mirror of
https://gitlab.com/qemu-project/qemu.git
synced 2024-10-12 13:21:55 +03:00
5b73b248a1
In particular, if an image has a large bss, we can hit EOF before reading all bytes of the mapping. Mirror the similar change to linux-user. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-Id: <20240820050848.165253-3-richard.henderson@linaro.org>
793 lines
24 KiB
C
793 lines
24 KiB
C
/*
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* mmap support for qemu
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*
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* Copyright (c) 2003 - 2008 Fabrice Bellard
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "qemu/osdep.h"
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#include "exec/page-protection.h"
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#include "qemu.h"
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static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER;
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static __thread int mmap_lock_count;
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void mmap_lock(void)
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{
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if (mmap_lock_count++ == 0) {
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pthread_mutex_lock(&mmap_mutex);
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}
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}
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void mmap_unlock(void)
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{
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assert(mmap_lock_count > 0);
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if (--mmap_lock_count == 0) {
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pthread_mutex_unlock(&mmap_mutex);
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}
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}
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bool have_mmap_lock(void)
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{
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return mmap_lock_count > 0 ? true : false;
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}
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/* Grab lock to make sure things are in a consistent state after fork(). */
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void mmap_fork_start(void)
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{
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if (mmap_lock_count)
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abort();
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pthread_mutex_lock(&mmap_mutex);
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}
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void mmap_fork_end(int child)
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{
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if (child)
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pthread_mutex_init(&mmap_mutex, NULL);
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else
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pthread_mutex_unlock(&mmap_mutex);
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}
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/* NOTE: all the constants are the HOST ones, but addresses are target. */
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int target_mprotect(abi_ulong start, abi_ulong len, int prot)
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{
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abi_ulong end, host_start, host_end, addr;
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int prot1, ret;
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qemu_log_mask(CPU_LOG_PAGE, "mprotect: start=0x" TARGET_ABI_FMT_lx
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" len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c\n", start, len,
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prot & PROT_READ ? 'r' : '-',
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prot & PROT_WRITE ? 'w' : '-',
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prot & PROT_EXEC ? 'x' : '-');
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if ((start & ~TARGET_PAGE_MASK) != 0)
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return -EINVAL;
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len = TARGET_PAGE_ALIGN(len);
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end = start + len;
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if (end < start)
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return -EINVAL;
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prot &= PROT_READ | PROT_WRITE | PROT_EXEC;
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if (len == 0)
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return 0;
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mmap_lock();
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host_start = start & qemu_host_page_mask;
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host_end = HOST_PAGE_ALIGN(end);
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if (start > host_start) {
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/* handle host page containing start */
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prot1 = prot;
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for (addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) {
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prot1 |= page_get_flags(addr);
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}
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if (host_end == host_start + qemu_host_page_size) {
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for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
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prot1 |= page_get_flags(addr);
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}
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end = host_end;
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}
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ret = mprotect(g2h_untagged(host_start),
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qemu_host_page_size, prot1 & PAGE_RWX);
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if (ret != 0)
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goto error;
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host_start += qemu_host_page_size;
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}
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if (end < host_end) {
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prot1 = prot;
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for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
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prot1 |= page_get_flags(addr);
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}
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ret = mprotect(g2h_untagged(host_end - qemu_host_page_size),
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qemu_host_page_size, prot1 & PAGE_RWX);
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if (ret != 0)
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goto error;
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host_end -= qemu_host_page_size;
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}
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/* handle the pages in the middle */
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if (host_start < host_end) {
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ret = mprotect(g2h_untagged(host_start), host_end - host_start, prot);
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if (ret != 0)
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goto error;
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}
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page_set_flags(start, start + len - 1, prot | PAGE_VALID);
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mmap_unlock();
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return 0;
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error:
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mmap_unlock();
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return ret;
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}
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/*
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* Perform a pread on behalf of target_mmap. We can reach EOF, we can be
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* interrupted by signals, and in general there's no good error return path.
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* If @zero, zero the rest of the block at EOF.
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* Return true on success.
