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Prevent guest reusing host memory allocations.

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git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4710 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
pbrook 2008-06-09 13:47:45 +00:00
parent 82e671d9ec
commit 17e2377abf
6 changed files with 134 additions and 40 deletions
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28
exec.c
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@ -263,13 +263,33 @@ static inline PageDesc *page_find_alloc(target_ulong index)
{
PageDesc **lp, *p;
#if TARGET_LONG_BITS > 32
/* Host memory outside guest VM. For 32-bit targets we have already
excluded high addresses. */
if (index > ((target_ulong)L2_SIZE * L1_SIZE * TARGET_PAGE_SIZE))
return NULL;
#endif
lp = &l1_map[index >> L2_BITS];
p = *lp;
if (!p) {
/* allocate if not found */
p = qemu_malloc(sizeof(PageDesc) * L2_SIZE);
memset(p, 0, sizeof(PageDesc) * L2_SIZE);
#if defined(CONFIG_USER_ONLY)
unsigned long addr;
size_t len = sizeof(PageDesc) * L2_SIZE;
/* Don't use qemu_malloc because it may recurse. */
p = mmap(0, len, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
*lp = p;
addr = h2g(p);
if (addr == (target_ulong)addr) {
page_set_flags(addr & TARGET_PAGE_MASK,
TARGET_PAGE_ALIGN(addr + len),
PAGE_RESERVED);
}
#else
p = qemu_mallocz(sizeof(PageDesc) * L2_SIZE);
*lp = p;
#endif
}
return p + (index & (L2_SIZE - 1));
}
@ -1912,6 +1932,10 @@ void page_set_flags(target_ulong start, target_ulong end, int flags)
flags |= PAGE_WRITE_ORG;
for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
p = page_find_alloc(addr >> TARGET_PAGE_BITS);
/* We may be called for host regions that are outside guest
address space. */
if (!p)
return;
/* if the write protection is set, then we invalidate the code
inside */
if (!(p->flags & PAGE_WRITE) &&