Commit 6909ba14 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Jesse Barnes
Browse files

resources: ensure callback doesn't allocate outside available space 



The alignment callback returns a proposed location, which may have been
adjusted to avoid ISA aliases or for other architecture-specific reasons.

We already had a check ("tmp.start < tmp.end") to make sure the callback
doesn't return an area that extends past the available area.  This patch
reworks the check to make sure it doesn't return an area that extends
either below or above the available area.

Signed-off-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 5d6b1fa3

kernel/resource.c

+11 −5
Original line number Diff line number Diff line
@@ -374,6 +374,11 @@ static void resource_clip(struct resource *res, resource_size_t min, 
		res->end = max;

}



static bool resource_contains(struct resource *res1, struct resource *res2)

{

	return res1->start <= res2->start && res1->end >= res2->end;

}



/*

 * Find empty slot in the resource tree given range and alignment.

 */
@@ -387,7 +392,7 @@ static int find_resource(struct resource *root, struct resource *new, 
			 void *alignf_data)

{

	struct resource *this = root->child;

	struct resource tmp = *new;

	struct resource tmp = *new, alloc;



	tmp.start = root->start;

	/*
@@ -407,10 +412,11 @@ static int find_resource(struct resource *root, struct resource *new, 
		resource_clip(&tmp, min, max);

		tmp.start = ALIGN(tmp.start, align);



		tmp.start = alignf(alignf_data, &tmp, size, align);

		if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {

			new->start = tmp.start;

			new->end = tmp.start + size - 1;

		alloc.start = alignf(alignf_data, &tmp, size, align);

		alloc.end = alloc.start + size - 1;

		if (resource_contains(&tmp, &alloc)) {

			new->start = alloc.start;

			new->end = alloc.end;

			return 0;

		}

		if (!this)

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