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*/
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static bool mmap_pread(int fd, void *p, size_t len, off_t offset, bool zero)
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{
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while (1) {
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ssize_t r = pread(fd, p, len, offset);
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if (likely(r == len)) {
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/* Complete */
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return true;
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}
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if (r == 0) {
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/* EOF */
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if (zero) {
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memset(p, 0, len);
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}
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return true;
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}
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if (r > 0) {
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/* Short read */
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p += r;
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len -= r;
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offset += r;
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} else if (errno != EINTR) {
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/* Error */
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return false;
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}
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}
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}
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/*
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* map an incomplete host page
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*
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* mmap_frag can be called with a valid fd, if flags doesn't contain one of
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* MAP_ANON, MAP_STACK, MAP_GUARD. If we need to map a page in those cases, we
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* pass fd == -1. However, if flags contains MAP_GUARD then MAP_ANON cannot be
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* added.
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*
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* * If fd is valid (not -1) we want to map the pages with MAP_ANON.
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* * If flags contains MAP_GUARD we don't want to add MAP_ANON because it
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* will be rejected. See kern_mmap's enforcing of constraints for MAP_GUARD
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* in sys/vm/vm_mmap.c.
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* * If flags contains MAP_ANON it doesn't matter if we add it or not.
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* * If flags contains MAP_STACK, mmap adds MAP_ANON when called so doesn't
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* matter if we add it or not either. See enforcing of constraints for
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* MAP_STACK in kern_mmap.
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*
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* Don't add MAP_ANON for the flags that use fd == -1 without specifying the
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* flags directly, with the assumption that future flags that require fd == -1
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* will also not require MAP_ANON.
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*/
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static int mmap_frag(abi_ulong real_start,
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abi_ulong start, abi_ulong end,
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int prot, int flags, int fd, abi_ulong offset)
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{
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abi_ulong real_end, addr;
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void *host_start;
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int prot1, prot_new;
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real_end = real_start + qemu_host_page_size;
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host_start = g2h_untagged(real_start);
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/* get the protection of the target pages outside the mapping */
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prot1 = 0;
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for (addr = real_start; addr < real_end; addr++) {
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if (addr < start || addr >= end)
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prot1 |= page_get_flags(addr);
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}
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if (prot1 == 0) {
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/* no page was there, so we allocate one. See also above. */
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void *p = mmap(host_start, qemu_host_page_size, prot,
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flags | ((fd != -1) ? MAP_ANON : 0), -1, 0);
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if (p == MAP_FAILED)
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return -1;
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prot1 = prot;
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}
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prot1 &= PAGE_RWX;
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prot_new = prot | prot1;
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if (fd != -1) {
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/* msync() won't work here, so we return an error if write is
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possible while it is a shared mapping */
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if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
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(prot & PROT_WRITE))
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return -1;
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/* adjust protection to be able to read */
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if (!(prot1 & PROT_WRITE))
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mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE);
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/* read the corresponding file data */
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if (!mmap_pread(fd, g2h_untagged(start), end - start, offset, true)) {
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return -1;
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}
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/* put final protection */
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if (prot_new != (prot1 | PROT_WRITE))
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mprotect(host_start, qemu_host_page_size, prot_new);
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} else {
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if (prot_new != prot1) {
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mprotect(host_start, qemu_host_page_size, prot_new);
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}
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if (prot_new & PROT_WRITE) {
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memset(g2h_untagged(start), 0, end - start);
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}
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}
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return 0;
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}
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#if HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 64
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# define TASK_UNMAPPED_BASE (1ul << 38)
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#else
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# define TASK_UNMAPPED_BASE 0x40000000
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#endif
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abi_ulong mmap_next_start = TASK_UNMAPPED_BASE;
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/*
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* Subroutine of mmap_find_vma, used when we have pre-allocated a chunk of guest
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* address space.
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*/
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static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
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abi_ulong alignment)
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{
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abi_ulong ret;
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ret = page_find_range_empty(start, reserved_va, size, alignment);
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if (ret == -1 && start > TARGET_PAGE_SIZE) {
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/* Restart at the beginning of the address space. */
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ret = page_find_range_empty(TARGET_PAGE_SIZE, start - 1,
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size, alignment);
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}
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return ret;
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}
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/*
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* Find and reserve a free memory area of size 'size'. The search
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* starts at 'start'.
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* It must be called with mmap_lock() held.
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* Return -1 if error.
