Messages in this thread Patch in this message | | | From | T Makphaibulchoke <> | Subject | [PATCH] kernel/resource.c: fix stack overflow in __reserve_region_with_split | Date | Mon, 27 Aug 2012 18:47:54 -0600 |
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Using recurvise call to try adding a non-conflicting region in the function __reserve_region_with_split() could result in a stack overflow in the case that the recursive calls are too deep. Convert the recursive calls to an iterative loop to avoid the problem.
Signed-off-by: T Makphaibulchoke <tmac@hp.com> --- kernel/resource.c | 32 ++++++++++++++++++-------------- 1 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/kernel/resource.c b/kernel/resource.c index 34d4588..d6e9f9c 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -768,25 +768,29 @@ static void __init __reserve_region_with_split(struct resource *root, return; res->name = name; - res->start = start; - res->end = end; res->flags = IORESOURCE_BUSY; - conflict = __request_resource(parent, res); - if (!conflict) - return; + while (1) { + res->start = start; + res->end = end; - /* failed, split and try again */ - kfree(res); + conflict = __request_resource(parent, res); + if (!conflict) + break; - /* conflict covered whole area */ - if (conflict->start <= start && conflict->end >= end) - return; + /* conflict covered whole area */ + if (conflict->start <= start && conflict->end >= end) { + kfree(res); + break; + } + + /* failed, split and try again */ + if (conflict->start > start) + end = conflict->start - 1; + if (conflict->end < end) + start = conflict->end + 1; + } - if (conflict->start > start) - __reserve_region_with_split(root, start, conflict->start-1, name); - if (conflict->end < end) - __reserve_region_with_split(root, conflict->end+1, end, name); } void __init reserve_region_with_split(struct resource *root, -- 1.7.1
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