9 files changed, 26 insertions, 11 deletions

diff --git a/arch/arm/include/asm/jump_label.h b/arch/arm/include/asm/jump_label.h
index bfc198c75913..863c892b4aaa 100644
--- a/arch/arm/include/asm/jump_label.h
+++ b/arch/arm/include/asm/jump_label.h
@@ -16,7 +16,7 @@
 
 static __always_inline bool arch_static_branch(struct static_key *key)
 {
-        asm goto("1:\n\t"
+        asm_volatile_goto("1:\n\t"
                  JUMP_LABEL_NOP "\n\t"
                  ".pushsection __jump_table,  \"aw\"\n\t"
                  ".word 1b, %l[l_yes], %c0\n\t"
diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h
index 4d6d77ed9b9d..e194f957ca8c 100644
--- a/arch/mips/include/asm/jump_label.h
+++ b/arch/mips/include/asm/jump_label.h
@@ -22,7 +22,7 @@
 
 static __always_inline bool arch_static_branch(struct static_key *key)
 {
-        asm goto("1:\tnop\n\t"
+        asm_volatile_goto("1:\tnop\n\t"
                 "nop\n\t"
                 ".pushsection __jump_table,  \"aw\"\n\t"
                 WORD_INSN " 1b, %l[l_yes], %0\n\t"
diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h
index ae098c438f00..f016bb699b5f 100644
--- a/arch/powerpc/include/asm/jump_label.h
+++ b/arch/powerpc/include/asm/jump_label.h
@@ -19,7 +19,7 @@
 
 static __always_inline bool arch_static_branch(struct static_key *key)
 {
-        asm goto("1:\n\t"
+        asm_volatile_goto("1:\n\t"
                  "nop\n\t"
                  ".pushsection __jump_table,  \"aw\"\n\t"
                  JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h
index 6c32190dc73e..346b1c85ffb4 100644
--- a/arch/s390/include/asm/jump_label.h
+++ b/arch/s390/include/asm/jump_label.h
@@ -15,7 +15,7 @@
 
 static __always_inline bool arch_static_branch(struct static_key *key)
 {
-        asm goto("0:    brcl 0,0\n"
+        asm_volatile_goto("0:   brcl 0,0\n"
                 ".pushsection __jump_table, \"aw\"\n"
                 ASM_ALIGN "\n"
                 ASM_PTR " 0b, %l[label], %0\n"
diff --git a/arch/sparc/include/asm/jump_label.h b/arch/sparc/include/asm/jump_label.h
index 5080d16a832f..ec2e2e2aba7d 100644
--- a/arch/sparc/include/asm/jump_label.h
+++ b/arch/sparc/include/asm/jump_label.h
@@ -9,7 +9,7 @@
 
 static __always_inline bool arch_static_branch(struct static_key *key)
 {
-                asm goto("1:\n\t"
+                asm_volatile_goto("1:\n\t"
                          "nop\n\t"
                          "nop\n\t"
                          ".pushsection __jump_table,  \"aw\"\n\t"
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index d3f5c63078d8..89270b4318db 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -374,7 +374,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit)
                  * Catch too early usage of this before alternatives
                  * have run.
                  */
-                asm goto("1: jmp %l[t_warn]\n"
+                asm_volatile_goto("1: jmp %l[t_warn]\n"
                          "2:\n"
                          ".section .altinstructions,\"a\"\n"
                          " .long 1b - .\n"
@@ -388,7 +388,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit)
 
 #endif
 
-                asm goto("1: jmp %l[t_no]\n"
+                asm_volatile_goto("1: jmp %l[t_no]\n"
                          "2:\n"
                          ".section .altinstructions,\"a\"\n"
                          " .long 1b - .\n"
@@ -453,7 +453,7 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit)
  * have. Thus, we force the jump to the widest, 4-byte, signed relative
  * offset even though the last would often fit in less bytes.
  */
-                asm goto("1: .byte 0xe9\n .long %l[t_dynamic] - 2f\n"
+                asm_volatile_goto("1: .byte 0xe9\n .long %l[t_dynamic] - 2f\n"
                          "2:\n"
                          ".section .altinstructions,\"a\"\n"
                          " .long 1b - .\n"              /* src offset */
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h
index 64507f35800c..6a2cefb4395a 100644
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -18,7 +18,7 @@
 
 static __always_inline bool arch_static_branch(struct static_key *key)
 {
-        asm goto("1:"
+        asm_volatile_goto("1:"
                 ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
                 ".pushsection __jump_table,  \"aw\" \n\t"
                 _ASM_ALIGN "\n\t"
diff --git a/arch/x86/include/asm/mutex_64.h b/arch/x86/include/asm/mutex_64.h
index e7e6751648ed..07537a44216e 100644
--- a/arch/x86/include/asm/mutex_64.h
+++ b/arch/x86/include/asm/mutex_64.h
@@ -20,7 +20,7 @@
 static inline void __mutex_fastpath_lock(atomic_t *v,
                                          void (*fail_fn)(atomic_t *))
 {
-        asm volatile goto(LOCK_PREFIX "   decl %0\n"
+        asm_volatile_goto(LOCK_PREFIX "   decl %0\n"
                           "   jns %l[exit]\n"
                           : : "m" (v->counter)
                           : "memory", "cc"
@@ -75,7 +75,7 @@ static inline int __mutex_fastpath_lock_retval(atomic_t *count)
 static inline void __mutex_fastpath_unlock(atomic_t *v,
                                            void (*fail_fn)(atomic_t *))
 {
-        asm volatile goto(LOCK_PREFIX "   incl %0\n"
+        asm_volatile_goto(LOCK_PREFIX "   incl %0\n"
                           "   jg %l[exit]\n"
                           : : "m" (v->counter)
                           : "memory", "cc"
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index 842de225055f..ded429966c1f 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -65,6 +65,21 @@
 #define __visible __attribute__((externally_visible))
 #endif
 
+/*
+ * GCC 'asm goto' miscompiles certain code sequences:
+ *
+ *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
+ *
+ * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
+ * Fixed in GCC 4.8.2 and later versions.
+ *
+ * (asm goto is automatically volatile - the naming reflects this.)
+ */
+#if GCC_VERSION <= 40801
+# define asm_volatile_goto(x...)        do { asm goto(x); asm (""); } while (0)
+#else
+# define asm_volatile_goto(x...)        do { asm goto(x); } while (0)
+#endif
 
 #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
 #if GCC_VERSION >= 40400