On Mon, May 19, 2008 at 04:10:02PM -0700, Linus Torvalds wrote:
> It also causes these warnings on 32-bit PAE:
>
> AS arch/x86/kernel/head_32.o
> arch/x86/kernel/head_32.S: Assembler messages:
> arch/x86/kernel/head_32.S:225: Warning: left operand is a bignum; integer 0 assumed
> arch/x86/kernel/head_32.S:609: Warning: left operand is a bignum; integer 0 assumed
>
> and I do not see why (the end result seems to be identical).
Fix head_32.S gcc bignum warnings when CONFIG_PAE=y.
arch/x86/kernel/head_32.S: Assembler messages:
arch/x86/kernel/head_32.S:225: Warning: left operand is a bignum; integer 0 assumed
arch/x86/kernel/head_32.S:609: Warning: left operand is a bignum; integer 0 assumed
The assembler was stumbling over the 64-bit constant 0x100000000 in the
KPMDS #define.
Testing: a cmp(1) on head_32.o before and after shows the binary is unchanged.
Signed-off-by: Joe Korty <joe.korty@ccur.com
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Gabriel C <nix.or.die@googlemail.com>
Cc: Keith Packard <keithp@keithp.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: "Siddha Suresh B" <suresh.b.siddha@intel.com>
Cc: bugme-daemon@bugzilla.kernel.org
Cc: airlied@linux.ie
Cc: "Barnes Jesse" <jesse.barnes@intel.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Page faults in kernel address space between PAGE_OFFSET up to
VMALLOC_START should not try to map as vmalloc.
Fix rarely endless page faults inside mount_block_root for root
filesystem at boot time.
All 32bit kernels up to 2.6.25 can fail into this hole.
I can not present this under native linux kernel. I see, that the 64bit
has fixed the problem. I copied the same lines into 32bit part.
Recorded debugs are from coLinux kernel 2.6.22.18 (virtualisation):
http://www.henrynestler.com/colinux/testing/pfn-check-0.7.3/20080410-antinx/bug16-recursive-page-fault-endless.txt
The physicaly memory was trimmed down to 192MB to better catch the bug.
More memory gets the bug more rarely.
Details, how every x86 32bit system can fail:
Start from "mount_block_root",
http://lxr.linux.no/linux/init/do_mounts.c#L297
There the variable "fs_names" got one memory page with 4096 bytes.
Variable "p" walks through the existing file system types. The first
string is no problem.
But, with the second loop in mount_block_root the offset of "p" is not
at beginning of page, the offset is for example +9, if "reiserfs" is the
first in list.
Than calls do_mount_root, and lands in sys_mount.
Remember: Variable "type_page" contains now "fs_type+9" and not contains
a full page.
The sys_mount copies 4096 bytes with function "exact_copy_from_user()":
http://lxr.linux.no/linux/fs/namespace.c#L1540
Mostly exist pages after the buffer "fs_names+4096+9" and the page fault
handler was not called. No problem.
In the case, if the page after "fs_names+4096" is not mapped, the page
fault handler was called from http://lxr.linux.no/linux/fs/namespace.c#L1320
The do_page_fault gots an address 0xc03b4000.
It's kernel address, address >= TASK_SIZE, but not from vmalloc! It's
from "__getname()" alias "kmem_cache_alloc".
The "error_code" is 0. "vmalloc_fault" will be call:
http://lxr.linux.no/linux/arch/i386/mm/fault.c#L332
"vmalloc_fault" tryed to find the physical page for a non existing
virtual memory area. The macro "pte_present" in vmalloc_fault()
got a next page fault for 0xc0000ed0 at:
http://lxr.linux.no/linux/arch/i386/mm/fault.c#L282
No PTE exist for such virtual address. The page fault handler was trying
to sync the physical page for the PTE lockup.
This called vmalloc_fault() again for address 0xc000000, and that also
was not existing. The endless began...
In normal case the cpu would still loop with disabled interrrupts. Under
coLinux this was catched by a stack overflow inside printk debugs.
Signed-off-by: Henry Nestler <henry.nestler@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6:
Blackfin serial driver: fix up tty core set_ldisc API change breakage bug
Blackfin arch: protect only the SPI bus controller with CONFIG_SPI_BFIN
Blackfin arch: fixup warnings with the new cplb saved values
Blackfin Serial Driver: Clean up BF54x macro in blackfin UART driver.
