linux/Documentation/dev-tools, branch v5.11

kasan: fix stack traces dependency for HW_TAGS

2021-02-10T01:26:44Z

Currently, whether the alloc/free stack traces collection is enabled by default for hardware tag-based KASAN depends on CONFIG_DEBUG_KERNEL. The intention for this dependency was to only enable collection on slow debug kernels due to a significant perf and memory impact. As it turns out, CONFIG_DEBUG_KERNEL is not considered a debug option and is enabled on many productions kernels including Android and Ubuntu. As the result, this dependency is pointless and only complicates the code and documentation. Having stack traces collection disabled by default would make the hardware mode work differently to to the software ones, which is confusing. This change removes the dependency and enables stack traces collection by default. Looking into the future, this default might makes sense for production kernels, assuming we implement a fast stack trace collection approach. Link: https://lkml.kernel.org/r/6678d77ceffb71f1cff2cf61560e2ffe7bb6bfe9.1612808820.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Catalin Marinas Cc: Vincenzo Frascino Cc: Dmitry Vyukov Cc: Alexander Potapenko Cc: Will Deacon Cc: Andrey Ryabinin Cc: Peter Collingbourne Cc: Evgenii Stepanov Cc: Branislav Rankov Cc: Kevin Brodsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kasan: fix HW_TAGS boot parameters

2021-01-24T18:34:52Z

The initially proposed KASAN command line parameters are redundant. This change drops the complex "kasan.mode=off/prod/full" parameter and adds a simpler kill switch "kasan=off/on" instead. The new parameter together with the already existing ones provides a cleaner way to express the same set of features. The full set of parameters with this change: kasan=off/on - whether KASAN is enabled kasan.fault=report/panic - whether to only print a report or also panic kasan.stacktrace=off/on - whether to collect alloc/free stack traces Default values: kasan=on kasan.fault=report kasan.stacktrace=on (if CONFIG_DEBUG_KERNEL=y) kasan.stacktrace=off (otherwise) Link: https://linux-review.googlesource.com/id/Ib3694ed90b1e8ccac6cf77dfd301847af4aba7b8 Link: https://lkml.kernel.org/r/4e9c4a4bdcadc168317deb2419144582a9be6e61.1610736745.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Vincenzo Frascino Reviewed-by: Marco Elver Cc: Dmitry Vyukov Cc: Alexander Potapenko Cc: Catalin Marinas Cc: Will Deacon Cc: Andrey Ryabinin Cc: Peter Collingbourne Cc: Evgenii Stepanov Cc: Branislav Rankov Cc: Kevin Brodsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Documentation: kunit: include example of a parameterized test

2021-01-16T00:47:39Z

Commit fadb08e7c750 ("kunit: Support for Parameterized Testing") introduced support but lacks documentation for how to use it. This patch builds on commit 1f0e943df68a ("Documentation: kunit: provide guidance for testing many inputs") to show a minimal example of the new feature. Signed-off-by: Daniel Latypov Reviewed-by: David Gow Tested-by: Brendan Higgins Acked-by: Brendan Higgins Signed-off-by: Shuah Khan

Merge branch 'akpm' (patches from Andrew)

2020-12-22T21:38:17Z

Merge KASAN updates from Andrew Morton. This adds a new hardware tag-based mode to KASAN. The new mode is similar to the existing software tag-based KASAN, but relies on arm64 Memory Tagging Extension (MTE) to perform memory and pointer tagging (instead of shadow memory and compiler instrumentation). By Andrey Konovalov and Vincenzo Frascino. * emailed patches from Andrew Morton : (60 commits) kasan: update documentation kasan, mm: allow cache merging with no metadata kasan: sanitize objects when metadata doesn't fit kasan: clarify comment in __kasan_kfree_large kasan: simplify assign_tag and set_tag calls kasan: don't round_up too much kasan, mm: rename kasan_poison_kfree kasan, mm: check kasan_enabled in annotations kasan: add and integrate kasan boot parameters kasan: inline (un)poison_range and check_invalid_free kasan: open-code kasan_unpoison_slab kasan: inline random_tag for HW_TAGS kasan: inline kasan_reset_tag for tag-based modes kasan: remove __kasan_unpoison_stack kasan: allow VMAP_STACK for HW_TAGS mode kasan, arm64: unpoison stack only with CONFIG_KASAN_STACK kasan: introduce set_alloc_info kasan: rename get_alloc/free_info kasan: simplify quarantine_put call site kselftest/arm64: check GCR_EL1 after context switch ...

