PowerPC: Consolidate NPTL/non versions of vfork

sysdeps/unix/sysv/linux/powerpc/powerpc32/vfork.S

@@ -19,6 +19,7 @@
 #define _ERRNO_H	1
 #include <bits/errno.h>
 #include <kernel-features.h>
+#include <tcb-offsets.h>
 
 /* Clone the calling process, but without copying the whole address space.
    The calling process is suspended until the new process exits or is
@@ -26,9 +27,39 @@
    and the process ID of the new process to the old process.  */
 
 ENTRY (__vfork)
+
+	/* Load the TCB-cached PID value and negates it. If It it is zero
+	   sets it to 0x800000.  And then sets its value again on TCB field.
+	   See raise.c for the logic that relies on this value.  */
+
+	lwz	r0,PID(r2)
+	cmpwi	cr0,r0,0
+	neg	r0,r0
+	bne-	cr0,1f
+	lis	r0,0x8000
+1:	stw	r0,PID(r2)
+
 	DO_CALL (SYS_ify (vfork))
+
+	cmpwi	cr1,r3,0
+	beqlr-	1
+
+	/* Restore the original value of the TCB cache of the PID, if we're
+	   the parent.  But in the child (syscall return value equals zero),
+	   leave things as they are.  */
+	lwz	r0,PID(r2)
+	/* Cannot use clrlwi. here, because cr0 needs to be preserved
+	   until PSEUDO_RET.  */
+	clrlwi	r4,r0,1
+	cmpwi	cr1,r4,0
+	beq-	cr1,1f
+	neg	r4,r0
+1:	stw	r4,PID(r2)
+
 	PSEUDO_RET
+
 PSEUDO_END (__vfork)
 libc_hidden_def (__vfork)
 
 weak_alias (__vfork, vfork)
+strong_alias (__vfork, __libc_vfork)