| /* |
| * mmap support for qemu |
| * |
| * Copyright (c) 2003 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, write to the Free Software |
| * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <stdarg.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <sys/mman.h> |
| |
| #include "qemu.h" |
| |
| //#define DEBUG_MMAP |
| |
| /* NOTE: all the constants are the HOST ones */ |
| int target_mprotect(unsigned long start, unsigned long len, int prot) |
| { |
| unsigned long end, host_start, host_end, addr; |
| int prot1, ret; |
| |
| #ifdef DEBUG_MMAP |
| printf("mprotect: start=0x%lx len=0x%lx prot=%c%c%c\n", start, len, |
| prot & PROT_READ ? 'r' : '-', |
| prot & PROT_WRITE ? 'w' : '-', |
| prot & PROT_EXEC ? 'x' : '-'); |
| #endif |
| |
| if ((start & ~TARGET_PAGE_MASK) != 0) |
| return -EINVAL; |
| len = TARGET_PAGE_ALIGN(len); |
| end = start + len; |
| if (end < start) |
| return -EINVAL; |
| if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) |
| return -EINVAL; |
| if (len == 0) |
| return 0; |
| |
| host_start = start & 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 + host_page_size) { |
| for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| prot1 |= page_get_flags(addr); |
| } |
| end = host_end; |
| } |
| ret = mprotect((void *)host_start, host_page_size, prot1 & PAGE_BITS); |
| if (ret != 0) |
| return ret; |
| host_start += 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((void *)(host_end - host_page_size), host_page_size, |
| prot1 & PAGE_BITS); |
| if (ret != 0) |
| return ret; |
| host_end -= host_page_size; |
| } |
| |
| /* handle the pages in the middle */ |
| if (host_start < host_end) { |
| ret = mprotect((void *)host_start, host_end - host_start, prot); |
| if (ret != 0) |
| return ret; |
| } |
| page_set_flags(start, start + len, prot | PAGE_VALID); |
| return 0; |
| } |
| |
| /* map an incomplete host page */ |
| int mmap_frag(unsigned long host_start, |
| unsigned long start, unsigned long end, |
| int prot, int flags, int fd, unsigned long offset) |
| { |
| unsigned long host_end, ret, addr; |
| int prot1, prot_new; |
| |
| host_end = host_start + host_page_size; |
| |
| /* get the protection of the target pages outside the mapping */ |
| prot1 = 0; |
| for(addr = host_start; addr < host_end; addr++) { |
| if (addr < start || addr >= end) |
| prot1 |= page_get_flags(addr); |
| } |
| |
| if (prot1 == 0) { |
| /* no page was there, so we allocate one */ |
| ret = (long)mmap((void *)host_start, host_page_size, prot, |
| flags | MAP_ANONYMOUS, -1, 0); |
| if (ret == -1) |
| return ret; |
| } |
| prot1 &= PAGE_BITS; |
| |
| prot_new = prot | prot1; |
| if (!(flags & MAP_ANONYMOUS)) { |
| /* msync() won't work here, so we return an error if write is |
| possible while it is a shared mapping */ |
| if ((flags & MAP_TYPE) == MAP_SHARED && |
| (prot & PROT_WRITE)) |
| return -EINVAL; |
| |
| /* adjust protection to be able to read */ |
| if (!(prot1 & PROT_WRITE)) |
| mprotect((void *)host_start, host_page_size, prot1 | PROT_WRITE); |
| |
| /* read the corresponding file data */ |
| pread(fd, (void *)start, end - start, offset); |
| |
| /* put final protection */ |
| if (prot_new != (prot1 | PROT_WRITE)) |
| mprotect((void *)host_start, host_page_size, prot_new); |
| } else { |
| /* just update the protection */ |
| if (prot_new != prot1) { |
| mprotect((void *)host_start, host_page_size, prot_new); |
