Invalidate cached pid in vfork.
Bug: http://b/23008979
Change-Id: I1dd900ac988cdbe10aad3abc53240c5d352891d5
diff --git a/libc/arch-arm/bionic/vfork.S b/libc/arch-arm/bionic/vfork.S
new file mode 100644
index 0000000..1b7cbad
--- /dev/null
+++ b/libc/arch-arm/bionic/vfork.S
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+ENTRY(vfork)
+ // __get_tls()[TLS_SLOT_THREAD_ID]->cached_pid_ = 0
+ mrc p15, 0, r3, c13, c0, 3
+ ldr r3, [r3, #4]
+ mov r0, #0
+ str r0, [r3, #12]
+
+ mov ip, r7
+ ldr r7, =__NR_vfork
+ swi #0
+ mov r7, ip
+ cmn r0, #(MAX_ERRNO + 1)
+ bxls lr
+ neg r0, r0
+ b __set_errno_internal
+END(vfork)