platform/kernel/linux-rpi.git
4 years agoMerge tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy...
Linus Torvalds [Tue, 22 Dec 2020 22:02:39 +0000 (14:02 -0800)]
Merge tag 'kbuild-v5.11' of git://git./linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Use /usr/bin/env for shebang lines in scripts

 - Remove useless -Wnested-externs warning flag

 - Update documents

 - Refactor log handling in modpost

 - Stop building modules without MODULE_LICENSE() tag

 - Make the insane combination of 'static' and EXPORT_SYMBOL an error

 - Improve genksyms to handle _Static_assert()

* tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Documentation/kbuild: Document platform dependency practises
  Documentation/kbuild: Document COMPILE_TEST dependencies
  genksyms: Ignore module scoped _Static_assert()
  modpost: turn static exports into error
  modpost: turn section mismatches to error from fatal()
  modpost: change license incompatibility to error() from fatal()
  modpost: turn missing MODULE_LICENSE() into error
  modpost: refactor error handling and clarify error/fatal difference
  modpost: rename merror() to error()
  kbuild: don't hardcode depmod path
  kbuild: doc: document subdir-y syntax
  kbuild: doc: clarify the difference between extra-y and always-y
  kbuild: doc: split if_changed explanation to a separate section
  kbuild: doc: merge 'Special Rules' and 'Custom kbuild commands' sections
  kbuild: doc: fix 'List directories to visit when descending' section
  kbuild: doc: replace arch/$(ARCH)/ with arch/$(SRCARCH)/
  kbuild: doc: update the description about kbuild Makefiles
  Makefile.extrawarn: remove -Wnested-externs warning
  tweewide: Fix most Shebang lines

4 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Tue, 22 Dec 2020 21:38:17 +0000 (13:38 -0800)]
Merge branch 'akpm' (patches from Andrew)

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 <akpm@linux-foundation.org>: (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
  ...

4 years agoMerge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux
Linus Torvalds [Tue, 22 Dec 2020 21:34:27 +0000 (13:34 -0800)]
Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux

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
  ...

4 years agoMerge tag 'for-5.11/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 22 Dec 2020 21:27:21 +0000 (13:27 -0800)]
Merge tag 'for-5.11/dm-changes' of git://git./linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - Add DM verity support for signature verification with 2nd keyring

 - Fix DM verity to skip verity work if IO completes with error while
   system is shutting down

 - Add new DM multipath "IO affinity" path selector that maps IO
   destined to a given path to a specific CPU based on user provided
   mapping

 - Rename DM multipath path selector source files to have "dm-ps" prefix

 - Add REQ_NOWAIT support to some other simple DM targets that don't
   block in more elaborate ways waiting for IO

 - Export DM crypt's kcryptd workqueue via sysfs (WQ_SYSFS)

 - Fix error return code in DM's target_message() if empty message is
   received

 - A handful of other small cleanups

* tag 'for-5.11/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache: simplify the return expression of load_mapping()
  dm ebs: avoid double unlikely() notation when using IS_ERR()
  dm verity: skip verity work if I/O error when system is shutting down
  dm crypt: export sysfs of kcryptd workqueue
  dm ioctl: fix error return code in target_message
  dm crypt: Constify static crypt_iv_operations
  dm: add support for REQ_NOWAIT to various targets
  dm: rename multipath path selector source files to have "dm-ps" prefix
  dm mpath: add IO affinity path selector
  dm verity: Add support for signature verification with 2nd keyring
  dm: remove unnecessary current->bio_list check when submitting split bio

4 years agoMerge tag 'hwmon-for-v5.11-take2' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 22 Dec 2020 21:24:33 +0000 (13:24 -0800)]
Merge tag 'hwmon-for-v5.11-take2' of git://git./linux/kernel/git/groeck/linux-staging

Pull another hwmon update from Guenter Roeck:
 "The only patch in this series is removal of voltage and current
  reporting for AMD Zen CPUs.

  Turns out that was not worth the trouble, because it's all
  undocumented and not maintainable"

* tag 'hwmon-for-v5.11-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (k10temp) Remove support for displaying voltage and current on Zen CPUs

4 years agoMerge tag 'dma-mapping-5.11' of git://git.infradead.org/users/hch/dma-mapping
Linus Torvalds [Tue, 22 Dec 2020 21:19:43 +0000 (13:19 -0800)]
Merge tag 'dma-mapping-5.11' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - support for a partial IOMMU bypass (Alexey Kardashevskiy)

 - add a DMA API benchmark (Barry Song)

 - misc fixes (Tiezhu Yang, tangjianqiang)

* tag 'dma-mapping-5.11' of git://git.infradead.org/users/hch/dma-mapping:
  selftests/dma: add test application for DMA_MAP_BENCHMARK
  dma-mapping: add benchmark support for streaming DMA APIs
  dma-contiguous: fix a typo error in a comment
  dma-pool: no need to check return value of debugfs_create functions
  powerpc/dma: Fallback to dma_ops when persistent memory present
  dma-mapping: Allow mixing bypass and mapped DMA operation

4 years agoMerge tag 'configfs-5.11' of git://git.infradead.org/users/hch/configfs
Linus Torvalds [Tue, 22 Dec 2020 21:17:03 +0000 (13:17 -0800)]
Merge tag 'configfs-5.11' of git://git.infradead.org/users/hch/configfs

Pull configfs update from Christoph Hellwig:
 "Fix a kerneldoc comment (Alex Shi)"

* tag 'configfs-5.11' of git://git.infradead.org/users/hch/configfs:
  configfs: fix kernel-doc markup issue

4 years agoMerge tag 'exfat-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linki...
Linus Torvalds [Tue, 22 Dec 2020 21:15:31 +0000 (13:15 -0800)]
Merge tag 'exfat-for-5.11-rc1' of git://git./linux/kernel/git/linkinjeon/exfat

Pull exfat update from Namjae Jeon:
 "Avoid page allocation failure from upcase table allocation"

* tag 'exfat-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
  exfat: Avoid allocating upcase table using kcalloc()

4 years agox86/split-lock: Avoid returning with interrupts enabled
Andi Kleen [Tue, 22 Dec 2020 17:40:10 +0000 (09:40 -0800)]
x86/split-lock: Avoid returning with interrupts enabled

When a split lock is detected always make sure to disable interrupts
before returning from the trap handler.

The kernel exit code assumes that all exits run with interrupts
disabled, otherwise the SWAPGS sequence can race against interrupts and
cause recursing page faults and later panics.

The problem will only happen on CPUs with split lock disable
functionality, so Icelake Server, Tiger Lake, Snow Ridge, Jacobsville.

Fixes: ca4c6a9858c2 ("x86/traps: Make interrupt enable/disable symmetric in C code")
Fixes: bce9b042ec73 ("x86/traps: Disable interrupts in exc_aligment_check()") # v5.8+
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: update documentation
Andrey Konovalov [Tue, 22 Dec 2020 20:03:35 +0000 (12:03 -0800)]
kasan: update documentation

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 <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, mm: allow cache merging with no metadata
Andrey Konovalov [Tue, 22 Dec 2020 20:03:31 +0000 (12:03 -0800)]
kasan, mm: allow cache merging with no metadata

The reason cache merging is disabled with KASAN is because KASAN puts its
metadata right after the allocated object. When the merged caches have
slightly different sizes, the metadata ends up in different places, which
KASAN doesn't support.

It might be possible to adjust the metadata allocation algorithm and make
it friendly to the cache merging code. Instead this change takes a simpler
approach and allows merging caches when no metadata is present. Which is
the case for hardware tag-based KASAN with kasan.mode=prod.

Link: https://lkml.kernel.org/r/37497e940bfd4b32c0a93a702a9ae4cf061d5392.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ia114847dfb2244f297d2cb82d592bf6a07455dba
Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: sanitize objects when metadata doesn't fit
Andrey Konovalov [Tue, 22 Dec 2020 20:03:28 +0000 (12:03 -0800)]
kasan: sanitize objects when metadata doesn't fit

KASAN marks caches that are sanitized with the SLAB_KASAN cache flag.
Currently if the metadata that is appended after the object (stores e.g.
stack trace ids) doesn't fit into KMALLOC_MAX_SIZE (can only happen with
SLAB, see the comment in the patch), KASAN turns off sanitization
completely.

With this change sanitization of the object data is always enabled.
However the metadata is only stored when it fits.  Instead of checking for
SLAB_KASAN flag accross the code to find out whether the metadata is
there, use cache->kasan_info.alloc/free_meta_offset.  As 0 can be a valid
value for free_meta_offset, introduce KASAN_NO_FREE_META as an indicator
that the free metadata is missing.

Without this change all sanitized KASAN objects would be put into
quarantine with generic KASAN.  With this change, only the objects that
have metadata (i.e.  when it fits) are put into quarantine, the rest is
freed right away.

Along the way rework __kasan_cache_create() and add claryfying comments.

Link: https://lkml.kernel.org/r/aee34b87a5e4afe586c2ac6a0b32db8dc4dcc2dc.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Icd947e2bea054cb5cfbdc6cf6652227d97032dcb
Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: clarify comment in __kasan_kfree_large
Andrey Konovalov [Tue, 22 Dec 2020 20:03:24 +0000 (12:03 -0800)]
kasan: clarify comment in __kasan_kfree_large

Currently it says that the memory gets poisoned by page_alloc code.
Clarify this by mentioning the specific callback that poisons the memory.

Link: https://lkml.kernel.org/r/1c8380fe0332a3bcc720fe29f1e0bef2e2974416.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I1334dffb69b87d7986fab88a1a039cc3ea764725
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: simplify assign_tag and set_tag calls
Andrey Konovalov [Tue, 22 Dec 2020 20:03:20 +0000 (12:03 -0800)]
kasan: simplify assign_tag and set_tag calls

set_tag() already ignores the tag for the generic mode, so just call it
as is. Add a check for the generic mode to assign_tag(), and simplify its
call in ____kasan_kmalloc().

Link: https://lkml.kernel.org/r/121eeab245f98555862b289d2ba9269c868fbbcf.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I18905ca78fb4a3d60e1a34a4ca00247272480438
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: don't round_up too much
Andrey Konovalov [Tue, 22 Dec 2020 20:03:17 +0000 (12:03 -0800)]
kasan: don't round_up too much

For hardware tag-based mode kasan_poison_memory() already rounds up the
size. Do the same for software modes and remove round_up() from the common
code.

Link: https://lkml.kernel.org/r/47b232474f1f89dc072aeda0fa58daa6efade377.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ib397128fac6eba874008662b4964d65352db4aa4
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, mm: rename kasan_poison_kfree
Andrey Konovalov [Tue, 22 Dec 2020 20:03:13 +0000 (12:03 -0800)]
kasan, mm: rename kasan_poison_kfree

Rename kasan_poison_kfree() to kasan_slab_free_mempool() as it better
reflects what this annotation does. Also add a comment that explains the
PageSlab() check.

No functional changes.

Link: https://lkml.kernel.org/r/141675fb493555e984c5dca555e9d9f768c7bbaa.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I5026f87364e556b506ef1baee725144bb04b8810
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, mm: check kasan_enabled in annotations
Andrey Konovalov [Tue, 22 Dec 2020 20:03:10 +0000 (12:03 -0800)]
kasan, mm: check kasan_enabled in annotations

Declare the kasan_enabled static key in include/linux/kasan.h and in
include/linux/mm.h and check it in all kasan annotations. This allows to
avoid any slowdown caused by function calls when kasan_enabled is
disabled.

Link: https://lkml.kernel.org/r/9f90e3c0aa840dbb4833367c2335193299f69023.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e
Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: add and integrate kasan boot parameters
Andrey Konovalov [Tue, 22 Dec 2020 20:03:06 +0000 (12:03 -0800)]
kasan: add and integrate kasan boot parameters

Hardware tag-based KASAN mode is intended to eventually be used in
production as a security mitigation. Therefore there's a need for finer
control over KASAN features and for an existence of a kill switch.

This change adds a few boot parameters for hardware tag-based KASAN that
allow to disable or otherwise control particular KASAN features.

The features that can be controlled are:

1. Whether KASAN is enabled at all.
2. Whether KASAN collects and saves alloc/free stacks.
3. Whether KASAN panics on a detected bug or not.

With this change a new boot parameter kasan.mode allows to choose one of
three main modes:

- kasan.mode=off - KASAN is disabled, no tag checks are performed
- kasan.mode=prod - only essential production features are enabled
- kasan.mode=full - all KASAN features are enabled

The chosen mode provides default control values for the features mentioned
above. However it's also possible to override the default values by
providing:

- kasan.stacktrace=off/on - enable alloc/free stack collection
                            (default: on for mode=full, otherwise off)
- kasan.fault=report/panic - only report tag fault or also panic
                             (default: report)

If kasan.mode parameter is not provided, it defaults to full when
CONFIG_DEBUG_KERNEL is enabled, and to prod otherwise.

It is essential that switching between these modes doesn't require
rebuilding the kernel with different configs, as this is required by
the Android GKI (Generic Kernel Image) initiative [1].

[1] https://source.android.com/devices/architecture/kernel/generic-kernel-image

[andreyknvl@google.com: don't use read-only static keys]
Link: https://lkml.kernel.org/r/f2ded589eba1597f7360a972226083de9afd86e2.1607537948.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/cb093613879d8d8841173f090133eddeb4c35f1f.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/If7d37003875b2ed3e0935702c8015c223d6416a4
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: inline (un)poison_range and check_invalid_free
Andrey Konovalov [Tue, 22 Dec 2020 20:03:03 +0000 (12:03 -0800)]
kasan: inline (un)poison_range and check_invalid_free

Using (un)poison_range() or check_invalid_free() currently results in
function calls. Move their definitions to mm/kasan/kasan.h and turn them
into static inline functions for hardware tag-based mode to avoid
unneeded function calls.

Link: https://lkml.kernel.org/r/7007955b69eb31b5376a7dc1e0f4ac49138504f2.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ia9d8191024a12d1374675b3d27197f10193f50bb
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: open-code kasan_unpoison_slab
Andrey Konovalov [Tue, 22 Dec 2020 20:02:59 +0000 (12:02 -0800)]
kasan: open-code kasan_unpoison_slab

There's the external annotation kasan_unpoison_slab() that is currently
defined as static inline and uses kasan_unpoison_range(). Open-code this
function in mempool.c. Otherwise with an upcoming change this function
will result in an unnecessary function call.

Link: https://lkml.kernel.org/r/131a6694a978a9a8b150187e539eecc8bcbf759b.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ia7c8b659f79209935cbaab3913bf7f082cc43a0e
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: inline random_tag for HW_TAGS
Andrey Konovalov [Tue, 22 Dec 2020 20:02:56 +0000 (12:02 -0800)]
kasan: inline random_tag for HW_TAGS

Using random_tag() currently results in a function call. Move its
definition to mm/kasan/kasan.h and turn it into a static inline function
for hardware tag-based mode to avoid uneeded function calls.

Link: https://lkml.kernel.org/r/be438471690e351e1d792e6bb432e8c03ccb15d3.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Iac5b2faf9a912900e16cca6834d621f5d4abf427
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: inline kasan_reset_tag for tag-based modes
Andrey Konovalov [Tue, 22 Dec 2020 20:02:52 +0000 (12:02 -0800)]
kasan: inline kasan_reset_tag for tag-based modes

Using kasan_reset_tag() currently results in a function call. As it's
called quite often from the allocator code, this leads to a noticeable
slowdown. Move it to include/linux/kasan.h and turn it into a static
inline function. Also remove the now unneeded reset_tag() internal KASAN
macro and use kasan_reset_tag() instead.

Link: https://lkml.kernel.org/r/6940383a3a9dfb416134d338d8fac97a9ebb8686.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I4d2061acfe91d480a75df00b07c22d8494ef14b5
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: remove __kasan_unpoison_stack
Andrey Konovalov [Tue, 22 Dec 2020 20:02:49 +0000 (12:02 -0800)]
kasan: remove __kasan_unpoison_stack

There's no need for __kasan_unpoison_stack() helper, as it's only
currently used in a single place. Removing it also removes unneeded
arithmetic.

No functional changes.

Link: https://lkml.kernel.org/r/93e78948704a42ea92f6248ff8a725613d721161.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ie5ba549d445292fe629b4a96735e4034957bcc50
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: allow VMAP_STACK for HW_TAGS mode
Andrey Konovalov [Tue, 22 Dec 2020 20:02:45 +0000 (12:02 -0800)]
kasan: allow VMAP_STACK for HW_TAGS mode

Even though hardware tag-based mode currently doesn't support checking
vmalloc allocations, it doesn't use shadow memory and works with
VMAP_STACK as is. Change VMAP_STACK definition accordingly.

Link: https://lkml.kernel.org/r/ecdb2a1658ebd88eb276dee2493518ac0e82de41.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I3552cbc12321dec82cd7372676e9372a2eb452ac
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: unpoison stack only with CONFIG_KASAN_STACK
Andrey Konovalov [Tue, 22 Dec 2020 20:02:42 +0000 (12:02 -0800)]
kasan, arm64: unpoison stack only with CONFIG_KASAN_STACK

There's a config option CONFIG_KASAN_STACK that has to be enabled for
KASAN to use stack instrumentation and perform validity checks for
stack variables.

There's no need to unpoison stack when CONFIG_KASAN_STACK is not enabled.
Only call kasan_unpoison_task_stack[_below]() when CONFIG_KASAN_STACK is
enabled.

Note, that CONFIG_KASAN_STACK is an option that is currently always
defined when CONFIG_KASAN is enabled, and therefore has to be tested
with #if instead of #ifdef.

Link: https://lkml.kernel.org/r/d09dd3f8abb388da397fd11598c5edeaa83fe559.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/If8a891e9fe01ea543e00b576852685afec0887e3
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: introduce set_alloc_info
Andrey Konovalov [Tue, 22 Dec 2020 20:02:38 +0000 (12:02 -0800)]
kasan: introduce set_alloc_info

Add set_alloc_info() helper and move kasan_set_track() into it. This will
simplify the code for one of the upcoming changes.

No functional changes.

