@@ -669,7 +669,8 @@ static void __init kvm_use_magic_page(vo
on_each_cpu(kvm_map_magic_page, &features, 1);
/* Quick self-test to see if the mapping works */
- if (fault_in_pages_readable((const char *)KVM_MAGIC_PAGE, sizeof(u32))) {
+ if (fault_in_readable((const char __user *)KVM_MAGIC_PAGE,
+ sizeof(u32))) {
kvm_patching_worked = false;
return;
}
@@ -1048,7 +1048,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucon
if (new_ctx == NULL)
return 0;
if (!access_ok(new_ctx, ctx_size) ||
- fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
+ fault_in_readable((char __user *)new_ctx, ctx_size))
return -EFAULT;
/*
@@ -1239,7 +1239,7 @@ SYSCALL_DEFINE3(debug_setcontext, struct
#endif
if (!access_ok(ctx, sizeof(*ctx)) ||
- fault_in_pages_readable((u8 __user *)ctx, sizeof(*ctx)))
+ fault_in_readable((char __user *)ctx, sizeof(*ctx)))
return -EFAULT;
/*
@@ -688,7 +688,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucon
if (new_ctx == NULL)
return 0;
if (!access_ok(new_ctx, ctx_size) ||
- fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
+ fault_in_readable((char __user *)new_ctx, ctx_size))
return -EFAULT;
/*
@@ -205,7 +205,7 @@ retry:
fpregs_unlock();
if (ret) {
- if (!fault_in_pages_writeable(buf_fx, fpu_user_xstate_size))
+ if (!fault_in_writeable(buf_fx, fpu_user_xstate_size))
goto retry;
return -EFAULT;
}
@@ -278,10 +278,9 @@ retry:
if (ret != -EFAULT)
return -EINVAL;
- ret = fault_in_pages_readable(buf, size);
- if (!ret)
+ if (!fault_in_readable(buf, size))
goto retry;
- return ret;
+ return -EFAULT;
}
/*
@@ -336,7 +336,7 @@ int armada_gem_pwrite_ioctl(struct drm_d
struct drm_armada_gem_pwrite *args = data;
struct armada_gem_object *dobj;
char __user *ptr;
- int ret;
+ int ret = 0;
DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
args->handle, args->offset, args->size, args->ptr);
@@ -349,9 +349,8 @@ int armada_gem_pwrite_ioctl(struct drm_d
if (!access_ok(ptr, args->size))
return -EFAULT;
- ret = fault_in_pages_readable(ptr, args->size);
- if (ret)
- return ret;
+ if (fault_in_readable(ptr, args->size))
+ return -EFAULT;
dobj = armada_gem_object_lookup(file, args->handle);
if (dobj == NULL)
@@ -2258,9 +2258,8 @@ static noinline int search_ioctl(struct
key.offset = sk->min_offset;
while (1) {
- ret = fault_in_pages_writeable(ubuf + sk_offset,
- *buf_size - sk_offset);
- if (ret)
+ ret = -EFAULT;
+ if (fault_in_writeable(ubuf + sk_offset, *buf_size - sk_offset))
break;
ret = btrfs_search_forward(root, &key, path, sk->min_transid);
@@ -733,61 +733,10 @@ int wait_on_page_private_2_killable(stru
extern void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter);
/*
- * Fault everything in given userspace address range in.
+ * Fault in userspace address range.
*/
-static inline int fault_in_pages_writeable(char __user *uaddr, size_t size)
-{
- char __user *end = uaddr + size - 1;
-
- if (unlikely(size == 0))
- return 0;
-
- if (unlikely(uaddr > end))
- return -EFAULT;
- /*
- * Writing zeroes into userspace here is OK, because we know that if
- * the zero gets there, we'll be overwriting it.
