[PATCH v3 05/12] Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs"

From: Masahiro Yamada
Date: Mon Dec 17 2018 - 11:11:02 EST


This reverts commit f81f8ad56fd1c7b99b2ed1c314527f7d9ac447c6.

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

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

arch/x86/include/asm/bug.h | 98 ++++++++++++++++++++--------------------------
arch/x86/kernel/macros.S | 1 -
include/asm-generic/bug.h | 8 ++--
3 files changed, 46 insertions(+), 61 deletions(-)

diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 5090035..6804d66 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -4,8 +4,6 @@

#include <linux/stringify.h>

-#ifndef __ASSEMBLY__
-
/*
* Despite that some emulators terminate on UD2, we use it for WARN().
*
@@ -22,15 +20,53 @@

#define LEN_UD2 2

+#ifdef CONFIG_GENERIC_BUG
+
+#ifdef CONFIG_X86_32
+# define __BUG_REL(val) ".long " __stringify(val)
+#else
+# define __BUG_REL(val) ".long " __stringify(val) " - 2b"
+#endif
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+
+#define _BUG_FLAGS(ins, flags) \
+do { \
+ asm volatile("1:\t" ins "\n" \
+ ".pushsection __bug_table,\"aw\"\n" \
+ "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
+ "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \
+ "\t.word %c1" "\t# bug_entry::line\n" \
+ "\t.word %c2" "\t# bug_entry::flags\n" \
+ "\t.org 2b+%c3\n" \
+ ".popsection" \
+ : : "i" (__FILE__), "i" (__LINE__), \
+ "i" (flags), \
+ "i" (sizeof(struct bug_entry))); \
+} while (0)
+
+#else /* !CONFIG_DEBUG_BUGVERBOSE */
+
#define _BUG_FLAGS(ins, flags) \
do { \
- asm volatile("ASM_BUG ins=\"" ins "\" file=%c0 line=%c1 " \
- "flags=%c2 size=%c3" \
- : : "i" (__FILE__), "i" (__LINE__), \
- "i" (flags), \
+ asm volatile("1:\t" ins "\n" \
+ ".pushsection __bug_table,\"aw\"\n" \
+ "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
+ "\t.word %c0" "\t# bug_entry::flags\n" \
+ "\t.org 2b+%c1\n" \
+ ".popsection" \
+ : : "i" (flags), \
"i" (sizeof(struct bug_entry))); \
} while (0)

+#endif /* CONFIG_DEBUG_BUGVERBOSE */
+
+#else
+
+#define _BUG_FLAGS(ins, flags) asm volatile(ins)
+
+#endif /* CONFIG_GENERIC_BUG */
+
#define HAVE_ARCH_BUG
#define BUG() \
do { \
@@ -46,54 +82,4 @@ do { \

#include <asm-generic/bug.h>

-#else /* __ASSEMBLY__ */
-
-#ifdef CONFIG_GENERIC_BUG
-
-#ifdef CONFIG_X86_32
-.macro __BUG_REL val:req
- .long \val
-.endm
-#else
-.macro __BUG_REL val:req
- .long \val - 2b
-.endm
-#endif
-
-#ifdef CONFIG_DEBUG_BUGVERBOSE
-
-.macro ASM_BUG ins:req file:req line:req flags:req size:req
-1: \ins
- .pushsection __bug_table,"aw"
-2: __BUG_REL val=1b # bug_entry::bug_addr
- __BUG_REL val=\file # bug_entry::file
- .word \line # bug_entry::line
- .word \flags # bug_entry::flags
- .org 2b+\size
- .popsection
-.endm
-
-#else /* !CONFIG_DEBUG_BUGVERBOSE */
-
-.macro ASM_BUG ins:req file:req line:req flags:req size:req
-1: \ins
- .pushsection __bug_table,"aw"
-2: __BUG_REL val=1b # bug_entry::bug_addr
- .word \flags # bug_entry::flags
- .org 2b+\size
- .popsection
-.endm
-
-#endif /* CONFIG_DEBUG_BUGVERBOSE */
-
-#else /* CONFIG_GENERIC_BUG */
-
-.macro ASM_BUG ins:req file:req line:req flags:req size:req
- \ins
-.endm
-
-#endif /* CONFIG_GENERIC_BUG */
-
-#endif /* __ASSEMBLY__ */
-
#endif /* _ASM_X86_BUG_H */
diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S
index 66ccb8e..852487a 100644
--- a/arch/x86/kernel/macros.S
+++ b/arch/x86/kernel/macros.S
@@ -9,4 +9,3 @@
#include <linux/compiler.h>
#include <asm/refcount.h>
#include <asm/alternative-asm.h>
-#include <asm/bug.h>
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index cdafa5e..20561a6 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -17,8 +17,10 @@
#ifndef __ASSEMBLY__
#include <linux/kernel.h>

-struct bug_entry {
+#ifdef CONFIG_BUG
+
#ifdef CONFIG_GENERIC_BUG
+struct bug_entry {
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
unsigned long bug_addr;
#else
@@ -33,10 +35,8 @@ struct bug_entry {
unsigned short line;
#endif
unsigned short flags;
-#endif /* CONFIG_GENERIC_BUG */
};
-
-#ifdef CONFIG_BUG
+#endif /* CONFIG_GENERIC_BUG */

/*
* Don't use BUG() or BUG_ON() unless there's really no way out; one
--
2.7.4