Commit 388e67e6 authored by Chuck Lever's avatar Chuck Lever Committed by Yu Kuai
Browse files

maple_tree: Add mtree_alloc_cyclic() 

mainline inclusion
from mainline-v6.9-rc1
commit 9b6713cc75229f25552c643083cbdbfb771e5bca
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAR5GW
CVE: CVE-2024-46701

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9b6713cc75229f25552c643083cbdbfb771e5bca



--------------------------------

I need a cyclic allocator for the simple_offset implementation in
fs/libfs.c.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/170820144179.6328.12838600511394432325.stgit@91.116.238.104.host.secureserver.net


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
parent 0499d672

include/linux/maple_tree.h

+7 −0
Original line number Diff line number Diff line
@@ -171,6 +171,7 @@ enum maple_type { 
#define MT_FLAGS_LOCK_IRQ	0x100

#define MT_FLAGS_LOCK_BH	0x200

#define MT_FLAGS_LOCK_EXTERN	0x300

#define MT_FLAGS_ALLOC_WRAPPED	0x0800



#define MAPLE_HEIGHT_MAX	31
@@ -319,6 +320,9 @@ int mtree_insert_range(struct maple_tree *mt, unsigned long first, 
int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,

		void *entry, unsigned long size, unsigned long min,

		unsigned long max, gfp_t gfp);

int mtree_alloc_cyclic(struct maple_tree *mt, unsigned long *startp,

		void *entry, unsigned long range_lo, unsigned long range_hi,

		unsigned long *next, gfp_t gfp);

int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,

		void *entry, unsigned long size, unsigned long min,

		unsigned long max, gfp_t gfp);
@@ -499,6 +503,9 @@ void *mas_find_range(struct ma_state *mas, unsigned long max); 
void *mas_find_rev(struct ma_state *mas, unsigned long min);

void *mas_find_range_rev(struct ma_state *mas, unsigned long max);

int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp);

int mas_alloc_cyclic(struct ma_state *mas, unsigned long *startp,

		void *entry, unsigned long range_lo, unsigned long range_hi,

		unsigned long *next, gfp_t gfp);



bool mas_nomem(struct ma_state *mas, gfp_t gfp);

void mas_pause(struct ma_state *mas);

lib/maple_tree.c

+93 −0
Original line number Diff line number Diff line
@@ -4337,6 +4337,56 @@ static inline void *mas_insert(struct ma_state *mas, void *entry) 


}



/**

 * mas_alloc_cyclic() - Internal call to find somewhere to store an entry

 * @mas: The maple state.

 * @startp: Pointer to ID.

 * @range_lo: Lower bound of range to search.

 * @range_hi: Upper bound of range to search.

 * @entry: The entry to store.

 * @next: Pointer to next ID to allocate.

 * @gfp: The GFP_FLAGS to use for allocations.

 *

 * Return: 0 if the allocation succeeded without wrapping, 1 if the

 * allocation succeeded after wrapping, or -EBUSY if there are no

 * free entries.

 */

int mas_alloc_cyclic(struct ma_state *mas, unsigned long *startp,

		void *entry, unsigned long range_lo, unsigned long range_hi,

		unsigned long *next, gfp_t gfp)

{

	unsigned long min = range_lo;

	int ret = 0;



	range_lo = max(min, *next);

	ret = mas_empty_area(mas, range_lo, range_hi, 1);

	if ((mas->tree->ma_flags & MT_FLAGS_ALLOC_WRAPPED) && ret == 0) {

		mas->tree->ma_flags &= ~MT_FLAGS_ALLOC_WRAPPED;

		ret = 1;

	}

	if (ret < 0 && range_lo > min) {

		ret = mas_empty_area(mas, min, range_hi, 1);

		if (ret == 0)

			ret = 1;

	}

	if (ret < 0)

		return ret;



	do {

		mas_insert(mas, entry);

	} while (mas_nomem(mas, gfp));

	if (mas_is_err(mas))

		return xa_err(mas->node);



	*startp = mas->index;

	*next = *startp + 1;

	if (*next == 0)

		mas->tree->ma_flags |= MT_FLAGS_ALLOC_WRAPPED;



	return ret;

}

EXPORT_SYMBOL(mas_alloc_cyclic);



static __always_inline void mas_rewalk(struct ma_state *mas, unsigned long index)

{

retry:
@@ -6490,6 +6540,49 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp, 
}

EXPORT_SYMBOL(mtree_alloc_range);



/**

 * mtree_alloc_cyclic() - Find somewhere to store this entry in the tree.

 * @mt: The maple tree.

 * @startp: Pointer to ID.

 * @range_lo: Lower bound of range to search.

 * @range_hi: Upper bound of range to search.

 * @entry: The entry to store.

 * @next: Pointer to next ID to allocate.

 * @gfp: The GFP_FLAGS to use for allocations.

 *

 * Finds an empty entry in @mt after @next, stores the new index into

 * the @id pointer, stores the entry at that index, then updates @next.

 *

 * @mt must be initialized with the MT_FLAGS_ALLOC_RANGE flag.

 *

 * Context: Any context.  Takes and releases the mt.lock.  May sleep if

 * the @gfp flags permit.

 *

 * Return: 0 if the allocation succeeded without wrapping, 1 if the

 * allocation succeeded after wrapping, -ENOMEM if memory could not be

 * allocated, -EINVAL if @mt cannot be used, or -EBUSY if there are no

 * free entries.

 */

int mtree_alloc_cyclic(struct maple_tree *mt, unsigned long *startp,

		void *entry, unsigned long range_lo, unsigned long range_hi,

		unsigned long *next, gfp_t gfp)

{

	int ret;



	MA_STATE(mas, mt, 0, 0);



	if (!mt_is_alloc(mt))

		return -EINVAL;

	if (WARN_ON_ONCE(mt_is_reserved(entry)))

		return -EINVAL;

	mtree_lock(mt);

	ret = mas_alloc_cyclic(&mas, startp, entry, range_lo, range_hi,

			       next, gfp);

	mtree_unlock(mt);

	return ret;

}

EXPORT_SYMBOL(mtree_alloc_cyclic);



int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,

		void *entry, unsigned long size, unsigned long min,

		unsigned long max, gfp_t gfp)