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux

2020-12-22T21:34:27Z

Pull ARM updates from Russell King: - Rework phys/virt translation - Add KASan support - Move DT out of linear map region - Use more PC-relative addressing in assembly - Remove FP emulation handling while in kernel mode - Link with '-z norelro' - remove old check for GCC <= 4.2 in ARM unwinder code - disable big endian if using clang's linker * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (46 commits) ARM: 9027/1: head.S: explicitly map DT even if it lives in the first physical section ARM: 9038/1: Link with '-z norelro' ARM: 9037/1: uncompress: Add OF_DT_MAGIC macro ARM: 9036/1: uncompress: Fix dbgadtb size parameter name ARM: 9035/1: uncompress: Add be32tocpu macro ARM: 9033/1: arm/smp: Drop the macro S(x,s) ARM: 9032/1: arm/mm: Convert PUD level pgtable helper macros into functions ARM: 9031/1: hyp-stub: remove unused .L__boot_cpu_mode_offset symbol ARM: 9044/1: vfp: use undef hook for VFP support detection ARM: 9034/1: __div64_32(): straighten up inline asm constraints ARM: 9030/1: entry: omit FP emulation for UND exceptions taken in kernel mode ARM: 9029/1: Make iwmmxt.S support Clang's integrated assembler ARM: 9028/1: disable KASAN in call stack capturing routines ARM: 9026/1: unwind: remove old check for GCC <= 4.2 ARM: 9025/1: Kconfig: CPU_BIG_ENDIAN depends on !LD_IS_LLD ARM: 9024/1: Drop useless cast of "u64" to "long long" ARM: 9023/1: Spelling s/mmeory/memory/ ARM: 9022/1: Change arch/arm/lib/mem*.S to use WEAK instead of .weak ARM: kvm: replace open coded VA->PA calculations with adr_l call ARM: head.S: use PC relative insn sequence to calculate PHYS_OFFSET ...

kasan: update documentation

2020-12-22T20:55:09Z

This change updates KASAN documentation to reflect the addition of boot parameters and also reworks and clarifies some of the existing sections, in particular: defines what a memory granule is, mentions quarantine, makes Kunit section more readable. Link: https://lkml.kernel.org/r/748daf013e17d925b0fe00c1c3b5dce726dd2430.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/Ib1f83e91be273264b25f42b04448ac96b858849f Signed-off-by: Andrey Konovalov Reviewed-by: Dmitry Vyukov Reviewed-by: Marco Elver Tested-by: Vincenzo Frascino Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kasan: add documentation for hardware tag-based mode

2020-12-22T20:55:08Z

Add documentation for hardware tag-based KASAN mode and also add some clarifications for software tag-based mode. Link: https://lkml.kernel.org/r/20ed1d387685e89fc31be068f890f070ef9fd5d5.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Signed-off-by: Vincenzo Frascino Reviewed-by: Marco Elver Reviewed-by: Alexander Potapenko Tested-by: Vincenzo Frascino Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_*

2020-12-22T20:55:06Z

This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory, but will still use the concept of memory granules. Each memory granule maps to a single metadata entry: 8 bytes per one shadow byte for generic mode, 16 bytes per one shadow byte for software tag-based mode, and 16 bytes per one allocation tag for hardware tag-based mode. Rename KASAN_SHADOW_SCALE_SIZE to KASAN_GRANULE_SIZE, and KASAN_SHADOW_MASK to KASAN_GRANULE_MASK. Also use MASK when used as a mask, otherwise use SIZE. No functional changes. Link: https://lkml.kernel.org/r/939b5754e47f528a6e6a6f28ffc5815d8d128033.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Signed-off-by: Vincenzo Frascino Reviewed-by: Marco Elver Reviewed-by: Alexander Potapenko Tested-by: Vincenzo Frascino Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'linux-kselftest-kunit-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2020-12-16T08:19:28Z

Pull Kunit updates from Shuah Khan: - documentation update and fix to kunit_tool to parse diagnostic messages correctly from David Gow - Support for Parameterized Testing and fs/ext4 test updates to use KUnit parameterized testing feature from Arpitha Raghunandan - Helper to derive file names depending on --build_dir argument from Andy Shevchenko * tag 'linux-kselftest-kunit-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: fs: ext4: Modify inode-test.c to use KUnit parameterized testing feature kunit: Support for Parameterized Testing kunit: kunit_tool: Correctly parse diagnostic messages Documentation: kunit: provide guidance for testing many inputs kunit: Introduce get_file_path() helper

ubsan: remove UBSAN_MISC in favor of individual options

2020-12-16T06:46:19Z

Make each UBSAN option individually selectable and remove UBSAN_MISC which no longer has any purpose. Add help text for each Kconfig, and include a reference to the Clang sanitizer documentation. Disable unsigned overflow by default (not available with GCC and makes x86 unbootable with Clang). Disable unreachable when objtool is in use (redundant and confuses things: instrumentation appears at unreachable locations). Link: https://lkml.kernel.org/r/20201203004437.389959-7-keescook@chromium.org Signed-off-by: Kees Cook Cc: Andrey Ryabinin Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Dmitry Vyukov Cc: George Popescu Cc: Herbert Xu Cc: Linus Torvalds Cc: Marco Elver Cc: Masahiro Yamada Cc: Michal Marek Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Oberparleiter Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds