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        linux-riscv@lists.infradead.org,
        Lai Jiangshan <laijs@linux.alibaba.com>,
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Subject: [PATCH -next V14 1/7] compiler_types.h: Add __noinstr_section() for noinstr
Date:   Thu, 12 Jan 2023 04:58:42 -0500
Message-Id: <20230112095848.1464404-2-guoren@kernel.org>
In-Reply-To: <20230112095848.1464404-1-guoren@kernel.org>
References: <20230112095848.1464404-1-guoren@kernel.org>
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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