Commit df092ea4 authored by Wang ShaoBo's avatar Wang ShaoBo Committed by Zheng Zengkai
Browse files

arm64/mpam: realign step entry when traversing rmid_transform 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SE03


CVE: NA

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

This makes step entry aligned with step_size*step_cnt but not step_size,
and check for alignment before traversing rmid_transform.

When modifying rmid with a value not aligned with step_size*step_cnt,
for_each_rmid_transform_point_step_from might miss next step point if
it has been occupied in case step_cnt or step_size not equals to 1,
which will cause the actual allocated rmid to be inconsistent with the
expected one.

Fixes: 8a2c07b5 ("arm64/mpam: rmid: refine allocation and release process")
Signed-off-by: default avatarWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: default avatarCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 8cfa786d

arch/arm64/kernel/mpam/mpam_resctrl.c

+11 −9
Original line number Diff line number Diff line
@@ -834,7 +834,8 @@ static inline unsigned long **__rmid_remap_bmp(u32 col) 
#define __step_xy_initialize(step, x, y, from)		\

	(x = from, step = 1, y = 0)

#define __step_align(from)				\

	(!(from % rmid_remap_matrix.step_size))

	(!(from % (rmid_remap_matrix.step_size *	\

		rmid_remap_matrix.step_cnt)))

#define __step_overflow(step)				\

	(__xy_overflow(x, y) ||				\

		(step > rmid_remap_matrix.step_cnt))
@@ -908,7 +909,7 @@ static int is_rmid_remap_bmp_full(unsigned long *bmp) 
			bitmap_full(bmp, rmid_remap_matrix.rows));

}



static int rmid_remap_bmp_find_first_avail_partid(int partid)

static int rmid_remap_bmp_find_step_entry(int partid)

{

	int x, y;

	unsigned long **bmp;
@@ -917,17 +918,18 @@ static int rmid_remap_bmp_find_first_avail_partid(int partid) 
		rmid_remap_matrix.cols)

		return 0;



	/* step entry should be non-occupied and aligned */

	bmp = __rmid_remap_bmp(partid);

	if (bmp && !is_rmid_remap_bmp_occ(*bmp))

		return partid;

	if (bmp)

		return (is_rmid_remap_bmp_occ(*bmp) ||

			!__step_align(partid)) ? -ENOSPC : partid;



	for_each_rmid_transform_point_from(bmp, x, y, 0) {

		/*

		 * do not waste partid resource, start

		 * from step_size aligned position.

		 * from step aligned position.

		 */

		if (!is_rmid_remap_bmp_occ(*bmp) &&

			(x % rmid_remap_matrix.step_size) == 0)

		if (__step_align(x) && !is_rmid_remap_bmp_occ(*bmp))

			return x;

	}
@@ -1021,8 +1023,8 @@ static int __rmid_alloc(int partid, int pmg) 
	if (pmg >= 0)

		checkpmg = true;



	/* traverse from first non-occupied and step_size aligned entry */

	ret = rmid_remap_bmp_find_first_avail_partid(partid);

	/* traverse from first non-occupied and step-aligned entry */

	ret = rmid_remap_bmp_find_step_entry(partid);

	if (ret < 0)

		goto out;

	partid = ret;