1  /*
       2   * Copyright (c) 2015-2021 The strace developers.
       3   * All rights reserved.
       4   *
       5   * SPDX-License-Identifier: LGPL-2.1-or-later
       6   */
       7  
       8  /* Return -1 on error or 1 on success (never 0!). */
       9  static int
      10  arch_get_syscall_args(struct tcb *tcp)
      11  {
      12  	if (x86_io.iov_len != sizeof(i386_regs)) {
      13  		/* x86-64 or x32 ABI */
      14  		if (tcp_sysent(tcp)->sys_flags & COMPAT_SYSCALL_TYPES) {
      15  			/*
      16  			 * X32 compat syscall: zero-extend from 32 bits.
      17  			 * Use truncate_klong_to_current_wordsize(tcp->u_arg[N])
      18  			 * in syscall handlers
      19  			 * if you need to use *sign-extended* parameter.
      20  			 */
      21  			tcp->u_arg[0] = (uint32_t) x86_64_regs.rdi;
      22  			tcp->u_arg[1] = (uint32_t) x86_64_regs.rsi;
      23  			tcp->u_arg[2] = (uint32_t) x86_64_regs.rdx;
      24  			tcp->u_arg[3] = (uint32_t) x86_64_regs.r10;
      25  			tcp->u_arg[4] = (uint32_t) x86_64_regs.r8;
      26  			tcp->u_arg[5] = (uint32_t) x86_64_regs.r9;
      27  		} else {
      28  			tcp->u_arg[0] = x86_64_regs.rdi;
      29  			tcp->u_arg[1] = x86_64_regs.rsi;
      30  			tcp->u_arg[2] = x86_64_regs.rdx;
      31  			tcp->u_arg[3] = x86_64_regs.r10;
      32  			tcp->u_arg[4] = x86_64_regs.r8;
      33  			tcp->u_arg[5] = x86_64_regs.r9;
      34  		}
      35  	} else {
      36  		/*
      37  		 * i386 ABI: zero-extend from 32 bits.
      38  		 * Use truncate_klong_to_current_wordsize(tcp->u_arg[N])
      39  		 * in syscall handlers
      40  		 * if you need to use *sign-extended* parameter.
      41  		 */
      42  		tcp->u_arg[0] = (uint32_t) i386_regs.ebx;
      43  		tcp->u_arg[1] = (uint32_t) i386_regs.ecx;
      44  		tcp->u_arg[2] = (uint32_t) i386_regs.edx;
      45  		tcp->u_arg[3] = (uint32_t) i386_regs.esi;
      46  		tcp->u_arg[4] = (uint32_t) i386_regs.edi;
      47  		tcp->u_arg[5] = (uint32_t) i386_regs.ebp;
      48  	}
      49  	return 1;
      50  }