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*/
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static abi_ulong mmap_find_vma_aligned(abi_ulong start, abi_ulong size,
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abi_ulong alignment)
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{
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void *ptr, *prev;
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abi_ulong addr;
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int flags;
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int wrapped, repeat;
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/* If 'start' == 0, then a default start address is used. */
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if (start == 0) {
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start = mmap_next_start;
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} else {
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start &= qemu_host_page_mask;
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}
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size = HOST_PAGE_ALIGN(size);
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if (reserved_va) {
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return mmap_find_vma_reserved(start, size,
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(alignment != 0 ? 1 << alignment :
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MAX(qemu_host_page_size, TARGET_PAGE_SIZE)));
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}
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addr = start;
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wrapped = repeat = 0;
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prev = 0;
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flags = MAP_ANON | MAP_PRIVATE;
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if (alignment != 0) {
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flags |= MAP_ALIGNED(alignment);
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}
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for (;; prev = ptr) {
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/*
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* Reserve needed memory area to avoid a race.
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* It should be discarded using:
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* - mmap() with MAP_FIXED flag
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* - mremap() with MREMAP_FIXED flag
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* - shmat() with SHM_REMAP flag
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*/
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ptr = mmap(g2h_untagged(addr), size, PROT_NONE,
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flags, -1, 0);
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/* ENOMEM, if host address space has no memory */
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if (ptr == MAP_FAILED) {
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return (abi_ulong)-1;
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}
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/*
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* Count the number of sequential returns of the same address.
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* This is used to modify the search algorithm below.
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*/
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repeat = (ptr == prev ? repeat + 1 : 0);
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if (h2g_valid(ptr + size - 1)) {
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addr = h2g(ptr);
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if ((addr & ~TARGET_PAGE_MASK) == 0) {
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/* Success. */
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if (start == mmap_next_start && addr >= TASK_UNMAPPED_BASE) {
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mmap_next_start = addr + size;
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}
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return addr;
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}
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/* The address is not properly aligned for the target. */
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switch (repeat) {
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case 0:
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/*
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* Assume the result that the kernel gave us is the
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* first with enough free space, so start again at the
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* next higher target page.
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*/
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addr = TARGET_PAGE_ALIGN(addr);
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break;
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case 1:
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/*
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* Sometimes the kernel decides to perform the allocation
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* at the top end of memory instead.
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*/
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addr &= TARGET_PAGE_MASK;
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break;
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case 2:
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/* Start over at low memory. */
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addr = 0;
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break;
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default:
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/* Fail. This unaligned block must the last. */
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addr = -1;
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break;
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}
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} else {
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/*
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* Since the result the kernel gave didn't fit, start
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* again at low memory. If any repetition, fail.
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*/
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addr = (repeat ? -1 : 0);
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}
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/* Unmap and try again. */
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munmap(ptr, size);
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/* ENOMEM if we checked the whole of the target address space. */
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if (addr == (abi_ulong)-1) {
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return (abi_ulong)-1;
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} else if (addr == 0) {
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if (wrapped) {
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return (abi_ulong)-1;
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}
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wrapped = 1;
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/*
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* Don't actually use 0 when wrapping, instead indicate
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* that we'd truly like an allocation in low memory.
