commit 0f672f6c0b52b7b0700b0915c72b540721af4465
author David Brazdil <dbrazdil@google.com> Tue Dec 10 10:32:29 2019 +0000
committer David Brazdil <dbrazdil@google.com> Tue Dec 10 19:03:18 2019 +0000
tree 85c8cba019caa205e4f8920d72d93f6d6deaf29c
parent 3a0ad55d848b50499b68d7141d4eca997fce28ef

Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd

arch/x86/include/asm/refcount.h

diff --git a/arch/x86/include/asm/refcount.h b/arch/x86/include/asm/refcount.h
index 19b9052..232f856 100644
--- a/arch/x86/include/asm/refcount.h
+++ b/arch/x86/include/asm/refcount.h
@@ -17,7 +17,7 @@
  */
 #define _REFCOUNT_EXCEPTION				\
 	".pushsection .text..refcount\n"		\
-	"111:\tlea %[counter], %%" _ASM_CX "\n"		\
+	"111:\tlea %[var], %%" _ASM_CX "\n"		\
 	"112:\t" ASM_UD2 "\n"				\
 	ASM_UNREACHABLE					\
 	".popsection\n"					\
@@ -43,7 +43,7 @@
 {
 	asm volatile(LOCK_PREFIX "addl %1,%0\n\t"
 		REFCOUNT_CHECK_LT_ZERO
-		: [counter] "+m" (r->refs.counter)
+		: [var] "+m" (r->refs.counter)
 		: "ir" (i)
 		: "cc", "cx");
 }
@@ -52,7 +52,7 @@
 {
 	asm volatile(LOCK_PREFIX "incl %0\n\t"
 		REFCOUNT_CHECK_LT_ZERO
-		: [counter] "+m" (r->refs.counter)
+		: [var] "+m" (r->refs.counter)
 		: : "cc", "cx");
 }
 
@@ -60,21 +60,37 @@
 {
 	asm volatile(LOCK_PREFIX "decl %0\n\t"
 		REFCOUNT_CHECK_LE_ZERO
-		: [counter] "+m" (r->refs.counter)
+		: [var] "+m" (r->refs.counter)
 		: : "cc", "cx");
 }
 
 static __always_inline __must_check
 bool refcount_sub_and_test(unsigned int i, refcount_t *r)
 {
-	GEN_BINARY_SUFFIXED_RMWcc(LOCK_PREFIX "subl", REFCOUNT_CHECK_LT_ZERO,
-				  r->refs.counter, "er", i, "%0", e, "cx");
+	bool ret = GEN_BINARY_SUFFIXED_RMWcc(LOCK_PREFIX "subl",
+					 REFCOUNT_CHECK_LT_ZERO,
+					 r->refs.counter, e, "er", i, "cx");
+
+	if (ret) {
+		smp_acquire__after_ctrl_dep();
+		return true;
+	}
+
+	return false;
 }
 
 static __always_inline __must_check bool refcount_dec_and_test(refcount_t *r)
 {
-	GEN_UNARY_SUFFIXED_RMWcc(LOCK_PREFIX "decl", REFCOUNT_CHECK_LT_ZERO,
-				 r->refs.counter, "%0", e, "cx");
+	bool ret = GEN_UNARY_SUFFIXED_RMWcc(LOCK_PREFIX "decl",
+					 REFCOUNT_CHECK_LT_ZERO,
+					 r->refs.counter, e, "cx");
+
+	if (ret) {
+		smp_acquire__after_ctrl_dep();
+		return true;
+	}
+
+	return false;
 }
 
 static __always_inline __must_check
@@ -92,7 +108,7 @@
 		/* Did we try to increment from/to an undesirable state? */
 		if (unlikely(c < 0 || c == INT_MAX || result < c)) {
 			asm volatile(REFCOUNT_ERROR
-				     : : [counter] "m" (r->refs.counter)
+				     : : [var] "m" (r->refs.counter)
 				     : "cc", "cx");
 			break;
 		}