* Tom Lendacky <thomas.lendacky@xxxxxxx> wrote:
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 cd4bbe8..682063b 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -166,6 +166,8 @@
#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 219f82f..63cbca1 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -470,6 +470,10 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
#define __visible
#endif
+#ifndef __nostackp
+#define __nostackp
+#endif
So I changed this from the hard to read and ambiguous "__nostackp" abbreviation
(does it mean 'no stack pointer?') to "__nostackprotector", plus added this detail
to the changelog:
| ( This is needed by the SME in-place kernel memory encryption feature,
| which activates encryption in its sme_enable() function and thus changes the
| visible value of the stack protection cookie on function return. )
Agreed?
Thanks,
Ingo