diff options
Diffstat (limited to 'qemu/bsd-user/mmap.c')
| -rw-r--r-- | qemu/bsd-user/mmap.c | 494 |
1 files changed, 0 insertions, 494 deletions
diff --git a/qemu/bsd-user/mmap.c b/qemu/bsd-user/mmap.c deleted file mode 100644 index 6ab533470..000000000 --- a/qemu/bsd-user/mmap.c +++ /dev/null @@ -1,494 +0,0 @@ -/* - * 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 <sys/mman.h> - -#include "qemu.h" -#include "qemu-common.h" -#include "bsd-mman.h" - -//#define DEBUG_MMAP - -#if defined(CONFIG_USE_NPTL) -pthread_mutex_t mmap_mutex; -static int __thread mmap_lock_count; - -void mmap_lock(void) -{ - if (mmap_lock_count++ == 0) { - pthread_mutex_lock(&mmap_mutex); - } -} - -void mmap_unlock(void) -{ - if (--mmap_lock_count == 0) { - pthread_mutex_unlock(&mmap_mutex); - } -} - -/* 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); -} -#else -/* We aren't threadsafe to start with, so no need to worry about locking. */ -void mmap_lock(void) -{ -} - -void mmap_unlock(void) -{ -} -#endif - -/* 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; - -#ifdef DEBUG_MMAP - printf("mprotect: start=0x" TARGET_FMT_lx - " len=0x" TARGET_FMT_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; - 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(host_start), qemu_host_page_size, prot1 & PAGE_BITS); - 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(host_end - qemu_host_page_size), qemu_host_page_size, - prot1 & PAGE_BITS); - 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(host_start), host_end - host_start, prot); - if (ret != 0) - goto error; - } - page_set_flags(start, start + len, prot | PAGE_VALID); - mmap_unlock(); - return 0; -error: - mmap_unlock(); - return ret; -} - -/* map an incomplete host page */ -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(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 */ - void *p = mmap(host_start, qemu_host_page_size, prot, - flags | MAP_ANON, -1, 0); - if (p == MAP_FAILED) - return -1; - prot1 = prot; - } - prot1 &= PAGE_BITS; - - prot_new = prot | prot1; - if (!(flags & MAP_ANON)) { - /* 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 */ - pread(fd, g2h(start), end - start, offset); - - /* put final protection */ - if (prot_new != (prot1 | PROT_WRITE)) - mprotect(host_start, qemu_host_page_size, prot_new); - } else { - /* just update the protection */ - if (prot_new != prot1) { - mprotect(host_start, qemu_host_page_size, prot_new); - } - } - return 0; -} - -#if defined(__CYGWIN__) -/* Cygwin doesn't have a whole lot of address space. */ -static abi_ulong mmap_next_start = 0x18000000; -#else -static abi_ulong mmap_next_start = 0x40000000; -#endif - -unsigned long last_brk; - -/* find a free memory area of size 'size'. The search starts at - 'start'. If 'start' == 0, then a default start address is used. - Return -1 if error. -*/ -/* page_init() marks pages used by the host as reserved to be sure not - to use them. */ -static abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size) -{ - abi_ulong addr, addr1, addr_start; - int prot; - unsigned long new_brk; - - new_brk = (unsigned long)sbrk(0); - if (last_brk && last_brk < new_brk && last_brk == (target_ulong)last_brk) { - /* This is a hack to catch the host allocating memory with brk(). - If it uses mmap then we loose. - FIXME: We really want to avoid the host allocating memory in - the first place, and maybe leave some slack to avoid switching - to mmap. */ - page_set_flags(last_brk & TARGET_PAGE_MASK, - TARGET_PAGE_ALIGN(new_brk), - PAGE_RESERVED); - } - last_brk = new_brk; - - size = HOST_PAGE_ALIGN(size); - start = start & qemu_host_page_mask; - addr = start; - if (addr == 0) - addr = mmap_next_start; - addr_start = addr; - for(;;) { - prot = 0; - for(addr1 = addr; addr1 < (addr + size); addr1 += TARGET_PAGE_SIZE) { - prot |= page_get_flags(addr1); - } - if (prot == 0) - break; - addr += qemu_host_page_size; - /* we found nothing */ - if (addr == addr_start) - return (abi_ulong)-1; - } - if (start == 0) - mmap_next_start = addr + size; - return addr; -} - -/* NOTE: all the constants are the HOST ones */ -abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, - int flags, int fd, abi_ulong offset) -{ - abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; - unsigned long host_start; - - mmap_lock(); -#ifdef DEBUG_MMAP - { - printf("mmap: start=0x" TARGET_FMT_lx - " len=0x" TARGET_FMT_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_ANON) - printf("MAP_ANON "); - switch(flags & TARGET_BSD_MAP_FLAGMASK) { - case MAP_PRIVATE: - printf("MAP_PRIVATE "); - break; - case MAP_SHARED: - printf("MAP_SHARED "); - break; - default: - printf("[MAP_FLAGMASK=0x%x] ", flags & TARGET_BSD_MAP_FLAGMASK); - break; - } - printf("fd=%d offset=" TARGET_FMT_lx "\n", fd, offset); - } -#endif - - if (offset & ~TARGET_PAGE_MASK) { - errno = EINVAL; - goto fail; - } - - len = TARGET_PAGE_ALIGN(len); - if (len == 0) - goto the_end; - real_start = start & qemu_host_page_mask; - - if (!(flags & MAP_FIXED)) { - abi_ulong mmap_start; - void *p; - host_offset = offset & qemu_host_page_mask; - host_len = len + offset - host_offset; - host_len = HOST_PAGE_ALIGN(host_len); - mmap_start = mmap_find_vma(real_start, host_len); - if (mmap_start == (abi_ulong)-1) { - errno = ENOMEM; - goto fail; - } - /* 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(mmap_start), - host_len, prot, flags | MAP_FIXED, fd, host_offset); - if (p == MAP_FAILED) - goto fail; - /* update start so that it points to the file position at 'offset' */ - host_start = (unsigned long)p; - if (!(flags & MAP_ANON)) - host_start += offset - host_offset; - start = h2g(host_start); - } else { - int flg; - target_ulong addr; - - if (start & ~TARGET_PAGE_MASK) { - errno = EINVAL; - goto fail; - } - end = start + len; - real_end = HOST_PAGE_ALIGN(end); - - for(addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) { - flg = page_get_flags(addr); - if (flg & PAGE_RESERVED) { - errno = ENXIO; - goto fail; - } - } - - /* worst case: we cannot map the file because the offset is not - aligned, so we read it */ - if (!(flags & MAP_ANON) && - (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; - pread(fd, g2h(start), len, offset); - if (!(prot & PROT_WRITE)) { - ret = target_mprotect(start, len, prot); - if (ret != 0) { - start = ret; - goto the_end; - } - } - goto the_end; - } - - /* 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, real_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(real_start), real_end - real_start, - prot, flags, fd, offset1); - if (p == MAP_FAILED) - goto fail; - } - } - the_end1: - page_set_flags(start, start + len, prot | PAGE_VALID); - the_end: -#ifdef DEBUG_MMAP - printf("ret=0x" TARGET_FMT_lx "\n", start); - page_dump(stdout); - printf("\n"); -#endif - mmap_unlock(); - return start; -fail: - mmap_unlock(); - return -1; -} - -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%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; - 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) { - ret = munmap(g2h(real_start), real_end - real_start); - } - - if (ret == 0) - page_set_flags(start, start + len, 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(start), end - start, flags); -} |