Link: https://lkml.kernel.org/r/b2393e8f1e311a70fc3aaa2196461b6acdee7d21.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I0316193cbb4ecc9b87b7c2eee0dd79f8ec908c1a
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: rename get_alloc/free_info
Andrey Konovalov [Tue, 22 Dec 2020 20:02:34 +0000 (12:02 -0800)]
kasan: rename get_alloc/free_info

Rename get_alloc_info() and get_free_info() to kasan_get_alloc_meta() and
kasan_get_free_meta() to better reflect what those do and avoid confusion
with kasan_set_free_info().

No functional changes.

Link: https://lkml.kernel.org/r/27b7c036b754af15a2839e945f6d8bfce32b4c2f.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ib6e4ba61c8b12112b403d3479a9799ac8fff8de1
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: simplify quarantine_put call site
Andrey Konovalov [Tue, 22 Dec 2020 20:02:31 +0000 (12:02 -0800)]
kasan: simplify quarantine_put call site

Patch series "kasan: boot parameters for hardware tag-based mode", v4.

=== Overview

Hardware tag-based KASAN mode [1] is intended to eventually be used in
production as a security mitigation. Therefore there's a need for finer
control over KASAN features and for an existence of a kill switch.

This patchset adds a few boot parameters for hardware tag-based KASAN that
allow to disable or otherwise control particular KASAN features, as well
as provides some initial optimizations for running KASAN in production.

There's another planned patchset what will further optimize hardware
tag-based KASAN, provide proper benchmarking and tests, and will fully
enable tag-based KASAN for production use.

Hardware tag-based KASAN relies on arm64 Memory Tagging Extension (MTE)
[2] to perform memory and pointer tagging. Please see [3] and [4] for
detailed analysis of how MTE helps to fight memory safety problems.

The features that can be controlled are:

1. Whether KASAN is enabled at all.
2. Whether KASAN collects and saves alloc/free stacks.
3. Whether KASAN panics on a detected bug or not.

The patch titled "kasan: add and integrate kasan boot parameters" of this
series adds a few new boot parameters.

kasan.mode allows to choose one of three main modes:

- kasan.mode=off - KASAN is disabled, no tag checks are performed
- kasan.mode=prod - only essential production features are enabled
- kasan.mode=full - all KASAN features are enabled

The chosen mode provides default control values for the features mentioned
above. However it's also possible to override the default values by
providing:

- kasan.stacktrace=off/on - enable stacks collection
                            (default: on for mode=full, otherwise off)
- kasan.fault=report/panic - only report tag fault or also panic
                             (default: report)

If kasan.mode parameter is not provided, it defaults to full when
CONFIG_DEBUG_KERNEL is enabled, and to prod otherwise.

It is essential that switching between these modes doesn't require
rebuilding the kernel with different configs, as this is required by
the Android GKI (Generic Kernel Image) initiative.

=== Benchmarks

For now I've only performed a few simple benchmarks such as measuring
kernel boot time and slab memory usage after boot. There's an upcoming
patchset which will optimize KASAN further and include more detailed
benchmarking results.

The benchmarks were performed in QEMU and the results below exclude the
slowdown caused by QEMU memory tagging emulation (as it's different from
the slowdown that will be introduced by hardware and is therefore
irrelevant).

KASAN_HW_TAGS=y + kasan.mode=off introduces no performance or memory
impact compared to KASAN_HW_TAGS=n.

kasan.mode=prod (manually excluding tagging) introduces 3% of performance
and no memory impact (except memory used by hardware to store tags)
compared to kasan.mode=off.

kasan.mode=full has about 40% performance and 30% memory impact over
kasan.mode=prod. Both come from alloc/free stack collection.

=== Notes

This patchset is available here:

https://github.com/xairy/linux/tree/up-boot-mte-v4

This patchset is based on v11 of "kasan: add hardware tag-based mode for
arm64" patchset [1].

For testing in QEMU hardware tag-based KASAN requires:

1. QEMU built from master [6] (use "-machine virt,mte=on -cpu max" arguments
   to run).
2. GCC version 10.

[1] https://lore.kernel.org/linux-arm-kernel/cover.1606161801.git.andreyknvl@google.com/T/#t
[2] https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety
[3] https://arxiv.org/pdf/1802.09517.pdf
[4] https://github.com/microsoft/MSRC-Security-Research/blob/master/papers/2020/Security%20analysis%20of%20memory%20tagging.pdf
[5] https://source.android.com/devices/architecture/kernel/generic-kernel-image
[6] https://github.com/qemu/qemu

=== Tags

Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
This patch (of 19):

Move get_free_info() call into quarantine_put() to simplify the call site.

No functional changes.

Link: https://lkml.kernel.org/r/cover.1606162397.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/312d0a3ef92cc6dc4fa5452cbc1714f9393ca239.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Iab0f04e7ebf8d83247024b7190c67c3c34c7940f
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokselftest/arm64: check GCR_EL1 after context switch
Vincenzo Frascino [Tue, 22 Dec 2020 20:02:27 +0000 (12:02 -0800)]
kselftest/arm64: check GCR_EL1 after context switch

This test is specific to MTE and verifies that the GCR_EL1 register is
context switched correctly.

It spawns 1024 processes and each process spawns 5 threads.  Each thread
writes a random setting of GCR_EL1 through the prctl() system call and
reads it back verifying that it is the same.  If the values are not the
same it reports a failure.

Note: The test has been extended to verify that even SYNC and ASYNC mode
setting is preserved correctly over context switching.

Link: https://lkml.kernel.org/r/b51a165426e906e7ec8a68d806ef3f8cd92581a6.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: add documentation for hardware tag-based mode
Andrey Konovalov [Tue, 22 Dec 2020 20:02:24 +0000 (12:02 -0800)]
kasan: add documentation for hardware tag-based mode

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 <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: enable CONFIG_KASAN_HW_TAGS
Andrey Konovalov [Tue, 22 Dec 2020 20:02:20 +0000 (12:02 -0800)]
kasan, arm64: enable CONFIG_KASAN_HW_TAGS

Hardware tag-based KASAN is now ready, enable the configuration option.

Link: https://lkml.kernel.org/r/a6fa50d3bb6b318e05c6389a44095be96442b8b0.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, mm: reset tags when accessing metadata
Andrey Konovalov [Tue, 22 Dec 2020 20:02:17 +0000 (12:02 -0800)]
kasan, mm: reset tags when accessing metadata

Kernel allocator code accesses metadata for slab objects, that may lie
out-of-bounds of the object itself, or be accessed when an object is
freed.  Such accesses trigger tag faults and lead to false-positive
reports with hardware tag-based KASAN.

Software KASAN modes disable instrumentation for allocator code via
KASAN_SANITIZE Makefile macro, and rely on kasan_enable/disable_current()
annotations which are used to ignore KASAN reports.

With hardware tag-based KASAN neither of those options are available, as
it doesn't use compiler instrumetation, no tag faults are ignored, and MTE
is disabled after the first one.

Instead, reset tags when accessing metadata (currently only for SLUB).

Link: https://lkml.kernel.org/r/a0f3cefbc49f34c843b664110842de4db28179d0.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: print report from tag fault handler
Andrey Konovalov [Tue, 22 Dec 2020 20:02:13 +0000 (12:02 -0800)]
kasan, arm64: print report from tag fault handler

Add error reporting for hardware tag-based KASAN.  When
CONFIG_KASAN_HW_TAGS is enabled, print KASAN report from the arm64 tag
fault handler.

SAS bits aren't set in ESR for all faults reported in EL1, so it's
impossible to find out the size of the access the caused the fault.  Adapt
KASAN reporting code to handle this case.

Link: https://lkml.kernel.org/r/b559c82b6a969afedf53b4694b475f0234067a1a.1606161801.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: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: implement HW_TAGS runtime
Andrey Konovalov [Tue, 22 Dec 2020 20:02:10 +0000 (12:02 -0800)]
kasan, arm64: implement HW_TAGS runtime

Provide implementation of KASAN functions required for the hardware
tag-based mode.  Those include core functions for memory and pointer
tagging (tags_hw.c) and bug reporting (report_tags_hw.c).  Also adapt
common KASAN code to support the new mode.

Link: https://lkml.kernel.org/r/cfd0fbede579a6b66755c98c88c108e54f9c56bf.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: expand CONFIG_KASAN checks
Andrey Konovalov [Tue, 22 Dec 2020 20:02:06 +0000 (12:02 -0800)]
kasan, arm64: expand CONFIG_KASAN checks

Some #ifdef CONFIG_KASAN checks are only relevant for software KASAN modes
(either related to shadow memory or compiler instrumentation).  Expand
those into CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS.

Link: https://lkml.kernel.org/r/e6971e432dbd72bb897ff14134ebb7e169bdcf0c.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, x86, s390: update undef CONFIG_KASAN
Andrey Konovalov [Tue, 22 Dec 2020 20:02:03 +0000 (12:02 -0800)]
kasan, x86, s390: update undef CONFIG_KASAN

With the intoduction of hardware tag-based KASAN some kernel checks of
this kind:

  ifdef CONFIG_KASAN

will be updated to:

  if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

x86 and s390 use a trick to #undef CONFIG_KASAN for some of the code
that isn't linked with KASAN runtime and shouldn't have any KASAN
annotations.

