| /* |
| * mmap support for qemu |
| * |
| * Copyright (c) 2003 - 2008 Fabrice Bellard |
| * |
| * 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/>. |
| */ |
| #include "qemu/osdep.h" |
| #include "exec/page-protection.h" |
| #include "user/page-protection.h" |
| |
| #include "qemu.h" |
| |
| static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER; |
| static __thread int mmap_lock_count; |
| |
| void mmap_lock(void) |
| { |
| if (mmap_lock_count++ == 0) { |
| pthread_mutex_lock(&mmap_mutex); |
| } |
| } |
| |
| void mmap_unlock(void) |
| { |
| assert(mmap_lock_count > 0); |
| if (--mmap_lock_count == 0) { |
| pthread_mutex_unlock(&mmap_mutex); |
| } |
| } |
| |
| bool have_mmap_lock(void) |
| { |
| return mmap_lock_count > 0 ? true : false; |
| } |
| |
| /* Grab lock to make sure things are in a consistent state after fork(). */ |
| void mmap_fork_start(void) |
| { |
| if (mmap_lock_count) |
| abort(); |
| pthread_mutex_lock(&mmap_mutex); |
| } |
| |
| void mmap_fork_end(int child) |
| { |
| if (child) |
| pthread_mutex_init(&mmap_mutex, NULL); |
| else |
| pthread_mutex_unlock(&mmap_mutex); |
| } |
| |
| /* NOTE: all the constants are the HOST ones, but addresses are target. */ |
| int target_mprotect(abi_ulong start, abi_ulong len, int prot) |
| { |
| abi_ulong end, host_start, host_end, addr; |
| int prot1, ret; |
| |
| qemu_log_mask(CPU_LOG_PAGE, "mprotect: start=0x" TARGET_ABI_FMT_lx |
| " len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c\n", start, len, |
| prot & PROT_READ ? 'r' : '-', |
| prot & PROT_WRITE ? 'w' : '-', |
| prot & PROT_EXEC ? 'x' : '-'); |
| if ((start & ~TARGET_PAGE_MASK) != 0) |
| return -EINVAL; |
| len = TARGET_PAGE_ALIGN(len); |
| end = start + len; |
| if (end < start) |
| return -EINVAL; |
| prot &= PROT_READ | PROT_WRITE | PROT_EXEC; |
| if (len == 0) |
| return 0; |
| |
| mmap_lock(); |
| host_start = start & qemu_host_page_mask; |
| host_end = HOST_PAGE_ALIGN(end); |
| if (start > host_start) { |
| /* handle host page containing start */ |
| prot1 = prot; |
| for (addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { |
| prot1 |= page_get_flags(addr); |
| } |
| if (host_end == host_start + qemu_host_page_size) { |
| for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| prot1 |= page_get_flags(addr); |
| } |
| end = host_end; |
| } |
| ret = mprotect(g2h_untagged(host_start), |
| qemu_host_page_size, prot1 & PAGE_RWX); |
| if (ret != 0) |
| goto error; |
| host_start += qemu_host_page_size; |
| } |
| if (end < host_end) { |
| prot1 = prot; |
| for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| prot1 |= page_get_flags(addr); |
| } |
| ret = mprotect(g2h_untagged(host_end - qemu_host_page_size), |
| qemu_host_page_size, prot1 & PAGE_RWX); |
| if (ret != 0) |
| goto error; |
| host_end -= qemu_host_page_size; |
| } |
| |
| /* handle the pages in the middle */ |
| if (host_start < host_end) { |
| ret = mprotect(g2h_untagged(host_start), host_end - host_start, prot); |
| if (ret != 0) |
| goto error; |
| } |
| page_set_flags(start, start + len - 1, prot | PAGE_VALID); |
| mmap_unlock(); |
| return 0; |
| error: |
| mmap_unlock(); |
| return ret; |
| } |
| |
| /* |
| * Perform a pread on behalf of target_mmap. We can reach EOF, we can be |
| * interrupted by signals, and in general there's no good error return path. |
