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user_vm_map_file() was broken after recent changes; it didn't allow the

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kernel to write to read-only userland areas.
Cleanup.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@7893 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Axel Dörfler
2004-06-11 00:39:40 +00:00
parent 55ab7bb31f
commit 7bdd1a7874
1 changed files with 39 additions and 32 deletions
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src/kernel/core/vm/vm.c
+39 -32
View File
@@ -998,7 +998,9 @@ region_id vm_create_null_region(aspace_id aid, char *name, void **address, int a
return region->id;
}
static region_id _vm_map_file(aspace_id aid, char *name, void **address, int addr_type,
static region_id
_vm_map_file(aspace_id aid, char *name, void **address, int addr_type,
addr_t size, int lock, int mapping, const char *path, off_t offset, bool kernel)
{
vm_region *region;
@@ -1009,9 +1011,8 @@ static region_id _vm_map_file(aspace_id aid, char *name, void **address, int add
// addr_t map_offset;
int err;
vm_address_space *aspace = vm_get_aspace_by_id(aid);
if(aspace == NULL)
if (aspace == NULL)
return ERR_VM_INVALID_ASPACE;
offset = ROUNDOWN(offset, PAGE_SIZE);
@@ -1020,22 +1021,22 @@ static region_id _vm_map_file(aspace_id aid, char *name, void **address, int add
restart:
// get the vnode for the object, this also grabs a ref to it
err = vfs_get_vnode_from_path(path, kernel, &v);
if(err < 0) {
if (err < 0) {
vm_put_aspace(aspace);
return err;
}
cache_ref = vfs_get_cache_ptr(v);
if(!cache_ref) {
if (!cache_ref) {
// create a vnode store object
store = vm_store_create_vnode(v);
if(store == NULL)
if (store == NULL)
panic("vm_map_file: couldn't create vnode store");
cache = vm_cache_create(store);
if(cache == NULL)
if (cache == NULL)
panic("vm_map_physical_memory: vm_cache_create returned NULL");
cache_ref = vm_cache_ref_create(cache);
if(cache_ref == NULL)
if (cache_ref == NULL)
panic("vm_map_physical_memory: vm_cache_ref_create returned NULL");
// acquire the cache ref once to represent the ref that the vnode will have
@@ -1043,7 +1044,7 @@ restart:
vm_cache_acquire_ref(cache_ref, false);
// try to set the cache ptr in the vnode
if(vfs_set_cache_ptr(v, cache_ref) < 0) {
if (vfs_set_cache_ptr(v, cache_ref) < 0) {
// the cache pointer was set between here and then
// this can only happen if someone else tries to map it
// at the same time. Rare enough to not worry about the
@@ -1065,22 +1066,25 @@ restart:
err = map_backing_store(aspace, store, address, offset, size, addr_type, 0, lock, mapping, &region, name);
vm_cache_release_ref(cache_ref);
vm_put_aspace(aspace);
if(err < 0) {
if (err < 0)
return err;
}
// modify the pointer returned to be offset back into the new region
// the same way the physical address in was offset
return region->id;
}
region_id vm_map_file(aspace_id aid, char *name, void **address, int addr_type,
region_id
vm_map_file(aspace_id aid, char *name, void **address, int addr_type,
addr_t size, int lock, int mapping, const char *path, off_t offset)
{
return _vm_map_file(aid, name, address, addr_type, size, lock, mapping, path, offset, true);
}
region_id user_vm_map_file(char *uname, void **uaddress, int addr_type,
region_id
user_vm_map_file(char *uname, void **uaddress, int addr_type,
addr_t size, int lock, int mapping, const char *upath, off_t offset)
{
char name[B_OS_NAME_LENGTH];
@@ -1094,6 +1098,9 @@ region_id user_vm_map_file(char *uname, void **uaddress, int addr_type,
|| user_memcpy(&address, uaddress, sizeof(address)) < B_OK)
return B_BAD_ADDRESS;
// userland created areas can always be accessed by the kernel
lock |= B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA;
rc = _vm_map_file(vm_get_current_user_aspace_id(), name, &address, addr_type, size, lock, mapping, path, offset, false);
if (rc < 0)
return rc;
@@ -2177,12 +2184,12 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
address = ROUNDOWN(address, PAGE_SIZE);
if (address >= KERNEL_BASE && address <= KERNEL_TOP) {
if (IS_KERNEL_ADDRESS(address)) {
aspace = vm_get_kernel_aspace();
} else if(address >= USER_BASE && address <= USER_TOP) {
} else if (IS_USER_ADDRESS(address)) {
aspace = vm_get_current_user_aspace();
if(aspace == NULL) {
if(is_user == false) {
if (aspace == NULL) {
if (is_user == false) {
dprintf("vm_soft_fault: kernel thread accessing invalid user memory!\n");
