1  /*
       2   * Copyright (c) 2018-2021 The strace developers.
       3   * All rights reserved.
       4   *
       5   * SPDX-License-Identifier: LGPL-2.1-or-later
       6   */
       7  
       8  #include "defs.h"
       9  
      10  /*
      11   * Fetch indirect syscall arguments that are provided as an array.
      12   * Return a pointer to a static array of kernel_ulong_t elements,
      13   * or NULL in case of fetch failure.
      14   */
      15  kernel_ulong_t *
      16  fetch_indirect_syscall_args(struct tcb *const tcp,
      17  			    const kernel_ulong_t addr,
      18  			    const unsigned int n_args)
      19  {
      20  	static kernel_ulong_t u_arg[MAX_ARGS];
      21  
      22  	if (current_wordsize == sizeof(*u_arg)) {
      23  		if (umoven(tcp, addr, sizeof(*u_arg) * n_args, u_arg))
      24  			return NULL;
      25  	} else {
      26  		uint32_t narrow_arg[ARRAY_SIZE(u_arg)];
      27  
      28  		if (umoven(tcp, addr, sizeof(*narrow_arg) * n_args, narrow_arg))
      29  			return NULL;
      30  		for (unsigned int i = 0; i < n_args; ++i)
      31  			u_arg[i] = narrow_arg[i];
      32  	}
      33  
      34  	return u_arg;
      35  }