Using a recursive call add a non-conflicting region in
__reserve_region_with_split() could result in a stack overflow in the case
that the recursive calls are too deep. Convert the recursive calls to an
iterative loop to avoid the problem.
Tested on a machine containing 135 regions. The kernel no longer panicked
with stack overflow.
Also tested with code arbitrarily adding regions with no conflict,
embedding two consecutive conflicts and embedding two non-consecutive
conflicts.
Signed-off-by: T Makphaibulchoke <tmac@hp.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@gmail.com>
Cc: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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 <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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 <weiyang@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
EXPORT_SYMBOL(adjust_resource) should be right after adjust_resource().
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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 <linux/module.h>
+#include <linux/export.h>
This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
__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 2bbc694227
("PCI : ability to relocate assigned pci-resources")
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Tested-by: Michal Ludvig <mludvig@logix.net.nz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <geert@linux-m68k.org>
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 <linuxram@us.ibm.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (27 commits)
x86: allocate space within a region top-down
x86: update iomem_resource end based on CPU physical address capabilities
x86/PCI: allocate space from the end of a region, not the beginning
PCI: allocate bus resources from the top down
resources: support allocating space within a region from the top down
resources: handle overflow when aligning start of available area
resources: ensure callback doesn't allocate outside available space
resources: factor out resource_clip() to simplify find_resource()
resources: add a default alignf to simplify find_resource()
x86/PCI: MMCONFIG: fix region end calculation
PCI: Add support for polling PME state on suspended legacy PCI devices
PCI: Export some PCI PM functionality
PCI: fix message typo
PCI: log vendor/device ID always
PCI: update Intel chipset names and defines
PCI: use new ccflags variable in Makefile
PCI: add PCI_MSIX_TABLE/PBA defines
PCI: add PCI vendor id for STmicroelectronics
x86/PCI: irq and pci_ids patch for Intel Patsburg DeviceIDs
PCI: OLPC: Only enable PCI configuration type override on XO-1
...
If the same resource is inserted to the resource tree (maybe not on
purpose), a dead loop will be created. In this situation, The kernel does
not report any warning or error :(
The command below will show a endless print.
#cat /proc/iomem
[akpm@linux-foundation.org: add WARN_ON()]
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allocate space from the top of a region first, then work downward,
if an architecture desires this.
When we allocate space from a resource, we look for gaps between children
of the resource. Previously, we always looked at gaps from the bottom up.
For example, given this:
[mem 0xbff00000-0xf7ffffff] PCI Bus 0000:00
[mem 0xbff00000-0xbfffffff] gap -- available
[mem 0xc0000000-0xdfffffff] PCI Bus 0000:02
[mem 0xe0000000-0xf7ffffff] gap -- available
we attempted to allocate from the [mem 0xbff00000-0xbfffffff] gap first,
then the [mem 0xe0000000-0xf7ffffff] gap.
With this patch an architecture can choose to allocate from the top gap
[mem 0xe0000000-0xf7ffffff] first.
We can't do this across the board because iomem_resource.end is initialized
to 0xffffffff_ffffffff on 64-bit architectures, and most machines can't
address the entire 64-bit physical address space. Therefore, we only
allocate top-down if the arch requests it by clearing
"resource_alloc_from_bottom".
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
If tmp.start is near ~0, ALIGN(tmp.start) may overflow, which would
make us think there's more available space than there really is. We
would likely return something that conflicts with a previous resource,
which would cause a failure when allocate_resource() requests the newly-
allocated region.
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=646027
Reported-by: Fabrice Bellet <fabrice@bellet.info>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The alignment callback returns a proposed location, which may have been
adjusted to avoid ISA aliases or for other architecture-specific reasons.
We already had a check ("tmp.start < tmp.end") to make sure the callback
doesn't return an area that extends past the available area. This patch
reworks the check to make sure it doesn't return an area that extends
either below or above the available area.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This factors out the min/max clipping to simplify find_resource().
No functional change.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This removes a test from find_resource(), which is getting cluttered.
No functional change.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
SuperIO devices share regions and use lock/unlock operations to chip
select. We therefore need to be able to request a resource and wait for
it to be freed by whichever other SuperIO device currently hogs it.
Right now you have to poll which is horrible.
