linux-toradex.git/Documentation/dev-tools, branch v5.12-rc5

kasan: clarify that only first bug is reported in HW_TAGS

2021-02-26T17:41:03+00:00

Hwardware tag-based KASAN only reports the first found bug. After that MTE
tag checking gets disabled. Clarify this in comments and documentation.

Link: https://lkml.kernel.org/r/00383ba88a47c3f8342d12263c24bdf95527b07d.1612546384.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov 
Reviewed-by: Marco Elver 
Cc: Alexander Potapenko 
Cc: Andrey Ryabinin 
Cc: Branislav Rankov 
Cc: Catalin Marinas 
Cc: Dmitry Vyukov 
Cc: Evgenii Stepanov 
Cc: Kevin Brodsky 
Cc: Peter Collingbourne 
Cc: Vincenzo Frascino 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kfence: report sensitive information based on no_hash_pointers

2021-02-26T17:41:02+00:00

We cannot rely on CONFIG_DEBUG_KERNEL to decide if we're running a "debug
kernel" where we can safely show potentially sensitive information in the
kernel log.

Instead, simply rely on the newly introduced "no_hash_pointers" to print
unhashed kernel pointers, as well as decide if our reports can include
other potentially sensitive information such as registers and corrupted
bytes.

Link: https://lkml.kernel.org/r/20210223082043.1972742-1-elver@google.com
Signed-off-by: Marco Elver 
Cc: Timur Tabi 
Cc: Alexander Potapenko 
Cc: Dmitry Vyukov 
Cc: Andrey Konovalov 
Cc: Jann Horn 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kfence: add test suite

2021-02-26T17:41:02+00:00

Add KFENCE test suite, testing various error detection scenarios. Makes
use of KUnit for test organization. Since KFENCE's interface to obtain
error reports is via the console, the test verifies that KFENCE outputs
expected reports to the console.

[elver@google.com: fix typo in test]
  Link: https://lkml.kernel.org/r/X9lHQExmHGvETxY4@elver.google.com
[elver@google.com: show access type in report]
  Link: https://lkml.kernel.org/r/20210111091544.3287013-2-elver@google.com

Link: https://lkml.kernel.org/r/20201103175841.3495947-9-elver@google.com
Signed-off-by: Alexander Potapenko 
Signed-off-by: Marco Elver 
Reviewed-by: Dmitry Vyukov 
Co-developed-by: Alexander Potapenko 
Reviewed-by: Jann Horn 
Cc: Andrey Konovalov 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Christopher Lameter 
Cc: Dave Hansen 
Cc: David Rientjes 
Cc: Eric Dumazet 
Cc: Greg Kroah-Hartman 
Cc: Hillf Danton 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Joern Engel 
Cc: Jonathan Corbet 
Cc: Joonsoo Kim 
Cc: Kees Cook 
Cc: Mark Rutland 
Cc: Paul E. McKenney 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: SeongJae Park 
Cc: Thomas Gleixner 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kfence, Documentation: add KFENCE documentation

2021-02-26T17:41:02+00:00

Add KFENCE documentation in dev-tools/kfence.rst, and add to index.

[elver@google.com: add missing copyright header to documentation]
  Link: https://lkml.kernel.org/r/20210118092159.145934-4-elver@google.com

Link: https://lkml.kernel.org/r/20201103175841.3495947-8-elver@google.com
Signed-off-by: Alexander Potapenko 
Signed-off-by: Marco Elver 
Reviewed-by: Dmitry Vyukov 
Co-developed-by: Alexander Potapenko 
Reviewed-by: Jann Horn 
Cc: Andrey Konovalov 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Christopher Lameter 
Cc: Dave Hansen 
Cc: David Rientjes 
Cc: Eric Dumazet 
Cc: Greg Kroah-Hartman 
Cc: Hillf Danton 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Joern Engel 
Cc: Jonathan Corbet 
Cc: Joonsoo Kim 
Cc: Kees Cook 
Cc: Mark Rutland 
Cc: Paul E. McKenney 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: SeongJae Park 
Cc: Thomas Gleixner 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kasan: rename CONFIG_TEST_KASAN_MODULE

2021-02-24T21:38:31+00:00

Rename CONFIG_TEST_KASAN_MODULE to CONFIG_KASAN_MODULE_TEST.

This naming is more consistent with the existing CONFIG_KASAN_KUNIT_TEST.

Link: https://linux-review.googlesource.com/id/Id347dfa5fe8788b7a1a189863e039f409da0ae5f
Link: https://lkml.kernel.org/r/f08250246683981bcf8a094fbba7c361995624d2.1610733117.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov 
Reviewed-by: Marco Elver 
Reviewed-by: Alexander Potapenko 
Cc: Andrey Ryabinin 
Cc: Branislav Rankov 
Cc: Catalin Marinas 
Cc: Dmitry Vyukov 
Cc: Evgenii Stepanov 
Cc: Kevin Brodsky 
Cc: Peter Collingbourne 
Cc: Vincenzo Frascino 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kasan: clarify HW_TAGS impact on TBI

2021-02-24T21:38:30+00:00

Mention in the documentation that enabling CONFIG_KASAN_HW_TAGS always
results in in-kernel TBI (Top Byte Ignore) being enabled.

