Messages in this thread Patch in this message | | | Subject | [PATCH v3 1/6] resources: ensure alignment callback doesn't allocate below available start | From | Bjorn Helgaas <> | Date | Wed, 13 Oct 2010 10:15:10 -0600 |
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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 a location above the available area.
This patch adds a check to make sure the callback doesn't return something *below* the available area, as may happen if the callback tries to allocate top-down.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> ---
kernel/resource.c | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/kernel/resource.c b/kernel/resource.c index 7b36976..ace2269 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -371,6 +371,7 @@ static int find_resource(struct resource *root, struct resource *new, { struct resource *this = root->child; struct resource tmp = *new; + resource_size_t start; tmp.start = root->start; /* @@ -391,8 +392,13 @@ static int find_resource(struct resource *root, struct resource *new, if (tmp.end > max) tmp.end = max; tmp.start = ALIGN(tmp.start, align); - if (alignf) - tmp.start = alignf(alignf_data, &tmp, size, align); + if (alignf) { + start = alignf(alignf_data, &tmp, size, align); + if (tmp.start <= start && start <= tmp.end) + tmp.start = start; + else + tmp.start = tmp.end; + } if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) { new->start = tmp.start; new->end = tmp.start + size - 1;
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