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[POWERPC] ehea: Remove dependency on MEMORY_HOTPLUG
[POWERPC] Make walk_memory_resource available with MEMORY_HOTPLUG=n
[POWERPC] Use dev_set_name in pci_64.c
[POWERPC] Fix incorrect enabling of VMX when building signal or user context
[POWERPC] boot/Makefile CONFIG_ variable fixes
Presently the --fdpic specifier and the --isa matching clash when
building with FDPIC toolchains. As we have no interest in building the
kernel with --fdpic in the first place, always try to add in -mno-fdpic
to the default flags.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
SH7763's setup code use old DECLARE_INTC_DESC.
There was a compile error because of this.
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The ehea driver was recently changed[1] to use walk_memory_resource() to
detect the system's memory layout. However, walk_memory_resource() is
available only when memory hotplug is enabled. So CONFIG_EHEA was
made to depend on MEMORY_HOTPLUG [2], but it is inappropriate for a
network driver to have such a dependency.
Make the declaration of walk_memory_resource() and its powerpc
implementation (ehea is powerpc-specific) unconditionally available.
[1] 48cfb14f8b
"ehea: Add DLPAR memory remove support"
[2] fb7b6ca2b6
"ehea: Add dependency to Kconfig"
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Acked-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
During the next merge window, pci_name()'s return value will become
const, so use the new dev_set_name() instead to avoid the warning (from
linux-next):
arch/powerpc/kernel/pci_64.c: In function 'of_create_pci_dev':
arch/powerpc/kernel/pci_64.c:193: warning: passing argument 1 of 'sprintf' discards qualifiers from pointer target type
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When building a signal or a ucontext, we can incorrectly set the MSR_VEC
bit of the kernel pt_regs->msr before returning to userspace if the task
-ever- used VMX.
This can lead to funny result if that stack used it in the past, then
"lost" it (ie. it wasn't enabled after a context switch for example)
and then called get_context. It can end up with VMX enabled and the
registers containing values from some other task.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This corrects the names of two CONFIG_ variables.
Note that the CONFIG_MPC86XADS fix uncovers another bug
(with mpc866_ads_defconfig) that will require fixing:
<-- snip -->
...
arch/powerpc/boot/dtc -O dtb -o arch/powerpc/boot/mpc866ads.dtb -b 0 /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/powerpc/boot/dts/mpc866ads.dts
DTC: dts->dtb on file "/home/bunk/linux/kernel-2.6/git/linux-2.6/arch/powerpc/boot/dts/mpc866ads.dts"
WRAP arch/powerpc/boot/cuImage.mpc866ads
powerpc64-linux-ld: arch/powerpc/boot/cuboot-mpc866ads.o: No such file: No such file or directory
make[2]: *** [arch/powerpc/boot/cuImage.mpc866ads] Error 1
<-- snip -->
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
x86/PCI: add workaround for bug in ASUS A7V600 BIOS (rev 1005)
PCI/x86: fix up PCI stuff so that PCI_GOANY supports OLPC
Change the name of the device from "rtc-ds1374" to just "ds1374", to match
what all other RTC drivers do. I seem to remember that this name was
chosen to avoid possible confusion with an older ds1374 driver, but that
driver was removed 3 months ago.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Although if people have questions about ARCnet, perhaps it's _better_
for them to be mailing dwmw2@cam.ac.uk about it...
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Include limits.h to get a definition of PATH_MAX.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We lost the marking of SIGWINCH as being OK to receive during stub
execution, causing a panic should that happen.
Cc: Benedict Verheyen <benedict.verheyen@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86_64 defines either memcpy or __memcpy depending on the gcc version, and
it looks like UML needs to follow that in its exporting.
Cc: Gabriel C <nix.or.die@googlemail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes os_get_task_size locate the bottom of the address space,
as well as the top. This is for systems which put a lower limit on mmap
addresses. It works by manually scanning pages from zero onwards until a
valid page is found.
Because the bottom of the address space may not be zero, it's not
sufficient to assume the top of the address space is the size of the
address space. The size is the difference between the top address and
bottom address.
[jdike@addtoit.com: changed the name to reflect that this function is
supposed to return the top of the process address space, not its size and
changed the return value to reflect that. Also some minor formatting
changes]
Signed-off-by: Tom Spink <tspink@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Removed duplicated include file "kern_util.h" in
arch/um/drivers/ubd_kern.c.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Protection against the host's time going backwards (eg, ntp activity on
the host) by keeping track of the time at the last tick and if it's
greater than the current time, keep time stopped until the host catches
up.