Also do a few minor documentation cleanups.

Link: https://linux-review.googlesource.com/id/Iba2a6697e3c6304cb53f89ec61dedc77fa29e3ae
Link: https://lkml.kernel.org/r/3b4ea6875bb14d312092ad14ac55cb456c83c08e.1610733117.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov 
Reviewed-by: Marco Elver 
Reviewed-by: Alexander Potapenko 
Cc: Andrey Ryabinin 
Cc: Branislav Rankov 
Cc: Catalin Marinas 
Cc: Dmitry Vyukov 
Cc: Evgenii Stepanov 
Cc: Kevin Brodsky 
Cc: Peter Collingbourne 
Cc: Vincenzo Frascino 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'linux-kselftest-kunit-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2021-02-22T19:03:00+00:00

Pull KUnit updates from Shuah Khan

 - support for filtering test suites using glob from Daniel Latypov.

     "kunit_filter.glob" command line option is passed to the UML
     kernel, which currently only supports filtering by suite name.
     This support allows running different subsets of tests, e.g.

      $ ./tools/testing/kunit/kunit.py build
      $ ./tools/testing/kunit/kunit.py exec 'list*'
      $ ./tools/testing/kunit/kunit.py exec 'kunit*'

 - several fixes and cleanups also from Daniel Latypov.

* tag 'linux-kselftest-kunit-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: tool: fix unintentional statefulness in run_kernel()
  kunit: tool: add support for filtering suites by glob
  kunit: add kunit.filter_glob cmdline option to filter suites
  kunit: don't show `1 == 1` in failed assertion messages
  kunit: make kunit_tool accept optional path to .kunitconfig fragment
  Documentation: kunit: add tips.rst for small examples
  KUnit: Docs: make start.rst example Kconfig follow style.rst
  kunit: tool: simplify kconfig is_subset_of() logic
  minor: kunit: tool: fix unit test so it can run from non-root dir
  kunit: tool: use `with open()` in unit test
  kunit: tool: stop using bare asserts in unit test
  kunit: tool: fix unit test cleanup handling

kasan: fix stack traces dependency for HW_TAGS

2021-02-10T01:26:44+00:00

Currently, whether the alloc/free stack traces collection is enabled by
default for hardware tag-based KASAN depends on CONFIG_DEBUG_KERNEL.
The intention for this dependency was to only enable collection on slow
debug kernels due to a significant perf and memory impact.

As it turns out, CONFIG_DEBUG_KERNEL is not considered a debug option
and is enabled on many productions kernels including Android and Ubuntu.
As the result, this dependency is pointless and only complicates the
code and documentation.

Having stack traces collection disabled by default would make the
hardware mode work differently to to the software ones, which is
confusing.

This change removes the dependency and enables stack traces collection
by default.

Looking into the future, this default might makes sense for production
kernels, assuming we implement a fast stack trace collection approach.

Link: https://lkml.kernel.org/r/6678d77ceffb71f1cff2cf61560e2ffe7bb6bfe9.1612808820.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov 
Reviewed-by: Marco Elver 
Cc: Catalin Marinas 
Cc: Vincenzo Frascino 
Cc: Dmitry Vyukov 
Cc: Alexander Potapenko 
Cc: Will Deacon 
Cc: Andrey Ryabinin 
Cc: Peter Collingbourne 
Cc: Evgenii Stepanov 
Cc: Branislav Rankov 
Cc: Kevin Brodsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Documentation: kunit: add tips.rst for small examples

2021-02-08T22:41:11+00:00

./usage.rst contains fairly long examples and explanations of things
like how to fake a class and how to use parameterized tests (and how you
could do table-driven tests yourself).

It's not exactly necessary information, so we add a new page with more
digestible tips like "use kunit_kzalloc() instead of kzalloc() so you
don't have to worry about calling kfree() yourself" and the like.

Change start.rst to point users to this new page first and let them know
that usage.rst is more of optional further reading.

Signed-off-by: Daniel Latypov 
Reviewed-by: Brendan Higgins 
Signed-off-by: Shuah Khan

KUnit: Docs: make start.rst example Kconfig follow style.rst

2021-02-08T22:40:12+00:00

The primary change is that we want to encourage people to respect
KUNIT_ALL_TESTS to make it easy to run all the relevant tests for a
given config.

Signed-off-by: Daniel Latypov 
Reviewed-by: Brendan Higgins 
Signed-off-by: Shuah Khan