Also #undef CONFIG_KASAN_GENERIC with CONFIG_KASAN.

Link: https://lkml.kernel.org/r/9d84bfaaf8fabe0fc89f913c9e420a30bd31a260.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: define KASAN_GRANULE_SIZE for HW_TAGS
Andrey Konovalov [Tue, 22 Dec 2020 20:01:59 +0000 (12:01 -0800)]
kasan: define KASAN_GRANULE_SIZE for HW_TAGS

Hardware tag-based KASAN has granules of MTE_GRANULE_SIZE.  Define
KASAN_GRANULE_SIZE to MTE_GRANULE_SIZE for CONFIG_KASAN_HW_TAGS.

Link: https://lkml.kernel.org/r/3d15794b3d1b27447fd7fdf862c073192ba657bd.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: kasan: add arch layer for memory tagging helpers
Andrey Konovalov [Tue, 22 Dec 2020 20:01:56 +0000 (12:01 -0800)]
arm64: kasan: add arch layer for memory tagging helpers

This patch add a set of arch_*() memory tagging helpers currently only
defined for arm64 when hardware tag-based KASAN is enabled.  These helpers
will be used by KASAN runtime to implement the hardware tag-based mode.

The arch-level indirection level is introduced to simplify adding hardware
tag-based KASAN support for other architectures in the future by defining
the appropriate arch_*() macros.

Link: https://lkml.kernel.org/r/fc9e5bb71201c03131a2fc00a74125723568dda9.1606161801.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: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: kasan: align allocations for HW_TAGS
Andrey Konovalov [Tue, 22 Dec 2020 20:01:52 +0000 (12:01 -0800)]
arm64: kasan: align allocations for HW_TAGS

Hardware tag-based KASAN uses the memory tagging approach, which requires
all allocations to be aligned to the memory granule size.  Align the
allocations to MTE_GRANULE_SIZE via ARCH_SLAB_MINALIGN when
CONFIG_KASAN_HW_TAGS is enabled.

Link: https://lkml.kernel.org/r/fe64131606b1c2aabfd34ae99554c0d9df18eb19.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, mm: untag page address in free_reserved_area
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:49 +0000 (12:01 -0800)]
kasan, mm: untag page address in free_reserved_area

free_reserved_area() memsets the pages belonging to a given memory area.
As that memory hasn't been allocated via page_alloc, the KASAN tags that
those pages have are 0x00.  As the result the memset might result in a tag
mismatch.

Untag the address to avoid spurious faults.

Link: https://lkml.kernel.org/r/ebef6425f4468d063e2f09c1b62ccbb2236b71d3.1606161801.git.andreyknvl@google.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: mte: switch GCR_EL1 in kernel entry and exit
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:45 +0000 (12:01 -0800)]
arm64: mte: switch GCR_EL1 in kernel entry and exit

When MTE is present, the GCR_EL1 register contains the tags mask that
allows to exclude tags from the random generation via the IRG instruction.

With the introduction of the new Tag-Based KASAN API that provides a
mechanism to reserve tags for special reasons, the MTE implementation has
to make sure that the GCR_EL1 setting for the kernel does not affect the
userspace processes and viceversa.

Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit.

Link: https://lkml.kernel.org/r/578b03294708cc7258fad0dc9c2a2e809e5a8214.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: mte: convert gcr_user into an exclude mask
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:42 +0000 (12:01 -0800)]
arm64: mte: convert gcr_user into an exclude mask

The gcr_user mask is a per thread mask that represents the tags that are
excluded from random generation when the Memory Tagging Extension is
present and an 'irg' instruction is invoked.

gcr_user affects the behavior on EL0 only.

Currently that mask is an include mask and it is controlled by the user
via prctl() while GCR_EL1 accepts an exclude mask.

Convert the include mask into an exclude one to make it easier the
register setting.

Note: This change will affect gcr_kernel (for EL1) introduced with a
future patch.

Link: https://lkml.kernel.org/r/946dd31be833b660334c4f93410acf6d6c4cf3c4.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: kasan: allow enabling in-kernel MTE
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:38 +0000 (12:01 -0800)]
arm64: kasan: allow enabling in-kernel MTE

Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) feature
and requires it to be enabled.  MTE supports

This patch adds a new mte_enable_kernel() helper, that enables MTE in
Synchronous mode in EL1 and is intended to be called from KASAN runtime
during initialization.

The Tag Checking operation causes a synchronous data abort as a
consequence of a tag check fault when MTE is configured in synchronous
mode.

As part of this change enable match-all tag for EL1 to allow the kernel to
access user pages without faulting.  This is required because the kernel
does not have knowledge of the tags set by the user in a page.

Note: For MTE, the TCF bit field in SCTLR_EL1 affects only EL1 in a
similar way as TCF0 affects EL0.

MTE that is built on top of the Top Byte Ignore (TBI) feature hence we
enable it as part of this patch as well.

Link: https://lkml.kernel.org/r/7352b0a0899af65c2785416c8ca6bf3845b66fa1.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: mte: add in-kernel tag fault handler
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:35 +0000 (12:01 -0800)]
arm64: mte: add in-kernel tag fault handler

Add the implementation of the in-kernel fault handler.

When a tag fault happens on a kernel address:
* MTE is disabled on the current CPU,
* the execution continues.

When a tag fault happens on a user address:
* the kernel executes do_bad_area() and panics.

The tag fault handler for kernel addresses is currently empty and will be
filled in by a future commit.

Link: https://lkml.kernel.org/r/20201203102628.GB2224@gaia
Link: https://lkml.kernel.org/r/ad31529b073e22840b7a2246172c2b67747ed7c4.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
[catalin.marinas@arm.com: ensure CONFIG_ARM64_PAN is enabled with MTE]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: mte: reset the page tag in page->flags
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:31 +0000 (12:01 -0800)]
arm64: mte: reset the page tag in page->flags

The hardware tag-based KASAN for compatibility with the other modes stores
the tag associated to a page in page->flags.  Due to this the kernel
faults on access when it allocates a page with an initial tag and the user
changes the tags.

Reset the tag associated by the kernel to a page in all the meaningful
places to prevent kernel faults on access.

Note: An alternative to this approach could be to modify page_to_virt().
This though could end up being racy, in fact if a CPU checks the
PG_mte_tagged bit and decides that the page is not tagged but another CPU
maps the same with PROT_MTE and becomes tagged the subsequent kernel
access would fail.

Link: https://lkml.kernel.org/r/9073d4e973747a6f78d5bdd7ebe17f290d087096.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: mte: add in-kernel MTE helpers
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:28 +0000 (12:01 -0800)]
arm64: mte: add in-kernel MTE helpers

Provide helper functions to manipulate allocation and pointer tags for
kernel addresses.

Low-level helper functions (mte_assign_*, written in assembly) operate tag
values from the [0x0, 0xF] range.  High-level helper functions
(mte_get/set_*) use the [0xF0, 0xFF] range to preserve compatibility with
normal kernel pointers that have 0xFF in their top byte.

MTE_GRANULE_SIZE and related definitions are moved to mte-def.h header
that doesn't have any dependencies and is safe to include into any
low-level header.

Link: https://lkml.kernel.org/r/c31bf759b4411b2d98cdd801eb928e241584fd1f.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoarm64: enable armv8.5-a asm-arch option
Vincenzo Frascino [Tue, 22 Dec 2020 20:01:24 +0000 (12:01 -0800)]
arm64: enable armv8.5-a asm-arch option

Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) which is
an armv8.5-a architecture extension.

Enable the correct asm option when the compiler supports it in order to
allow the usage of ALTERNATIVE()s with MTE instructions.

Link: https://lkml.kernel.org/r/d03d1157124ea3532eaeb77507988733f5734986.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: introduce CONFIG_KASAN_HW_TAGS
Andrey Konovalov [Tue, 22 Dec 2020 20:01:20 +0000 (12:01 -0800)]
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/44906a209d3a44f9c6f5a21841e90988e365601e.1606161801.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>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: separate metadata_fetch_row for each mode
Andrey Konovalov [Tue, 22 Dec 2020 20:01:17 +0000 (12:01 -0800)]
kasan: separate metadata_fetch_row for each mode

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Rework print_memory_metadata() to make it agnostic with regard to the way
metadata is stored.  Allow providing a separate metadata_fetch_row()
implementation for each KASAN mode.  Hardware tag-based KASAN will provide
its own implementation that doesn't use shadow memory.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/5fb1ec0152bb1f521505017800387ec3e36ffe18.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: rename SHADOW layout macros to META
Andrey Konovalov [Tue, 22 Dec 2020 20:01:14 +0000 (12:01 -0800)]
kasan: rename SHADOW layout macros to META

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Hardware tag-based KASAN won't be using shadow memory, but will reuse
these macros.  Rename "SHADOW" to implementation-neutral "META".

No functional changes.

