of functions, see
_

Patches currently in -mm which might be from andreyknvl@google.com are

kasan-drop-unnecessary-gpl-text-from-comment-headers.patch
kasan-kasan_vmalloc-depends-on-kasan_generic.patch
kasan-group-vmalloc-code.patch
s390-kasan-include-asm-pageh-from-asm-kasanh.patch
kasan-shadow-declarations-only-for-software-modes.patch
kasan-rename-unpoison_shadow-to-unpoison_memory.patch
kasan-rename-kasan_shadow_-to-kasan_granule_.patch
kasan-only-build-initc-for-software-modes.patch
kasan-split-out-shadowc-from-commonc.patch
kasan-define-kasan_granule_page.patch
kasan-rename-report-and-tags-files.patch
kasan-dont-duplicate-config-dependencies.patch
kasan-hide-invalid-free-check-implementation.patch
kasan-decode-stack-frame-only-with-kasan_stack_enable.patch
kasan-arm64-only-init-shadow-for-software-modes.patch
kasan-arm64-only-use-kasan_depth-for-software-modes.patch
kasan-arm64-move-initialization-message.patch
kasan-arm64-rename-kasan_init_tags-and-mark-as-__init.patch
kasan-rename-addr_has_shadow-to-addr_has_metadata.patch
kasan-rename-print_shadow_for_address-to-print_memory_metadata.patch
kasan-kasan_non_canonical_hook-only-for-software-modes.patch
kasan-rename-shadow-layout-macros-to-meta.patch
kasan-separate-metadata_fetch_row-for-each-mode.patch
kasan-arm64-dont-allow-sw_tags-with-arm64_mte.patch
kasan-introduce-config_kasan_hw_tags.patch
arm64-kasan-align-allocations-for-hw_tags.patch
arm64-kasan-add-arch-layer-for-memory-tagging-helpers.patch
kasan-define-kasan_granule_size-for-hw_tags.patch
kasan-x86-s390-update-undef-config_kasan.patch
kasan-arm64-expand-config_kasan-checks.patch
kasan-arm64-implement-hw_tags-runtime.patch
kasan-arm64-print-report-from-tag-fault-handler.patch
kasan-mm-reset-tags-when-accessing-metadata.patch
kasan-arm64-enable-config_kasan_hw_tags.patch
kasan-add-documentation-for-hardware-tag-based-mode.patch


^ permalink raw reply	[flat|nested] 2+ messages in thread