This fixes a memory-corrupting bug: not only does it cause the warning,
but as a result of dropping the refcount to zero, it causes the
pcmcia_socket0 device structure to be freed while it still has
references, causing slab caches corruption. A fatal oops quickly
follows this warning - often even just a 'dmesg' following the warning
causes the kernel to oops.
While testing suspend/resume on an ARM device with PCMCIA support, and a
CF card inserted, I found that after five suspend and resumes, the
kernel would complain, and shortly die after with slab corruption.
WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()
As the message doesn't give a clue about which kobject, and the built-in
debugging in drivers/base/power/main.c happens too late, this was added
right before each get_device():
printk("%s: %p [%s] %u\n", __func__, dev, kobject_name(&dev->kobj), atomic_read(&dev->kobj.kref.refcount));
and on the 3rd s2ram cycle, the following behaviour observed:
On the 3rd suspend/resume cycle:
dpm_prepare: c1a0d998 [pcmcia_socket0] 3
dpm_suspend: c1a0d998 [pcmcia_socket0] 3
dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 3
dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 3
dpm_resume: c1a0d998 [pcmcia_socket0] 3
dpm_complete: c1a0d998 [pcmcia_socket0] 2
4th:
dpm_prepare: c1a0d998 [pcmcia_socket0] 2
dpm_suspend: c1a0d998 [pcmcia_socket0] 2
dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 2
dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 2
dpm_resume: c1a0d998 [pcmcia_socket0] 2
dpm_complete: c1a0d998 [pcmcia_socket0] 1
5th:
dpm_prepare: c1a0d998 [pcmcia_socket0] 1
dpm_suspend: c1a0d998 [pcmcia_socket0] 1
dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 1
dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 1
dpm_resume: c1a0d998 [pcmcia_socket0] 1
dpm_complete: c1a0d998 [pcmcia_socket0] 0
------------[ cut here ]------------
WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()
Modules linked in: ucb1x00_core
Backtrace:
[<c0212090>] (dump_backtrace+0x0/0x110) from [<c04799dc>] (dump_stack+0x18/0x1c)
[<c04799c4>] (dump_stack+0x0/0x1c) from [<c021cba0>] (warn_slowpath_common+0x50/0x68)
[<c021cb50>] (warn_slowpath_common+0x0/0x68) from [<c021cbdc>] (warn_slowpath_null+0x24/0x28)
[<c021cbb8>] (warn_slowpath_null+0x0/0x28) from [<c0335374>] (kobject_get+0x28/0x50)
[<c033534c>] (kobject_get+0x0/0x50) from [<c03804f4>] (get_device+0x1c/0x24)
[<c0388c90>] (dpm_complete+0x0/0x1a0) from [<c0389cc0>] (dpm_resume_end+0x1c/0x20)
...
Looking at commit 7b24e79882 ("pcmcia: split up central event handler"),
the following change was made to cs.c:
return 0;
}
#endif
-
- send_event(skt, CS_EVENT_PM_RESUME, CS_EVENT_PRI_LOW);
+ if (!(skt->state & SOCKET_CARDBUS) && (skt->callback))
+ skt->callback->early_resume(skt);
return 0;
}
And the corresponding change in ds.c is from:
-static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
-{
- struct pcmcia_socket *s = pcmcia_get_socket(skt);
...
- switch (event) {
...
- case CS_EVENT_PM_RESUME:
- if (verify_cis_cache(skt) != 0) {
- dev_dbg(&skt->dev, "cis mismatch - different card\n");
- /* first, remove the card */
- ds_event(skt, CS_EVENT_CARD_REMOVAL, CS_EVENT_PRI_HIGH);
- mutex_lock(&s->ops_mutex);
- destroy_cis_cache(skt);
- kfree(skt->fake_cis);
- skt->fake_cis = NULL;
- s->functions = 0;
- mutex_unlock(&s->ops_mutex);
- /* now, add the new card */
- ds_event(skt, CS_EVENT_CARD_INSERTION,
- CS_EVENT_PRI_LOW);
- }
- break;
...