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*/
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addr = TARGET_PAGE_SIZE;
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} else if (wrapped && addr >= start) {
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return (abi_ulong)-1;
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}
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}
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}
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abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
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{
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return mmap_find_vma_aligned(start, size, 0);
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}
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/* NOTE: all the constants are the HOST ones */
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abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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int flags, int fd, off_t offset)
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{
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abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len;
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mmap_lock();
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if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
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qemu_log("mmap: start=0x" TARGET_ABI_FMT_lx
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" len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c flags=",
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start, len,
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prot & PROT_READ ? 'r' : '-',
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prot & PROT_WRITE ? 'w' : '-',
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prot & PROT_EXEC ? 'x' : '-');
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if (flags & MAP_ALIGNMENT_MASK) {
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qemu_log("MAP_ALIGNED(%u) ",
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(flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT);
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}
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if (flags & MAP_GUARD) {
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qemu_log("MAP_GUARD ");
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}
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if (flags & MAP_FIXED) {
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qemu_log("MAP_FIXED ");
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}
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if (flags & MAP_ANON) {
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qemu_log("MAP_ANON ");
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}
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if (flags & MAP_EXCL) {
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qemu_log("MAP_EXCL ");
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}
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if (flags & MAP_PRIVATE) {
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qemu_log("MAP_PRIVATE ");
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}
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if (flags & MAP_SHARED) {
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qemu_log("MAP_SHARED ");
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}
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if (flags & MAP_NOCORE) {
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qemu_log("MAP_NOCORE ");
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}
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if (flags & MAP_STACK) {
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qemu_log("MAP_STACK ");
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}
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qemu_log("fd=%d offset=0x%lx\n", fd, offset);
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}
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if ((flags & MAP_ANON) && fd != -1) {
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errno = EINVAL;
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goto fail;
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}
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if (flags & MAP_STACK) {
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if ((fd != -1) || ((prot & (PROT_READ | PROT_WRITE)) !=
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(PROT_READ | PROT_WRITE))) {
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errno = EINVAL;
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goto fail;
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}
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}
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if ((flags & MAP_GUARD) && (prot != PROT_NONE || fd != -1 ||
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offset != 0 || (flags & (MAP_SHARED | MAP_PRIVATE |
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/* MAP_PREFAULT | */ /* MAP_PREFAULT not in mman.h */
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MAP_PREFAULT_READ | MAP_ANON | MAP_STACK)) != 0)) {
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errno = EINVAL;
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goto fail;
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}
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if (offset & ~TARGET_PAGE_MASK) {
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errno = EINVAL;
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goto fail;
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}
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if (len == 0) {
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errno = EINVAL;
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goto fail;
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}
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/* Check for overflows */
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len = TARGET_PAGE_ALIGN(len);
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if (len == 0) {
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errno = ENOMEM;
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goto fail;
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}
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real_start = start & qemu_host_page_mask;
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host_offset = offset & qemu_host_page_mask;
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/*
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* If the user is asking for the kernel to find a location, do that
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* before we truncate the length for mapping files below.
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*/
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if (!(flags & MAP_FIXED)) {
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host_len = len + offset - host_offset;
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host_len = HOST_PAGE_ALIGN(host_len);
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if ((flags & MAP_ALIGNMENT_MASK) != 0)
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start = mmap_find_vma_aligned(real_start, host_len,
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(flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT);
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else
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start = mmap_find_vma(real_start, host_len);
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if (start == (abi_ulong)-1) {
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errno = ENOMEM;
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goto fail;
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}
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}
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/*
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* When mapping files into a memory area larger than the file, accesses
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* to pages beyond the file size will cause a SIGBUS.
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|
*
|
|
* For example, if mmaping a file of 100 bytes on a host with 4K pages
|
|
* emulating a target with 8K pages, the target expects to be able to
|
|
* access the first 8K. But the host will trap us on any access beyond
|
|
* 4K.
|
|
*
|
|
* When emulating a target with a larger page-size than the hosts, we
|
|
* may need to truncate file maps at EOF and add extra anonymous pages
|
|
* up to the targets page boundary.
|
|
*/
|
|
|
|
if ((qemu_real_host_page_size() < qemu_host_page_size) && fd != -1) {
|
|
struct stat sb;
|
|
|
|
if (fstat(fd, &sb) == -1) {
|
|
goto fail;
|
|
}
|
|
|
|
/* Are we trying to create a map beyond EOF?. */
|
|
if (offset + len > sb.st_size) {
|
|
/*
|
|
* If so, truncate the file map at eof aligned with
|
|
* the hosts real pagesize. Additional anonymous maps
|
|
* will be created beyond EOF.
