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From: Sami Tolvanen <samitolvanen@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	 Masahiro Yamada <masahiroy@kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	 Nick Desaulniers <ndesaulniers@google.com>,
	Will Deacon <will@kernel.org>,
	 linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,  llvm@lists.linux.dev,
	Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH 2/3] linux/compiler-clang.h: define function_nocfi
Date: Fri,  1 Apr 2022 13:19:15 -0700	[thread overview]
Message-ID: <20220401201916.1487500-3-samitolvanen@google.com> (raw)
In-Reply-To: <20220401201916.1487500-1-samitolvanen@google.com>

Use __builtin_function_start() to implement the function_nocfi() macro
when CONFIG_CFI_CLANG is selected.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 include/linux/compiler-clang.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index babb1347148c..c84fec767445 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -69,6 +69,16 @@
 #define __nocfi		__attribute__((__no_sanitize__("cfi")))
 #define __cficanonical	__attribute__((__cfi_canonical_jump_table__))
 
+#if defined(CONFIG_CFI_CLANG)
+/*
+ * With CONFIG_CFI_CLANG, the compiler replaces function address
+ * references with the address of the function's CFI jump table
+ * entry. The function_nocfi macro always returns the address of the
+ * actual function instead.
+ */
+#define function_nocfi(x)	__builtin_function_start(x)
+#endif
+
 /*
  * Turn individual warnings and errors on and off locally, depending
  * on version.
-- 
2.35.0


WARNING: multiple messages have this Message-ID (diff)
From: Sami Tolvanen <samitolvanen@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	 Masahiro Yamada <masahiroy@kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	 Nick Desaulniers <ndesaulniers@google.com>,
	Will Deacon <will@kernel.org>,
	 linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,  llvm@lists.linux.dev,
	Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH 2/3] linux/compiler-clang.h: define function_nocfi
Date: Fri,  1 Apr 2022 13:19:15 -0700	[thread overview]
Message-ID: <20220401201916.1487500-3-samitolvanen@google.com> (raw)
In-Reply-To: <20220401201916.1487500-1-samitolvanen@google.com>

Use __builtin_function_start() to implement the function_nocfi() macro
when CONFIG_CFI_CLANG is selected.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 include/linux/compiler-clang.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index babb1347148c..c84fec767445 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -69,6 +69,16 @@
 #define __nocfi		__attribute__((__no_sanitize__("cfi")))
 #define __cficanonical	__attribute__((__cfi_canonical_jump_table__))
 
+#if defined(CONFIG_CFI_CLANG)
+/*
+ * With CONFIG_CFI_CLANG, the compiler replaces function address
+ * references with the address of the function's CFI jump table
+ * entry. The function_nocfi macro always returns the address of the
+ * actual function instead.
+ */
+#define function_nocfi(x)	__builtin_function_start(x)
+#endif
+
 /*
  * Turn individual warnings and errors on and off locally, depending
  * on version.
-- 
2.35.0


_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2022-04-01 20:19 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-01 20:19 [PATCH 0/3] cfi: Use __builtin_function_start Sami Tolvanen
2022-04-01 20:19 ` Sami Tolvanen
2022-04-01 20:19 ` [PATCH 1/3] kbuild: Change CFI_CLANG to depend on __builtin_function_start Sami Tolvanen
2022-04-01 20:19   ` Sami Tolvanen
2022-04-02 13:31   ` Masahiro Yamada
2022-04-02 13:31     ` Masahiro Yamada
2022-04-04 19:40     ` Sami Tolvanen
2022-04-04 19:40       ` Sami Tolvanen
2022-04-04 22:52       ` Nathan Chancellor
2022-04-04 22:52         ` Nathan Chancellor
2022-04-05  2:53         ` Kees Cook
2022-04-05  2:53           ` Kees Cook
2022-04-01 20:19 ` Sami Tolvanen [this message]
2022-04-01 20:19   ` [PATCH 2/3] linux/compiler-clang.h: define function_nocfi Sami Tolvanen
2022-04-05 16:16   ` Mark Rutland
2022-04-05 16:16     ` Mark Rutland
2022-04-01 20:19 ` [PATCH 3/3] arm64: Drop the inline assembly implementation of function_nocfi Sami Tolvanen
2022-04-01 20:19   ` Sami Tolvanen
2022-04-04  9:03   ` Will Deacon
2022-04-04  9:03     ` Will Deacon
2022-04-05 16:23   ` Mark Rutland
2022-04-05 16:23     ` Mark Rutland
2022-04-01 20:49 ` [PATCH 0/3] cfi: Use __builtin_function_start Nick Desaulniers
2022-04-01 20:49   ` Nick Desaulniers

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