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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
+16 -9
View File
@@ -998,7 +998,9 @@ region_id vm_create_null_region(aspace_id aid, char *name, void **address, int a
return region->id; 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) addr_t size, int lock, int mapping, const char *path, off_t offset, bool kernel)
{ {
vm_region *region; vm_region *region;
@@ -1009,7 +1011,6 @@ static region_id _vm_map_file(aspace_id aid, char *name, void **address, int add
// addr_t map_offset; // addr_t map_offset;
int err; int err;
vm_address_space *aspace = vm_get_aspace_by_id(aid); vm_address_space *aspace = vm_get_aspace_by_id(aid);
if (aspace == NULL) if (aspace == NULL)
return ERR_VM_INVALID_ASPACE; return ERR_VM_INVALID_ASPACE;
@@ -1065,22 +1066,25 @@ restart:
err = map_backing_store(aspace, store, address, offset, size, addr_type, 0, lock, mapping, &region, name); err = map_backing_store(aspace, store, address, offset, size, addr_type, 0, lock, mapping, &region, name);
vm_cache_release_ref(cache_ref); vm_cache_release_ref(cache_ref);
vm_put_aspace(aspace); vm_put_aspace(aspace);
if(err < 0) { if (err < 0)
return err; return err;
}
// modify the pointer returned to be offset back into the new region // modify the pointer returned to be offset back into the new region
// the same way the physical address in was offset // the same way the physical address in was offset
return region->id; 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) 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); 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) addr_t size, int lock, int mapping, const char *upath, off_t offset)
{ {
char name[B_OS_NAME_LENGTH]; 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) || user_memcpy(&address, uaddress, sizeof(address)) < B_OK)
return B_BAD_ADDRESS; 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); rc = _vm_map_file(vm_get_current_user_aspace_id(), name, &address, addr_type, size, lock, mapping, path, offset, false);
if (rc < 0) if (rc < 0)
return rc; return rc;
@@ -2177,9 +2184,9 @@ vm_soft_fault(addr_t address, bool is_write, bool is_user)
address = ROUNDOWN(address, PAGE_SIZE); address = ROUNDOWN(address, PAGE_SIZE);
if (address >= KERNEL_BASE && address <= KERNEL_TOP) { if (IS_KERNEL_ADDRESS(address)) {
aspace = vm_get_kernel_aspace(); 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(); aspace = vm_get_current_user_aspace();
if (aspace == NULL) { if (aspace == NULL) {
if (is_user == false) { if (is_user == false) {
@@ -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) { if (is_write && (region->lock & (B_WRITE_AREA | (is_user ? 0 : B_KERNEL_WRITE_AREA))) == 0) {
release_sem_etc(map->sem, READ_COUNT, 0); release_sem_etc(map->sem, READ_COUNT, 0);
vm_put_aspace(aspace); 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 return ERR_VM_PF_BAD_PERM; // BAD_PERMISSION
} }