From 1e5ad9679016275d422e36b12a98b0927d76f556 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Mon, 2 Nov 2009 10:45:36 -0700 Subject: [PATCH] resources: when allocate_resource() fails, leave resource untouched When "allocate_resource(root, new, size, ...)" fails, we currently clobber "new". This is inconvenient for the caller, who might care about the original contents of the resource. For example, when pci_bus_alloc_resource() fails, the "can't allocate mem resource %pR" message from pci_assign_resources() currently contains junk for the resource start/end. This patch delays the "new" update until we're about to return success. Acked-by: Linus Torvalds Acked-by: Yinghai Lu Signed-off-by: Bjorn Helgaas Signed-off-by: Jesse Barnes --- kernel/resource.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index fb11a58b959..dc15686b7a7 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -308,35 +308,37 @@ static int find_resource(struct resource *root, struct resource *new, void *alignf_data) { struct resource *this = root->child; + resource_size_t start, end; - new->start = root->start; + start = root->start; /* * Skip past an allocated resource that starts at 0, since the assignment * of this->start - 1 to new->end below would cause an underflow. */ if (this && this->start == 0) { - new->start = this->end + 1; + start = this->end + 1; this = this->sibling; } for(;;) { if (this) - new->end = this->start - 1; + end = this->start - 1; else - new->end = root->end; - if (new->start < min) - new->start = min; - if (new->end > max) - new->end = max; - new->start = ALIGN(new->start, align); + end = root->end; + if (start < min) + start = min; + if (end > max) + end = max; + start = ALIGN(start, align); if (alignf) alignf(alignf_data, new, size, align); - if (new->start < new->end && new->end - new->start >= size - 1) { - new->end = new->start + size - 1; + if (start < end && end - start >= size - 1) { + new->start = start; + new->end = start + size - 1; return 0; } if (!this) break; - new->start = this->end + 1; + start = this->end + 1; this = this->sibling; } return -EBUSY; -- 2.39.5