[PATCH -next V12 1/7] compiler_types.h: Add __noinstr_section() for noinstr

guoren
2023-01-03T03:36:22Z

From: Lai Jiangshan <laijs@linux.alibaba.com>

Using __noinstr_section() doesn't automatically disable all
instrumentations on the section. Inhibition for some
instrumentations requires extra code. I.E. KPROBES explicitly
avoids instrumenting on .noinstr.text.

Cc: Borislav Petkov <bp@alien8.de>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
include/linux/compiler_types.h | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 7c1afe0f4129..0a2ca5755be7 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -231,12 +231,19 @@ struct ftrace_likely_data {
#define __no_sanitize_or_inline __always_inline
#endif

-/* Section for code which can't be instrumented at all */
-#define noinstr \
- noinline notrace __attribute((__section__(".noinstr.text"))) \
- __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage \
+/*
+ * Using __noinstr_section() doesn't automatically disable all instrumentations
+ * on the section. Inhibition for some instrumentations requires extra code.
+ * I.E. KPROBES explicitly avoids instrumenting on .noinstr.text.
+ */
+#define __noinstr_section(section) \
+ noinline notrace __section(section) __no_profile \
+ __no_kcsan __no_sanitize_address __no_sanitize_coverage \
__no_sanitize_memory

+/* Section for code which can't be instrumented at all */
+#define noinstr __noinstr_section(".noinstr.text")
+
#endif /* __KERNEL__ */

#endif /* __ASSEMBLY__ */
--
2.36.1