If the i2c bus receives an interrupt with both BB (bus busy) and
ARDY (register access ready) statuses set during the tranfer of the last message
the bus was put to idle while still busy.
This caused bus to timeout.
Signed-off-by: Mathias Nyman <mathias.nyman@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix nohz balance kick
sched: Fix user time incorrectly accounted as system time on 32-bit
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: select CRYPTO
ceph: check mapping to determine if FILE_CACHE cap is used
ceph: only send one flushsnap per cap_snap per mds session
ceph: fix cap_snap and realm split
ceph: stop sending FLUSHSNAPs when we hit a dirty capsnap
ceph: correctly set 'follows' in flushsnap messages
ceph: fix dn offset during readdir_prepopulate
ceph: fix file offset wrapping at 4GB on 32-bit archs
ceph: fix reconnect encoding for old servers
ceph: fix pagelist kunmap tail
ceph: fix null pointer deref on anon root dentry release
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel:
drm/i915: Hold a reference to the object whilst unbinding the eviction list
drm/i915,agp/intel: Add second set of PCI-IDs for B43
drm/i915: Fix Sandybridge fence registers
drm/i915/crt: Downgrade warnings for hotplug failures
drm/i915: Ensure that the crtcinfo is populated during mode_fixup()
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
lguest: update comments to reflect LHCALL_LOAD_GDT_ENTRY.
virtio: console: Prevent userspace from submitting NULL buffers
virtio: console: Fix poll blocking even though there is data to read
There's a situation where the nohz balancer will try to wake itself:
cpu-x is idle which is also ilb_cpu
got a scheduler tick during idle
and the nohz_kick_needed() in trigger_load_balance() checks for
rq_x->nr_running which might not be zero (because of someone waking a
task on this rq etc) and this leads to the situation of the cpu-x
sending a kick to itself.
And this can cause a lockup.
Avoid this by not marking ourself eligible for kicking.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1284400941.2684.19.camel@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Mike reported a kernel crash when a usb key hotplug is performed while all
kernel thrads are not in a root cgroup and are running in one of the child
cgroups of blkio controller.
BUG: unable to handle kernel NULL pointer dereference at 0000002c
IP: [<c11c7b08>] cfq_get_queue+0x232/0x412
*pde = 00000000
Oops: 0000 [#1] PREEMPT
last sysfs file: /sys/devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:1.0/host3/scsi_host/host3/uevent
[..]
Pid: 30039, comm: scsi_scan_3 Not tainted 2.6.35.2-fg.roam #1 Volvi2 /Aspire 4315
EIP: 0060:[<c11c7b08>] EFLAGS: 00010086 CPU: 0
EIP is at cfq_get_queue+0x232/0x412
EAX: f705f9c0 EBX: e977abac ECX: 00000000 EDX: 00000000
ESI: f00da400 EDI: f00da4ec EBP: e977a800 ESP: dff8fd00
DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
Process scsi_scan_3 (pid: 30039, ti=dff8e000 task=f6b6c9a0 task.ti=dff8e000)
Stack:
00000000 00000000 00000001 01ff0000 f00da508 00000000 f00da524 f00da540
<0> e7994940 dd631750 f705f9c0 e977a820 e977ac44 f00da4d0 00000001 f6b6c9a0
<0> 00000010 00008010 0000000b 00000000 00000001 e977a800 dd76fac0 00000246
Call Trace:
[<c11c7f10>] ? cfq_set_request+0x228/0x34c
[<c11c7ce8>] ? cfq_set_request+0x0/0x34c
[<c11bb3b9>] ? elv_set_request+0xf/0x1c
[<c11bdd51>] ? get_request+0x1ad/0x22f
[<c11bddf2>] ? get_request_wait+0x1f/0x11a
[<c11d013b>] ? kvasprintf+0x33/0x3b
[<c127b537>] ? scsi_execute+0x1d/0x103
[<c127b675>] ? scsi_execute_req+0x58/0x83
[<c127c391>] ? scsi_probe_and_add_lun+0x188/0x7c2
[<c12718c6>] ? attribute_container_add_device+0x15/0xfa
[<c11c95d1>] ? kobject_get+0xf/0x13
[<c126d1db>] ? get_device+0x10/0x14
[<c127be93>] ? scsi_alloc_target+0x217/0x24d
[<c127cbd8>] ? __scsi_scan_target+0x95/0x480
[<c10204eb>] ? dequeue_entity+0x14/0x1fe
[<c1020491>] ? update_curr+0x165/0x1ab
[<c1020491>] ? update_curr+0x165/0x1ab
[<c127d00d>] ? scsi_scan_channel+0x4a/0x76
[<c127d0b0>] ? scsi_scan_host_selected+0x77/0xad
[<c127d13c>] ? do_scan_async+0x0/0x11a
[<c127d137>] ? do_scsi_scan_host+0x51/0x56
[<c127d13c>] ? do_scan_async+0x0/0x11a
[<c127d14a>] ? do_scan_async+0xe/0x11a
[<c127d13c>] ? do_scan_async+0x0/0x11a
[<c10354c5>] ? kthread+0x5e/0x63
[<c1035467>] ? kthread+0x0/0x63
[<c1002af6>] ? kernel_thread_helper+0x6/0x10
