1. input and backlight devices were registered after acpi notifications
are enabled. This left a window where eeepc_hotk_notify() might
find these devices in an inconsistent (half-initialized) state.
-> Move all device registration into eeepc_hotk_add(), which is called
before enabling acpi notifications.
2. input and backlight devices were unregistered before acpi
notifications are disabled. This left a window where
eeepc_hotk_notify() might find these devices in an inconsistent
(half-destroyed) state.
-> Move all device unregistration into eeepc_hotk_remove(), which is
called after disabling acpi notifications.
3. The acpi driver was not freed if an error occured further down in
eeepc_laptop_init().
-> The rest of eeepc_laptop_init() has been moved to eeepc_hotk_add(),
so this is no longer a problem.
4. The acpi driver was unregistered before the platform driver. This
left a window where a sysfs access could attempt to read the ehotk
structure after it had been freed by eeepc_hotk_remove().
-> The acpi driver is now unregistered as the last step in
eeepc_laptop_exit(), so this is no longer a problem.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
Wifi rfkill state changes can race with pci hotplug cleanup. A simple
fix is to refresh the hotplug state just before deregistering the pci
hotplug slot.
There is also potential for a hotplug notification to fire too early
during setup, while the structures it uses are still being initialised.
(This could only happen if the BIOS performs hotplug itself; a bug
triggered by removing the battery while hibernated). Avoid this by
registering the notifier later. The same refresh mechanism is used
to handle rfkill state changes which can now race with registration.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
Commit d0265f0 "eeepc-laptop: fix hot-unplug on resume" used a workqueue
to protect pci hotplug against multiple simultaneous calls during
resume. It seems to work, but a mutex would be more appropriate.
This is in preparation to fix the potential pci hotplug race on unload.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
The whole point of registering as a PCI hotplug driver was to prevent
conflict with pciehp. At the moment it happens to work because
eeepc-laptop is loaded first, but it doesn't work the other way round.
If pciehp is loaded first then we fail to claim the slot - we need to
respect this and not handle hotplug events.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
The root cause is a duplicate section name (.text); is this legal?
[ Amerigo Wang: "AFAIK, yes." ]
However, there's a problem with commit
6d76013381 in that if you fail to allocate
a mod->sect_attrs (in this case it's null because of the duplication),
it still gets used without checking in add_notes_attrs()
This should fix it
[ This patch leaves other problems, particularly the sections directory,
but recent parisc toolchains seem to produce these modules and this
prevents a crash and is a minimal change -- RR ]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The rarely-used symbol_put_addr() needs to use dereference_function_descriptor
on powerpc.
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As soon as the framebuffer is registered, our methods may be called by the
kernel. This leads to a crash as xenfb_refresh() gets called before we have
the irq.
Connect to the backend before registering our framebuffer with the kernel.
[ Fixes bug http://bugzilla.kernel.org/show_bug.cgi?id=14059 ]
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.infradead.org/users/eparis/notify:
inotify: Ensure we alwasy write the terminating NULL.
inotify: fix locking around inotify watching in the idr
inotify: do not BUG on idr entries at inotify destruction
inotify: seperate new watch creation updating existing watches
We call lmb_end_of_DRAM() to test whether a DMA mask is ok on a machine
without IOMMU, but this function is marked as __init.
I don't think there's a clean way to get the top of RAM max_pfn doesn't
appear to include highmem or I missed (or we have a bug :-) so for now,
let's just avoid having a broken 2.6.31 by making this function
non-__init and we can revisit later.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
9p: update documentation pointers
9p: remove unnecessary v9fses->options which duplicates the mount string
net/9p: insulate the client against an invalid error code sent by a 9p server
9p: Add missing cast for the error return value in v9fs_get_inode
9p: Remove redundant inode uid/gid assignment
9p: Fix possible regressions when ->get_sb fails.
9p: Fix v9fs show_options
9p: Fix possible memleak in v9fs_inode_from fid.
9p: minor comment fixes
9p: Fix possible inode leak in v9fs_get_inode.
9p: Check for error in return value of v9fs_fid_add
Add a check in ip_append_data() for NULL *rtp to prevent future bugs in
callers from being exploitable.
Signed-off-by: Julien Tinnes <julien@cr0.org>
Signed-off-by: Tavis Ormandy <taviso@sdf.lonestar.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kAFS crashes when asked to read a symbolic link because page_getlink()
passes a NULL file pointer to read_mapping_page(), but afs_readpage()
expects a file pointer from which to extract a key.