Link: https://lkml.kernel.org/r/f96244ec59dc17db35173ec352c5592b14aefaf8.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: rename print_shadow_for_address to print_memory_metadata
Andrey Konovalov [Tue, 22 Dec 2020 20:01:10 +0000 (12:01 -0800)]
kasan: rename print_shadow_for_address to print_memory_metadata

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Hardware tag-based KASAN won't be using shadow memory, but will reuse this
function.  Rename "shadow" to implementation-neutral "metadata".

No functional changes.

Link: https://lkml.kernel.org/r/dd955c5aadaee16aef451a6189d19172166a23f5.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: rename addr_has_shadow to addr_has_metadata
Andrey Konovalov [Tue, 22 Dec 2020 20:01:07 +0000 (12:01 -0800)]
kasan: rename addr_has_shadow to addr_has_metadata

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Hardware tag-based KASAN won't be using shadow memory, but will reuse this
function.  Rename "shadow" to implementation-neutral "metadata".

No functional changes.

Link: https://lkml.kernel.org/r/370466fba590a4596b55ffd38adfd990f8886db4.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: rename kasan_init_tags and mark as __init
Andrey Konovalov [Tue, 22 Dec 2020 20:01:03 +0000 (12:01 -0800)]
kasan, arm64: rename kasan_init_tags and mark as __init

Rename kasan_init_tags() to kasan_init_sw_tags() as the upcoming hardware
tag-based KASAN mode will have its own initialization routine.  Also
similarly to kasan_init() mark kasan_init_tags() as __init.

Link: https://lkml.kernel.org/r/71e52af72a09f4b50c8042f16101c60e50649fbb.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: move initialization message
Andrey Konovalov [Tue, 22 Dec 2020 20:01:00 +0000 (12:01 -0800)]
kasan, arm64: move initialization message

Software tag-based KASAN mode is fully initialized with kasan_init_tags(),
while the generic mode only requires kasan_init().  Move the
initialization message for tag-based mode into kasan_init_tags().

Also fix pr_fmt() usage for KASAN code: generic.c doesn't need it as it
doesn't use any printing functions; tag-based mode should use "kasan:"
instead of KBUILD_MODNAME (which stands for file name).

Link: https://lkml.kernel.org/r/29a30ea4e1750450dd1f693d25b7b6cb05913ecf.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: only use kasan_depth for software modes
Andrey Konovalov [Tue, 22 Dec 2020 20:00:56 +0000 (12:00 -0800)]
kasan, arm64: only use kasan_depth for software modes

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Hardware tag-based KASAN won't use kasan_depth.  Only define and use it
when one of the software KASAN modes are enabled.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/e16f15aeda90bc7fb4dfc2e243a14b74cc5c8219.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan, arm64: only init shadow for software modes
Andrey Konovalov [Tue, 22 Dec 2020 20:00:53 +0000 (12:00 -0800)]
kasan, arm64: only init shadow for software modes

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Hardware tag-based KASAN won't be using shadow memory.  Only initialize it
when one of the software KASAN modes are enabled.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/d1742eea2cd728d150d49b144e49b6433405c7ba.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: decode stack frame only with KASAN_STACK_ENABLE
Andrey Konovalov [Tue, 22 Dec 2020 20:00:49 +0000 (12:00 -0800)]
kasan: decode stack frame only with KASAN_STACK_ENABLE

Decoding routines aren't needed when CONFIG_KASAN_STACK_ENABLE is not
enabled.  Currently only generic KASAN mode implements stack error
reporting.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/05a24db36f5ec876af876a299bbea98c29468ebd.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: hide invalid free check implementation
Andrey Konovalov [Tue, 22 Dec 2020 20:00:46 +0000 (12:00 -0800)]
kasan: hide invalid free check implementation

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

For software KASAN modes the check is based on the value in the shadow
memory.  Hardware tag-based KASAN won't be using shadow, so hide the
implementation of the check in check_invalid_free().

Also simplify the code for software tag-based mode.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/d01534a4b977f97d87515dc590e6348e1406de81.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: don't duplicate config dependencies
Andrey Konovalov [Tue, 22 Dec 2020 20:00:42 +0000 (12:00 -0800)]
kasan: don't duplicate config dependencies

Both KASAN_GENERIC and KASAN_SW_TAGS have common dependencies, move those
to KASAN.

Link: https://lkml.kernel.org/r/c1cc0d562608a318c607afe22db5ec2a7af72e47.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: rename report and tags files
Andrey Konovalov [Tue, 22 Dec 2020 20:00:39 +0000 (12:00 -0800)]
kasan: rename report and tags files

Rename generic_report.c to report_generic.c and tags_report.c to
report_sw_tags.c, as their content is more relevant to report.c file.
Also rename tags.c to sw_tags.c to better reflect that this file contains
code for software tag-based mode.

No functional changes.

Link: https://lkml.kernel.org/r/a6105d416da97d389580015afed66c4c3cfd4c08.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: define KASAN_MEMORY_PER_SHADOW_PAGE
Andrey Konovalov [Tue, 22 Dec 2020 20:00:35 +0000 (12:00 -0800)]
kasan: define KASAN_MEMORY_PER_SHADOW_PAGE

Define KASAN_MEMORY_PER_SHADOW_PAGE as (KASAN_GRANULE_SIZE << PAGE_SHIFT),
which is the same as (KASAN_GRANULE_SIZE * PAGE_SIZE) for software modes
that use shadow memory, and use it across KASAN code to simplify it.

Link: https://lkml.kernel.org/r/8329391cfe14b5cffd3decf3b5c535b6ce21eef6.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: split out shadow.c from common.c
Andrey Konovalov [Tue, 22 Dec 2020 20:00:32 +0000 (12:00 -0800)]
kasan: split out shadow.c from common.c

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.  Move all shadow-related code
to shadow.c, which is only enabled for software KASAN modes that use
shadow memory.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/17d95cfa7d5cf9c4fcd9bf415f2a8dea911668df.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: only build init.c for software modes
Andrey Konovalov [Tue, 22 Dec 2020 20:00:28 +0000 (12:00 -0800)]
kasan: only build init.c for software modes

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, so only build init.c that
contains shadow initialization code for software modes.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/bae0a6a35b7a9b1a443803c1a55e6e3fecc311c9.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: rename KASAN_SHADOW_* to KASAN_GRANULE_*
Andrey Konovalov [Tue, 22 Dec 2020 20:00:24 +0000 (12:00 -0800)]
kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_*

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 <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: rename (un)poison_shadow to (un)poison_range
Andrey Konovalov [Tue, 22 Dec 2020 20:00:21 +0000 (12:00 -0800)]
kasan: rename (un)poison_shadow to (un)poison_range

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.  Rename external annotation
kasan_unpoison_shadow() to kasan_unpoison_range(), and introduce internal
functions (un)poison_range() (without kasan_ prefix).

Co-developed-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/fccdcaa13dc6b2211bf363d6c6d499279a54fe3a.1606161801.git.andreyknvl@google.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: shadow declarations only for software modes
Andrey Konovalov [Tue, 22 Dec 2020 20:00:17 +0000 (12:00 -0800)]
kasan: shadow declarations only for software modes

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Group shadow-related KASAN function declarations and only define them for
the two existing software modes.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/35126.1606402815@turing-police
Link: https://lore.kernel.org/linux-arm-kernel/24105.1606397102@turing-police/
Link: https://lkml.kernel.org/r/e88d94eff94db883a65dca52e1736d80d28dd9bc.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
[valdis.kletnieks@vt.edu: fix build issue with asmlinkage]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: group vmalloc code
Andrey Konovalov [Tue, 22 Dec 2020 20:00:14 +0000 (12:00 -0800)]
kasan: group vmalloc code

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Group all vmalloc-related function declarations in include/linux/kasan.h,
and their implementations in mm/kasan/common.c.

No functional changes.

Link: https://lkml.kernel.org/r/80a6fdd29b039962843bd6cf22ce2643a7c8904e.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: KASAN_VMALLOC depends on KASAN_GENERIC
Andrey Konovalov [Tue, 22 Dec 2020 20:00:10 +0000 (12:00 -0800)]
kasan: KASAN_VMALLOC depends on KASAN_GENERIC

Currently only generic KASAN mode supports vmalloc, reflect that in the
config.

Link: https://lkml.kernel.org/r/0c493d3a065ad95b04313d00244e884a7e2498ff.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokasan: drop unnecessary GPL text from comment headers
Andrey Konovalov [Tue, 22 Dec 2020 20:00:07 +0000 (12:00 -0800)]
kasan: drop unnecessary GPL text from comment headers

Patch series "kasan: add hardware tag-based mode for arm64", v11.

This patchset adds a new hardware tag-based mode to KASAN [1].  The new
mode is similar to the existing software tag-based KASAN, but relies on
arm64 Memory Tagging Extension (MTE) [2] to perform memory and pointer
tagging (instead of shadow memory and compiler instrumentation).

This patchset is co-developed and tested by
Vincenzo Frascino <vincenzo.frascino@arm.com>.

This patchset is available here:

https://github.com/xairy/linux/tree/up-kasan-mte-v11

For testing in QEMU hardware tag-based KASAN requires:

1. QEMU built from master [4] (use "-machine virt,mte=on -cpu max" arguments
   to run).
2. GCC version 10.

[1] https://www.kernel.org/doc/html/latest/dev-tools/kasan.html
[2] https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety
[3] git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux for-next/mte
[4] https://github.com/qemu/qemu

====== Overview

The underlying ideas of the approach used by hardware tag-based KASAN are:

1. By relying on the Top Byte Ignore (TBI) arm64 CPU feature, pointer tags
   are stored in the top byte of each kernel pointer.

