qemu/bsd-user/bsd-mem.h
Michael Tokarev 9bfba08a1f bsd-user: spelling fixes: necesary, agrument, undocummented
Fixes: a99d740347 "bsd-user: Implement do_obreak function"
Fixes: 8632729060 "bsd-user: Implement freebsd_exec_common, used in implementing execve/fexecve."
Fixes: bf14f13d8b "bsd-user: Implement stat related syscalls"
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2023-11-15 11:09:17 +03:00

453 lines
12 KiB
C

/*
* memory management system call shims and definitions
*
* Copyright (c) 2013-15 Stacey D. Son
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#ifndef BSD_USER_BSD_MEM_H
#define BSD_USER_BSD_MEM_H
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/mman.h>
#include <sys/shm.h>
#include <fcntl.h>
#include "qemu-bsd.h"
extern struct bsd_shm_regions bsd_shm_regions[];
extern abi_ulong target_brk;
extern abi_ulong initial_target_brk;
/* mmap(2) */
static inline abi_long do_bsd_mmap(void *cpu_env, abi_long arg1, abi_long arg2,
abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6, abi_long arg7,
abi_long arg8)
{
if (regpairs_aligned(cpu_env) != 0) {
arg6 = arg7;
arg7 = arg8;
}
return get_errno(target_mmap(arg1, arg2, arg3,
target_to_host_bitmask(arg4, mmap_flags_tbl),
arg5, target_arg64(arg6, arg7)));
}
/* munmap(2) */
static inline abi_long do_bsd_munmap(abi_long arg1, abi_long arg2)
{
return get_errno(target_munmap(arg1, arg2));
}
/* mprotect(2) */
static inline abi_long do_bsd_mprotect(abi_long arg1, abi_long arg2,
abi_long arg3)
{
return get_errno(target_mprotect(arg1, arg2, arg3));
}
/* msync(2) */
static inline abi_long do_bsd_msync(abi_long addr, abi_long len, abi_long flags)
{
if (!guest_range_valid_untagged(addr, len)) {
/* It seems odd, but POSIX wants this to be ENOMEM */
return -TARGET_ENOMEM;
}
return get_errno(msync(g2h_untagged(addr), len, flags));
}
/* mlock(2) */
static inline abi_long do_bsd_mlock(abi_long arg1, abi_long arg2)
{
if (!guest_range_valid_untagged(arg1, arg2)) {
return -TARGET_EINVAL;
}
return get_errno(mlock(g2h_untagged(arg1), arg2));
}
/* munlock(2) */
static inline abi_long do_bsd_munlock(abi_long arg1, abi_long arg2)
{
if (!guest_range_valid_untagged(arg1, arg2)) {
return -TARGET_EINVAL;
}
return get_errno(munlock(g2h_untagged(arg1), arg2));
}
/* mlockall(2) */
static inline abi_long do_bsd_mlockall(abi_long arg1)
{
return get_errno(mlockall(arg1));
}
/* munlockall(2) */
static inline abi_long do_bsd_munlockall(void)
{
return get_errno(munlockall());
}
/* madvise(2) */
static inline abi_long do_bsd_madvise(abi_long arg1, abi_long arg2,
abi_long arg3)
{
abi_ulong len;
int ret = 0;
abi_long start = arg1;
abi_long len_in = arg2;
abi_long advice = arg3;
if (start & ~TARGET_PAGE_MASK) {
return -TARGET_EINVAL;
}
if (len_in == 0) {
return 0;
}
len = TARGET_PAGE_ALIGN(len_in);
if (len == 0 || !guest_range_valid_untagged(start, len)) {
return -TARGET_EINVAL;
}
/*
* Most advice values are hints, so ignoring and returning success is ok.
*
* However, some advice values such as MADV_DONTNEED, are not hints and
* need to be emulated.
*
* A straight passthrough for those may not be safe because qemu sometimes
* turns private file-backed mappings into anonymous mappings.
* If all guest pages have PAGE_PASSTHROUGH set, mappings have the
* same semantics for the host as for the guest.
*
* MADV_DONTNEED is passed through, if possible.
* If passthrough isn't possible, we nevertheless (wrongly!) return
* success, which is broken but some userspace programs fail to work
* otherwise. Completely implementing such emulation is quite complicated
* though.
*/
mmap_lock();
switch (advice) {
case MADV_DONTNEED:
if (page_check_range(start, len, PAGE_PASSTHROUGH)) {
ret = get_errno(madvise(g2h_untagged(start), len, advice));
if (ret == 0) {
page_reset_target_data(start, start + len - 1);
}
}
}
mmap_unlock();
return ret;
}
/* minherit(2) */
static inline abi_long do_bsd_minherit(abi_long addr, abi_long len,
abi_long inherit)
{
return get_errno(minherit(g2h_untagged(addr), len, inherit));
}
/* mincore(2) */
static inline abi_long do_bsd_mincore(abi_ulong target_addr, abi_ulong len,
abi_ulong target_vec)
{
abi_long ret;
void *p;
abi_ulong vec_len = DIV_ROUND_UP(len, TARGET_PAGE_SIZE);
if (!guest_range_valid_untagged(target_addr, len)
|| !page_check_range(target_addr, len, PAGE_VALID)) {
return -TARGET_EFAULT;
}
p = lock_user(VERIFY_WRITE, target_vec, vec_len, 0);
if (p == NULL) {
return -TARGET_EFAULT;
}
ret = get_errno(mincore(g2h_untagged(target_addr), len, p));
unlock_user(p, target_vec, vec_len);
return ret;
}
/* do_brk() must return target values and target errnos. */
static inline abi_long do_obreak(abi_ulong brk_val)
{
abi_long mapped_addr;
abi_ulong new_brk;
abi_ulong old_brk;
/* brk pointers are always untagged */
/* do not allow to shrink below initial brk value */
if (brk_val < initial_target_brk) {
return target_brk;
}
new_brk = TARGET_PAGE_ALIGN(brk_val);
old_brk = TARGET_PAGE_ALIGN(target_brk);
/* new and old target_brk might be on the same page */
if (new_brk == old_brk) {
target_brk = brk_val;
return target_brk;
}
/* Release heap if necessary */
if (new_brk < old_brk) {
target_munmap(new_brk, old_brk - new_brk);
target_brk = brk_val;
return target_brk;
}
mapped_addr = target_mmap(old_brk, new_brk - old_brk,
PROT_READ | PROT_WRITE,
MAP_FIXED | MAP_EXCL | MAP_ANON | MAP_PRIVATE,
-1, 0);
if (mapped_addr == old_brk) {
target_brk = brk_val;
return target_brk;
}
/* For everything else, return the previous break. */
return target_brk;
}
/* shm_open(2) */
static inline abi_long do_bsd_shm_open(abi_ulong arg1, abi_long arg2,
abi_long arg3)
{
int ret;
void *p;
if (arg1 == (uintptr_t)SHM_ANON) {
p = SHM_ANON;
} else {
p = lock_user_string(arg1);
if (p == NULL) {
return -TARGET_EFAULT;
}
}
ret = get_errno(shm_open(p, target_to_host_bitmask(arg2, fcntl_flags_tbl),
arg3));
if (p != SHM_ANON) {
unlock_user(p, arg1, 0);
}
return ret;
}
/* shm_unlink(2) */
static inline abi_long do_bsd_shm_unlink(abi_ulong arg1)
{
int ret;
void *p;
p = lock_user_string(arg1);
if (p == NULL) {
return -TARGET_EFAULT;
}
ret = get_errno(shm_unlink(p)); /* XXX path(p)? */
unlock_user(p, arg1, 0);
return ret;
}
/* shmget(2) */
static inline abi_long do_bsd_shmget(abi_long arg1, abi_ulong arg2,
abi_long arg3)
{
return get_errno(shmget(arg1, arg2, arg3));
}
/* shmctl(2) */
static inline abi_long do_bsd_shmctl(abi_long shmid, abi_long cmd,
abi_ulong buff)
{
struct shmid_ds dsarg;
abi_long ret = -TARGET_EINVAL;
cmd &= 0xff;
switch (cmd) {
case IPC_STAT:
if (target_to_host_shmid_ds(&dsarg, buff)) {
return -TARGET_EFAULT;
}
ret = get_errno(shmctl(shmid, cmd, &dsarg));
if (host_to_target_shmid_ds(buff, &dsarg)) {
return -TARGET_EFAULT;
}
break;
case IPC_SET:
if (target_to_host_shmid_ds(&dsarg, buff)) {
return -TARGET_EFAULT;
}
ret = get_errno(shmctl(shmid, cmd, &dsarg));
break;
case IPC_RMID:
ret = get_errno(shmctl(shmid, cmd, NULL));
break;
default:
ret = -TARGET_EINVAL;
break;
}
return ret;
}
/* shmat(2) */
static inline abi_long do_bsd_shmat(int shmid, abi_ulong shmaddr, int shmflg)
{
abi_ulong raddr;
abi_long ret;
struct shmid_ds shm_info;
/* Find out the length of the shared memory segment. */
ret = get_errno(shmctl(shmid, IPC_STAT, &shm_info));
if (is_error(ret)) {
/* Can't get the length */
return ret;
}
if (!guest_range_valid_untagged(shmaddr, shm_info.shm_segsz)) {
return -TARGET_EINVAL;
}
WITH_MMAP_LOCK_GUARD() {
void *host_raddr;
if (shmaddr) {
host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
} else {
abi_ulong mmap_start;
mmap_start = mmap_find_vma(0, shm_info.shm_segsz);
if (mmap_start == -1) {
return -TARGET_ENOMEM;
}
host_raddr = shmat(shmid, g2h_untagged(mmap_start),
shmflg | SHM_REMAP);
}
if (host_raddr == (void *)-1) {
return get_errno(-1);
}
raddr = h2g(host_raddr);
page_set_flags(raddr, raddr + shm_info.shm_segsz - 1,
PAGE_VALID | PAGE_RESET | PAGE_READ |
(shmflg & SHM_RDONLY ? 0 : PAGE_WRITE));
for (int i = 0; i < N_BSD_SHM_REGIONS; i++) {
if (bsd_shm_regions[i].start == 0) {
bsd_shm_regions[i].start = raddr;
bsd_shm_regions[i].size = shm_info.shm_segsz;
break;
}
}
}
return raddr;
}
/* shmdt(2) */
static inline abi_long do_bsd_shmdt(abi_ulong shmaddr)
{
abi_long ret;
WITH_MMAP_LOCK_GUARD() {
int i;
for (i = 0; i < N_BSD_SHM_REGIONS; ++i) {
if (bsd_shm_regions[i].start == shmaddr) {
break;
}
}
if (i == N_BSD_SHM_REGIONS) {
return -TARGET_EINVAL;
}
ret = get_errno(shmdt(g2h_untagged(shmaddr)));
if (ret == 0) {
abi_ulong size = bsd_shm_regions[i].size;
bsd_shm_regions[i].start = 0;
page_set_flags(shmaddr, shmaddr + size - 1, 0);
mmap_reserve(shmaddr, size);
}
}
return ret;
}
static inline abi_long do_bsd_vadvise(void)
{
/* See sys_ovadvise() in vm_unix.c */
return -TARGET_EINVAL;
}
static inline abi_long do_bsd_sbrk(void)
{
/* see sys_sbrk() in vm_mmap.c */
return -TARGET_EOPNOTSUPP;
}
static inline abi_long do_bsd_sstk(void)
{
/* see sys_sstk() in vm_mmap.c */
return -TARGET_EOPNOTSUPP;
}
#endif /* BSD_USER_BSD_MEM_H */