- */
- do {
- if (unlikely(__put_user(0, uaddr) != 0))
- return -EFAULT;
- uaddr += PAGE_SIZE;
- } while (uaddr <= end);
-
- /* Check whether the range spilled into the next page. */
- if (((unsigned long)uaddr & PAGE_MASK) ==
- ((unsigned long)end & PAGE_MASK))
- return __put_user(0, end);
-
- return 0;
-}
-
-static inline int fault_in_pages_readable(const char __user *uaddr, size_t size)
-{
- volatile char c;
- const char __user *end = uaddr + size - 1;
-
- if (unlikely(size == 0))
- return 0;
-
- if (unlikely(uaddr > end))
- return -EFAULT;
-
- do {
- if (unlikely(__get_user(c, uaddr) != 0))
- return -EFAULT;
- uaddr += PAGE_SIZE;
- } while (uaddr <= end);
-
- /* Check whether the range spilled into the next page. */
- if (((unsigned long)uaddr & PAGE_MASK) ==
- ((unsigned long)end & PAGE_MASK)) {
- return __get_user(c, end);
- }
-
- (void)c;
- return 0;
-}
+size_t fault_in_writeable(char __user *uaddr, size_t size);
+size_t fault_in_readable(const char __user *uaddr, size_t size);
int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
pgoff_t index, gfp_t gfp_mask);
@@ -191,7 +191,7 @@ static size_t copy_page_to_iter_iovec(st
buf = iov->iov_base + skip;
copy = min(bytes, iov->iov_len - skip);
- if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) {
+ if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_writeable(buf, copy)) {
kaddr = kmap_atomic(page);
from = kaddr + offset;
@@ -275,7 +275,7 @@ static size_t copy_page_from_iter_iovec(
buf = iov->iov_base + skip;
copy = min(bytes, iov->iov_len - skip);
- if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) {
+ if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_readable(buf, copy)) {
kaddr = kmap_atomic(page);
to = kaddr + offset;
@@ -447,13 +447,11 @@ int iov_iter_fault_in_readable(const str
bytes = i->count;
for (p = i->iov, skip = i->iov_offset; bytes; p++, skip = 0) {
size_t len = min(bytes, p->iov_len - skip);
- int err;
if (unlikely(!len))
continue;
- err = fault_in_pages_readable(p->iov_base + skip, len);
- if (unlikely(err))
- return err;
+ if (fault_in_readable(p->iov_base + skip, len))
+ return -EFAULT;
bytes -= len;
}
}
@@ -90,7 +90,7 @@
* ->lock_page (filemap_fault, access_process_vm)
*
* ->i_rwsem (generic_perform_write)
- * ->mmap_lock (fault_in_pages_readable->do_page_fault)
+ * ->mmap_lock (fault_in_readable->do_page_fault)
*
* bdi->wb.list_lock
* sb_lock (fs/fs-writeback.c)
@@ -1682,6 +1682,78 @@ finish_or_fault:
#endif /* !CONFIG_MMU */
/**
+ * fault_in_writeable - fault in userspace address range for writing
+ * @uaddr: start of address range
+ * @size: size of address range
+ *
+ * Returns the number of bytes not faulted in (like copy_to_user() and
+ * copy_from_user()).
+ */
+size_t fault_in_writeable(char __user *uaddr, size_t size)
+{
+ char __user *start = uaddr, *end;
+
+ if (unlikely(size == 0))
+ return 0;
+ if (!PAGE_ALIGNED(uaddr)) {
+ if (unlikely(__put_user(0, uaddr) != 0))
+ return size;
+ uaddr = (char __user *)PAGE_ALIGN((unsigned long)uaddr);
+ }
+ end = (char __user *)PAGE_ALIGN((unsigned long)start + size);
+ if (unlikely(end < start))
+ end = NULL;
+ while (uaddr != end) {
+ if (unlikely(__put_user(0, uaddr) != 0))
+ goto out;
+ uaddr += PAGE_SIZE;
+ }
+
+out:
+ if (size > uaddr - start)
+ return size - (uaddr - start);
+ return 0;
+}
+EXPORT_SYMBOL(fault_in_writeable);
+
+/**
+ * fault_in_readable - fault in userspace address range for reading
+ * @uaddr: start of user address range
+ * @size: size of user address range
+ *
+ * Returns the number of bytes not faulted in (like copy_to_user() and
+ * copy_from_user()).
+ */
+size_t fault_in_readable(const char __user *uaddr, size_t size)
+{
+ const char __user *start = uaddr, *end;
+ volatile char c;
+
+ if (unlikely(size == 0))
+ return 0;
+ if (!PAGE_ALIGNED(uaddr)) {
+ if (unlikely(__get_user(c, uaddr) != 0))
+ return size;
+ uaddr = (const char __user *)PAGE_ALIGN((unsigned long)uaddr);
+ }
+ end = (const char __user *)PAGE_ALIGN((unsigned long)start + size);
+ if (unlikely(end < start))
+ end = NULL;
+ while (uaddr != end) {
+ if (unlikely(__get_user(c, uaddr) != 0))
+ goto out;
+ uaddr += PAGE_SIZE;
+ }
+
+out:
+ (void)c;
+ if (size > uaddr - start)
+ return size - (uaddr - start);
+ return 0;
+}
+EXPORT_SYMBOL(fault_in_readable);
+
+/**
* get_dump_page() - pin user page in memory while writing it to core dump
* @addr: user address
*