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linux-user: fix page_unprotect when host page size > target page size

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When the host page size is bigger that the target one, unprotecting a
page should:
- mark all the target pages corresponding to the host page as writable
- invalidate all tb corresponding to the host page (and not the target
  page)

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Aurelien Jarno 2010-03-29 02:12:51 +02:00
parent 60e99246d6
commit 45d679d643
1 changed files with 22 additions and 23 deletions
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45
exec.c
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@ -2498,8 +2498,8 @@ int page_check_range(target_ulong start, target_ulong len, int flags)
page. Return TRUE if the fault was successfully handled. */
int page_unprotect(target_ulong address, unsigned long pc, void *puc)
{
unsigned int page_index, prot, pindex;
PageDesc *p, *p1;
unsigned int prot;
PageDesc *p;
target_ulong host_start, host_end, addr;
/* Technically this isn't safe inside a signal handler. However we
@ -2507,37 +2507,36 @@ int page_unprotect(target_ulong address, unsigned long pc, void *puc)
practice it seems to be ok. */
mmap_lock();
host_start = address & qemu_host_page_mask;
page_index = host_start >> TARGET_PAGE_BITS;
p1 = page_find(page_index);
if (!p1) {
p = page_find(address >> TARGET_PAGE_BITS);
if (!p) {
mmap_unlock();
return 0;
}
host_end = host_start + qemu_host_page_size;
p = p1;
prot = 0;
for(addr = host_start;addr < host_end; addr += TARGET_PAGE_SIZE) {
prot |= p->flags;
p++;
}
/* if the page was really writable, then we change its
protection back to writable */
if (prot & PAGE_WRITE_ORG) {
pindex = (address - host_start) >> TARGET_PAGE_BITS;
if (!(p1[pindex].flags & PAGE_WRITE)) {
mprotect((void *)g2h(host_start), qemu_host_page_size,
(prot & PAGE_BITS) | PAGE_WRITE);
p1[pindex].flags |= PAGE_WRITE;
if ((p->flags & PAGE_WRITE_ORG) && !(p->flags & PAGE_WRITE)) {
host_start = address & qemu_host_page_mask;
host_end = host_start + qemu_host_page_size;
prot = 0;
for (addr = host_start ; addr < host_end ; addr += TARGET_PAGE_SIZE) {
p = page_find(addr >> TARGET_PAGE_BITS);
p->flags |= PAGE_WRITE;
prot |= p->flags;
/* and since the content will be modified, we must invalidate
the corresponding translated code. */
tb_invalidate_phys_page(address, pc, puc);
tb_invalidate_phys_page(addr, pc, puc);
#ifdef DEBUG_TB_CHECK
tb_invalidate_check(address);
tb_invalidate_check(addr);
#endif
mmap_unlock();
return 1;
}
mprotect((void *)g2h(host_start), qemu_host_page_size,
prot & PAGE_BITS);
mmap_unlock();
return 1;
}
mmap_unlock();
return 0;