- }
- pcmcia_put_socket(s);
- return 0;
-} /* ds_event */
to:
+static int pcmcia_bus_early_resume(struct pcmcia_socket *skt)
+{
+ if (!verify_cis_cache(skt)) {
+ pcmcia_put_socket(skt);
+ return 0;
+ }
+ dev_dbg(&skt->dev, "cis mismatch - different card\n");
+ /* first, remove the card */
+ pcmcia_bus_remove(skt);
+ mutex_lock(&skt->ops_mutex);
+ destroy_cis_cache(skt);
+ kfree(skt->fake_cis);
+ skt->fake_cis = NULL;
+ skt->functions = 0;
+ mutex_unlock(&skt->ops_mutex);
+ /* now, add the new card */
+ pcmcia_bus_add(skt);
+ return 0;
+}
As can be seen, the original function called pcmcia_get_socket() and
pcmcia_put_socket() around the guts, whereas the replacement code
calls pcmcia_put_socket() only in one path. This creates an imbalance
in the refcounting.
Testing with pcmcia_put_socket() put removed shows that the bug is gone:
dpm_suspend: c1a10998 [pcmcia_socket0] 5
dpm_suspend_noirq: c1a10998 [pcmcia_socket0] 5
dpm_resume_noirq: c1a10998 [pcmcia_socket0] 5
dpm_resume: c1a10998 [pcmcia_socket0] 5
dpm_complete: c1a10998 [pcmcia_socket0] 5
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y
CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false,
and so triggers some BUGs in Transparent HugePage codepaths.
asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x);
but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE,
VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In current code, pltfm->als_vmin is set to LM3530_ALS_WINDOW_mV and
pltfm->als_vmax is 0. This does not make sense. I think what we want
here is setting pltfm->als_vmax to LM3530_ALS_WINDOW_mV.
Both als_vmin and als_vmax local variables will be set to
pltfm->als_vmin and pltfm->als_vmax by a few lines latter. Thus also
remove a redundant assignment for als_vmin and als_vmax in this patch.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Acked-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Tested-by: Milo(Woogyom) Kim <milo.kim@ti.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 isolating pages for migration, migration starts at the start of a
zone while the free scanner starts at the end of the zone. Migration
avoids entering a new zone by never going beyond the free scanned.
Unfortunately, in very rare cases nodes can overlap. When this happens,
migration isolates pages without the LRU lock held, corrupting lists
which will trigger errors in reclaim or during page free such as in the
following oops
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [<ffffffff810f795c>] free_pcppages_bulk+0xcc/0x450
PGD 1dda554067 PUD 1e1cb58067 PMD 0
Oops: 0000 [#1] SMP
CPU 37
Pid: 17088, comm: memcg_process_s Tainted: G X
RIP: free_pcppages_bulk+0xcc/0x450
Process memcg_process_s (pid: 17088, threadinfo ffff881c2926e000, task ffff881c2926c0c0)
Call Trace:
free_hot_cold_page+0x17e/0x1f0
__pagevec_free+0x90/0xb0
release_pages+0x22a/0x260
pagevec_lru_move_fn+0xf3/0x110
putback_lru_page+0x66/0xe0
unmap_and_move+0x156/0x180
migrate_pages+0x9e/0x1b0
compact_zone+0x1f3/0x2f0
compact_zone_order+0xa2/0xe0
try_to_compact_pages+0xdf/0x110
__alloc_pages_direct_compact+0xee/0x1c0
__alloc_pages_slowpath+0x370/0x830
__alloc_pages_nodemask+0x1b1/0x1c0
alloc_pages_vma+0x9b/0x160
do_huge_pmd_anonymous_page+0x160/0x270
do_page_fault+0x207/0x4c0
page_fault+0x25/0x30
The "X" in the taint flag means that external modules were loaded but but
is unrelated to the bug triggering. The real problem was because the PFN
layout looks like this
Zone PFN ranges:
DMA 0x00000010 -> 0x00001000
DMA32 0x00001000 -> 0x00100000
Normal 0x00100000 -> 0x01e80000
Movable zone start PFN for each node
early_node_map[14] active PFN ranges
0: 0x00000010 -> 0x0000009b
0: 0x00000100 -> 0x0007a1ec
0: 0x0007a354 -> 0x0007a379
0: 0x0007f7ff -> 0x0007f800
0: 0x00100000 -> 0x00680000
1: 0x00680000 -> 0x00e80000
0: 0x00e80000 -> 0x01080000
1: 0x01080000 -> 0x01280000
0: 0x01280000 -> 0x01480000
1: 0x01480000 -> 0x01680000
0: 0x01680000 -> 0x01880000
1: 0x01880000 -> 0x01a80000
0: 0x01a80000 -> 0x01c80000
1: 0x01c80000 -> 0x01e80000
The fix is straight-forward. isolate_migratepages() has to make a
similar check to isolate_freepage to ensure that it never isolates pages
from a zone it does not hold the LRU lock for.
