[PATCH v3 03/12] Revert "x86/extable: Macrofy inline assembly code to work around GCC inlining bugs"

From: Masahiro Yamada
Date: Mon Dec 17 2018 - 11:11:23 EST


This reverts commit 0474d5d9d2f7f3b11262f7bf87d0e7314ead9200.

The in-kernel workarounds will be replaced with GCC's new
"asm inline" syntax.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

I blindly reverted here, but I will clean it up
in a different way later.

arch/x86/include/asm/asm.h | 53 +++++++++++++++++++++++++++++-----------------
arch/x86/kernel/macros.S | 1 -
2 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 21b0867..6467757b 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -120,25 +120,12 @@
/* Exception table entry */
#ifdef __ASSEMBLY__
# define _ASM_EXTABLE_HANDLE(from, to, handler) \
- ASM_EXTABLE_HANDLE from to handler
-
-.macro ASM_EXTABLE_HANDLE from:req to:req handler:req
- .pushsection "__ex_table","a"
- .balign 4
- .long (\from) - .
- .long (\to) - .
- .long (\handler) - .
+ .pushsection "__ex_table","a" ; \
+ .balign 4 ; \
+ .long (from) - . ; \
+ .long (to) - . ; \
+ .long (handler) - . ; \
.popsection
-.endm
-#else /* __ASSEMBLY__ */
-
-# define _ASM_EXTABLE_HANDLE(from, to, handler) \
- "ASM_EXTABLE_HANDLE from=" #from " to=" #to \
- " handler=\"" #handler "\"\n\t"
-
-/* For C file, we already have NOKPROBE_SYMBOL macro */
-
-#endif /* __ASSEMBLY__ */

# define _ASM_EXTABLE(from, to) \
_ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
@@ -161,7 +148,6 @@
_ASM_PTR (entry); \
.popsection

-#ifdef __ASSEMBLY__
.macro ALIGN_DESTINATION
/* check for bad alignment of destination */
movl %edi,%ecx
@@ -185,7 +171,34 @@
_ASM_EXTABLE_UA(100b, 103b)
_ASM_EXTABLE_UA(101b, 103b)
.endm
-#endif /* __ASSEMBLY__ */
+
+#else
+# define _EXPAND_EXTABLE_HANDLE(x) #x
+# define _ASM_EXTABLE_HANDLE(from, to, handler) \
+ " .pushsection \"__ex_table\",\"a\"\n" \
+ " .balign 4\n" \
+ " .long (" #from ") - .\n" \
+ " .long (" #to ") - .\n" \
+ " .long (" _EXPAND_EXTABLE_HANDLE(handler) ") - .\n" \
+ " .popsection\n"
+
+# define _ASM_EXTABLE(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
+
+# define _ASM_EXTABLE_UA(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess)
+
+# define _ASM_EXTABLE_FAULT(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
+
+# define _ASM_EXTABLE_EX(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
+
+# define _ASM_EXTABLE_REFCOUNT(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_refcount)
+
+/* For C file, we already have NOKPROBE_SYMBOL macro */
+#endif

#ifndef __ASSEMBLY__
/*
diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S
index 7baa40d..71d8b71 100644
--- a/arch/x86/kernel/macros.S
+++ b/arch/x86/kernel/macros.S
@@ -11,4 +11,3 @@
#include <asm/alternative-asm.h>
#include <asm/bug.h>
#include <asm/paravirt.h>
-#include <asm/asm.h>
--
2.7.4