Cc: Nix <nix@esperi.org.uk>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As some m68k machines have plenty of libc5 binaries in active use, enable
CONFIG_COMPAT_BRK by default.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This BIOS claims the VIA 8237 south bridge to be compatible with VIA 586,
which it is not.
Without this patch, I get the following warning while booting,
among others,
| PCI: Using IRQ router VIA [1106/3227] at 0000:00:11.0
| ------------[ cut here ]------------
| WARNING: at arch/x86/pci/irq.c:265 pirq_via586_get+0x4a/0x60()
| Modules linked in:
| Pid: 1, comm: swapper Not tainted 2.6.26-rc4-00015-g1ec7d99 #1
| [<c0119fd4>] warn_on_slowpath+0x54/0x70
| [<c02246e0>] ? vt_console_print+0x210/0x2b0
| [<c02244d0>] ? vt_console_print+0x0/0x2b0
| [<c011a413>] ? __call_console_drivers+0x43/0x60
| [<c011a482>] ? _call_console_drivers+0x52/0x80
| [<c011aa89>] ? release_console_sem+0x1c9/0x200
| [<c0291d21>] ? raw_pci_read+0x41/0x70
| [<c0291e8f>] ? pci_read+0x2f/0x40
| [<c029151a>] pirq_via586_get+0x4a/0x60
| [<c02914d0>] ? pirq_via586_get+0x0/0x60
| [<c029178d>] pcibios_lookup_irq+0x15d/0x430
| [<c03b895a>] pcibios_irq_init+0x17a/0x3e0
| [<c03a66f0>] ? kernel_init+0x0/0x250
| [<c03a6763>] kernel_init+0x73/0x250
| [<c03b87e0>] ? pcibios_irq_init+0x0/0x3e0
| [<c0114d00>] ? schedule_tail+0x10/0x40
| [<c0102dee>] ? ret_from_fork+0x6/0x1c
| [<c03a66f0>] ? kernel_init+0x0/0x250
| [<c03a66f0>] ? kernel_init+0x0/0x250
| [<c010324b>] kernel_thread_helper+0x7/0x1c
| =======================
| ---[ end trace 4eaa2a86a8e2da22 ]---
and IRQ trouble later,
| irq 10: nobody cared (try booting with the "irqpoll" option)
Now that's an VIA 8237 chip, so pirq_via586_get shouldn't be called
at all; adding this workaround to via_router_probe() fixes the
problem for me.
Amazingly I have a 2.6.23.8 kernel that somehow works fine ... I'll
never understand why.
Signed-off-by: Bertram Felgenhauer <int-e@gmx.de>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
Fix divide by zero error in build_clear_page() and build_copy_page()
[MIPS] Fix typo in header guard
[MIPS] Fix build error - Delete debugging crap that crept in with CMP
[MIPS] Add accessors for random register.
[MIPS] IP27: misc fixes
[MIPS] IP27: Fix clockevent setup
[MIPS] IP27: Fix bootmem memory setup
[MIPS] remove CONFIG_CPU_R4000 line from Makefile
[MIPS] Fix check for valid stack pointer during backtrace
[MIPS] Add missing braces to pte_mkyoung
[MIPS] R4700: Fix build_tlb_probe_entry
[MIPS] Alchemy: dbdma: add API to delete custom DDMA device ids.
[MIPS] Alchemy: export get_au1x00_speed for modules
Previously, one would have to specifically choose CONFIG_OLPC and
CONFIG_PCI_GOOLPC in order to enable PCI_OLPC. That doesn't really work
for distro kernels, so this patch allows one to choose CONFIG_OLPC and
CONFIG_PCI_GOANY in order to build in OLPC support in a generic kernel (as
requested by Robert Millan).
This also moves GOOLPC before GOANY in the menuconfig list.
Finally, make pci_access_init return early if we detect OLPC hardware.
There's no need to continue probing stuff, and pci_pcbios_init
specifically trashes our settings (we didn't run into that before because
PCI_GOANY wasn't supported).
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Here is an attempt to translate the prompt and help text into something
which is legible and, as a bonus, correct.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Changes in the generic bootmem code broke memory setup for IP27. This
patch fixes this by replacing lots of special IP27 code with generic
bootmon code. This has been tested only on a single node.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The existing options are named CONFIG_CPU_R4300 and CONFIG_CPU_R4X00,
and they are directly below.
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The newly added check for valid stack pointer address breaks at least for
64bit kernels. Use __get_user() for accessing stack content to avoid crashes,
when doing the backtrace.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Treat R4700 like R4600 in build_tlb_probe_entry. Without this fix kernel
will lock up.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add API to delete custom DDMA device ids create with
au1xxx_ddma_device_add().