This was discovered in a 3.0-based kernel but it affects 3.1.x, 3.2.x
and current mainline.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fbdev fixes for 3.3
It includes:
- compile fix for fsl-diu-fb
- fix for a suspend/resume issue in atmel_lcdfb
- fix for a suspend/resume issue in OMAP
- workaround for a hardware bug to avoid physical damage in OMAP
- really trivial dead code removal in intelfb
* tag 'fbdev-fixes-for-3.3-1' of git://github.com/schandinat/linux-2.6:
atmel_lcdfb: fix usage of CONTRAST_CTR in suspend/resume
intelfb: remove some dead code
drivers/video: compile fixes for fsl-diu-fb.c
OMAPDSS: HDMI: PHY burnout fix
OMAP: 4430SDP/Panda: add HDMI HPD gpio
OMAP: 4430SDP/Panda: setup HDMI GPIO muxes
OMAPDSS: remove wrong HDMI HPD muxing
OMAP: 4430SDP/Panda: rename HPD GPIO to CT_CP_HPD
OMAP: 4430SDP/Panda: use gpio_free_array to free HDMI gpios
OMAPDSS: use sync versions of pm_runtime_put
Overly indented code should be refactored.
Suggest refactoring excessive indentation of of
if/else/for/do/while/switch statements.
For example:
$ cat t.c
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv)
{
if (1)
if (2)
if (3)
if (4)
if (5)
if (6)
if (7)
if (8)
;
return 0;
}
$ ./scripts/checkpatch.pl -f t.c
WARNING: Too many leading tabs - consider code refactoring
#12: FILE: t.c:12:
+ if (6)
WARNING: Too many leading tabs - consider code refactoring
#13: FILE: t.c:13:
+ if (7)
WARNING: Too many leading tabs - consider code refactoring
#14: FILE: t.c:14:
+ if (8)
total: 0 errors, 3 warnings, 17 lines checked
t.c has style problems, please review.
If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanups and error path fixes for the new SRP (SCSI RDMA protocol) target.
* tag 'ib-srpt-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
IB/srpt: Don't return freed pointer from srpt_alloc_ioctx_ring()
IB/srpt: Fix ERR_PTR() vs. NULL checking confusion
IB/srpt: Remove unneeded <linux/version.h> include
IB/srpt: Use ARRAY_SIZE() instead of open-coding
IB/srpt: Use DEFINE_SPINLOCK()/LIST_HEAD()
arch: fix ioport mapping on mips,sh
Kevin Cernekee reported that recent cleanup that replaced pci_iomap with
a generic function failed to take into account the differences in io
port handling on mips and sh architectures.
Rather than revert the changes reintroducing the code duplication, this
patchset fixes this by adding ability for architectures to override
ioport mapping for pci devices.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
sh: use the the PCI channels's io_map_base
mips: use the the PCI controller's io_map_base
lib: add NO_GENERIC_PCI_IOPORT_MAP
* git://git.samba.org/sfrench/cifs-2.6:
cifs: Fix oops in session setup code for null user mounts
[CIFS] Update cifs Kconfig title to match removal of experimental dependency
cifs: fix printk format warnings
cifs: check offset in decode_ntlmssp_challenge()
cifs: NULL dereference on allocation failure
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6:
mfd: Avoid twl6040-codec PLL reconfiguration when not needed
mfd: Store twl6040-codec mclk configuration
Analogically to d7cb3dbd1 ("HID: wacom: Fix invalid power_supply_powers
calls"), fix also the same occurence in wiimote driver.
