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Commit5ff8c11775("KMSAN: Remove tautological checks") changed CONFIG_HAVE_KMSAN_COMPILER from a dynamic check for '-fsanitize=kernel-memory' to just being true for CONFIG_CC_IS_CLANG. This missed the fact that not all architectures supported '-fsanitize=kernel-memory' at the same time. For example, SystemZ / s390 gained support for KMSAN in clang-18 [1], so builds with clang-15 through clang-17 can select KMSAN but they error with: clang-16: error: unsupported option '-fsanitize=kernel-memory' for target 's390x-unknown-linux-gnu' Restore the cc-option check for '-fsanitize=kernel-memory' to make sure the compiler target properly supports '-fsanitize=kernel-memory'. The check for '-msan-disable-checks=1' does not need to be restored because all supported clang versions for building the kernel support it. Fixes:5ff8c11775("KMSAN: Remove tautological checks") Link:a3e56a8792[1] Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/r/202510220236.AVuXXCYy-lkp@intel.com/ Acked-by: Nicolas Schier <nsc@kernel.org> Link: https://patch.msgid.link/20251023-fix-kmsan-check-s390-clang-v1-1-4e6df477a4cc@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
55 lines
1.9 KiB
Plaintext
55 lines
1.9 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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config HAVE_ARCH_KMSAN
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bool
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config HAVE_KMSAN_COMPILER
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def_bool $(cc-option,-fsanitize=kernel-memory)
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config KMSAN
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bool "KMSAN: detector of uninitialized values use"
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depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER
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depends on DEBUG_KERNEL && !KASAN && !KCSAN
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depends on !PREEMPT_RT
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select STACKDEPOT
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select STACKDEPOT_ALWAYS_INIT
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help
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KernelMemorySanitizer (KMSAN) is a dynamic detector of uses of
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uninitialized values in the kernel. It is based on compiler
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instrumentation provided by Clang and thus requires Clang to build.
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An important note is that KMSAN is not intended for production use,
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because it drastically increases kernel memory footprint and slows
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the whole system down.
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See <file:Documentation/dev-tools/kmsan.rst> for more details.
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if KMSAN
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config KMSAN_CHECK_PARAM_RETVAL
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bool "Check for uninitialized values passed to and returned from functions"
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default y
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help
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If the compiler supports -fsanitize-memory-param-retval, KMSAN will
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eagerly check every function parameter passed by value and every
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function return value.
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Disabling KMSAN_CHECK_PARAM_RETVAL will result in tracking shadow for
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function parameters and return values across function borders. This
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is a more relaxed mode, but it generates more instrumentation code and
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may potentially report errors in corner cases when non-instrumented
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functions call instrumented ones.
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config KMSAN_KUNIT_TEST
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tristate "KMSAN integration test suite" if !KUNIT_ALL_TESTS
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default KUNIT_ALL_TESTS
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depends on TRACEPOINTS && KUNIT
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help
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Test suite for KMSAN, testing various error detection scenarios,
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and checking that reports are correctly output to console.
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Say Y here if you want the test to be built into the kernel and run
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during boot; say M if you want the test to build as a module; say N
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if you are unsure.
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endif
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