| * If @zero, zero the rest of the block at EOF. |
| * Return true on success. |
| */ |
| static bool mmap_pread(int fd, void *p, size_t len, off_t offset, bool zero) |
| { |
| while (1) { |
| ssize_t r = pread(fd, p, len, offset); |
| |
| if (likely(r == len)) { |
| /* Complete */ |
| return true; |
| } |
| if (r == 0) { |
| /* EOF */ |
| if (zero) { |
| memset(p, 0, len); |
| } |
| return true; |
| } |
| if (r > 0) { |
| /* Short read */ |
| p += r; |
| len -= r; |
| offset += r; |
| } else if (errno != EINTR) { |
| /* Error */ |
| return false; |
| } |
| } |
| } |
| |
| /* |
| * map an incomplete host page |
| * |
| * mmap_frag can be called with a valid fd, if flags doesn't contain one of |
| * MAP_ANON, MAP_STACK, MAP_GUARD. If we need to map a page in those cases, we |
| * pass fd == -1. However, if flags contains MAP_GUARD then MAP_ANON cannot be |
| * added. |
| * |
| * * If fd is valid (not -1) we want to map the pages with MAP_ANON. |
| * * If flags contains MAP_GUARD we don't want to add MAP_ANON because it |
| * will be rejected. See kern_mmap's enforcing of constraints for MAP_GUARD |
| * in sys/vm/vm_mmap.c. |
| * * If flags contains MAP_ANON it doesn't matter if we add it or not. |
| * * If flags contains MAP_STACK, mmap adds MAP_ANON when called so doesn't |
| * matter if we add it or not either. See enforcing of constraints for |
| * MAP_STACK in kern_mmap. |
| * |
| * Don't add MAP_ANON for the flags that use fd == -1 without specifying the |
| * flags directly, with the assumption that future flags that require fd == -1 |
| * will also not require MAP_ANON. |
| */ |
| static int mmap_frag(abi_ulong real_start, |
| abi_ulong start, abi_ulong end, |
| int prot, int flags, int fd, abi_ulong offset) |
| { |
| abi_ulong real_end, addr; |
| void *host_start; |
| int prot1, prot_new; |
| |
| real_end = real_start + qemu_host_page_size; |
| host_start = g2h_untagged(real_start); |
| |
| /* get the protection of the target pages outside the mapping */ |
| prot1 = 0; |
| for (addr = real_start; addr < real_end; addr++) { |
| if (addr < start || addr >= end) |
| prot1 |= page_get_flags(addr); |
| } |
| |
| if (prot1 == 0) { |
| /* no page was there, so we allocate one. See also above. */ |
| void *p = mmap(host_start, qemu_host_page_size, prot, |
| flags | ((fd != -1) ? MAP_ANON : 0), -1, 0); |
| if (p == MAP_FAILED) |
| return -1; |
| prot1 = prot; |
| } |
| prot1 &= PAGE_RWX; |
| |
| prot_new = prot | prot1; |
| if (fd != -1) { |
| /* 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)) |
| return -1; |
| |
| /* adjust protection to be able to read */ |
| if (!(prot1 & PROT_WRITE)) |
| mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE); |
| |
| /* read the corresponding file data */ |
| if (!mmap_pread(fd, g2h_untagged(start), end - start, offset, true)) { |
| return -1; |
| } |
| |
| /* put final protection */ |
| if (prot_new != (prot1 | PROT_WRITE)) |
| mprotect(host_start, qemu_host_page_size, prot_new); |
| } else { |
| if (prot_new != prot1) { |
| mprotect(host_start, qemu_host_page_size, prot_new); |
| } |
| if (prot_new & PROT_WRITE) { |
| memset(g2h_untagged(start), 0, end - start); |
| } |
| } |
| return 0; |
| } |
| |
| #if HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 64 |
| # define TASK_UNMAPPED_BASE (1ul << 38) |