Reported-by: przemo@firszt.eu
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Fixing a regression with the PMU MSRs when PMU virtualization is
disabled, a guest-internal DoS with the SYSCALL instruction, and a dirty
memory logging race that may cause live migration to fail.
* 'kvm-updates/3.3' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: do not #GP on perf MSR writes when vPMU is disabled
KVM: x86: fix missing checks in syscall emulation
KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid"
KVM: Fix __set_bit() race in mark_page_dirty() during dirty logging
GPIO fixes for v3.3-rc2
Straight forward bug fixes in this branch. A couple of x86 gpio drivers
missing spinlock initialization, an API change fixup for the samsung driver
and a name typo fix.
* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6:
gpio: Add missing spin_lock_init in gpio-ml-ioh driver
gpio: Add missing spin_lock_init in gpio-pch driver
gpio: samsung: adapt to changes in gpio specifier translator function declaration
Correct bad gpio naming
One patch to fix fan detection on NCT6776F.
* tag 'hwmon-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (w83627ehf) Fix number of fans for NCT6776F
Setting the task name is done within setup_new_exec() by accessing
bprm->filename. However this happens after flush_old_exec().
This may result in a use after free bug, flush_old_exec() may
"complete" vfork_done, which will wake up the parent which in turn
may free the passed in filename.
To fix this add a new tcomm field in struct linux_binprm which
contains the now early generated task name until it is used.
Fixes this bug on s390:
Unable to handle kernel pointer dereference at virtual kernel address 0000000039768000
Process kworker/u:3 (pid: 245, task: 000000003a3dc840, ksp: 0000000039453818)
Krnl PSW : 0704000180000000 0000000000282e94 (setup_new_exec+0xa0/0x374)
Call Trace:
([<0000000000282e2c>] setup_new_exec+0x38/0x374)
[<00000000002dd12e>] load_elf_binary+0x402/0x1bf4
[<0000000000280a42>] search_binary_handler+0x38e/0x5bc
[<0000000000282b6c>] do_execve_common+0x410/0x514
[<0000000000282cb6>] do_execve+0x46/0x58
[<00000000005bce58>] kernel_execve+0x28/0x70
[<000000000014ba2e>] ____call_usermodehelper+0x102/0x140
[<00000000005bc8da>] kernel_thread_starter+0x6/0xc
[<00000000005bc8d4>] kernel_thread_starter+0x0/0xc
Last Breaking-Event-Address:
[<00000000002830f0>] setup_new_exec+0x2fc/0x374
Kernel panic - not syncing: Fatal exception: panic_on_oops
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
power_supply_powers calls added in 35b4c01e2 ("power_supply: add "powers" links
to self-powered HID devices") have to be called after power device is created.
This patch also fixes the second call - it has to be "ac" instead of "battery"
Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Chris Bagwell <chris@cnpbagwell.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Sync with Linus' tree. This is necessary to have a base for
patch that fixes commit 35b4c01e29 ("power_supply: add "powers"
links to self-powered HID devices") which went in through Anton's
tree.
NCT6776F can select fan input pins for fans 3 to 5 with a secondary set of
chip register bits. Check that second set of bits in addition to the first set
to detect if fans 3..5 are monitored.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org # 3.0+
Acked-by: Jean Delvare <khali@linux-fr.org>
Power management fixes for 3.3-rc3
Three power management regression fixes, one for a recent regression introcuded
by the freezer changes during the 3.3 merge window and two for regressions
in cpuidle (resulting from PM QoS changes) and in the hibernate user space
interface, both introduced during the 3.2 development cycle.
They include:
* Two hibernate (s2disk) regression fixes from Srivatsa S. Bhat (for
regressions introduced during the 3.3 merge window and during the 3.2
development cycle).
* A cpuidle fix from Venki Pallipadi for a regression resulting from PM QoS
changes during the 3.2 development cycle causing cpuidle to work incorrectly
for CONFIG_PM unset.
* tag 'pm-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / QoS: CPU C-state breakage with PM Qos change
PM / Freezer: Thaw only kernel threads if freezing of kernel threads fails
PM / Hibernate: Thaw kernel threads in SNAPSHOT_CREATE_IMAGE ioctl path
Looks like change "PM QoS: Move and rename the implementation files"
merged during the 3.2 development cycle made PM QoS depend on
CONFIG_PM which depends on (PM_SLEEP || PM_RUNTIME).
