linux/arm/raw_syscall.h

/*
 * Raw syscalls.
 *
 * Copyright (c) 2018 The strace developers.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#ifndef STRACE_RAW_SYSCALL_H
#define STRACE_RAW_SYSCALL_H

# include "kernel_types.h"

static inline kernel_ulong_t
raw_syscall_0(const kernel_ulong_t nr, kernel_ulong_t *err)
{
	*err = 0;

#ifdef __thumb__ /* && FRAME_POINTERS_ENABLED */

	register kernel_ulong_t rt;
	register kernel_ulong_t r0 __asm__("r0");
	__asm__ __volatile__("mov %1,r7; mov r7,%2; swi 0x0; mov r7,%1"
			     : "=r"(r0), "=&r"(rt)
			     : "r"(nr)
			     : "memory");

#else

	register kernel_ulong_t r7 __asm__("r7") = nr;
	register kernel_ulong_t r0 __asm__("r0");
	__asm__ __volatile__("swi 0x0"
			     : "=r"(r0)
			     : "r"(r7)
			     : "memory");

#endif

	return r0;
}
# define raw_syscall_0 raw_syscall_0

#endif /* !STRACE_RAW_SYSCALL_H */