| #else |
| # define TASK_UNMAPPED_BASE 0x40000000 |
| #endif |
| abi_ulong mmap_next_start = TASK_UNMAPPED_BASE; |
| |
| /* |
| * Subroutine of mmap_find_vma, used when we have pre-allocated a chunk of guest |
| * address space. |
| */ |
| static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size, |
| abi_ulong alignment) |
| { |
| abi_ulong ret; |
| |
| ret = page_find_range_empty(start, reserved_va, size, alignment); |
| if (ret == -1 && start > TARGET_PAGE_SIZE) { |
| /* Restart at the beginning of the address space. */ |
| ret = page_find_range_empty(TARGET_PAGE_SIZE, start - 1, |
| size, alignment); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Find and reserve a free memory area of size 'size'. The search |
| * starts at 'start'. |
| * It must be called with mmap_lock() held. |
| * Return -1 if error. |
| */ |
| abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong alignment) |
| { |
| void *ptr, *prev; |
| abi_ulong addr; |
| int flags; |
| int wrapped, repeat; |
| |
| /* If 'start' == 0, then a default start address is used. */ |
| if (start == 0) { |
| start = mmap_next_start; |
| } else { |
| start &= qemu_host_page_mask; |
| } |
| |
| size = HOST_PAGE_ALIGN(size); |
| |
| if (reserved_va) { |
| return mmap_find_vma_reserved(start, size, |
| (alignment != 0 ? 1 << alignment : |
| MAX(qemu_host_page_size, TARGET_PAGE_SIZE))); |
| } |
| |
| addr = start; |
| wrapped = repeat = 0; |
| prev = 0; |
| flags = MAP_ANON | MAP_PRIVATE; |
| if (alignment != 0) { |
| flags |= MAP_ALIGNED(alignment); |
| } |
| |
| for (;; prev = ptr) { |
| /* |
| * Reserve needed memory area to avoid a race. |
| * It should be discarded using: |
| * - mmap() with MAP_FIXED flag |
| * - mremap() with MREMAP_FIXED flag |
| * - shmat() with SHM_REMAP flag |
| */ |
| ptr = mmap(g2h_untagged(addr), size, PROT_NONE, |
| flags, -1, 0); |
| |
| /* ENOMEM, if host address space has no memory */ |
| if (ptr == MAP_FAILED) { |
| return (abi_ulong)-1; |
| } |
| |
| /* |
| * Count the number of sequential returns of the same address. |
| * This is used to modify the search algorithm below. |
| */ |
| repeat = (ptr == prev ? repeat + 1 : 0); |
| |
| if (h2g_valid(ptr + size - 1)) { |
| addr = h2g(ptr); |
| |
| if ((addr & ~TARGET_PAGE_MASK) == 0) { |
| /* Success. */ |
| if (start == mmap_next_start && addr >= TASK_UNMAPPED_BASE) { |
| mmap_next_start = addr + size; |
| } |
| return addr; |
| } |
| |
| /* The address is not properly aligned for the target. */ |
| switch (repeat) { |
| case 0: |
| /* |
| * Assume the result that the kernel gave us is the |
| * first with enough free space, so start again at the |
| * next higher target page. |
| */ |
| addr = TARGET_PAGE_ALIGN(addr); |
| break; |
| case 1: |
| /* |
| * Sometimes the kernel decides to perform the allocation |
| * at the top end of memory instead. |
| */ |
| addr &= TARGET_PAGE_MASK; |
| break; |
| case 2: |
| /* Start over at low memory. */ |
| addr = 0; |
| break; |
| default: |
| /* Fail. This unaligned block must the last. */ |
| addr = -1; |
| break; |
| } |
| } else { |
| /* |
| * Since the result the kernel gave didn't fit, start |
| * again at low memory. If any repetition, fail. |
| */ |
| addr = (repeat ? -1 : 0); |
| } |
| |
| /* Unmap and try again. */ |
| munmap(ptr, size); |
| |