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
au1xmmc.c driver depends on it, so export it for modules.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip:
x86, fpu: fix CONFIG_PREEMPT=y corruption of application's FPU stack
suspend-vs-iommu: prevent suspend if we could not resume
x86: section mismatch fix
x86: fix Xorg crash with xf86MapVidMem error
x86: fix pointer type warning in arch/x86/mm/init_64.c:early_memtest
x86: fix bad pmd ffff810000207xxx(9090909090909090)
x86: ioremap fix failing nesting check
x86: fix broken math-emu with lazy allocation of fpu area
x86: enable preemption in delay
x86: disable preemption in native_smp_prepare_cpus
x86: fix APIC warning on 32bit v2
Jürgen Mell reported an FPU state corruption bug under CONFIG_PREEMPT,
and bisected it to commit v2.6.19-1363-gacc2076, "i386: add sleazy FPU
optimization".
Add tsk_used_math() checks to prevent calling math_state_restore()
which can sleep in the case of !tsk_used_math(). This prevents
making a blocking call in __switch_to().
Apparently "fpu_counter > 5" check is not enough, as in some signal handling
and fork/exec scenarios, fpu_counter > 5 and !tsk_used_math() is possible.
It's a side effect though. This is the failing scenario:
process 'A' in save_i387_ia32() just after clear_used_math()
Got an interrupt and pre-empted out.
At the next context switch to process 'A' again, kernel tries to restore
the math state proactively and sees a fpu_counter > 0 and !tsk_used_math()
This results in init_fpu() during the __switch_to()'s math_state_restore()
And resulting in fpu corruption which will be saved/restored
(save_i387_fxsave and restore_i387_fxsave) during the remaining
part of the signal handling after the context switch.
Bisected-by: Jürgen Mell <j.mell@t-online.de>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Jürgen Mell <j.mell@t-online.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
iommu/gart support misses suspend/resume code, which can do bad stuff,
including memory corruption on resume. Prevent system suspend in case we
would be unable to resume.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Tested-by: Patrick <ragamuffin@datacomm.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix this:
WARNING: vmlinux.o(.text+0x114bb): Section mismatch in reference from
the function nopat() to the function .cpuinit.text:pat_disable()
The function nopat() references
the function __cpuinit pat_disable().
This is often because nopat lacks a __cpuinit
annotation or the annotation of pat_disable is wrong.
Reported-by: "Fabio Comolli" <fabio.comolli@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Clarify the usage of mtrr_lookup() in PAT code, and to make PAT code
resilient to mtrr lookup problems.
Specifically, pat_x_mtrr_type() is restructured to highlight, under what
conditions we look for mtrr hint. pat_x_mtrr_type() uses a default type
when there are any errors in mtrr lookup (still maintaining the pat
consistency). And, reserve_memtype() highlights its usage ot mtrr_lookup
for request type of '-1' and also defaults in a sane way on any mtrr
lookup failure.
pat.c looks at mtrr type of a range to get a hint on what mapping type
to request when user/API: (1) hasn't specified any type (/dev/mem
mapping) and we do not want to take performance hit by always mapping
UC_MINUS. This will be the case for /dev/mem mappings used to map BIOS
area or ACPI region which are WB'able. In this case, as long as MTRR is
not WB, PAT will request UC_MINUS for such mappings.
(2) user/API requests WB mapping while in reality MTRR may have UC or
WC. In this case, PAT can map as WB (without checking MTRR) and still
effective type will be UC or WC. But, a subsequent request to map same
region as UC or WC may fail, as the region will get trackked as WB in
PAT list. Looking at MTRR hint helps us to track based on effective type
rather than what user requested. Again, here mtrr_lookup is only used as
hint and we fallback to WB mapping (as requested by user) as default.
In both cases, after using the mtrr hint, we still go through the
memtype list to make sure there are no inconsistencies among multiple
users.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Rufus & Azrael <rufus-azrael@numericable.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Changed the call to find_e820_area_size to pass u64 instead of unsigned long.
Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
OGAWA Hirofumi and Fede have reported rare pmd_ERROR messages:
mm/memory.c:127: bad pmd ffff810000207xxx(9090909090909090).
Initialization's cleanup_highmap was leaving alignment filler
behind in the pmd for MODULES_VADDR: when vmalloc's guard page
would occupy a new page table, it's not allocated, and then
module unload's vfree hits the bad 9090 pmd entry left over.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