return ERR_VM_PF_FATAL;
} else {
@@ -2217,7 +2224,7 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
if (is_write && (region->lock & (B_WRITE_AREA | (is_user ? 0 : B_KERNEL_WRITE_AREA))) == 0) {
release_sem_etc(map->sem, READ_COUNT, 0);
vm_put_aspace(aspace);
dprintf("write access attempted on read-only region\n");
dprintf("write access attempted on read-only region 0x%lx at %p\n", region->id, (void *)address);
return ERR_VM_PF_BAD_PERM; // BAD_PERMISSION
}
@@ -2256,7 +2263,7 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
break;
}
if(page == NULL)
if (page == NULL)
break;
TRACEPFAULT;
@@ -2283,7 +2290,7 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
// see if the vm_store has it
if (cache_ref->cache->store->ops->has_page) {
if(cache_ref->cache->store->ops->has_page(cache_ref->cache->store, cache_offset)) {
if (cache_ref->cache->store->ops->has_page(cache_ref->cache->store, cache_offset)) {
IOVECS(vecs, 1);
TRACEPFAULT;
@@ -2302,7 +2309,7 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
mutex_lock(&cache_ref->lock);
if(cache_ref == top_cache_ref) {
if (cache_ref == top_cache_ref) {
vm_cache_remove_page(cache_ref, &dummy_page);
dummy_page.state = PAGE_STATE_INACTIVE;
}
@@ -2320,8 +2327,8 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
// we rolled off the end of the cache chain, so we need to decide which
// cache will get the new page we're about to create
if(!cache_ref) {
if(!is_write)
if (!cache_ref) {
if (!is_write)
cache_ref = last_cache_ref; // put it in the deepest cache
else
cache_ref = top_cache_ref; // put it in the topmost cache
@@ -2329,18 +2336,18 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
TRACEPFAULT;
if(page == NULL) {
if (page == NULL) {
// still haven't found a page, so zero out a new one
page = vm_page_allocate_page(PAGE_STATE_CLEAR);
// dprintf("vm_soft_fault: just allocated page 0x%x\n", page->ppn);
mutex_lock(&cache_ref->lock);
if(dummy_page.state == PAGE_STATE_BUSY && dummy_page.cache_ref == cache_ref) {
if (dummy_page.state == PAGE_STATE_BUSY && dummy_page.cache_ref == cache_ref) {
vm_cache_remove_page(cache_ref, &dummy_page);
dummy_page.state = PAGE_STATE_INACTIVE;
}
vm_cache_insert_page(cache_ref, page, cache_offset);
mutex_unlock(&cache_ref->lock);
if(dummy_page.state == PAGE_STATE_BUSY) {
if (dummy_page.state == PAGE_STATE_BUSY) {
vm_cache_ref *temp_cache = dummy_page.cache_ref;
mutex_lock(&temp_cache->lock);
vm_cache_remove_page(temp_cache, &dummy_page);
@@ -2351,7 +2358,7 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
TRACEPFAULT;
if(page->cache_ref != top_cache_ref && is_write) {
if (page->cache_ref != top_cache_ref && is_write) {
// now we have a page that has the data we want, but in the wrong cache object
// so we need to copy it and stick it into the top cache
vm_page *src_page = page;
@@ -2360,10 +2367,10 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
page = vm_page_allocate_page(PAGE_STATE_FREE);
// try to get a mapping for the src and dest page so we can copy it
for(;;) {
for (;;) {
(*aspace->translation_map.ops->get_physical_page)(src_page->ppn * PAGE_SIZE, (addr_t *)&src, PHYSICAL_PAGE_CAN_WAIT);
err = (*aspace->translation_map.ops->get_physical_page)(page->ppn * PAGE_SIZE, (addr_t *)&dest, PHYSICAL_PAGE_NO_WAIT);
if(err == B_NO_ERROR)
if (err == B_NO_ERROR)
break;
// it couldn't map the second one, so sleep and retry
@@ -2379,14 +2386,14 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
vm_page_set_state(src_page, PAGE_STATE_ACTIVE);
mutex_lock(&top_cache_ref->lock);
if(dummy_page.state == PAGE_STATE_BUSY && dummy_page.cache_ref == top_cache_ref) {
if (dummy_page.state == PAGE_STATE_BUSY && dummy_page.cache_ref == top_cache_ref) {
vm_cache_remove_page(top_cache_ref, &dummy_page);
dummy_page.state = PAGE_STATE_INACTIVE;
}
vm_cache_insert_page(top_cache_ref, page, cache_offset);
mutex_unlock(&top_cache_ref->lock);
if(dummy_page.state == PAGE_STATE_BUSY) {
if (dummy_page.state == PAGE_STATE_BUSY) {
vm_cache_ref *temp_cache = dummy_page.cache_ref;
mutex_lock(&temp_cache->lock);
vm_cache_remove_page(temp_cache, &dummy_page);
@@ -2431,7 +2438,7 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
TRACEPFAULT;
if(dummy_page.state == PAGE_STATE_BUSY) {
if (dummy_page.state == PAGE_STATE_BUSY) {
vm_cache_ref *temp_cache = dummy_page.cache_ref;
mutex_lock(&temp_cache->lock);
vm_cache_remove_page(temp_cache, &dummy_page);