Add a simple test stub where we will add common supported patterns that should not generate false positives for each new supported context lock.
Signed-off-by: Marco Elver <[email protected]> --- v5: * Rename "context guard" -> "context lock". v4: * Rename capability -> context analysis. --- lib/Kconfig.debug | 14 ++++++++++++++ lib/Makefile | 3 +++ lib/test_context-analysis.c | 18 ++++++++++++++++++ 3 files changed, 35 insertions(+) create mode 100644 lib/test_context-analysis.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index cd557e7653a4..8ca42526ee43 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2835,6 +2835,20 @@ config LINEAR_RANGES_TEST If unsure, say N. +config CONTEXT_ANALYSIS_TEST + bool "Compiler context-analysis warnings test" + depends on EXPERT + help + This builds the test for compiler-based context analysis. The test + does not add executable code to the kernel, but is meant to test that + common patterns supported by the analysis do not result in false + positive warnings. + + When adding support for new context locks, it is strongly recommended + to add supported patterns to this test. + + If unsure, say N. + config CMDLINE_KUNIT_TEST tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index aaf677cf4527..89defefbf6c0 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -331,4 +331,7 @@ obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o obj-$(CONFIG_FIRMWARE_TABLE) += fw_table.o +CONTEXT_ANALYSIS_test_context-analysis.o := y +obj-$(CONFIG_CONTEXT_ANALYSIS_TEST) += test_context-analysis.o + subdir-$(CONFIG_FORTIFY_SOURCE) += test_fortify diff --git a/lib/test_context-analysis.c b/lib/test_context-analysis.c new file mode 100644 index 000000000000..68f075dec0e0 --- /dev/null +++ b/lib/test_context-analysis.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Compile-only tests for common patterns that should not generate false + * positive errors when compiled with Clang's context analysis. + */ + +#include <linux/build_bug.h> + +/* + * Test that helper macros work as expected. + */ +static void __used test_common_helpers(void) +{ + BUILD_BUG_ON(context_unsafe(3) != 3); /* plain expression */ + BUILD_BUG_ON(context_unsafe((void)2; 3) != 3); /* does not swallow semi-colon */ + BUILD_BUG_ON(context_unsafe((void)2, 3) != 3); /* does not swallow commas */ + context_unsafe(do { } while (0)); /* works with void statements */ +} -- 2.52.0.322.g1dd061c0dc-goog
