Implement mmap64 for arm

1 files changed, 79 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/arm/mmap64.S b/libc/sysdeps/linux/arm/mmap64.S
new file mode 100644
index 000000000..0da4afbb0
--- /dev/null
+++ b/libc/sysdeps/linux/arm/mmap64.S
@@ -0,0 +1,79 @@
+/* Copyright (C) 2000 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#define _ERRNO_H	1
+#include <features.h>
+#include <bits/errno.h>
+#include <sys/syscall.h>
+
+#if defined __UCLIBC_HAS_LFS__ && defined __NR_mmap2
+
+
+	/* The mmap2 system call takes six arguments, all in registers.  */
+	.text
+	.global mmap64;
+	.type mmap64,%function
+	.align 4;
+
+mmap64:
+	stmfd	sp!, {r4, r5, lr}
+	ldr	r5, [sp, $16]
+	ldr	r4, [sp, $12]
+	movs	ip, r5, lsl $20		@ check that offset is page-aligned
+	bne	.Linval
+	ldr	ip, [sp, $20]
+	mov	r5, r5, lsr $12
+	orr	r5, r5, ip, lsl $20	@ compose page offset
+	movs	ip, ip, lsr $12
+	bne	.Linval			@ check for overflow
+	mov	ip, r0
+	swi	__NR_mmap2
+	cmn	r0, $4096
+	ldmccfd	sp!, {r4, r5, pc}
+	cmn	r0, $ENOSYS
+	ldmnefd	sp!, {r4, r5, lr}
+	bne	__syscall_error (PLT)
+	/* The current kernel does not support mmap2.  Fall back to plain
+	   mmap if the offset is small enough.  */
+	ldr	r5, [sp, $20]
+	mov	r0, ip			@ first arg was clobbered
+	teq	r5, $0
+	ldmeqfd	sp!, {r4, r5, lr}
+	beq	mmap (PLT)
+.Linval:
+	mov	r0, $-EINVAL
+	ldmfd	sp!, {r4, r5, lr}
+	b	__syscall_error (PLT)
+
+__syscall_error:
+	/* Looks like the syscall choked -- set errno */
+	ldr  r3, .L4
+	/* Calculate the - of the syscall result, in case we need it */
+	rsb  r2, r0, $0
+
+	/* errno = -result */
+	str  r2, [r9,r3]
+
+	/* return -1 */
+	mvn  r0, $0
+	mov  pc, lr
+.size mmap64,.-mmap64;
+
+.L4:  .word errno
+
+#endif