[PATCH V4 07/50] x86/entry: Introduce __entry_text for entry code written in C

From: Lai Jiangshan
Date: Tue Oct 26 2021 - 10:21:55 EST


From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>

Some entry code will be implemented in C files. __entry_text is needed
to set them in .entry.text section. __entry_text disables instrumentation
like noinstr, but it doesn't disable stack protector since not all
compiler supported by kernel supporting function level granular
attribute to disable stack protector. It will be disabled by C file
level.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/idtentry.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 1345088e9902..6779def97591 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -11,6 +11,9 @@

#include <asm/irq_stack.h>

+/* Entry code written in C. */
+#define __entry_text __noinstr_section(".entry.text")
+
/**
* DECLARE_IDTENTRY - Declare functions for simple IDT entry points
* No error code pushed by hardware
--
2.19.1.6.gb485710b