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authorBjorn Helgaas <bjorn.helgaas@hp.com>2009-11-02 12:45:36 -0500
committerJesse Barnes <jbarnes@virtuousgeek.org>2009-11-04 16:06:46 -0500
commit1e5ad9679016275d422e36b12a98b0927d76f556 (patch)
treebde97d71c5ce1d4ecd238e1d187dc548078b928c /kernel
parent03db42adfeeabe856dbb6894dd3aaff55838330a (diff)
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 <torvalds@linux-foundation.org> Acked-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/resource.c26
1 files changed, 14 insertions, 12 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index fb11a58b9594..dc15686b7a77 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -308,35 +308,37 @@ static int find_resource(struct resource *root, struct resource *new,
308 void *alignf_data) 308 void *alignf_data)
309{ 309{
310 struct resource *this = root->child; 310 struct resource *this = root->child;
311 resource_size_t start, end;
311 312
312 new->start = root->start; 313 start = root->start;
313 /* 314 /*
314 * Skip past an allocated resource that starts at 0, since the assignment 315 * Skip past an allocated resource that starts at 0, since the assignment
315 * of this->start - 1 to new->end below would cause an underflow. 316 * of this->start - 1 to new->end below would cause an underflow.
316 */ 317 */
317 if (this && this->start == 0) { 318 if (this && this->start == 0) {
318 new->start = this->end + 1; 319 start = this->end + 1;
319 this = this->sibling; 320 this = this->sibling;
320 } 321 }
321 for(;;) { 322 for(;;) {
322 if (this) 323 if (this)
323 new->end = this->start - 1; 324 end = this->start - 1;
324 else 325 else
325 new->end = root->end; 326 end = root->end;
326 if (new->start < min) 327 if (start < min)
327 new->start = min; 328 start = min;
328 if (new->end > max) 329 if (end > max)
329 new->end = max; 330 end = max;
330 new->start = ALIGN(new->start, align); 331 start = ALIGN(start, align);
331 if (alignf) 332 if (alignf)
332 alignf(alignf_data, new, size, align); 333 alignf(alignf_data, new, size, align);
333 if (new->start < new->end && new->end - new->start >= size - 1) { 334 if (start < end && end - start >= size - 1) {
334 new->end = new->start + size - 1; 335 new->start = start;
336 new->end = start + size - 1;
335 return 0; 337 return 0;
336 } 338 }
337 if (!this) 339 if (!this)
338 break; 340 break;
339 new->start = this->end + 1; 341 start = this->end + 1;
340 this = this->sibling; 342 this = this->sibling;
341 } 343 }
342 return -EBUSY; 344 return -EBUSY;