Calling the getpid() function from within the INTERNAL_SYSCALL macro results in
some registers being randomly corrupted by the function after they've been loaded
by the macro. Here, we had r1 (mask size) corrupted by getpid() when building with
gcc 4.7.[23] or linaro-gcc-4.7-2013*.

--- ./sysdeps/unix/sysv/linux/sched_setaffinity.c.orig	2013-06-18 23:34:52.163483621 +0200
+++ ./sysdeps/unix/sysv/linux/sched_setaffinity.c	2013-06-18 23:35:13.660128735 +0200
@@ -41,8 +41,9 @@
 
       size_t psize = 128;
       void *p = alloca (psize);
+      pid_t mypid = getpid();
 
-      while (res = INTERNAL_SYSCALL (sched_getaffinity, err, 3, getpid (),
+      while (res = INTERNAL_SYSCALL (sched_getaffinity, err, 3, mypid,
 				     psize, p),
 	     INTERNAL_SYSCALL_ERROR_P (res, err)
 	     && INTERNAL_SYSCALL_ERRNO (res, err) == EINVAL)