linux/kernel/resource.c, branch v3.6

resource: make sure requested range is included in the root range

2012-07-31T00:25:21Z

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

resources: allow adjust_resource() for resources with no parent

2012-06-13T21:42:22Z

If a resource has no parent, allow its start/end to be set arbitrarily as long as any children are still contained within the new range. [bhelgaas: changelog] Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas

kernel/resource.c: correct the comment of allocate_resource()

2012-06-01T00:49:26Z

In the comment of allocate_resource(), the explanation of parameter max and min is not correct. Actually, these two parameters are used to specify the range of the resource that will be allocated, not the min/max size that will be allocated. Signed-off-by: Wei Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel/resource.c: move EXPORT_SYMBOL right after definition

2012-02-03T22:37:07Z

EXPORT_SYMBOL(adjust_resource) should be right after adjust_resource(). Signed-off-by: WANG Cong Signed-off-by: Jiri Kosina

kernel: Map most files to use export.h instead of module.h

2011-10-31T13:20:12Z

The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include +#include This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker

Resource: fix wrong resource window calculation

2011-09-30T03:04:34Z

__find_resource() incorrectly returns a resource window which overlaps an existing allocated window. This happens when the parent's resource-window spans 0x00000000 to 0xffffffff and is entirely allocated to all its children resource-windows. __find_resource() looks for gaps in resource allocation among the children resource windows. When it encounters the last child window it blindly tries the range next to one allocated to the last child. Since the last child's window ends at 0xffffffff the calculation overflows, leading the algorithm to believe that any window in the range 0x0000000 to 0xfffffff is available for allocation. This leads to a conflicting window allocation. Michal Ludvig reported this issue seen on his platform. The following patch fixes the problem and has been verified by Michal. I believe this bug has been there for ages. It got exposed by git commit 2bbc6942273b ("PCI : ability to relocate assigned pci-resources") Signed-off-by: Ram Pai Tested-by: Michal Ludvig Signed-off-by: Linus Torvalds

resources: Add lookup_resource()

2011-07-30T19:21:39Z

Add a function to find an existing resource by a resource start address. This allows to implement simple allocators (with a malloc/free-alike API) on top of the resource system. Signed-off-by: Geert Uytterhoeven

resource: ability to resize an allocated resource

2011-07-06T17:54:08Z

Provides the ability to resize a resource that is already allocated. This functionality is put in place to support reallocation needs of pci resources. Signed-off-by: Ram Pai Acked-by: Jesse Barnes Signed-off-by: Linus Torvalds

resources: add arch hook for preventing allocation in reserved areas

2010-12-17T18:01:09Z

This adds arch_remove_reservations(), which an arch can implement if it needs to protect part of the address space from allocation. Sometimes that can be done by just putting a region in the resource tree, but there are cases where that doesn't work well. For example, x86 BIOS E820 reservations are not related to devices, so they may overlap part of, all of, or more than a device resource, so they may not end up at the correct spot in the resource tree. Acked-by: H. Peter Anvin Signed-off-by: Bjorn Helgaas Signed-off-by: Jesse Barnes

Revert "resources: support allocating space within a region from the top down"

2010-12-17T18:00:59Z

This reverts commit e7f8567db9a7f6b3151b0b275e245c1cef0d9c70. Acked-by: H. Peter Anvin Signed-off-by: Bjorn Helgaas Signed-off-by: Jesse Barnes