Modify afs_readpage() to request the appropriate key from the calling
process's keyrings if a file struct is not supplied with one attached.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before the rewrite copy_event_to_user always wrote a terqminating '\0'
byte to user space after the filename. Since the rewrite that
terminating byte was skipped if your filename is exactly a multiple of
event_size. Ouch!
So add one byte to name_size before we round up and use clear_user to
set userspace to zero like /dev/zero does instead of copying the
strange nul_inotify_event. I can't quite convince myself len_to_zero
will never exceed 16 and even if it doesn't clear_user should be more
efficient and a more accurate reflection of what the code is trying to
do.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
The are races around the idr storage of inotify watches. It's possible
that a watch could be found from sys_inotify_rm_watch() in the idr, but it
could be removed from the idr before that code does it's removal. Move the
locking and the refcnt'ing so that these have to happen atomically.
Signed-off-by: Eric Paris <eparis@redhat.com>
If an inotify watch is left in the idr when an fsnotify group is destroyed
this will lead to a BUG. This is not a dangerous situation and really
indicates a programming bug and leak of memory. This patch changes it to
use a WARN and a printk rather than killing people's boxes.
Signed-off-by: Eric Paris <eparis@redhat.com>
There is nothing known wrong with the inotify watch addition/modification
but this patch seperates the two code paths to make them each easy to
verify as correct.
Signed-off-by: Eric Paris <eparis@redhat.com>
Update ps3_defconfig.
o Refresh for 2.6.31.
o Remove MTD support.
o Add more HID drivers.
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On non-PS3, we get:
| kernel BUG at drivers/rtc/rtc-ps3.c:36!
because the rtc-ps3 platform device is registered unconditionally in a kernel
with builtin support for PS3.
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k,m68knommu: Wire up rt_tgsigqueueinfo and perf_counter_open
m68k: Fix redefinition of pgprot_noncached
arch/m68k/include/asm/motorola_pgalloc.h: fix kunmap arg
m68k: cnt reaches -1, not 0
m68k: count can reach 51, not 50
If we change the inverted attribute to another value, the LED will not be
inverted until we change the GPIO state.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Cc: Samuel R. C. Vale <srcvale@holoscopio.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When setting the same GPIO number, multiple IRQ shared requests will be
done without freing the previous request. It will also try to free a
failed request or an already freed IRQ if 0 was written to the gpio file.
All these oops and leaks were fixed with the following solution: keep the
previous allocated GPIO (if any) still allocated in case the new request
fails. The alternative solution would desallocate the previous allocated
GPIO and set gpio as 0.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Samuel R. C. Vale <srcvale@holoscopio.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This failure is very common on many platforms. Handling it in the ACPI
processor driver is enough, and we don't need a warning message unless
CONFIG_ACPI_DEBUG is set.
Based on a patch from Zhang Rui.
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13389
Signed-off-by: Frans Pop <elendil@planet.nl>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the BIOS reports an invalid throttling state (which seems to be
fairly common after system boot), a reset is done to state T0.
Because of a check in acpi_processor_get_throttling_ptc(), the reset
never actually gets executed, which results in the error reoccurring
on every access of for example /proc/acpi/processor/CPU0/throttling.
Add a 'force' option to acpi_processor_set_throttling() to ensure
the reset really takes effect.
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13389
This patch, together with the next one, fixes a regression introduced in
2.6.30, listed on the regression list. They have been available for 2.5
months now in bugzilla, but have not been picked up, despite various
reminders and without any reason given.
Google shows that numerous people are hitting this issue. The issue is in
itself relatively minor, but the bug in the code is clear.
The patches have been in all my kernels and today testing has shown that
throttling works correctly with the patches applied when the system
overheats (http://bugzilla.kernel.org/show_bug.cgi?id=13918#c14).
Signed-off-by: Frans Pop <elendil@planet.nl>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Summary:
Kernel panic arise when stack protection is enabled, since strncat will
add a null terminating byte '\0'; So in functions
like this one (wmi_query_block):
char wc[4]="WC";
....
strncat(method, block->object_id, 2);
...
the length of wc should be n+1 (wc[5]) or stack protection
fault will arise. This is not noticeable when stack protection is
disabled,but , isn't good either.
