Merge 5.5.6-rc to the main tree.

include/atomic/x86-gcc.h

@@ -111,9 +111,9 @@
   On some platforms (e.g. Mac OS X and Solaris) the ebx register
   is held as a pointer to the global offset table. Thus we're not
   allowed to use the b-register on those platforms when compiling
-  PIC code, to avoid this we push ebx and pop ebx and add a movl
-  instruction to avoid having ebx in the interface of the assembler
-  instruction.
+  PIC code, to avoid this we push ebx and pop ebx. The new value
+  is copied directly from memory to avoid problems with a implicit
+  manipulation of the stack pointer by the push.
 
   cmpxchg8b works on both 32-bit platforms and 64-bit platforms but
   the code here is only used on 32-bit platforms, on 64-bit
@@ -121,11 +121,13 @@
   fine.
 */
 #define make_atomic_cas_body64                                    \
-  int32 ebx=(set & 0xFFFFFFFF), ecx=(set >> 32);                  \
-  asm volatile ("push %%ebx; movl %3, %%ebx;"                     \
-                LOCK_prefix "; cmpxchg8b %0; setz %2; pop %%ebx"  \
+  asm volatile ("push %%ebx;"                                     \
+                "movl (%%ecx), %%ebx;"                            \
+                "movl 4(%%ecx), %%ecx;"                           \
+                LOCK_prefix "; cmpxchg8b %0;"                     \
+                "setz %2; pop %%ebx"                              \
                 : "=m" (*a), "+A" (*cmp), "=c" (ret)              \
-                : "m" (ebx), "c" (ecx), "m" (*a)                  \
+                : "c" (&set), "m" (*a)                            \
                 : "memory", "esp")
 #endif
 

storage/perfschema/ha_perfschema.cc

@@ -20,6 +20,7 @@
 
 #include "my_global.h"
 #include "my_pthread.h"
+#include "my_atomic.h"
 #include "sql_plugin.h"
 #include "mysql/plugin.h"
 #include "ha_perfschema.h"
@@ -28,6 +29,17 @@
 #include "pfs_instr_class.h"
 #include "pfs_instr.h"
 
+#ifdef MY_ATOMIC_MODE_DUMMY
+/*
+  The performance schema can can not function with MY_ATOMIC_MODE_DUMMY,
+  a fully functional implementation of MY_ATOMIC should be used instead.
+  If the build fails with this error message:
+  - either use a different ./configure --with-atomic-ops option
+  - or do not build with the performance schema.
+*/
+#error "The performance schema needs a functional MY_ATOMIC implementation."
+#endif
+
 handlerton *pfs_hton= NULL;
 
 static handler* pfs_create_handler(handlerton *hton,