| } |
| } |
| return 0; |
| } |
| |
| /* NOTE: all the constants are the HOST ones */ |
| long target_mmap(unsigned long start, unsigned long len, int prot, |
| int flags, int fd, unsigned long offset) |
| { |
| unsigned long ret, end, host_start, host_end, retaddr, host_offset, host_len; |
| |
| #ifdef DEBUG_MMAP |
| { |
| printf("mmap: start=0x%lx len=0x%lx prot=%c%c%c flags=", |
| start, len, |
| prot & PROT_READ ? 'r' : '-', |
| prot & PROT_WRITE ? 'w' : '-', |
| prot & PROT_EXEC ? 'x' : '-'); |
| if (flags & MAP_FIXED) |
| printf("MAP_FIXED "); |
| if (flags & MAP_ANONYMOUS) |
| printf("MAP_ANON "); |
| switch(flags & MAP_TYPE) { |
| case MAP_PRIVATE: |
| printf("MAP_PRIVATE "); |
| break; |
| case MAP_SHARED: |
| printf("MAP_SHARED "); |
| break; |
| default: |
| printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE); |
| break; |
| } |
| printf("fd=%d offset=%lx\n", fd, offset); |
| } |
| #endif |
| |
| if (offset & ~TARGET_PAGE_MASK) |
| return -EINVAL; |
| |
| len = TARGET_PAGE_ALIGN(len); |
| if (len == 0) |
| return start; |
| host_start = start & host_page_mask; |
| |
| if (!(flags & MAP_FIXED)) { |
| #if defined(__alpha__) || defined(__sparc__) |
| /* tell the kenel to search at the same place as i386 */ |
| if (host_start == 0) |
| host_start = 0x40000000; |
| #endif |
| if (host_page_size != real_host_page_size) { |
| /* NOTE: this code is only for debugging with '-p' option */ |
| /* reserve a memory area */ |
| host_len = HOST_PAGE_ALIGN(len) + host_page_size - TARGET_PAGE_SIZE; |
| host_start = (long)mmap((void *)host_start, host_len, PROT_NONE, |
| MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| if (host_start == -1) |
| return host_start; |
| host_end = host_start + host_len; |
| start = HOST_PAGE_ALIGN(host_start); |
| end = start + HOST_PAGE_ALIGN(len); |
| if (start > host_start) |
| munmap((void *)host_start, start - host_start); |
| if (end < host_end) |
| munmap((void *)end, host_end - end); |
| /* use it as a fixed mapping */ |
| flags |= MAP_FIXED; |
| } else { |
| /* if not fixed, no need to do anything */ |
| host_offset = offset & host_page_mask; |
| host_len = len + offset - host_offset; |
| start = (long)mmap((void *)host_start, host_len, |
| prot, flags, fd, host_offset); |
| if (start == -1) |
| return start; |
| /* update start so that it points to the file position at 'offset' */ |
| if (!(flags & MAP_ANONYMOUS)) |
| start += offset - host_offset; |
| goto the_end1; |
| } |
| } |
| |
| if (start & ~TARGET_PAGE_MASK) |
| return -EINVAL; |
| end = start + len; |
| host_end = HOST_PAGE_ALIGN(end); |
| |
| /* worst case: we cannot map the file because the offset is not |
| aligned, so we read it */ |
| if (!(flags & MAP_ANONYMOUS) && |
| (offset & ~host_page_mask) != (start & ~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 & MAP_TYPE) == MAP_SHARED && |
| (prot & PROT_WRITE)) |
| return -EINVAL; |
| retaddr = target_mmap(start, len, prot | PROT_WRITE, |
| MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, |
| -1, 0); |
| if (retaddr == -1) |
| return retaddr; |
| pread(fd, (void *)start, len, offset); |
| if (!(prot & PROT_WRITE)) { |
| ret = target_mprotect(start, len, prot); |
| if (ret != 0) |
| return ret; |
| } |
| goto the_end; |
| } |
| |
| /* handle the start of the mapping */ |
| if (start > host_start) { |
| if (host_end == host_start + host_page_size) { |
