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authorMarco Elver <elver@google.com>2019-12-12 01:07:08 +0100
committerPaul E. McKenney <paulmck@kernel.org>2020-01-07 07:47:23 -0800
commit7161177481d521e725a7bc6c9308ac2968fee038 (patch)
tree44befe4362236710abe6cc3798ee2ac1c45eab21 /Documentation/dev-tools
parent944bc9cca7c392879fa2c3f911bbef7422707679 (diff)
downloadlinux-next-7161177481d521e725a7bc6c9308ac2968fee038.tar.gz
kcsan: Document static blacklisting options
Updates the section on "Selective analysis", listing all available options to blacklist reporting data races for: specific accesses, functions, compilation units, and entire directories. These options should provide adequate control for maintainers to opt out of KCSAN analysis at varying levels of granularity. It is hoped to provide the required control to reflect preferences for handling data races across the kernel. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'Documentation/dev-tools')
-rw-r--r--Documentation/dev-tools/kcsan.rst24
1 files changed, 17 insertions, 7 deletions
diff --git a/Documentation/dev-tools/kcsan.rst b/Documentation/dev-tools/kcsan.rst
index a6f4f92df2fa..65a0be513b7d 100644
--- a/Documentation/dev-tools/kcsan.rst
+++ b/Documentation/dev-tools/kcsan.rst
@@ -101,18 +101,28 @@ instrumentation or e.g. DMA accesses.
Selective analysis
~~~~~~~~~~~~~~~~~~
-To disable KCSAN data race detection for an entire subsystem, add to the
-respective ``Makefile``::
+It may be desirable to disable data race detection for specific accesses,
+functions, compilation units, or entire subsystems. For static blacklisting,
+the below options are available:
- KCSAN_SANITIZE := n
+* KCSAN understands the ``data_race(expr)`` annotation, which tells KCSAN that
+ any data races due to accesses in ``expr`` should be ignored and resulting
+ behaviour when encountering a data race is deemed safe.
+
+* Disabling data race detection for entire functions can be accomplished by
+ using the function attribute ``__no_kcsan`` (or ``__no_kcsan_or_inline`` for
+ ``__always_inline`` functions). To dynamically control for which functions
+ data races are reported, see the `debugfs`_ blacklist/whitelist feature.
-To disable KCSAN on a per-file basis, add to the ``Makefile``::
+* To disable data race detection for a particular compilation unit, add to the
+ ``Makefile``::
KCSAN_SANITIZE_file.o := n
-KCSAN also understands the ``data_race(expr)`` annotation, which tells KCSAN
-that any data races due to accesses in ``expr`` should be ignored and resulting
-behaviour when encountering a data race is deemed safe.
+* To disable data race detection for all compilation units listed in a
+ ``Makefile``, add to the respective ``Makefile``::
+
+ KCSAN_SANITIZE := n
debugfs
~~~~~~~