|
|
*/
|
|
len = REAL_HOST_PAGE_ALIGN(sb.st_size - offset);
|
|
}
|
|
}
|
|
|
|
if (!(flags & MAP_FIXED)) {
|
|
unsigned long host_start;
|
|
void *p;
|
|
|
|
host_len = len + offset - host_offset;
|
|
host_len = HOST_PAGE_ALIGN(host_len);
|
|
|
|
/*
|
|
* Note: we prefer to control the mapping address. It is
|
|
* especially important if qemu_host_page_size >
|
|
* qemu_real_host_page_size
|
|
*/
|
|
p = mmap(g2h_untagged(start), host_len, prot,
|
|
flags | MAP_FIXED | ((fd != -1) ? MAP_ANON : 0), -1, 0);
|
|
if (p == MAP_FAILED)
|
|
goto fail;
|
|
/* update start so that it points to the file position at 'offset' */
|
|
host_start = (unsigned long)p;
|
|
if (fd != -1) {
|
|
p = mmap(g2h_untagged(start), len, prot,
|
|
flags | MAP_FIXED, fd, host_offset);
|
|
if (p == MAP_FAILED) {
|
|
munmap(g2h_untagged(start), host_len);
|
|
goto fail;
|
|
}
|
|
host_start += offset - host_offset;
|
|
}
|
|
start = h2g(host_start);
|
|
} else {
|
|
if (start & ~TARGET_PAGE_MASK) {
|
|
errno = EINVAL;
|
|
goto fail;
|
|
}
|
|
end = start + len;
|
|
real_end = HOST_PAGE_ALIGN(end);
|
|
|
|
/*
|
|
* Test if requested memory area fits target address space
|
|
* It can fail only on 64-bit host with 32-bit target.
|
|
* On any other target/host host mmap() handles this error correctly.
|
|
*/
|
|
if (!guest_range_valid_untagged(start, len)) {
|
|
errno = EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* worst case: we cannot map the file because the offset is not
|
|
* aligned, so we read it
|
|
*/
|
|
if (fd != -1 &&
|
|
(offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
|
|
/*
|
|
* msync() won't work here, so we return an error if write is
|
|
* possible while it is a shared mapping
|
|
*/
|
|
if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
|
|
(prot & PROT_WRITE)) {
|
|
errno = EINVAL;
|
|
goto fail;
|
|
}
|
|
retaddr = target_mmap(start, len, prot | PROT_WRITE,
|
|
MAP_FIXED | MAP_PRIVATE | MAP_ANON,
|
|
-1, 0);
|
|
if (retaddr == -1)
|
|
goto fail;
|
|
if (!mmap_pread(fd, g2h_untagged(start), len, offset, false)) {
|
|
goto fail;
|
|
}
|
|
if (!(prot & PROT_WRITE)) {
|
|
ret = target_mprotect(start, len, prot);
|
|
assert(ret == 0);
|
|
}
|
|
goto the_end;
|
|
}
|
|
|
|
/* Reject the mapping if any page within the range is mapped */
|
|
if ((flags & MAP_EXCL) && !page_check_range_empty(start, end - 1)) {
|
|
errno = EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
/* handle the start of the mapping */
|
|
if (start > real_start) {
|
|
if (real_end == real_start + qemu_host_page_size) {
|
|
/* one single host page */
|
|
ret = mmap_frag(real_start, start, end,
|
|
prot, flags, fd, offset);
|
|
if (ret == -1)
|
|
goto fail;
|
|
goto the_end1;
|
|
}
|
|
ret = mmap_frag(real_start, start, real_start + qemu_host_page_size,
|
|
prot, flags, fd, offset);
|
|
if (ret == -1)
|
|
goto fail;
|
|
real_start += qemu_host_page_size;
|
|
}
|
|
/* handle the end of the mapping */
|
|
if (end < real_end) {
|
|
ret = mmap_frag(real_end - qemu_host_page_size,
|
|
real_end - qemu_host_page_size, end,
|
|
prot, flags, fd,
|
|
offset + real_end - qemu_host_page_size - start);
|
|
if (ret == -1)
|
|
goto fail;
|
|
real_end -= qemu_host_page_size;
|
|
}
|
|
|
|
/* map the middle (easier) */
|
|
if (real_start < real_end) {
|
|
void *p;
|
|
unsigned long offset1;
|
|
if (flags & MAP_ANON)
|
|
offset1 = 0;
|
|
else
|
|