Config used: [CONFIG_CC_STACKPROTECTOR_ALL=y,
CONFIG_CC_STACKPROTECTOR=y]
Panic Trace
------------
.... stack-protector: kernel stack corrupted in : fa7b182c
2.6.30-rc8-obelisco-generic
call_trace:
[<c04a6c40>] ? panic+0x45/0xd9
[<c012925d>] ? __stack_chk_fail+0x1c/0x40
[<fa7b182c>] ? wmi_query_block+0x15a/0x162 [wmi]
[<fa7b182c>] ? wmi_query_block+0x15a/0x162 [wmi]
[<fa7e7000>] ? acer_wmi_init+0x00/0x61a [acer_wmi]
[<fa7e7135>] ? acer_wmi_init+0x135/0x61a [acer_wmi]
[<c0101159>] ? do_one_initcall+0x50+0x126
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13514
Signed-off-by: Costantino Leandro <lcostantino@gmail.com>
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Len Brown <len.brown@intel.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The return value of the get_temp function is not checked when doing a
thermal zone update. This may lead to a critical shutdown if get_temp
fails and the content of the temp variable is incorrectly set higher than
the critical trip point.
This has been observed on a system with incorrect ACPI implementation
where the corresponding methods were not serialized and therefore
sometimes triggered ACPI errors (AE_ALREADY_EXISTS). The following
critical shutdowns indicated a temperature of 2097 C, which was obviously
wrong.
The patch adds a return value check that jumps over all trip point
evaluations printing a warning if get_temp fails. The trip points are
evaluated again on the next polling interval with successful get_temp
execution.
Signed-off-by: Michael Brunner <mibru@gmx.de>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Spotted by Hiroshi Shimamoto who also provided the test-case below.
copy_process() uses signal->count as a reference counter, but it is not.
This test case
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <pthread.h>
void *null_thread(void *p)
{
for (;;)
sleep(1);
return NULL;
}
void *exec_thread(void *p)
{
execl("/bin/true", "/bin/true", NULL);
return null_thread(p);
}
int main(int argc, char **argv)
{
for (;;) {
pid_t pid;
int ret, status;
pid = fork();
if (pid < 0)
break;
if (!pid) {
pthread_t tid;
pthread_create(&tid, NULL, exec_thread, NULL);
for (;;)
pthread_create(&tid, NULL, null_thread, NULL);
}
do {
ret = waitpid(pid, &status, 0);
} while (ret == -1 && errno == EINTR);
}
return 0;
}
quickly creates an unkillable task.
If copy_process(CLONE_THREAD) races with de_thread()
copy_signal()->atomic(signal->count) breaks the signal->notify_count
logic, and the execing thread can hang forever in kernel space.
Change copy_process() to increment count/live only when we know for sure
we can't fail. In this case the forked thread will take care of its
reference to signal correctly.
If copy_process() fails, check CLONE_THREAD flag. If it it set - do
nothing, the counters were not changed and current belongs to the same
thread group. If it is not set, ->signal must be released in any case
(and ->count must be == 1), the forked child is the only thread in the
thread group.
We need more cleanups here, in particular signal->count should not be used
by de_thread/__exit_signal at all. This patch only fixes the bug.
Reported-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Tested-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
An mlocked page might lose the isolatation race. This causes the page to
clear PG_mlocked while it remains in a VM_LOCKED vma. This means it can
be put onto the [in]active list. We can rescue it by using try_to_unmap()
in shrink_page_list().
But now, As Wu Fengguang pointed out, vmscan has a bug. If the page has
PG_referenced, it can't reach try_to_unmap() in shrink_page_list() but is
put into the active list. If the page is referenced repeatedly, it can
remain on the [in]active list without being moving to the unevictable
list.
This patch fixes it.
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <<kosaki.motohiro@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's problematic to allow signed element_nr's or total's to be passed as
part of the flex array API.
flex_array_alloc() allows total_nr_elements to be set to a negative
quantity, which is obviously erroneous.
flex_array_get() and flex_array_put() allows negative array indices in
dereferencing an array part, which could address memory mapped before
struct flex_array.