| /* ENOMEM if we checked the whole of the target address space. */ |
| if (addr == (abi_ulong)-1) { |
| return (abi_ulong)-1; |
| } else if (addr == 0) { |
| if (wrapped) { |
| return (abi_ulong)-1; |
| } |
| wrapped = 1; |
| /* |
| * Don't actually use 0 when wrapping, instead indicate |
| * that we'd truly like an allocation in low memory. |
| */ |
| addr = TARGET_PAGE_SIZE; |
| } else if (wrapped && addr >= start) { |
| return (abi_ulong)-1; |
| } |
| } |
| } |
| |
| /* NOTE: all the constants are the HOST ones */ |
| abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, |
| int flags, int fd, off_t offset) |
| { |
| abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; |
| |
| mmap_lock(); |
| if (qemu_loglevel_mask(CPU_LOG_PAGE)) { |
| qemu_log("mmap: start=0x" TARGET_ABI_FMT_lx |
| " len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c flags=", |
| start, len, |
| prot & PROT_READ ? 'r' : '-', |
| prot & PROT_WRITE ? 'w' : '-', |
| prot & PROT_EXEC ? 'x' : '-'); |
| if (flags & MAP_ALIGNMENT_MASK) { |
| qemu_log("MAP_ALIGNED(%u) ", |
| (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT); |
| } |
| if (flags & MAP_GUARD) { |
| qemu_log("MAP_GUARD "); |
| } |
| if (flags & MAP_FIXED) { |
| qemu_log("MAP_FIXED "); |
| } |
| if (flags & MAP_ANON) { |
| qemu_log("MAP_ANON "); |
| } |
| if (flags & MAP_EXCL) { |
| qemu_log("MAP_EXCL "); |
| } |
| if (flags & MAP_PRIVATE) { |
| qemu_log("MAP_PRIVATE "); |
| } |
| if (flags & MAP_SHARED) { |
| qemu_log("MAP_SHARED "); |
| } |
| if (flags & MAP_NOCORE) { |
| qemu_log("MAP_NOCORE "); |
| } |
| if (flags & MAP_STACK) { |
| qemu_log("MAP_STACK "); |
| } |
| qemu_log("fd=%d offset=0x%lx\n", fd, offset); |
| } |
| |
| if ((flags & MAP_ANON) && fd != -1) { |
| errno = EINVAL; |
| goto fail; |
| } |
| if (flags & MAP_STACK) { |
| if ((fd != -1) || ((prot & (PROT_READ | PROT_WRITE)) != |
| (PROT_READ | PROT_WRITE))) { |
| errno = EINVAL; |
| goto fail; |
| } |
| } |
| if ((flags & MAP_GUARD) && (prot != PROT_NONE || fd != -1 || |
| offset != 0 || (flags & (MAP_SHARED | MAP_PRIVATE | |
| /* MAP_PREFAULT | */ /* MAP_PREFAULT not in mman.h */ |
| MAP_PREFAULT_READ | MAP_ANON | MAP_STACK)) != 0)) { |
| errno = EINVAL; |
| goto fail; |
| } |
| |
| if (offset & ~TARGET_PAGE_MASK) { |
| errno = EINVAL; |
| goto fail; |
| } |
| |
| if (len == 0) { |
| errno = EINVAL; |
| goto fail; |
| } |
| |
| /* Check for overflows */ |
| len = TARGET_PAGE_ALIGN(len); |
| if (len == 0) { |
| errno = ENOMEM; |
| goto fail; |
| } |
| |
| real_start = start & qemu_host_page_mask; |
| host_offset = offset & qemu_host_page_mask; |
| |
| /* |
| * If the user is asking for the kernel to find a location, do that |
| * before we truncate the length for mapping files below. |
| */ |
| if (!(flags & MAP_FIXED)) { |
| abi_ulong alignment; |
| |
| host_len = len + offset - host_offset; |
| host_len = HOST_PAGE_ALIGN(host_len); |
| alignment = (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT; |
| start = mmap_find_vma(real_start, host_len, alignment); |
| if (start == (abi_ulong)-1) { |
| errno = ENOMEM; |
| goto fail; |
| } |
| } |
| |
| /* |
| * When mapping files into a memory area larger than the file, accesses |
| * to pages beyond the file size will cause a SIGBUS. |
| * |
| * 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); |
| } |
