Add missing rcu_cmpxchg_pointer define

[urcu.git] / arch_x86.h

diff --git a/arch_x86.h b/arch_x86.h
index e7d945e3859393edece5eb4b2aee4c99538083e2..8a5732536c9d3106af919b5467dab1f58c5f9313 100644 (file)
--- a/arch_x86.h
+++ b/arch_x86.h
@@ -97,10 +97,22 @@ static inline void cpu_relax(void)
 /*
  * Serialize core instruction execution. Also acts as a compiler barrier.
  */
+#ifdef __PIC__
+/*
+ * Cannot use cpuid because it clobbers the ebx register and clashes
+ * with -fPIC :
+ * error: PIC register 'ebx' clobbered in 'asm'
+ */
+static inline void sync_core(void)
+{
+       mb();
+}
+#else
 static inline void sync_core(void)
 {
        asm volatile("cpuid" : : : "memory", "eax", "ebx", "ecx", "edx");
 }
+#endif
 
 #define rdtscll(val)                                                     \
        do {                                                              \