Add a MUXED field to IO port resources. If the MUXED field is set on the
resource and on the request (via request_muxed_region) then we block
until the previous owner of the muxed resource releases their region.
This allows us to implement proper resource sharing and locking for
superio chips using code of the form
enable_my_superio_dev() {
request_muxed_region(0x44, 0x02, "superio:watchdog");
outb() ..sequence to enable chip
}
disable_my_superio_dev() {
outb() .. sequence of disable chip
release_region(0x44, 0x02);
}
Signed-off-by: Giel van Schijndel <me@mortis.eu>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
request_resource() and insert_resource() only return success or failure,
which no information about what existing resource conflicted with the
proposed new reservation. This patch adds request_resource_conflict()
and insert_resource_conflict(), which return the conflicting resource.
Callers may use this for better error messages or to adjust the new
resource and retry the request.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The System RAM walk shall skip partial RAM pages and avoid calling
func() on them. So that page_is_ram() return 0 for a partial RAM page.
In particular, it shall not call func() with len=0.
This fixes a boot time bug reported by Sachin and root caused by Thomas:
> >>> WARNING: at arch/x86/mm/ioremap.c:111 __ioremap_caller+0x169/0x2f1()
> >>> Hardware name: BladeCenter LS21 -[79716AA]-
> >>> Modules linked in:
> >>> Pid: 0, comm: swapper Not tainted 2.6.33-git6-autotest #1
> >>> Call Trace:
> >>> [<ffffffff81047cff>] ? __ioremap_caller+0x169/0x2f1
> >>> [<ffffffff81063b7d>] warn_slowpath_common+0x77/0xa4
> >>> [<ffffffff81063bb9>] warn_slowpath_null+0xf/0x11
> >>> [<ffffffff81047cff>] __ioremap_caller+0x169/0x2f1
> >>> [<ffffffff813747a3>] ? acpi_os_map_memory+0x12/0x1b
> >>> [<ffffffff81047f10>] ioremap_nocache+0x12/0x14
> >>> [<ffffffff813747a3>] acpi_os_map_memory+0x12/0x1b
> >>> [<ffffffff81282fa0>] acpi_tb_verify_table+0x29/0x5b
> >>> [<ffffffff812827f0>] acpi_load_tables+0x39/0x15a
> >>> [<ffffffff8191c8f8>] acpi_early_init+0x60/0xf5
> >>> [<ffffffff818f2cad>] start_kernel+0x397/0x3a7
> >>> [<ffffffff818f2295>] x86_64_start_reservations+0xa5/0xa9
> >>> [<ffffffff818f237a>] x86_64_start_kernel+0xe1/0xe8
> >>> ---[ end trace 4eaa2a86a8e2da22 ]---
> >>> ioremap reserve_memtype failed -22
The return code is -EINVAL, so it failed in the is_ram check, which is
not too surprising
> BIOS-provided physical RAM map:
> BIOS-e820: 0000000000000000 - 000000000009c000 (usable)
> BIOS-e820: 000000000009c000 - 00000000000a0000 (reserved)
> BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
> BIOS-e820: 0000000000100000 - 00000000cffa3900 (usable)
> BIOS-e820: 00000000cffa3900 - 00000000cffa7400 (ACPI data)
The ACPI data is not starting on a page boundary and neither does the
usable RAM area end on a page boundary. Very useful !
> ACPI: DSDT 00000000cffa3900 036CE (v01 IBM SERLEWIS 00001000 INTL 20060912)
ACPI is trying to map DSDT at cffa3900, which results in a check
vs. cffa3000 which is the relevant page boundary. The generic is_ram
check correctly identifies that as RAM because it's in the usable
resource area. The old e820 based is_ram check does not take
overlapping resource areas into account. That's why it works.
CC: Sachin Sant <sachinp@in.ibm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
LKML-Reference: <20100301135551.GA9998@localhost>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, mm: Unify kernel_physical_mapping_init() API
x86, mm: Allow highmem user page tables to be disabled at boot time
x86: Do not reserve brk for DMI if it's not going to be used
x86: Convert tlbstate_lock to raw_spinlock
x86: Use the generic page_is_ram()
x86: Remove BIOS data range from e820
Move page_is_ram() declaration to mm.h
Generic page_is_ram: use __weak
resources: introduce generic page_is_ram()
