aosp12/external/strace/fetch_indirect_syscall_args.c

56 lines
2.1 KiB
C

/*
* 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.
*/
#include "defs.h"
/*
* Fetch indirect syscall arguments that are provided as an array.
* Return a pointer to a static array of kernel_ulong_t elements,
* or NULL in case of fetch failure.
*/
kernel_ulong_t *
fetch_indirect_syscall_args(struct tcb *const tcp,
const kernel_ulong_t addr,
const unsigned int n_args)
{
static kernel_ulong_t u_arg[MAX_ARGS];
if (current_wordsize == sizeof(*u_arg)) {
if (umoven(tcp, addr, sizeof(*u_arg) * n_args, u_arg))
return NULL;
} else {
uint32_t narrow_arg[ARRAY_SIZE(u_arg)];
if (umoven(tcp, addr, sizeof(*narrow_arg) * n_args, narrow_arg))
return NULL;
for (unsigned int i = 0; i < n_args; ++i)
u_arg[i] = narrow_arg[i];
}
return u_arg;
}