linux/scripts/Makefile.kcsan

# SPDX-License-Identifier: GPL-2.0
ifdef CONFIG_KCSAN

# GCC and Clang accept backend options differently. Do not wrap in cc-option,
# because Clang accepts "--param" even if it is unused.
ifdef CONFIG_CC_IS_CLANG
cc-param = -mllvm -$(1)
else
cc-param = --param -$(1)
endif

CFLAGS_KCSAN := -fsanitize=thread \
	$(call cc-option,$(call cc-param,tsan-instrument-func-entry-exit=0) -fno-optimize-sibling-calls)

endif # CONFIG_KCSAN
kcsan: Add Kernel Concurrency Sanitizer infrastructure Kernel Concurrency Sanitizer (KCSAN) is a dynamic data-race detector for kernel space. KCSAN is a sampling watchpoint-based data-race detector. See the included Documentation/dev-tools/kcsan.rst for more details. This patch adds basic infrastructure, but does not yet enable KCSAN for any architecture. Signed-off-by: Marco Elver <elver@google.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 2019-11-14 18:02:54 +00:00			`# SPDX-License-Identifier: GPL-2.0`
			`ifdef CONFIG_KCSAN`

kcsan: Avoid inserting __tsan_func_entry/exit if possible To avoid inserting __tsan_func_{entry,exit}, add option if supported by compiler. Currently only Clang can be told to not emit calls to these functions. It is safe to not emit these, since KCSAN does not rely on them. Note that, if we disable __tsan_func_{entry,exit}(), we need to disable tail-call optimization in sanitized compilation units, as otherwise we may skip frames in the stack trace; in particular when the tail called function is one of the KCSAN's runtime functions, and a report is generated, we might miss the function where the actual access occurred. Since __tsan_func_{entry,exit}() insertion effectively disabled tail-call optimization, there should be no observable change. This was caught and confirmed with kcsan-test & UNWINDER_ORC. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Will Deacon <will@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200521142047.169334-3-elver@google.com 2020-05-21 14:20:38 +00:00			`# GCC and Clang accept backend options differently. Do not wrap in cc-option,`
			`# because Clang accepts "--param" even if it is unused.`
			`ifdef CONFIG_CC_IS_CLANG`
			`cc-param = -mllvm -$(1)`
			`else`
			`cc-param = --param -$(1)`
			`endif`

			`CFLAGS_KCSAN := -fsanitize=thread \`
			`$(call cc-option,$(call cc-param,tsan-instrument-func-entry-exit=0) -fno-optimize-sibling-calls)`
kcsan: Add Kernel Concurrency Sanitizer infrastructure Kernel Concurrency Sanitizer (KCSAN) is a dynamic data-race detector for kernel space. KCSAN is a sampling watchpoint-based data-race detector. See the included Documentation/dev-tools/kcsan.rst for more details. This patch adds basic infrastructure, but does not yet enable KCSAN for any architecture. Signed-off-by: Marco Elver <elver@google.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> 2019-11-14 18:02:54 +00:00
			`endif # CONFIG_KCSAN`