Fix mmap to handle differing host/target page sizes, by Edgar E. Iglesias.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3291 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
ths 2007-09-30 14:32:45 +00:00
parent 0574b6fb10
commit a5b85f7959
2 changed files with 67 additions and 39 deletions

View File

@ -36,7 +36,8 @@ int target_mprotect(target_ulong start, target_ulong len, int prot)
int prot1, ret;
#ifdef DEBUG_MMAP
printf("mprotect: start=0x%lx len=0x%lx prot=%c%c%c\n", start, len,
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' : '-');
@ -151,11 +152,11 @@ static int mmap_frag(target_ulong real_start,
}
/* NOTE: all the constants are the HOST ones */
long target_mmap(target_ulong start, target_ulong len, int prot,
target_long target_mmap(target_ulong start, target_ulong len, int prot,
int flags, int fd, target_ulong offset)
{
target_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len;
long host_start;
unsigned long host_start;
#if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) || \
defined(__ia64) || defined(__mips__)
static target_ulong last_start = 0x40000000;
@ -166,7 +167,8 @@ long target_mmap(target_ulong start, target_ulong len, int prot,
#ifdef DEBUG_MMAP
{
printf("mmap: start=0x%lx len=0x%lx prot=%c%c%c flags=",
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' : '-',
@ -186,7 +188,7 @@ long target_mmap(target_ulong start, target_ulong len, int prot,
printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE);
break;
}
printf("fd=%d offset=%lx\n", fd, offset);
printf("fd=%d offset=" TARGET_FMT_lx "\n", fd, offset);
}
#endif
@ -209,34 +211,59 @@ long target_mmap(target_ulong start, target_ulong len, int prot,
last_start += HOST_PAGE_ALIGN(len);
}
#endif
if (0 && qemu_host_page_size != qemu_real_host_page_size) {
/* NOTE: this code is only for debugging with '-p' option */
/* ??? Can also occur when TARGET_PAGE_SIZE > host page size. */
/* reserve a memory area */
/* ??? This needs fixing for remapping. */
abort();
host_len = HOST_PAGE_ALIGN(len) + qemu_host_page_size - TARGET_PAGE_SIZE;
real_start = (long)mmap(g2h(real_start), host_len, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (real_start == -1)
return real_start;
real_end = real_start + host_len;
start = HOST_PAGE_ALIGN(real_start);
end = start + HOST_PAGE_ALIGN(len);
if (start > real_start)
munmap((void *)g2h(real_start), start - real_start);
if (end < real_end)
munmap((void *)g2h(end), real_end - end);
/* use it as a fixed mapping */
flags |= MAP_FIXED;
} else {
/* if not fixed, no need to do anything */
host_offset = offset & qemu_host_page_mask;
host_len = len + offset - host_offset;
if (qemu_host_page_size > qemu_real_host_page_size) {
/*
* The guest expects to see mmapped areas aligned to it's pagesize.
* If the host's real page size is smaller than the guest's, we need
* to fixup the maps. It is done by allocating a larger area,
* displacing the map (if needed) and finally chopping off the spare
* room at the edges.
*/
/*
* We assume qemu_host_page_size is always the same as
* TARGET_PAGE_SIZE, see exec.c. qemu_real_host_page_size is the
* hosts real page size.
*/
target_ulong host_end;
unsigned long host_aligned_start;
host_len = HOST_PAGE_ALIGN(host_len + qemu_host_page_size
- qemu_real_host_page_size);
host_start = (unsigned long) mmap(real_start ?
g2h(real_start) : NULL,
host_len, prot, flags,
fd, host_offset);
if (host_start == -1)
return -1;
host_end = host_start + host_len;
/* Find start and end, aligned to the targets pagesize with-in the
large mmaped area. */
host_aligned_start = TARGET_PAGE_ALIGN(host_start);
if (!(flags & MAP_ANONYMOUS))
host_aligned_start += offset - host_offset;
start = h2g(host_aligned_start);
end = start + TARGET_PAGE_ALIGN(len);
/* Chop off the leftovers, if any. */
if (host_aligned_start > host_start)
munmap((void *)host_start, host_aligned_start - host_start);
if (end < host_end)
munmap((void *)g2h(end), host_end - end);
goto the_end1;
} else {
/* if not fixed, no need to do anything */
host_start = (long)mmap(real_start ? g2h(real_start) : NULL,
host_len, prot, flags, fd, host_offset);
if (host_start == -1)
return host_start;
return -1;
/* update start so that it points to the file position at 'offset' */
if (!(flags & MAP_ANONYMOUS))
host_start += offset - host_offset;
@ -267,7 +294,7 @@ abort();
MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
-1, 0);
if (retaddr == -1)
return retaddr;
return -1;
pread(fd, g2h(start), len, offset);
if (!(prot & PROT_WRITE)) {
ret = target_mprotect(start, len, prot);
@ -300,7 +327,7 @@ abort();
prot, flags, fd,
offset + real_end - qemu_host_page_size - start);
if (ret == -1)
return ret;
return -1;
real_end -= qemu_host_page_size;
}
@ -314,13 +341,13 @@ abort();
ret = (long)mmap(g2h(real_start), real_end - real_start,
prot, flags, fd, offset1);
if (ret == -1)
return ret;
return -1;
}
the_end1:
page_set_flags(start, start + len, prot | PAGE_VALID);
the_end:
#ifdef DEBUG_MMAP
printf("ret=0x%lx\n", (long)start);
printf("ret=0x%llx\n", start);
page_dump(stdout);
printf("\n");
#endif
@ -381,17 +408,18 @@ int target_munmap(target_ulong start, target_ulong len)
/* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED
blocks which have been allocated starting on a host page */
long target_mremap(target_ulong old_addr, target_ulong old_size,
target_long target_mremap(target_ulong old_addr, target_ulong old_size,
target_ulong new_size, unsigned long flags,
target_ulong new_addr)
{
int prot;
unsigned long host_addr;
/* XXX: use 5 args syscall */
new_addr = (long)mremap(g2h(old_addr), old_size, new_size, flags);
if (new_addr == -1)
return new_addr;
new_addr = h2g(new_addr);
host_addr = (long)mremap(g2h(old_addr), old_size, new_size, flags);
if (host_addr == -1)
return -1;
new_addr = h2g(host_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);

View File

@ -164,10 +164,10 @@ int do_vm86(CPUX86State *env, long subfunction, target_ulong v86_addr);
/* mmap.c */
int target_mprotect(target_ulong start, target_ulong len, int prot);
long target_mmap(target_ulong start, target_ulong len, int prot,
target_long target_mmap(target_ulong start, target_ulong len, int prot,
int flags, int fd, target_ulong offset);
int target_munmap(target_ulong start, target_ulong len);
long target_mremap(target_ulong old_addr, target_ulong old_size,
target_long target_mremap(target_ulong old_addr, target_ulong old_size,
target_ulong new_size, unsigned long flags,
target_ulong new_addr);
int target_msync(target_ulong start, target_ulong len, int flags);