2. With the Memory Tagging Extension (MTE) arm64 CPU feature, memory tags
   for kernel memory allocations are stored in a dedicated memory not
   accessible via normal instuctions.

3. On each memory allocation, a random tag is generated, embedded it into
   the returned pointer, and the corresponding memory is tagged with the
   same tag value.

4. With MTE the CPU performs a check on each memory access to make sure
   that the pointer tag matches the memory tag.

5. On a tag mismatch the CPU generates a tag fault, and a KASAN report is
   printed.

Same as other KASAN modes, hardware tag-based KASAN is intended as a
debugging feature at this point.

====== Rationale

There are two main reasons for this new hardware tag-based mode:

1. Previously implemented software tag-based KASAN is being successfully
   used on dogfood testing devices due to its low memory overhead (as
   initially planned). The new hardware mode keeps the same low memory
   overhead, and is expected to have significantly lower performance
   impact, due to the tag checks being performed by the hardware.
   Therefore the new mode can be used as a better alternative in dogfood
   testing for hardware that supports MTE.

2. The new mode lays the groundwork for the planned in-kernel MTE-based
   memory corruption mitigation to be used in production.

====== Technical details

Considering the implementation perspective, hardware tag-based KASAN is
almost identical to the software mode.  The key difference is using MTE
for assigning and checking tags.

Compared to the software mode, the hardware mode uses 4 bits per tag, as
dictated by MTE.  Pointer tags are stored in bits [56:60), the top 4 bits
have the normal value 0xF.  Having less distict tags increases the
probablity of false negatives (from ~1/256 to ~1/16) in certain cases.

Only synchronous exceptions are set up and used by hardware tag-based KASAN.

====== Benchmarks

Note: all measurements have been performed with software emulation of Memory
Tagging Extension, performance numbers for hardware tag-based KASAN on the
actual hardware are expected to be better.

Boot time [1]:
* 2.8 sec for clean kernel
* 5.7 sec for hardware tag-based KASAN
* 11.8 sec for software tag-based KASAN
* 11.6 sec for generic KASAN

Slab memory usage after boot [2]:
* 7.0 kb for clean kernel
* 9.7 kb for hardware tag-based KASAN
* 9.7 kb for software tag-based KASAN
* 41.3 kb for generic KASAN

Measurements have been performed with:
* defconfig-based configs
* Manually built QEMU master
* QEMU arguments: -machine virt,mte=on -cpu max
* CONFIG_KASAN_STACK_ENABLE disabled
* CONFIG_KASAN_INLINE enabled
* clang-10 as the compiler and gcc-10 as the assembler

[1] Time before the ext4 driver is initialized.
[2] Measured as `cat /proc/meminfo | grep Slab`.

====== Notes

The cover letter for software tag-based KASAN patchset can be found here:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0116523cfffa62aeb5aa3b85ce7419f3dae0c1b8

===== Tags

Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
This patch (of 41):

Don't mention "GNU General Public License version 2" text explicitly, as
it's already covered by the SPDX-License-Identifier.

Link: https://lkml.kernel.org/r/cover.1606161801.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/6ea9f5f4aa9dbbffa0d0c0a780b37699a4531034.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agohwmon: (k10temp) Remove support for displaying voltage and current on Zen CPUs
Guenter Roeck [Mon, 14 Dec 2020 18:26:22 +0000 (10:26 -0800)]
hwmon: (k10temp) Remove support for displaying voltage and current on Zen CPUs

Voltages and current are reported by Zen CPUs. However, the means
to do so is undocumented, changes from CPU to CPU, and the raw data
is not calibrated. Calibration information is available, but again
not documented. This results in less than perfect user experience,
up to concerns that loading the driver might possibly damage
the hardware (by reporting out-of range voltages). Effectively
support for reporting voltages and current is not maintainable.
Drop it.

Cc: Artem S. Tashkinov <aros@gmx.com>
Cc: Wei Huang <wei.huang2@amd.com>
Tested-by: Wei Huang <wei.huang2@amd.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
4 years agodm cache: simplify the return expression of load_mapping()
Zheng Yongjun [Thu, 10 Dec 2020 14:01:03 +0000 (22:01 +0800)]
dm cache: simplify the return expression of load_mapping()

Simplify the return expression.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
4 years agoexfat: Avoid allocating upcase table using kcalloc()
Artem Labazov [Mon, 7 Dec 2020 00:04:36 +0000 (09:04 +0900)]
exfat: Avoid allocating upcase table using kcalloc()

The table for Unicode upcase conversion requires an order-5 allocation,
which may fail on a highly-fragmented system:

 pool-udisksd: page allocation failure: order:5,
 mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null),
 cpuset=/,mems_allowed=0
 CPU: 4 PID: 3756880 Comm: pool-udisksd Tainted: G U
 5.8.10-200.fc32.x86_64 #1
 Hardware name: Dell Inc. XPS 13 9360/0PVG6D, BIOS 2.13.0 11/14/2019
 Call Trace:
  dump_stack+0x6b/0x88
  warn_alloc.cold+0x75/0xd9
  ? _cond_resched+0x16/0x40
  ? __alloc_pages_direct_compact+0x144/0x150
  __alloc_pages_slowpath.constprop.0+0xcfa/0xd30
  ? __schedule+0x28a/0x840
  ? __wait_on_bit_lock+0x92/0xa0
  __alloc_pages_nodemask+0x2df/0x320
  kmalloc_order+0x1b/0x80
  kmalloc_order_trace+0x1d/0xa0
  exfat_create_upcase_table+0x115/0x390 [exfat]
  exfat_fill_super+0x3ef/0x7f0 [exfat]
  ? sget_fc+0x1d0/0x240
  ? exfat_init_fs_context+0x120/0x120 [exfat]
  get_tree_bdev+0x15c/0x250
  vfs_get_tree+0x25/0xb0
  do_mount+0x7c3/0xaf0
  ? copy_mount_options+0xab/0x180
  __x64_sys_mount+0x8e/0xd0
  do_syscall_64+0x4d/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Make the driver use kvcalloc() to eliminate the issue.

Fixes: 370e812b3ec1 ("exfat: add nls operations")
Cc: stable@vger.kernel.org #v5.7+
Signed-off-by: Artem Labazov <123321artyom@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
4 years agodm ebs: avoid double unlikely() notation when using IS_ERR()
Antonio Quartulli [Thu, 10 Dec 2020 08:50:49 +0000 (09:50 +0100)]
dm ebs: avoid double unlikely() notation when using IS_ERR()

The definition of IS_ERR() already applies the unlikely() notation
when checking the error status of the passed pointer. For this
reason there is no need to have the same notation outside of
IS_ERR() itself.

Clean up code by removing redundant notation.

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
4 years agodm verity: skip verity work if I/O error when system is shutting down
Hyeongseok Kim [Thu, 3 Dec 2020 00:46:59 +0000 (09:46 +0900)]
dm verity: skip verity work if I/O error when system is shutting down

If emergency system shutdown is called, like by thermal shutdown,
a dm device could be alive when the block device couldn't process
I/O requests anymore. In this state, the handling of I/O errors
by new dm I/O requests or by those already in-flight can lead to
a verity corruption state, which is a misjudgment.

So, skip verity work in response to I/O error when system is shutting
down.

Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
4 years agoMerge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Linus Torvalds [Mon, 21 Dec 2020 18:39:37 +0000 (10:39 -0800)]
Merge tag 'clk-for-linus' of git://git./linux/kernel/git/clk/linux

Pull clk updates from Stephen Boyd:
 "The core framework got some nice improvements this time around. We
  gained the ability to get struct clk pointers from a struct clk_hw so
  that clk providers can consume the clks they provide, if they need to
  do something like that. This has been a long missing part of the clk
  provider API that will help us move away from exposing a struct clk
  pointer in the struct clk_hw. Tracepoints are added for the
  clk_set_rate() "range" functions, similar to the tracepoints we
  already have for clk_set_rate() and we added a column to debugfs to
  help developers understand the hardware enable state of clks in case
  firmware or bootloader state is different than what is expected.
  Overall the core changes are mostly improving the clk driver writing
  experience.

  At the driver level, we have the usual collection of driver updates
  and new drivers for new SoCs. This time around the Qualcomm folks
  introduced a good handful of clk drivers for various parts of three or
  four SoCs. The SiFive folks added a new clk driver for their FU740
  SoCs, coming in second on the diffstat and then Atmel AT91 and Amlogic
  SoCs had lots of work done after that for various new features. One
  last thing to note in the driver area is that the i.MX driver has
  gained a new binding to support SCU clks after being on the list for
  many months. It uses a two cell binding which is sort of rare in clk
  DT bindings. Beyond that we have the usual set of driver fixes and
  tweaks that come from more testing and finding out that some
  configuration was wrong or that a driver could support being built as
  a module.

