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authorOctavian Purdila <octavian.purdila@intel.com>2012-07-30 14:42:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 17:25:21 -0700
commit65fed8f6f23070b56d0ed3841173ddd410130a89 (patch)
treed9549d5cc05f74789bd34a400ce3275c9c224c01
parentf7e1becb078c2b996420a61f2a411ef19335e2da (diff)
downloadop-kernel-dev-65fed8f6f23070b56d0ed3841173ddd410130a89.zip
op-kernel-dev-65fed8f6f23070b56d0ed3841173ddd410130a89.tar.gz
resource: make sure requested range is included in the root range
When the requested range is outside of the root range the logic in __reserve_region_with_split will cause an infinite recursion which will overflow the stack as seen in the warning bellow. This particular stack overflow was caused by requesting the (100000000-107ffffff) range while the root range was (0-ffffffff). In this case __request_resource would return the whole root range as conflict range (i.e. 0-ffffffff). Then, the logic in __reserve_region_with_split would continue the recursion requesting the new range as (conflict->end+1, end) which incidentally in this case equals the originally requested range. This patch aborts looking for an usable range when the request does not intersect with the root range. When the request partially overlaps with the root range, it ajust the request to fall in the root range and then continues with the new request. When the request is modified or aborted errors and a stack trace are logged to allow catching the errors in the upper layers. [ 5.968374] WARNING: at kernel/sched.c:4129 sub_preempt_count+0x63/0x89() [ 5.975150] Modules linked in: [ 5.978184] Pid: 1, comm: swapper Not tainted 3.0.22-mid27-00004-gb72c817 #46 [ 5.985324] Call Trace: [ 5.987759] [<c1039dfc>] ? console_unlock+0x17b/0x18d [ 5.992891] [<c1039620>] warn_slowpath_common+0x48/0x5d [ 5.998194] [<c1031758>] ? sub_preempt_count+0x63/0x89 [ 6.003412] [<c1039644>] warn_slowpath_null+0xf/0x13 [ 6.008453] [<c1031758>] sub_preempt_count+0x63/0x89 [ 6.013499] [<c14d60c4>] _raw_spin_unlock+0x27/0x3f [ 6.018453] [<c10c6349>] add_partial+0x36/0x3b [ 6.022973] [<c10c7c0a>] deactivate_slab+0x96/0xb4 [ 6.027842] [<c14cf9d9>] __slab_alloc.isra.54.constprop.63+0x204/0x241 [ 6.034456] [<c103f78f>] ? kzalloc.constprop.5+0x29/0x38 [ 6.039842] [<c103f78f>] ? kzalloc.constprop.5+0x29/0x38 [ 6.045232] [<c10c7dc9>] kmem_cache_alloc_trace+0x51/0xb0 [ 6.050710] [<c103f78f>] ? kzalloc.constprop.5+0x29/0x38 [ 6.056100] [<c103f78f>] kzalloc.constprop.5+0x29/0x38 [ 6.061320] [<c17b45e9>] __reserve_region_with_split+0x1c/0xd1 [ 6.067230] [<c17b4693>] __reserve_region_with_split+0xc6/0xd1 ... [ 7.179057] [<c17b4693>] __reserve_region_with_split+0xc6/0xd1 [ 7.184970] [<c17b4779>] reserve_region_with_split+0x30/0x42 [ 7.190709] [<c17a8ebf>] e820_reserve_resources_late+0xd1/0xe9 [ 7.196623] [<c17c9526>] pcibios_resource_survey+0x23/0x2a [ 7.202184] [<c17cad8a>] pcibios_init+0x23/0x35 [ 7.206789] [<c17ca574>] pci_subsys_init+0x3f/0x44 [ 7.211659] [<c1002088>] do_one_initcall+0x72/0x122 [ 7.216615] [<c17ca535>] ? pci_legacy_init+0x3d/0x3d [ 7.221659] [<c17a27ff>] kernel_init+0xa6/0x118 [ 7.226265] [<c17a2759>] ? start_kernel+0x334/0x334 [ 7.231223] [<c14d7482>] kernel_thread_helper+0x6/0x10 Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/resource.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index dc8b477..34d4588 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -7,6 +7,8 @@
* Arbitrary resource management.
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/ioport.h>
@@ -791,8 +793,28 @@ void __init reserve_region_with_split(struct resource *root,
resource_size_t start, resource_size_t end,
const char *name)
{
+ int abort = 0;
+
write_lock(&resource_lock);
- __reserve_region_with_split(root, start, end, name);
+ if (root->start > start || root->end < end) {
+ pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
+ (unsigned long long)start, (unsigned long long)end,
+ root);
+ if (start > root->end || end < root->start)
+ abort = 1;
+ else {
+ if (end > root->end)
+ end = root->end;
+ if (start < root->start)
+ start = root->start;
+ pr_err("fixing request to [0x%llx-0x%llx]\n",
+ (unsigned long long)start,
+ (unsigned long long)end);
+ }
+ dump_stack();
+ }
+ if (!abort)
+ __reserve_region_with_split(root, start, end, name);
write_unlock(&resource_lock);
}
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