| /* one single host page */ |
| ret = mmap_frag(host_start, start, end, |
| prot, flags, fd, offset); |
| if (ret == -1) |
| return ret; |
| goto the_end1; |
| } |
| ret = mmap_frag(host_start, start, host_start + host_page_size, |
| prot, flags, fd, offset); |
| if (ret == -1) |
| return ret; |
| host_start += host_page_size; |
| } |
| /* handle the end of the mapping */ |
| if (end < host_end) { |
| ret = mmap_frag(host_end - host_page_size, |
| host_end - host_page_size, host_end, |
| prot, flags, fd, |
| offset + host_end - host_page_size - start); |
| if (ret == -1) |
| return ret; |
| host_end -= host_page_size; |
| } |
| |
| /* map the middle (easier) */ |
| if (host_start < host_end) { |
| unsigned long offset1; |
| if (flags & MAP_ANONYMOUS) |
| offset1 = 0; |
| else |
| offset1 = offset + host_start - start; |
| ret = (long)mmap((void *)host_start, host_end - host_start, |
| prot, flags, fd, offset1); |
| if (ret == -1) |
| return ret; |
| } |
| the_end1: |
| page_set_flags(start, start + len, prot | PAGE_VALID); |
| the_end: |
| #ifdef DEBUG_MMAP |
| printf("ret=0x%lx\n", (long)start); |
| page_dump(stdout); |
| printf("\n"); |
| #endif |
| return start; |
| } |
| |
| int target_munmap(unsigned long start, unsigned long len) |
| { |
| unsigned long end, host_start, host_end, addr; |
| int prot, ret; |
| |
| #ifdef DEBUG_MMAP |
| printf("munmap: start=0x%lx len=0x%lx\n", start, len); |
| #endif |
| if (start & ~TARGET_PAGE_MASK) |
| return -EINVAL; |
| len = TARGET_PAGE_ALIGN(len); |
| if (len == 0) |
| return -EINVAL; |
| end = start + len; |
| host_start = start & host_page_mask; |
| host_end = HOST_PAGE_ALIGN(end); |
| |
| if (start > host_start) { |
| /* handle host page containing start */ |
| prot = 0; |
| for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { |
| prot |= page_get_flags(addr); |
| } |
| if (host_end == host_start + host_page_size) { |
| for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| prot |= page_get_flags(addr); |
| } |
| end = host_end; |
| } |
| if (prot != 0) |
| host_start += host_page_size; |
| } |
| if (end < host_end) { |
| prot = 0; |
| for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| prot |= page_get_flags(addr); |
| } |
| if (prot != 0) |
| host_end -= host_page_size; |
| } |
| |
| /* unmap what we can */ |
| if (host_start < host_end) { |
| ret = munmap((void *)host_start, host_end - host_start); |
| if (ret != 0) |
| return ret; |
| } |
| |
| page_set_flags(start, start + len, 0); |
| return 0; |
| } |
| |
| /* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED |
| blocks which have been allocated starting on a host page */ |
| long target_mremap(unsigned long old_addr, unsigned long old_size, |
| unsigned long new_size, unsigned long flags, |
| unsigned long new_addr) |
| { |
| int prot; |
| |
| /* XXX: use 5 args syscall */ |
| new_addr = (long)mremap((void *)old_addr, old_size, new_size, flags); |
| if (new_addr == -1) |
| return new_addr; |
| prot = page_get_flags(old_addr); |
| page_set_flags(old_addr, old_addr + old_size, 0); |
| page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); |
| return new_addr; |
| } |
| |
| int target_msync(unsigned long start, unsigned long len, int flags) |
| { |
| unsigned long 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 &= host_page_mask; |
| return msync((void *)start, end - start, flags); |
| } |
| |