  Summary:

  Core:
   - Add some trace points for clk_set_rate() "range" functions
   - Add hardware enable information to clk_summary debugfs
   - Replace clk-provider.h with of_clk.h when possible
   - Add devm variant of clk_notifier_register()
   - Add clk_hw_get_clk() to generate a struct clk from a struct clk_hw

  New Drivers:
   - Bindings for Canaan K210 SoC clks
   - Support for SiFive FU740 PRCI
   - Camera clks on Qualcomm SC7180 SoCs
   - GCC and RPMh clks on Qualcomm SDX55 SoCs
   - RPMh clks on Qualcomm SM8350 SoCs
   - LPASS clks on Qualcomm SM8250 SoCs

  Updates:
   - DVFS support for AT91 clk driver
   - Update git repo branch for Renesas clock drivers
   - Add camera (CSI) and video-in (VIN) clocks on Renesas R-Car V3U
   - Add RPC (QSPI/HyperFLASH) clocks on Renesas RZ/G2M, RZ/G2N, and RZ/G2E
   - Stop using __raw_*() I/O accessors in Renesas clk drivers
   - One more conversion of DT bindings to json-schema
   - Make i.MX clk-gate2 driver more flexible
   - New two cell binding for i.MX SCU clks
   - Drop of_match_ptr() in i.MX8 clk drivers
   - Add arch dependencies for Rockchip clk drivers
   - Fix i2s on Rockchip rk3066
   - Add MIPI DSI clks on Amlogic axg and g12 SoCs
   - Support modular builds of Amlogic clk drivers
   - Fix an Amlogic Video PLL clock dependency
   - Samsung Kconfig dependencies updates for better compile test coverage
   - Refactoring of the Samsung PLL clocks driver
   - Small Tegra driver cleanups
   - Minor fixes to Ingenic and VC5 clk drivers
   - Cleanup patches to remove unused variables and plug memory leaks"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (134 commits)
  dt-binding: clock: Document canaan,k210-clk bindings
  dt-bindings: Add Canaan vendor prefix
  clk: vc5: Use "idt,voltage-microvolt" instead of "idt,voltage-microvolts"
  clk: ingenic: Fix divider calculation with div tables
  clk: sunxi-ng: Make sure divider tables have sentinel
  clk: s2mps11: Fix a resource leak in error handling paths in the probe function
  clk: mvebu: a3700: fix the XTAL MODE pin to MPP1_9
  clk: si5351: Wait for bit clear after PLL reset
  clk: at91: sam9x60: remove atmel,osc-bypass support
  clk: at91: sama7g5: register cpu clock
  clk: at91: clk-master: re-factor master clock
  clk: at91: sama7g5: do not allow cpu pll to go higher than 1GHz
  clk: at91: sama7g5: decrease lower limit for MCK0 rate
  clk: at91: sama7g5: remove mck0 from parent list of other clocks
  clk: at91: clk-sam9x60-pll: allow runtime changes for pll
  clk: at91: sama7g5: add 5th divisor for mck0 layout and characteristics
  clk: at91: clk-master: add 5th divisor for mck master
  clk: at91: sama7g5: allow SYS and CPU PLLs to be exported and referenced in DT
  dt-bindings: clock: at91: add sama7g5 pll defines
  clk: at91: sama7g5: fix compilation error
  ...

4 years agoMerge tag 'm68knommu-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Mon, 21 Dec 2020 18:35:11 +0000 (10:35 -0800)]
Merge tag 'm68knommu-for-v5.11' of git://git./linux/kernel/git/gerg/m68knommu

Pull m68knommu updates from Greg Ungerer:

 - cleanup of 68328 code

 - align BSS section to 32bit

* tag 'm68knommu-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: m68328: remove duplicate code
  m68k: m68328: move platform code to separate files
  m68knommu: align BSS section to 4-byte boundaries

4 years agoMerge tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux
Linus Torvalds [Mon, 21 Dec 2020 18:28:02 +0000 (10:28 -0800)]
Merge tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux

Pull 9p update from Dominique Martinet:

 - fix long-standing limitation on open-unlink-fop pattern

 - add refcount to p9_fid (fixes the above and will allow for more
   cleanups and simplifications in the future)

* tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux:
  9p: Remove unnecessary IS_ERR() check
  9p: Uninitialized variable in v9fs_writeback_fid()
  9p: Fix writeback fid incorrectly being attached to dentry
  9p: apply review requests for fid refcounting
  9p: add refcount to p9_fid struct
  fs/9p: search open fids first
  fs/9p: track open fids
  fs/9p: fix create-unlink-getattr idiom

4 years agoMerge branch 'devel-stable' into for-next
Russell King [Mon, 21 Dec 2020 11:19:26 +0000 (11:19 +0000)]
Merge branch 'devel-stable' into for-next

4 years agoMerge branches 'fixes' and 'misc' into for-next
Russell King [Mon, 21 Dec 2020 11:19:24 +0000 (11:19 +0000)]
Merge branches 'fixes' and 'misc' into for-next

4 years agoARM: 9027/1: head.S: explicitly map DT even if it lives in the first physical section
Ard Biesheuvel [Tue, 17 Nov 2020 07:41:01 +0000 (08:41 +0100)]
ARM: 9027/1: head.S: explicitly map DT even if it lives in the first physical section

The early ATAGS/DT mapping code uses SECTION_SHIFT to mask low order
bits of R2, and decides that no ATAGS/DTB were provided if the resulting
value is 0x0.

This means that on systems where DRAM starts at 0x0 (such as Raspberry
Pi), no explicit mapping of the DT will be created if R2 points into the
first 1 MB section of memory. This was not a problem before, because the
decompressed kernel is loaded at the base of DRAM and mapped using
sections as well, and so as long as the DT is referenced via a virtual
address that uses the same translation (the linear map, in this case),
things work fine.

However, commit 7a1be318f579 ("9012/1: move device tree mapping out of
linear region") changes this, and now the DT is referenced via a virtual
address that is disjoint from the linear mapping of DRAM, and so we need
the early code to create the DT mapping unconditionally.

So let's create the early DT mapping for any value of R2 != 0x0.

Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9038/1: Link with '-z norelro'
Nathan Chancellor [Tue, 8 Dec 2020 00:34:16 +0000 (01:34 +0100)]
ARM: 9038/1: Link with '-z norelro'

When linking a multi_v7_defconfig + CONFIG_KASAN=y kernel with
LD=ld.lld, the following error occurs:

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LLVM=1 zImage
ld.lld: error: section: .exit.data is not contiguous with other relro sections

LLD defaults to '-z relro', which is unneeded for the kernel because
program headers are not used nor is there any position independent code
generation or linking for ARM. Add '-z norelro' to LDFLAGS_vmlinux to
avoid this error.

Link: https://github.com/ClangBuiltLinux/linux/issues/1189
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9037/1: uncompress: Add OF_DT_MAGIC macro
Geert Uytterhoeven [Fri, 4 Dec 2020 09:39:10 +0000 (10:39 +0100)]
ARM: 9037/1: uncompress: Add OF_DT_MAGIC macro

The DTB magic marker is stored as a 32-bit big-endian value, and thus
depends on the CPU's endianness.  Add a macro to define this value in
native endianness, to reduce #ifdef clutter and (future) duplication.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9036/1: uncompress: Fix dbgadtb size parameter name
Geert Uytterhoeven [Fri, 4 Dec 2020 09:37:14 +0000 (10:37 +0100)]
ARM: 9036/1: uncompress: Fix dbgadtb size parameter name

The dbgadtb macro is passed the size of the appended DTB, not the end
address.

Fixes: c03e41470e901123 ("ARM: 9010/1: uncompress: Print the location of appended DTB")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9035/1: uncompress: Add be32tocpu macro
Geert Uytterhoeven [Fri, 4 Dec 2020 09:37:47 +0000 (10:37 +0100)]
ARM: 9035/1: uncompress: Add be32tocpu macro

DTB stores all values as 32-bit big-endian integers.
Add a macro to convert such values to native CPU endianness, to reduce
duplication.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9033/1: arm/smp: Drop the macro S(x,s)
Anshuman Khandual [Mon, 30 Nov 2020 10:24:09 +0000 (11:24 +0100)]
ARM: 9033/1: arm/smp: Drop the macro S(x,s)

Mapping between IPI type index and its string is direct without requiring
an additional offset. Hence the existing macro S(x, s) is now redundant
and can just be dropped. This also makes the code clean and simple.