That breaks CPU C-states with kernels not having these CONFIGs, causing CPUs
to spend time in Polling loop idle instead of going into deep C-states,
consuming way way more power. This is with either acpi idle or intel idle
enabled.
Either CONFIG_PM should be enabled with any pm_qos users or
the !CONFIG_PM pm_qos_request() should return sane defaults not to break
the existing users. Here's is the patch for the latter option.
[rjw: Modified the changelog slightly.]
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@vger.kernel.org
If freezing of kernel threads fails, we are expected to automatically
thaw tasks in the error recovery path. However, at times, we encounter
situations in which we would like the automatic error recovery path
to thaw only the kernel threads, because we want to be able to do
some more cleanup before we thaw userspace. Something like:
error = freeze_kernel_threads();
if (error) {
/* Do some cleanup */
/* Only then thaw userspace tasks*/
thaw_processes();
}
An example of such a situation is where we freeze/thaw filesystems
during suspend/hibernation. There, if freezing of kernel threads
fails, we would like to thaw the frozen filesystems before thawing
the userspace tasks.
So, modify freeze_kernel_threads() to thaw only kernel threads in
case of freezing failure. And change suspend_freeze_processes()
accordingly. (At the same time, let us also get rid of the rather
cryptic usage of the conditional operator (:?) in that function.)
[rjw: In fact, this patch fixes a regression introduced during the
3.3 merge window, because without it thaw_processes() may be called
before swsusp_free() in some situations and that may lead to massive
memory allocation failures.]
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Upstream commit d1fce9c115
"ARM: restart: bcmring: use new restart hook"
breaks building of this platform, since what used to be the
last field of the MACHINE_START/END block didn't have a
trailing comma. Once another field was added below, we get:
arch/arm/mach-bcmring/arch.c:198: error: request for member 'restart' in something not a structure or union
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Remove BCMRING DMA map code which is no longer used.
This also fixes a build error with dma.c introduced by
bfcd2ea6a4.
Signed-off-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
i.MX SDMA: Fix burstsize settings
ARM: mach-shmobile: both USB DMAC instances on sh7372 are slave-only
dma: sh_dma: not all SH DMAC implementations support MEMCPY
at_hdmac: bugfix for enabling channel irq
dmaengine: fix missing 'cnt' in ?: in dmatest
- Fix a regression in 16-bit Atmel NAND flash which was introduced in 3.1
- Fix breakage with MTD suspend caused by the API rework
- Fix a problem with resetting the MX28 BCH module
- A couple of other trivial fixes
* tag 'for-linus-3.3-20120204' of git://git.infradead.org/~dwmw2/mtd-3.3:
Revert "mtd: atmel_nand: optimize read/write buffer functions"
mtd: fix MTD suspend
jffs2: do not initialize variable unnecessarily
mtd: gpmi-nand bugfix: reset the BCH module when it is not MX23
mtd: nand: fix typo in comment
This reverts commit fb5427508a.
The reason is that it breaks 16 bits NAND flash as it was reported by
Nikolaus Voss and confirmed by Eric Bénard.
Nicolas Ferre <nicolas.ferre@atmel.com> alco confirmed:
"After double checking with designers, I must admit that I misunderstood
the way of optimizing accesses to SMC. 16 bit nand is not so common
those days..."
Reported-by: Nikolaus Voss <n.voss@weinmann.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [3.1+]
When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned. Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned. This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash. This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.
PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s"
#0 [d72d3ad0] crash_kexec at c028cfdb
#1 [d72d3b24] oops_end at c05c5322
#2 [d72d3b38] __bad_area_nosemaphore at c0227e60
#3 [d72d3bec] bad_area at c0227fb6
#4 [d72d3c00] do_page_fault at c05c72ec
#5 [d72d3c80] error_code (via page_fault) at c05c47a4
EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000
DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50
CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002
#6 [d72d3cb4] isolate_migratepages at c030b15a
#7 [d72d3d14] zone_watermark_ok at c02d26cb
#8 [d72d3d2c] compact_zone at c030b8de
#9 [d72d3d68] compact_zone_order at c030bba1
#10 [d72d3db4] try_to_compact_pages at c030bc84
#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
#14 [d72d3eb8] alloc_pages_vma at c030a845
#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
#16 [d72d3f00] handle_mm_fault at c02f36c6
#17 [d72d3f30] do_page_fault at c05c70ed
#18 [d72d3fb0] error_code (via page_fault) at c05c47a4
EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431
DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788
SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50
CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202
It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.
BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000
It is expected that it also affects 3.2.x and current mainline.
The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned. Lets say we have a case
like this
H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole
H------|------H------|----m-Hoooooo|ooooooH-f----|------H
The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole. When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.
This patch ensures that isolate_migratepages calls pfn_valid when
necessary.
Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Herbert Poetzl reported a performance regression since 2.6.39. The test
is a simple dd read, but with big block size. The reason is:
T1: ra (A, A+128k), (A+128k, A+256k)
T2: lock_page for page A, submit the 256k
T3: hit page A+128K, ra (A+256k, A+384). the range isn't submitted
because of plug and there isn't any lock_page till we hit page A+256k
because all pages from A to A+256k is in memory
T4: hit page A+256k, ra (A+384, A+ 512). Because of plug, the range isn't
submitted again.
T5: lock_page A+256k, so (A+256k, A+512k) will be submitted. The task is
waitting for (A+256k, A+512k) finish.
There is no request to disk in T3 and T4, so readahead pipeline breaks.
We really don't need block plug for generic_file_aio_read() for buffered
I/O. The readahead already has plug and has fine grained control when I/O
should be submitted. Deleting plug for buffered I/O fixes the regression.
One side effect is plug makes the request size 256k, the size is 128k
without it. This is because default ra size is 128k and not a reason we
need plug here.
Vivek said:
: We submit some readahead IO to device request queue but because of nested
: plug, queue never gets unplugged. When read logic reaches a page which is
: not in page cache, it waits for page to be read from the disk
: (lock_page_killable()) and that time we flush the plug list.
:
: So effectively read ahead logic is kind of broken in parts because of
: nested plugging. Removing top level plug (generic_file_aio_read()) for
: buffered reads, will allow unplugging queue earlier for readahead.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reported-by: Herbert Poetzl <herbert@13thfloor.at>
Tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In function pre_handler_kretprobe(), the allocated kretprobe_instance
object will get leaked if the entry_handler callback returns non-zero.
This may cause all the preallocated kretprobe_instance objects exhausted.
This issue can be reproduced by changing
samples/kprobes/kretprobe_example.c to probe "mutex_unlock". And the fix
is straightforward: just put the allocated kretprobe_instance object back
onto the free_instances list.
[akpm@linux-foundation.org: use raw_spin_lock/unlock]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KDFONTOP(GET) currently fails with EIO when being run in a 32bit userland
with a 64bit kernel if the font width is not 8.
This is because of the setting of the KD_FONT_FLAG_OLD flag, which makes
con_font_get return EIO in such case.
This flag should *not* be set for KDFONTOP, since it's actually the whole
point of this flag (see comment in con_font_set for instance).
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Arthur Taylor <art@ified.ca>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a race condition that shows in conjunction with xip_file_fault() when
two threads of the same user process fault on the same memory page.
In this case, the race winner will install the page table entry and the
unlucky loser will cause an oops: xip_file_fault calls vm_insert_pfn (via
vm_insert_mixed) which drops out at this check:
retval = -EBUSY;
if (!pte_none(*pte))
goto out_unlock;
The resulting -EBUSY return value will trigger a BUG_ON() in
xip_file_fault.
This fix simply considers the fault as fixed in this case, because the
race winner has successfully installed the pte.
[akpm@linux-foundation.org: use conventional (and consistent) comment layout]
Reported-by: David Sadler <dsadler@us.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Reported-by: Louis Alex Eisner <leisner@cs.ucsd.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Defining memscan() as memchr() is wrong, because the return values of
memscan() and memchr() are different when the character is not found. So
use the generic memscan() implementation to fix this.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
