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/* $NetBSD: linux_exec_machdep.c,v 1.24 2020/09/05 16:30:10 riastradh Exp $ */
/*-
* Copyright (c) 2005 Emmanuel Dreyfus, 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Emmanuel Dreyfus
* 4. 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 THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS
* 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_exec_machdep.c,v 1.24 2020/09/05 16:30:10 riastradh Exp $");
#define ELFSIZE 64
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/resource.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/kmem.h>
#include <sys/exec_elf.h>
#include <sys/vnode.h>
#include <sys/lwp.h>
#include <sys/exec.h>
#include <sys/stat.h>
#include <sys/kauth.h>
#include <sys/cprng.h>
#include <sys/cpu.h>
#include <machine/vmparam.h>
#include <sys/syscallargs.h>
#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_machdep.h>
#include <compat/linux/common/linux_util.h>
#include <compat/linux/common/linux_ioctl.h>
#include <compat/linux/common/linux_hdio.h>
#include <compat/linux/common/linux_exec.h>
#include <compat/linux/common/linux_errno.h>
#include <compat/linux/common/linux_prctl.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>
#include <compat/linux/linux_syscallargs.h>
int
linux_exec_setup_stack(struct lwp *l, struct exec_package *epp)
{
u_long max_stack_size;
u_long access_linear_min, access_size;
u_long noaccess_linear_min, noaccess_size;
#ifndef USRSTACK32
#define USRSTACK32 (0x00000000ffffffffL & ~PGOFSET)
#endif
if (epp->ep_flags & EXEC_32) {
epp->ep_minsaddr = USRSTACK32;
max_stack_size = MAXSSIZ;
if (epp->ep_minsaddr > LINUX_USRSTACK32)
epp->ep_minsaddr = LINUX_USRSTACK32;
} else {
epp->ep_minsaddr = USRSTACK;
max_stack_size = MAXSSIZ;
if (epp->ep_minsaddr > LINUX_USRSTACK)
epp->ep_minsaddr = LINUX_USRSTACK;
}
epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr,
max_stack_size);
epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur;
/*
* set up commands for stack. note that this takes *two*, one to
* map the part of the stack which we can access, and one to map
* the part which we can't.
*
* arguably, it could be made into one, but that would require the
* addition of another mapping proc, which is unnecessary
*/
access_size = epp->ep_ssize;
access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size);
noaccess_size = max_stack_size - access_size;
noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr,
access_size), noaccess_size);
if (noaccess_size > 0) {
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size,
noaccess_linear_min, NULLVP, 0, VM_PROT_NONE, VMCMD_STACK);
}
KASSERT(access_size > 0);
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, access_size,
access_linear_min, NULLVP, 0, VM_PROT_READ | VM_PROT_WRITE,
VMCMD_STACK);
return 0;
}
int
ELFNAME2(linux,copyargs)(struct lwp *l, struct exec_package *pack,
struct ps_strings *arginfo, char **stackp, void *argp)
{
struct linux_extra_stack_data64 *esdp, esd;
struct elf_args *ap;
struct vattr *vap;
Elf_Ehdr *eh;
Elf_Phdr *ph;
u_long phsize;
Elf_Addr phdr = 0;
int error;
int i;
if ((error = copyargs(l, pack, arginfo, stackp, argp)) != 0)
return error;
/*
* Push extra arguments on the stack needed by dynamically
* linked binaries and static binaries as well.
*/
memset(&esd, 0, sizeof(esd));
esdp = (struct linux_extra_stack_data64 *)(*stackp);
ap = (struct elf_args *)pack->ep_emul_arg;
vap = pack->ep_vap;
eh = (Elf_Ehdr *)pack->ep_hdr;
/*
* We forgot this, so we need to reload it now. XXX keep track of it?
*/
if (ap == NULL) {
phsize = eh->e_phnum * sizeof(Elf_Phdr);
ph = (Elf_Phdr *)kmem_alloc(phsize, KM_SLEEP);
error = exec_read(l, pack->ep_vp, eh->e_phoff, ph, phsize, 0);
if (error != 0) {
for (i = 0; i < eh->e_phnum; i++) {
if (ph[i].p_type == PT_PHDR) {
phdr = ph[i].p_vaddr;
break;
}
}
}
kmem_free(ph, phsize);
}
/*
* The exec_package doesn't have a proc pointer and it's not
* exactly trivial to add one since the credentials are
* changing. XXX Linux uses curlwp's credentials.
* Why can't we use them too?
*/
i = 0;
esd.ai[i].a_type = LINUX_AT_HWCAP;
esd.ai[i++].a_v = rcr4();
esd.ai[i].a_type = AT_PAGESZ;
esd.ai[i++].a_v = PAGE_SIZE;
esd.ai[i].a_type = LINUX_AT_CLKTCK;
esd.ai[i++].a_v = hz;
esd.ai[i].a_type = AT_PHDR;
esd.ai[i++].a_v = (ap ? ap->arg_phaddr: phdr);
esd.ai[i].a_type = AT_PHENT;
esd.ai[i++].a_v = (ap ? ap->arg_phentsize : eh->e_phentsize);
esd.ai[i].a_type = AT_PHNUM;
esd.ai[i++].a_v = (ap ? ap->arg_phnum : eh->e_phnum);
esd.ai[i].a_type = AT_BASE;
esd.ai[i++].a_v = (ap ? ap->arg_interp : 0);
esd.ai[i].a_type = AT_FLAGS;
esd.ai[i++].a_v = 0;
esd.ai[i].a_type = AT_ENTRY;
esd.ai[i++].a_v = (ap ? ap->arg_entry : eh->e_entry);
esd.ai[i].a_type = LINUX_AT_EGID;
esd.ai[i++].a_v = ((vap->va_mode & S_ISGID) ?
vap->va_gid : kauth_cred_getegid(l->l_cred));
esd.ai[i].a_type = LINUX_AT_GID;
esd.ai[i++].a_v = kauth_cred_getgid(l->l_cred);
esd.ai[i].a_type = LINUX_AT_EUID;
esd.ai[i++].a_v = ((vap->va_mode & S_ISUID) ?
vap->va_uid : kauth_cred_geteuid(l->l_cred));
esd.ai[i].a_type = LINUX_AT_UID;
esd.ai[i++].a_v = kauth_cred_getuid(l->l_cred);
esd.ai[i].a_type = LINUX_AT_SECURE;
esd.ai[i++].a_v = 0;
esd.ai[i].a_type = LINUX_AT_PLATFORM;
esd.ai[i++].a_v = (Elf_Addr)&esdp->hw_platform[0];
esd.ai[i].a_type = LINUX_AT_RANDOM;
esd.ai[i++].a_v = (Elf_Addr)&esdp->randbytes[0];
esd.randbytes[0] = cprng_strong32();
esd.randbytes[1] = cprng_strong32();
esd.randbytes[2] = cprng_strong32();
esd.randbytes[3] = cprng_strong32();
esd.ai[i].a_type = AT_NULL;
esd.ai[i++].a_v = 0;
KASSERT(i == LINUX_ELF_AUX_ENTRIES);
strcpy(esd.hw_platform, LINUX_PLATFORM);
exec_free_emul_arg(pack);
/*
* Copy out the ELF auxiliary table and hw platform name
*/
if ((error = copyout(&esd, esdp, sizeof(esd))) != 0)
return error;
*stackp += sizeof(esd);
return 0;
}
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