The fix is to convert all existing element_nr formals to be qualified as
unsigned. Existing checks to compare it to total_nr_elements or the max
array size based on element_size need not be changed.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The `parts' member of struct flex_array should evaluate to an incomplete
type so that sizeof() cannot be used and C99 does not require the
zero-length specification.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
flex_array_free_parts() does not take `src' or `element_nr' formals, so
remove their respective comments.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If all array elements fit into the base structure and data is copied using
flex_array_put() starting at a non-zero index, flex_array_get() will fail
to return the data.
This fixes the bug by only checking for NULL parts when all elements do
not fit in the base structure when flex_array_get() is used. Otherwise,
fa_element_to_part_nr() will always be 0 since there are no parts
structures needed and such element may never have been put. Thus, it will
remain NULL due to the kzalloc() of the base.
Additionally, flex_array_put() now only checks for a NULL part when all
elements do not fit in the base structure. This is otherwise unnecessary
since the base structure is guaranteed to exist (or we would have already
hit a NULL pointer).
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ima_counts_get() calls ima_iint_find_insert_get() which takes a reference
to the iint in question, but does not put that reference at the end of the
function. This can lead to a nasty memory leak. Easy enough to reproduce:
#include <sys/mman.h>
#include <stdio.h>
int main (void)
{
int i;
void *ptr;
for (i=0; i < 100000; i++) {
ptr = mmap(NULL, 4096, PROT_READ|PROT_WRITE,
MAP_SHARED|MAP_ANONYMOUS, -1, 0);
if (ptr == MAP_FAILED)
return 2;
munmap(ptr, 4096);
}
return 0;
}
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
arch/m68k/include/asm/pgtable_mm.h:148:1: warning: "pgprot_noncached" redefined
In file included from arch/m68k/include/asm/pgtable_mm.h:138,
from arch/m68k/include/asm/pgtable.h:4,
from include/linux/mm.h:40,
from include/linux/pagemap.h:7,
from include/linux/blkdev.h:12,
from arch/m68k/emu/nfblock.c:17:
include/asm-generic/pgtable.h:133:1: warning: this is the location of the previous definition
pgprot_noncached() should be defined _before_ including asm-generic/pgtable.h
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
arch/m68k/include/asm/motorola_pgalloc.h: In function 'pte_alloc_one':
arch/m68k/include/asm/motorola_pgalloc.h:44: warning: passing argument 1 of 'kunmap' from incompatible pointer type
Also, remove unneeded test for kmap() failure.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
With while (count++ < 50) { ... } count can reach 51, not 50, so we
shouldn't give an error message on a count of 50.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
If we run out of memory, use keventd to fill the buffer. There's a
report of this happening: "Page allocation failures in guest",
Message-ID: <20090713115158.0a4892b0@mjolnir.ossman.eu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is based on commit d2f3ad4 (pxaficp-ir: remove incorrect
net_device_ops). Do the same for sa1100_ir.
Untested.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is based on commit d2f3ad4 (pxaficp-ir: remove incorrect
net_device_ops). Do the same for au1k_ir.
Untested.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When page alloc debugging is not enabled, we essentially accept any
virtual address for linear kernel TLB misses. But with kgdb, kernel
address probing, and other facilities we can try to access arbitrary
crap.
So, make sure the address we miss on will translate to physical memory
that actually exists.
In order to make this work we have to embed the valid address bitmap
into the kernel image. And in order to make that less expensive we
make an adjustment, in that the max physical memory address is
decreased to "1 << 41", even on the chips that support a 42-bit
physical address space. We can do this because bit 41 indicates
"I/O space" and thus covers non-memory ranges.
The result of this is that:
1) kpte_linear_bitmap shrinks from 2K to 1K in size
2) we need 64K more for the valid address bitmap
We can't let the valid address bitmap be dynamically allocated
once we start using it to validate TLB misses, otherwise we have
crazy issues to deal with wrt. recursive TLB misses and such.
If we're in a TLB miss it could be the deepest trap level that's legal
inside of the cpu. So if we TLB miss referencing the bitmap, the cpu
will be out of trap levels and enter RED state.
To guard against out-of-range accesses to the bitmap, we have to check
to make sure no bits in the physical address above bit 40 are set. We
could export and use last_valid_pfn for this check, but that's just an
unnecessary extra memory reference.
On the plus side of all this, since we load all of these translations
into the special 4MB mapping TSB, and we check the TSB first for TLB
misses, there should be absolutely no real cost for these new checks
in the TLB miss path.
Reported-by: heyongli@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Alan Jenkins