offset1 = offset + real_start - start;
|
|
p = mmap(g2h_untagged(real_start), real_end - real_start,
|
|
prot, flags, fd, offset1);
|
|
if (p == MAP_FAILED)
|
|
goto fail;
|
|
}
|
|
}
|
|
the_end1:
|
|
page_set_flags(start, start + len - 1, prot | PAGE_VALID);
|
|
the_end:
|
|
#ifdef DEBUG_MMAP
|
|
printf("ret=0x" TARGET_ABI_FMT_lx "\n", start);
|
|
page_dump(stdout);
|
|
printf("\n");
|
|
#endif
|
|
mmap_unlock();
|
|
return start;
|
|
fail:
|
|
mmap_unlock();
|
|
return -1;
|
|
}
|
|
|
|
void mmap_reserve(abi_ulong start, abi_ulong size)
|
|
{
|
|
abi_ulong real_start;
|
|
abi_ulong real_end;
|
|
abi_ulong addr;
|
|
abi_ulong end;
|
|
int prot;
|
|
|
|
real_start = start & qemu_host_page_mask;
|
|
real_end = HOST_PAGE_ALIGN(start + size);
|
|
end = start + size;
|
|
if (start > real_start) {
|
|
/* handle host page containing start */
|
|
prot = 0;
|
|
for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(addr);
|
|
}
|
|
if (real_end == real_start + qemu_host_page_size) {
|
|
for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(addr);
|
|
}
|
|
end = real_end;
|
|
}
|
|
if (prot != 0) {
|
|
real_start += qemu_host_page_size;
|
|
}
|
|
}
|
|
if (end < real_end) {
|
|
prot = 0;
|
|
for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(addr);
|
|
}
|
|
if (prot != 0) {
|
|
real_end -= qemu_host_page_size;
|
|
}
|
|
}
|
|
if (real_start != real_end) {
|
|
mmap(g2h_untagged(real_start), real_end - real_start, PROT_NONE,
|
|
MAP_FIXED | MAP_ANON | MAP_PRIVATE, -1, 0);
|
|
}
|
|
}
|
|
|
|
int target_munmap(abi_ulong start, abi_ulong len)
|
|
{
|
|
abi_ulong end, real_start, real_end, addr;
|
|
int prot, ret;
|
|
|
|
#ifdef DEBUG_MMAP
|
|
printf("munmap: start=0x" TARGET_ABI_FMT_lx " len=0x"
|
|
TARGET_ABI_FMT_lx "\n",
|
|
start, len);
|
|
#endif
|
|
if (start & ~TARGET_PAGE_MASK)
|
|
return -EINVAL;
|
|
len = TARGET_PAGE_ALIGN(len);
|
|
if (len == 0)
|
|
return -EINVAL;
|
|
mmap_lock();
|
|
end = start + len;
|
|
real_start = start & qemu_host_page_mask;
|
|
real_end = HOST_PAGE_ALIGN(end);
|
|
|
|
if (start > real_start) {
|
|
/* handle host page containing start */
|
|
prot = 0;
|
|
for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(addr);
|
|
}
|
|
if (real_end == real_start + qemu_host_page_size) {
|
|
for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(addr);
|
|
}
|
|
end = real_end;
|
|
}
|
|
if (prot != 0)
|
|
real_start += qemu_host_page_size;
|
|
}
|
|
if (end < real_end) {
|
|
prot = 0;
|
|
for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
|
|
prot |= page_get_flags(addr);
|
|
}
|
|
if (prot != 0)
|
|
real_end -= qemu_host_page_size;
|
|
}
|
|
|
|
ret = 0;
|
|
/* unmap what we can */
|
|
if (real_start < real_end) {
|
|
if (reserved_va) {
|
|
mmap_reserve(real_start, real_end - real_start);
|
|
} else {
|
|
ret = munmap(g2h_untagged(real_start), real_end - real_start);
|
|
}
|
|
}
|
|
|
|
if (ret == 0) {
|
|
page_set_flags(start, start + len - 1, 0);
|
|
}
|
|
mmap_unlock();
|
|
return ret;
|
|
}
|
|
|
|
int target_msync(abi_ulong start, abi_ulong len, int flags)
|
|
{
|
|
abi_ulong end;
|
|
|
|
if (start & ~TARGET_PAGE_MASK)
|
|
return -EINVAL;
|
|
len = TARGET_PAGE_ALIGN(len);
|
|
end = start + len;
|
|
if (end < start)
|
|
return -EINVAL;
|
|
if (end == start)
|
|
return 0;
|
|
|
|
start &= qemu_host_page_mask;
|
|
return msync(g2h_untagged(start), end - start, flags);
|
|
}
|