From 65fed8f6f23070b56d0ed3841173ddd410130a89 Mon Sep 17 00:00:00 2001 From: Octavian Purdila Date: Mon, 30 Jul 2012 14:42:58 -0700 Subject: [PATCH] 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] [] ? console_unlock+0x17b/0x18d [ 5.992891] [] warn_slowpath_common+0x48/0x5d [ 5.998194] [] ? sub_preempt_count+0x63/0x89 [ 6.003412] [] warn_slowpath_null+0xf/0x13 [ 6.008453] [] sub_preempt_count+0x63/0x89 [ 6.013499] [] _raw_spin_unlock+0x27/0x3f [ 6.018453] [] add_partial+0x36/0x3b [ 6.022973] [] deactivate_slab+0x96/0xb4 [ 6.027842] [] __slab_alloc.isra.54.constprop.63+0x204/0x241 [ 6.034456] [] ? kzalloc.constprop.5+0x29/0x38 [ 6.039842] [] ? kzalloc.constprop.5+0x29/0x38 [ 6.045232] [] kmem_cache_alloc_trace+0x51/0xb0 [ 6.050710] [] ? kzalloc.constprop.5+0x29/0x38 [ 6.056100] [] kzalloc.constprop.5+0x29/0x38 [ 6.061320] [] __reserve_region_with_split+0x1c/0xd1 [ 6.067230] [] __reserve_region_with_split+0xc6/0xd1 ... [ 7.179057] [] __reserve_region_with_split+0xc6/0xd1 [ 7.184970] [] reserve_region_with_split+0x30/0x42 [ 7.190709] [] e820_reserve_resources_late+0xd1/0xe9 [ 7.196623] [] pcibios_resource_survey+0x23/0x2a [ 7.202184] [] pcibios_init+0x23/0x35 [ 7.206789] [] pci_subsys_init+0x3f/0x44 [ 7.211659] [] do_one_initcall+0x72/0x122 [ 7.216615] [] ? pci_legacy_init+0x3d/0x3d [ 7.221659] [] kernel_init+0xa6/0x118 [ 7.226265] [] ? start_kernel+0x334/0x334 [ 7.231223] [] kernel_thread_helper+0x6/0x10 Signed-off-by: Octavian Purdila Signed-off-by: Ram Pai Cc: Jesse Barnes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/resource.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/kernel/resource.c b/kernel/resource.c index dc8b47764443..34d45886ee84 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -7,6 +7,8 @@ * Arbitrary resource management. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -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); } -- 2.20.1