1 files changed, 99 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S
new file mode 100644
index 0000000000..03fe9ab728
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/clone.S
@@ -0,0 +1,99 @@
+/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Pat Beirne <patb@corelcomputer.com>
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* clone() is even more special than fork() as it mucks with stacks
+   and invokes a function in the right context after its all over.  */
+
+#include <sysdep.h>
+#define _ERRNO_H	1
+#include <bits/errno.h>
+
+#define CLONE_VM      0x00000100
+#define CLONE_THREAD  0x00010000
+
+/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
+	     pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
+
+        .text
+ENTRY(__clone)
+	@ sanity check args
+	cmp	r0, #0
+	ite	ne
+	cmpne	r1, #0
+	moveq	r0, #-EINVAL
+	beq	PLTJMP(syscall_error)
+
+	@ insert the args onto the new stack
+	str	r3, [r1, #-4]!
+	str	r0, [r1, #-4]!
+
+	@ do the system call
+	@ get flags
+	mov	r0, r2
+#ifdef RESET_PID
+	mov	ip, r2
+#endif
+	@ new sp is already in r1
+	push	{r4, r7}
+	cfi_adjust_cfa_offset (8)
+	cfi_rel_offset (r4, 0)
+	cfi_rel_offset (r7, 4)
+	ldr	r2, [sp, #8]
+	ldr	r3, [sp, #12]
+	ldr	r4, [sp, #16]
+	ldr	r7, =SYS_ify(clone)
+	swi	0x0
+	cfi_endproc
+	cmp	r0, #0
+	beq	1f
+	pop	{r4, r7}
+	blt	PLTJMP(C_SYMBOL_NAME(__syscall_error))
+	RETINSTR(, lr)
+
+	cfi_startproc
+PSEUDO_END (__clone)
+
+1:
+	.fnstart
+	.cantunwind
+#ifdef RESET_PID
+	tst	ip, #CLONE_THREAD
+	bne	3f
+	GET_TLS (lr)
+	mov	r1, r0
+	tst	ip, #CLONE_VM
+	ldr	r7, =SYS_ify(getpid)
+	ite	ne
+	movne	r0, #-1
+	swieq	0x0
+	NEGOFF_ADJ_BASE (r1, TID_OFFSET)
+	str	r0, NEGOFF_OFF1 (r1, TID_OFFSET)
+	str	r0, NEGOFF_OFF2 (r1, PID_OFFSET, TID_OFFSET)
+3:
+#endif
+	@ pick the function arg and call address off the stack and execute
+	ldr	r0, [sp, #4]
+	ldr 	ip, [sp], #8
+	BLX (ip)
+
+	@ and we are done, passing the return value through r0
+	b	PLTJMP(HIDDEN_JUMPTARGET(_exit))
+
+	.fnend
+
+weak_alias (__clone, clone)