Clean up forking and cloning.
The kernel now maintains the pthread_internal_t::tid field for us,
and __clone was only used in one place so let's inline it so we don't
have to leave such a dangerous function lying around. Also rename
files to match their content and remove some useless #includes.
Change-Id: I24299fb4a940e394de75f864ee36fdabbd9438f9
diff --git a/libc/arch-x86_64/bionic/__bionic_clone.S b/libc/arch-x86_64/bionic/__bionic_clone.S
new file mode 100644
index 0000000..309c365
--- /dev/null
+++ b/libc/arch-x86_64/bionic/__bionic_clone.S
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2013 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 <asm/unistd.h>
+#include <machine/asm.h>
+
+// pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg);
+ENTRY(__bionic_clone)
+ # Enforce 16-byte alignment for child stack.
+ andq $~15, %rsi
+
+ # Copy 'fn' and 'arg' onto the child stack.
+ movq %r9, -16(%rsi) # fn
+ movq 8(%rsp), %rax # Read 'arg'.
+ movq %rax, -8(%rsi) # Write 'arg'.
+
+ subq $16, %rsi
+
+ # Translate to the kernel calling convention and swap the 'tls' and 'child_tid' arguments.
+ # They're flipped for x86-64 compared to all our other architectures and __bionic_clone.
+ movq %r8, %r10
+ movq %rcx, %r8
+
+ # Make the system call.
+ movl $__NR_clone, %eax
+ syscall
+ testl %eax, %eax
+ jns 1f
+
+ # An error occurred, set errno and return -1.
+ negl %eax
+ movl %eax, %edi
+ call __set_errno
+ orl $-1, %eax
+ jmp 2f
+1:
+ jnz 2f
+
+ # We're in the child now, so call __bionic_clone_entry
+ # with the arguments from the child stack moved into
+ # the appropriate registers.
+ popq %rdi # fn
+ popq %rsi # arg
+ call __bionic_clone_entry
+ hlt
+2:
+ ret