kernel/linux.git/Documentation/dev-tools/kcsan.rst, branch v6.12.80

docs: update dev-tools/kcsan.rst url about KTSAN

2024-09-04T14:04:10+00:00

The KTSAN doc has moved to https://github.com/google/kernel-sanitizers/blob/master/KTSAN.md. Update the url in kcsan.rst accordingly. Signed-off-by: Haoyang Liu Reviewed-by: Dongliang Mu Acked-by: Marco Elver Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20240725174632.23803-1-tttturtleruss@hust.edu.cn

kcsan, compiler_types: Introduce __data_racy type qualifier

2024-05-07T18:39:50+00:00

Based on the discussion at [1], it would be helpful to mark certain variables as explicitly "data racy", which would result in KCSAN not reporting data races involving any accesses on such variables. To do that, introduce the __data_racy type qualifier: struct foo { ... int __data_racy bar; ... }; In KCSAN-kernels, __data_racy turns into volatile, which KCSAN already treats specially by considering them "marked". In non-KCSAN kernels the type qualifier turns into no-op. The generated code between KCSAN-instrumented kernels and non-KCSAN kernels is already huge (inserted calls into runtime for every memory access), so the extra generated code (if any) due to volatile for few such __data_racy variables are unlikely to have measurable impact on performance. Link: https://lore.kernel.org/all/CAHk-=wi3iondeh_9V2g3Qz5oHTRjLsOpoy83hb58MVh=nRZe0A@mail.gmail.com/ [1] Suggested-by: Linus Torvalds Signed-off-by: Marco Elver Cc: Paul E. McKenney Cc: Tetsuo Handa Signed-off-by: Paul E. McKenney

Documentation: *san: drop "the" from article titles

2023-10-18T21:34:15+00:00

Drop "the" from the titles of documentation articles for KASAN, KCSAN, and KMSAN, as it is redundant. Also add SPDX-License-Identifier for kasan.rst. Link: https://lkml.kernel.org/r/1c4eb354a3a7b8ab56bf0c2fc6157c22050793ca.1696605143.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: kernel test robot Cc: Marco Elver Signed-off-by: Andrew Morton

kcsan: Document modeling of weak memory

2021-12-10T00:42:27+00:00

Document how KCSAN models a subset of weak memory and the subset of missing memory barriers it can detect as a result. Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney

kcsan: Rework atomic.h into permissive.h

2021-07-20T20:49:43+00:00

Rework atomic.h into permissive.h to better reflect its purpose, and introduce kcsan_ignore_address() and kcsan_ignore_data_race(). Introduce CONFIG_KCSAN_PERMISSIVE and update the stub functions in preparation for subsequent changes. As before, developers who choose to use KCSAN in "strict" mode will see all data races and are not affected. Furthermore, by relying on the value-change filter logic for kcsan_ignore_data_race(), even if the permissive rules are enabled, the opt-outs in report.c:skip_report() override them (such as for RCU-related functions by default). The option CONFIG_KCSAN_PERMISSIVE is disabled by default, so that the documented default behaviour of KCSAN does not change. Instead, like CONFIG_KCSAN_IGNORE_ATOMICS, the option needs to be explicitly opted in. Signed-off-by: Marco Elver Acked-by: Mark Rutland Signed-off-by: Paul E. McKenney

kcsan: Introduce CONFIG_KCSAN_STRICT

2021-07-20T20:49:43+00:00

Add a simpler Kconfig variable to configure KCSAN's "strict" mode. This makes it simpler in documentation or messages to suggest just a single configuration option to select the strictest checking mode (vs. currently having to list several options). Signed-off-by: Marco Elver Acked-by: Mark Rutland Signed-off-by: Paul E. McKenney

kcsan: Use URL link for pointing access-marking.txt

2021-05-18T17:58:15+00:00

For consistency within kcsan.rst, use a URL link as the same as in section "Data Races". Acked-by: Marco Elver Signed-off-by: Akira Yokosawa Signed-off-by: Paul E. McKenney

kcsan: Document "value changed" line

2021-05-18T17:58:15+00:00

Update the example reports based on the latest reports generated by kcsan_test module, which now include the "value changed" line. Add a brief description of the "value changed" line. Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney

kcsan: Add pointer to access-marking.txt to data_race() bullet

2021-05-18T17:58:14+00:00

This commit references tools/memory-model/Documentation/access-marking.txt in the bullet introducing data_race(). The access-marking.txt file gives advice on when data_race() should and should not be used. Suggested-by: Akira Yokosawa Signed-off-by: Paul E. McKenney

kcsan: Add missing license and copyright headers

2021-03-08T22:27:43+00:00

Adds missing license and/or copyright headers for KCSAN source files. Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney