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/*
* Copyright (c) 1999-2000 Wichert Akkerman <wichert@cistron.nl>
* Copyright (c) 2002-2005 Roland McGrath <roland@redhat.com>
* Copyright (c) 2008 Jan Kratochvil <jan.kratochvil@redhat.com>
* Copyright (c) 2009-2013 Denys Vlasenko <dvlasenk@redhat.com>
* Copyright (c) 2006-2015 Dmitry V. Levin <ldv@altlinux.org>
* Copyright (c) 2014-2018 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"
#include <sched.h>
#include <asm/unistd.h>
#ifndef CSIGNAL
# define CSIGNAL 0x000000ff
#endif
#include "xlat/clone_flags.h"
#include "xlat/setns_types.h"
#include "xlat/unshare_flags.h"
#if defined IA64
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_STACKSIZE (tcp->scno == __NR_clone2 ? 2 : -1)
# define ARG_PTID (tcp->scno == __NR_clone2 ? 3 : 2)
# define ARG_CTID (tcp->scno == __NR_clone2 ? 4 : 3)
# define ARG_TLS (tcp->scno == __NR_clone2 ? 5 : 4)
#elif defined S390 || defined S390X
# define ARG_STACK 0
# define ARG_FLAGS 1
# define ARG_PTID 2
# define ARG_CTID 3
# define ARG_TLS 4
#elif defined X86_64 || defined X32
/* x86 personality processes have the last two arguments flipped. */
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_PTID 2
# define ARG_CTID ((current_personality != 1) ? 3 : 4)
# define ARG_TLS ((current_personality != 1) ? 4 : 3)
#elif defined ALPHA || defined TILE || defined OR1K || defined RISCV
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_PTID 2
# define ARG_CTID 3
# define ARG_TLS 4
#else
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_PTID 2
# define ARG_TLS 3
# define ARG_CTID 4
#endif
static void
print_tls_arg(struct tcb *const tcp, const kernel_ulong_t addr)
{
#ifdef HAVE_STRUCT_USER_DESC
# if SUPPORTED_PERSONALITIES > 1
if (current_personality == 1)
# endif
{
print_user_desc(tcp, tcp->u_arg[ARG_TLS], USER_DESC_BOTH);
}
# if SUPPORTED_PERSONALITIES > 1
else
# endif
#endif /* HAVE_STRUCT_USER_DESC */
{
printaddr(tcp->u_arg[ARG_TLS]);
}
}
SYS_FUNC(clone)
{
if (exiting(tcp)) {
const char *sep = "|";
kernel_ulong_t flags = tcp->u_arg[ARG_FLAGS];
tprints("child_stack=");
printaddr(tcp->u_arg[ARG_STACK]);
tprints(", ");
#ifdef ARG_STACKSIZE
if (ARG_STACKSIZE != -1)
tprintf("stack_size=%#" PRI_klx ", ",
tcp->u_arg[ARG_STACKSIZE]);
#endif
tprints("flags=");
if (!printflags64(clone_flags, flags & ~CSIGNAL, NULL))
sep = "";
if ((flags & CSIGNAL) != 0)
tprintf("%s%s", sep, signame(flags & CSIGNAL));
if ((flags & (CLONE_PARENT_SETTID|CLONE_CHILD_SETTID
|CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
return 0;
if (flags & CLONE_PARENT_SETTID) {
tprints(", parent_tidptr=");
printaddr(tcp->u_arg[ARG_PTID]);
}
if (flags & CLONE_SETTLS) {
tprints(", tls=");
print_tls_arg(tcp, tcp->u_arg[ARG_TLS]);
}
if (flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) {
tprints(", child_tidptr=");
printaddr(tcp->u_arg[ARG_CTID]);
}
}
/* TODO on syscall entry:
* We can clear CLONE_PTRACE here since it is an ancient hack
* to allow us to catch children, and we use another hack for that.
* But CLONE_PTRACE can conceivably be used by malicious programs
* to subvert us. By clearing this bit, we can defend against it:
* in untraced execution, CLONE_PTRACE should have no effect.
*
* We can also clear CLONE_UNTRACED, since it allows to start
* children outside of our control. At the moment
* I'm trying to figure out whether there is a *legitimate*
* use of this flag which we should respect.
*/
return 0;
}
SYS_FUNC(setns)
{
printfd(tcp, tcp->u_arg[0]);
tprints(", ");
printxval(setns_types, tcp->u_arg[1], "CLONE_NEW???");
return RVAL_DECODED;
}
SYS_FUNC(unshare)
{
printflags64(unshare_flags, tcp->u_arg[0], "CLONE_???");
return RVAL_DECODED;
}
SYS_FUNC(fork)
{
return RVAL_DECODED;
}
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