Revert "x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs"

Ingo Molnar · Ingo Molnar · commit 851a4cd7cc11 · 2018-12-19T12:00:04.000+01:00
This reverts commit 77f48ec. See this commit for details about the revert: e769742 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Richard Biener <rguenther@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nadav Amit <namit@vmware.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
@@ -7,24 +7,16 @@
 #include <asm/asm.h>
 
 #ifdef CONFIG_SMP
-.macro LOCK_PREFIX_HERE
+	.macro LOCK_PREFIX
+672:	lock
 	.pushsection .smp_locks,"a"
 	.balign 4
-	.long 671f - .		# offset
+	.long 672b - .
 	.popsection
-671:
-.endm
-
-.macro LOCK_PREFIX insn:vararg
-	LOCK_PREFIX_HERE
-	lock \insn
-.endm
+	.endm
 #else
-.macro LOCK_PREFIX_HERE
-.endm
-
-.macro LOCK_PREFIX insn:vararg
-.endm
+	.macro LOCK_PREFIX
+	.endm
 #endif
 
 /*
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
@@ -31,8 +31,15 @@
  */
 
 #ifdef CONFIG_SMP
-#define LOCK_PREFIX_HERE "LOCK_PREFIX_HERE\n\t"
-#define LOCK_PREFIX "LOCK_PREFIX "
+#define LOCK_PREFIX_HERE \
+		".pushsection .smp_locks,\"a\"\n"	\
+		".balign 4\n"				\
+		".long 671f - .\n" /* offset */		\
+		".popsection\n"				\
+		"671:"
+
+#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
+
 #else /* ! CONFIG_SMP */
 #define LOCK_PREFIX_HERE ""
 #define LOCK_PREFIX ""
diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S
@@ -8,4 +8,3 @@
 
 #include <linux/compiler.h>
 #include <asm/refcount.h>
-#include <asm/alternative-asm.h>

Original file line number	Diff line number	Diff line change
`@@ -8,4 +8,3 @@`
`8`	`8`
`9`	`9`	`#include <linux/compiler.h>`
`10`	`10`	`#include <asm/refcount.h>`
`11`		`-#include <asm/alternative-asm.h>`