Cc: Marc Zyngier <maz@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9032/1: arm/mm: Convert PUD level pgtable helper macros into functions
Anshuman Khandual [Mon, 30 Nov 2020 09:28:20 +0000 (10:28 +0100)]
ARM: 9032/1: arm/mm: Convert PUD level pgtable helper macros into functions

Macros used as functions can be problematic from the compiler perspective.
There was a build failure report caused primarily because of non reference
of an argument variable. Hence convert PUD level pgtable helper macros into
functions in order to avoid such problems in the future. In the process, it

fixes the argument variables sequence in set_pud() which probably remained
hidden for being a macro.

https://lore.kernel.org/linux-mm/202011020749.5XQ3Hfzc-lkp@intel.com/
https://lore.kernel.org/linux-mm/5fa49698.Vu2O3r+dU20UoEJ+%25lkp@intel.com/

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9031/1: hyp-stub: remove unused .L__boot_cpu_mode_offset symbol
Ard Biesheuvel [Fri, 27 Nov 2020 12:07:22 +0000 (13:07 +0100)]
ARM: 9031/1: hyp-stub: remove unused .L__boot_cpu_mode_offset symbol

Commit aaac3733171fca94 ("ARM: kvm: replace open coded VA->PA calculations
with adr_l call") removed all uses of .L__boot_cpu_mode_offset, so there
is no longer a need to define it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoARM: 9044/1: vfp: use undef hook for VFP support detection
Ard Biesheuvel [Sat, 19 Dec 2020 15:29:58 +0000 (16:29 +0100)]
ARM: 9044/1: vfp: use undef hook for VFP support detection

Commit f77ac2e378be9dd6 ("ARM: 9030/1: entry: omit FP emulation for UND
exceptions taken in kernel mode") failed to take into account that there
is in fact a case where we relied on this code path: during boot, the
VFP detection code issues a read of FPSID, which will trigger an undef
exception on cores that lack VFP support.

So let's reinstate this logic using an undef hook which is registered
only for the duration of the initcall to vpf_init(), and which sets
VFP_arch to a non-zero value - as before - if no VFP support is present.

Fixes: f77ac2e378be9dd6 ("ARM: 9030/1: entry: omit FP emulation for UND ...")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
4 years agoDocumentation/kbuild: Document platform dependency practises
Geert Uytterhoeven [Tue, 8 Dec 2020 15:28:57 +0000 (16:28 +0100)]
Documentation/kbuild: Document platform dependency practises

Document best practises for using architecture and platform dependencies.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agoDocumentation/kbuild: Document COMPILE_TEST dependencies
Geert Uytterhoeven [Tue, 8 Dec 2020 15:28:56 +0000 (16:28 +0100)]
Documentation/kbuild: Document COMPILE_TEST dependencies

Document best practises for using COMPILE_TEST dependencies.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agogenksyms: Ignore module scoped _Static_assert()
Marco Elver [Tue, 1 Dec 2020 15:20:18 +0000 (16:20 +0100)]
genksyms: Ignore module scoped _Static_assert()

The C11 _Static_assert() keyword may be used at module scope, and we
need to teach genksyms about it to not abort with an error. We currently
have a growing number of static_assert() (but also direct usage of
_Static_assert()) users at module scope:

git grep -E '^_Static_assert\(|^static_assert\(' | grep -v '^tools' | wc -l
135

More recently, when enabling CONFIG_MODVERSIONS with CONFIG_KCSAN, we
observe a number of warnings:

WARNING: modpost: EXPORT symbol "<..all kcsan symbols..>" [vmlinux] [...]

When running a preprocessed source through 'genksyms -w' a number of
syntax errors point at usage of static_assert()s. In the case of
kernel/kcsan/encoding.h, new static_assert()s had been introduced which
used expressions that appear to cause genksyms to not even be able to
recover from the syntax error gracefully (as it appears was the case
previously).

Therefore, make genksyms ignore all _Static_assert() and the contained
expression. With the fix, usage of _Static_assert() no longer cause
"syntax error" all over the kernel, and the above modpost warnings for
KCSAN are gone, too.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agomodpost: turn static exports into error
Quentin Perret [Tue, 1 Dec 2020 16:52:22 +0000 (16:52 +0000)]
modpost: turn static exports into error

Using EXPORT_SYMBOL*() on static functions is fundamentally wrong.
Modpost currently reports that as a warning, but clearly this is not a
pattern we should allow, and all in-tree occurences should have been
fixed by now. So, promote the warn() message to error() to make sure
this never happens again.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agomodpost: turn section mismatches to error from fatal()
Masahiro Yamada [Tue, 1 Dec 2020 10:34:18 +0000 (19:34 +0900)]
modpost: turn section mismatches to error from fatal()

There is code that reports static EXPORT_SYMBOL a few lines below.
It is not a good idea to bail out here.

I renamed sec_mismatch_fatal to sec_mismatch_warn_only (with logical
inversion) to match to CONFIG_SECTION_MISMATCH_WARN_ONLY.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agomodpost: change license incompatibility to error() from fatal()
Masahiro Yamada [Tue, 1 Dec 2020 10:34:17 +0000 (19:34 +0900)]
modpost: change license incompatibility to error() from fatal()

Change fatal() to error() to continue running to report more possible
issues.

There is no difference in the fact that modpost will fail anyway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agomodpost: turn missing MODULE_LICENSE() into error
Masahiro Yamada [Tue, 1 Dec 2020 10:34:16 +0000 (19:34 +0900)]
modpost: turn missing MODULE_LICENSE() into error

Do not create modules with no license tag.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agomodpost: refactor error handling and clarify error/fatal difference
Masahiro Yamada [Tue, 1 Dec 2020 10:34:15 +0000 (19:34 +0900)]
modpost: refactor error handling and clarify error/fatal difference

We have 3 log functions. fatal() is special because it lets modpost bail
out immediately. The difference between warn() and error() is the only
prefix parts ("WARNING:" vs "ERROR:").

In my understanding, the expected handling of error() is to propagate
the return code of the function to the exit code of modpost, as
check_exports() etc. already does. This is a good manner in general
because we should display as many error messages as possible in a
single run of modpost.

What is annoying about fatal() is that it kills modpost at the first
error. People would need to run Kbuild again and again until they fix
all errors.

But, unfortunately, people tend to do:
"This case should not be allowed. Let's replace warn() with fatal()."

One of the reasons is probably it is tedious to manually hoist the error
code to the main() function.

This commit refactors error() so any single call for it automatically
makes modpost return the error code.

I also added comments in modpost.h for warn(), error(), and fatal().

Please use fatal() only when you have a strong reason to do so.
For example:

  - Memory shortage (i.e. malloc() etc. has failed)
  - The ELF file is broken, and there is no point to continue parsing
  - Something really odd has happened

For general coding errors, please use error().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Quentin Perret <qperret@google.com>
4 years agomodpost: rename merror() to error()
Masahiro Yamada [Tue, 1 Dec 2020 10:34:14 +0000 (19:34 +0900)]
modpost: rename merror() to error()

The log function names, warn(), merror(), fatal() are inconsistent.

Commit 2a11665945d5 ("kbuild: distinguish between errors and warnings
in modpost") intentionally chose merror() to avoid the conflict with
the library function error(). See man page of error(3).

But, we are already causing the conflict with warn() because it is also
a library function. See man page of warn(3). err() would be a problem
for the same reason.

The common technique to work around name conflicts is to use macros.
For example:

    /* in a header */
    #define error(fmt, ...)  __error(fmt, ##__VA_ARGS__)
    #define warn(fmt, ...)   __warn(fmt, ##__VA_ARGS__)

    /* function definition */
    void __error(const char *fmt, ...)
    {
            <our implementation>
    }

    void __warn(const char *fmt, ...)
    {
            <our implementation>
    }

In this way, we can implement our own warn() and error(), still we can
include <error.h> and <err.h> with no problem.

And, commit 93c95e526a4e ("modpost: rework and consolidate logging
interface") already did that.

Since the log functions are all macros, we can use error() without
causing "conflicting types" errors.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agokbuild: don't hardcode depmod path
Dominique Martinet [Tue, 1 Dec 2020 13:17:30 +0000 (14:17 +0100)]
kbuild: don't hardcode depmod path

depmod is not guaranteed to be in /sbin, just let make look for
it in the path like all the other invoked programs

Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
4 years agokbuild: doc: document subdir-y syntax
Masahiro Yamada [Sat, 28 Nov 2020 11:51:08 +0000 (20:51 +0900)]
kbuild: doc: document subdir-y syntax

There is no explanation about subdir-y.

Let's document it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
4 years agokbuild: doc: clarify the difference between extra-y and always-y
Masahiro Yamada [Sat, 28 Nov 2020 11:51:07 +0000 (20:51 +0900)]
kbuild: doc: clarify the difference between extra-y and always-y

The difference between extra-y and always-y is obscure.

Basically, Kbuild builds targets listed in extra-y and always-y in
visited Makefiles without relying on any dependency.

The difference is that extra-y is used to list the targets needed for
vmlinux whereas always-y is used to list the targets that must be always
built irrespective of final targets.

Kbuild skips extra-y when it is building only modules (i.e.
'make modules'). This is the long-standing behavior since extra-y was
introduced in 2003, and it is explained in that commit log [1].

For clarification, this is the extra-y vs always-y table:

                  extra-y    always-y
  'make'             y          y
  'make vmlinux'     y          y
  'make modules'     n          y

Kbuild skips extra-y also when building external modules since obviously
it never builds vmlinux.

Unfortunately, extra-y is wrongly used in many places of upstream code,
and even in external modules.

Using extra-y in external module Makefiles is wrong. What you should
use is probably always-y or 'targets'.

The current documentation for extra-y is misleading. I rewrote it, and
moved it to the section 3.7.

always-y is not documented anywhere. I added.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=f94e5fd7e5d09a56a60670a9bb211a791654bba8

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>