From: Tom Lendacky <thomas.lendacky@amd.com>
Subject: [PATCH v9 37/38] compiler-gcc.h: Introduce __nostackp function
 attribute
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Cc: Brijesh Singh <brijesh.singh@amd.com>,
        Toshimitsu Kani <toshi.kani@hpe.com>,
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Date: Fri, 07 Jul 2017 08:45:02 -0500
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Create a new function attribute, __nostackp, that can used to turn off
stack protection on a per function basis.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 include/linux/compiler-gcc.h |    2 ++
 include/linux/compiler.h     |    4 ++++
 2 files changed, 6 insertions(+)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 0efef9c..de48b32 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -162,6 +162,8 @@
 
 #if GCC_VERSION >= 40100
 # define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
+
+#define __nostackp	__attribute__((__optimize__("no-stack-protector")))
 #endif
 
 #if GCC_VERSION >= 40300
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 707242f..615d50d 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -458,6 +458,10 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 #define __visible
 #endif
 
+#ifndef __nostackp
+#define __nostackp
+#endif
+
 /*
  * Assume alignment of return value.
  */