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authorAndrey Konovalov <andreyknvl@google.com>2021-01-24 08:01:34 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-01-24 21:34:52 +0300
commit76bc99e81a7cb78a78e058107e4b5b1d8ed3c874 (patch)
tree3423d3456f96ac8d2fb60f39d3f60aa95ccce417 /Documentation
parent5dabd1712cd056814f9ab15f1d68157ceb04e741 (diff)
downloadlinux-76bc99e81a7cb78a78e058107e4b5b1d8ed3c874.tar.xz
kasan: fix HW_TAGS boot parameters
The initially proposed KASAN command line parameters are redundant. This change drops the complex "kasan.mode=off/prod/full" parameter and adds a simpler kill switch "kasan=off/on" instead. The new parameter together with the already existing ones provides a cleaner way to express the same set of features. The full set of parameters with this change: kasan=off/on - whether KASAN is enabled kasan.fault=report/panic - whether to only print a report or also panic kasan.stacktrace=off/on - whether to collect alloc/free stack traces Default values: kasan=on kasan.fault=report kasan.stacktrace=on (if CONFIG_DEBUG_KERNEL=y) kasan.stacktrace=off (otherwise) Link: https://linux-review.googlesource.com/id/Ib3694ed90b1e8ccac6cf77dfd301847af4aba7b8 Link: https://lkml.kernel.org/r/4e9c4a4bdcadc168317deb2419144582a9be6e61.1610736745.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/dev-tools/kasan.rst27
1 files changed, 6 insertions, 21 deletions
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 0fc3fb1860c4..1651d961f06a 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -160,29 +160,14 @@ intended for use in production as a security mitigation. Therefore it supports
boot parameters that allow to disable KASAN competely or otherwise control
particular KASAN features.
-The things that can be controlled are:
+- ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
-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.
+- ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
+ traces collection (default: ``on`` for ``CONFIG_DEBUG_KERNEL=y``, otherwise
+ ``off``).
-The ``kasan.mode`` boot parameter 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`` or ``=on`` - enable alloc/free stack collection
- (default: ``on`` for ``mode=full``,
- otherwise ``off``)
-- ``kasan.fault=report`` or ``=panic`` - only print KASAN report 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.
+- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
+ report or also panic the kernel (default: ``report``).
For developers
~~~~~~~~~~~~~~