Commit c44aa5e8 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

XArray: Fix xas_find returning too many entries 



If you call xas_find() with the initial index > max, it should have
returned NULL but was returning the entry at index.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org
parent 19c30f4d

lib/test_xarray.c

+5 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
/*

 * test_xarray.c: Test the XArray API

 * Copyright (c) 2017-2018 Microsoft Corporation

 * Copyright (c) 2019-2020 Oracle

 * Author: Matthew Wilcox <willy@infradead.org>

 */
@@ -911,6 +912,7 @@ static noinline void check_multi_find_1(struct xarray *xa, unsigned order) 


	xa_store_order(xa, multi, order, xa_mk_value(multi), GFP_KERNEL);

	XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL) != NULL);

	XA_BUG_ON(xa, xa_store_index(xa, next + 1, GFP_KERNEL) != NULL);



	index = 0;

	XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
@@ -923,9 +925,12 @@ static noinline void check_multi_find_1(struct xarray *xa, unsigned order) 
	XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) !=

			xa_mk_value(next));

	XA_BUG_ON(xa, index != next);

	XA_BUG_ON(xa, xa_find_after(xa, &index, next, XA_PRESENT) != NULL);

	XA_BUG_ON(xa, index != next);



	xa_erase_index(xa, multi);

	xa_erase_index(xa, next);

	xa_erase_index(xa, next + 1);

	XA_BUG_ON(xa, !xa_empty(xa));

#endif

}

lib/xarray.c

+8 −2
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * XArray implementation

 * Copyright (c) 2017 Microsoft Corporation

 * Copyright (c) 2017-2018 Microsoft Corporation

 * Copyright (c) 2018-2020 Oracle

 * Author: Matthew Wilcox <willy@infradead.org>

 */
@@ -1083,6 +1084,8 @@ void *xas_find(struct xa_state *xas, unsigned long max) 


	if (xas_error(xas) || xas->xa_node == XAS_BOUNDS)

		return NULL;

	if (xas->xa_index > max)

		return set_bounds(xas);



	if (!xas->xa_node) {

		xas->xa_index = 1;
@@ -1152,6 +1155,8 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark) 


	if (xas_error(xas))

		return NULL;

	if (xas->xa_index > max)

		goto max;



	if (!xas->xa_node) {

		xas->xa_index = 1;
@@ -1869,7 +1874,8 @@ void *xa_find_after(struct xarray *xa, unsigned long *indexp, 
			entry = xas_find_marked(&xas, max, filter);

		else

			entry = xas_find(&xas, max);

		if (xas.xa_node == XAS_BOUNDS)



		if (xas_invalid(&xas))

			break;

		if (xas_sibling(&xas))

			continue;