[PATCH v8 RESEND 37/38] compiler-gcc.h: Introduce __nostackp function attribute

From: Tom Lendacky
Date: Tue Jun 27 2017 - 11:31:36 EST


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@xxxxxxx>
---
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.
*/