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authorAndrey Konovalov <andreyknvl@google.com>2022-05-13 06:23:09 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-05-13 17:20:19 +0300
commitca89f2a2e66d0bc0a5929dafaf6270d35374c7a6 (patch)
tree6481284b88cc9d6e0bfcb2799fb3d1385c9d2e36 /Documentation/dev-tools
parentc2ec0c8f687711e671d865b0a36344440c1e8b1f (diff)
downloadlinux-ca89f2a2e66d0bc0a5929dafaf6270d35374c7a6.tar.xz
kasan: move boot parameters section in documentation
Move the "Boot parameters" section in KASAN documentation next to the section that describes KASAN build options. No content changes. Link: https://lkml.kernel.org/r/870628e1293b4f44edf7cbcb92374ff9eb7503d7.1652203271.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/ec9c923f35e7c5312836c4624a7f317dc1ee2c1c.1652123204.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation/dev-tools')
-rw-r--r--Documentation/dev-tools/kasan.rst82
1 files changed, 41 insertions, 41 deletions
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 2ed0b77d1db6..1772fd457fed 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -94,6 +94,47 @@ To include alloc and free stack traces of affected slab objects into reports,
enable ``CONFIG_STACKTRACE``. To include alloc and free stack traces of affected
physical pages, enable ``CONFIG_PAGE_OWNER`` and boot with ``page_owner=on``.
+Boot parameters
+~~~~~~~~~~~~~~~
+
+KASAN is affected by the generic ``panic_on_warn`` command line parameter.
+When it is enabled, KASAN panics the kernel after printing a bug report.
+
+By default, KASAN prints a bug report only for the first invalid memory access.
+With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
+effectively disables ``panic_on_warn`` for KASAN reports.
+
+Alternatively, independent of ``panic_on_warn``, the ``kasan.fault=`` boot
+parameter can be used to control panic and reporting behaviour:
+
+- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
+ report or also panic the kernel (default: ``report``). The panic happens even
+ if ``kasan_multi_shot`` is enabled.
+
+Hardware Tag-Based KASAN mode (see the section about various modes below) is
+intended for use in production as a security mitigation. Therefore, it supports
+additional boot parameters that allow disabling KASAN or controlling features:
+
+- ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
+
+- ``kasan.mode=sync``, ``=async`` or ``=asymm`` controls whether KASAN
+ is configured in synchronous, asynchronous or asymmetric mode of
+ execution (default: ``sync``).
+ Synchronous mode: a bad access is detected immediately when a tag
+ check fault occurs.
+ Asynchronous mode: a bad access detection is delayed. When a tag check
+ fault occurs, the information is stored in hardware (in the TFSR_EL1
+ register for arm64). The kernel periodically checks the hardware and
+ only reports tag faults during these checks.
+ Asymmetric mode: a bad access is detected synchronously on reads and
+ asynchronously on writes.
+
+- ``kasan.vmalloc=off`` or ``=on`` disables or enables tagging of vmalloc
+ allocations (default: ``on``).
+
+- ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
+ traces collection (default: ``on``).
+
Error reports
~~~~~~~~~~~~~
@@ -208,47 +249,6 @@ traces point to places in code that interacted with the object but that are not
directly present in the bad access stack trace. Currently, this includes
call_rcu() and workqueue queuing.
-Boot parameters
-~~~~~~~~~~~~~~~
-
-KASAN is affected by the generic ``panic_on_warn`` command line parameter.
-When it is enabled, KASAN panics the kernel after printing a bug report.
-
-By default, KASAN prints a bug report only for the first invalid memory access.
-With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
-effectively disables ``panic_on_warn`` for KASAN reports.
-
-Alternatively, independent of ``panic_on_warn``, the ``kasan.fault=`` boot
-parameter can be used to control panic and reporting behaviour:
-
-- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
- report or also panic the kernel (default: ``report``). The panic happens even
- if ``kasan_multi_shot`` is enabled.
-
-Hardware Tag-Based KASAN mode (see the section about various modes below) is
-intended for use in production as a security mitigation. Therefore, it supports
-additional boot parameters that allow disabling KASAN or controlling features:
-
-- ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
-
-- ``kasan.mode=sync``, ``=async`` or ``=asymm`` controls whether KASAN
- is configured in synchronous, asynchronous or asymmetric mode of
- execution (default: ``sync``).
- Synchronous mode: a bad access is detected immediately when a tag
- check fault occurs.
- Asynchronous mode: a bad access detection is delayed. When a tag check
- fault occurs, the information is stored in hardware (in the TFSR_EL1
- register for arm64). The kernel periodically checks the hardware and
- only reports tag faults during these checks.
- Asymmetric mode: a bad access is detected synchronously on reads and
- asynchronously on writes.
-
-- ``kasan.vmalloc=off`` or ``=on`` disables or enables tagging of vmalloc
- allocations (default: ``on``).
-
-- ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
- traces collection (default: ``on``).
-
Implementation details
----------------------