Code: 44 24 1c 54 83 44 24 18 54 83 fa 03 75 94 8b 06 c7 86 64 02 00 00 01 00 00 00 83 e0 03 09 f0 89 06 8b 44 24 28 8b 90 58 01 00 00 <8b> 42 2c 85 c0 75 03 8b 42 08 8d 54 24 48 52 8d 4c 24 50 51 68
EIP: [<c11c7b08>] cfq_get_queue+0x232/0x412 SS:ESP 0068:dff8fd00
CR2: 000000000000002c
---[ end trace 9a88306573f69b12 ]---
The problem here is that we don't have bdi->dev information available when
thread does some IO. Hence when dev_name() tries to access bdi->dev, it
crashes.
This problem does not happen if kernel threads are in root group as root
group is statically allocated at device initialization time and we don't
hit this piece of code.
Fix it by delaying the filling of major and minor number information of
device in blk_group. Initially a blk_group is created with 0 as device
information and this information is filled later once some more IO comes
in from same group.
Reported-by: Mike Kazantsev <mk.fraggod@gmail.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This bug was introduced in 7b6d91daee
"block: unify flags for struct bio and struct request"
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The "h->scatter_list" is allocated inside a for loop. If any of those
allocations fail, then the rest of the list is uninitialized data. When
we free it we should start from the top and free backwards so that we
don't call kfree() on uninitialized pointers.
Also if the allocation for "h->scatter_list" fails then we would get an
Oops here. I should have noticed this when I send: 4ee69851c "cciss:
handle allocation failure." but I didn't. Sorry about that.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
If another cpu does a very wide munmap() on the signal frame area,
it can tear down the page table hierarchy from underneath us.
Borrow an idea from the 64-bit fault path's get_user_insn(), and
disable cross call interrupts during the page table traversal
to lock them in place while we operate.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
pcpu_first/last_unit_cpu are used to track which cpu has the first and
last units assigned. This in turn is used to determine the span of a
chunk for man/unmap cache flushes and whether an address belongs to
the first chunk or not in per_cpu_ptr_to_phys().
When the number of possible CPUs isn't power of two, a chunk may
contain unassigned units towards the end of a chunk. The logic to
determine pcpu_last_unit_cpu was incorrect when there was an unused
unit at the end of a chunk. It failed to ignore the unused unit and
assigned the unused marker NR_CPUS to pcpu_last_unit_cpu.
This was discovered through kdump failure which was caused by
malfunctioning per_cpu_ptr_to_phys() on a kvm setup with 50 possible
CPUs by CAI Qian.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: CAI Qian <caiqian@redhat.com>
Cc: stable@kernel.org
We used to have a hypercall which reloaded the entire GDT, then we
switched to one which loaded a single entry (to match the IDT code).
Some comments were not updated, so fix them.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reported by: Eviatar Khen <eviatarkhen@gmail.com>
A userspace could submit a buffer with 0 length to be written to the
host. Prevent such a situation.
This was not needed previously, but recent changes in the way write()
works exposed this condition to trigger a virtqueue event to the host,
causing a NULL buffer to be sent across.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: stable@kernel.org
I found this while working on a Linux agent for spice, the symptom I was
seeing was select blocking on the spice vdagent virtio serial port even
though there were messages queued up there.
virtio_console's port_fops_poll checks port->inbuf != NULL to determine
if read won't block. However if an application reads enough bytes from
inbuf through port_fops_read, to empty the current port->inbuf,
port->inbuf will be NULL even though there may be buffers left in the
virtqueue.
This causes poll() to block even though there is data to be read,
this patch fixes this by using will_read_block(port) instead of the
port->inbuf != NULL check.
Signed-off-By: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
"param->u.wpa_associate.wpa_ie_len" comes from the user. We should
check it so that the copy_from_user() doesn't overflow the buffer.
Also further down in the function, we assume that if
"param->u.wpa_associate.wpa_ie_len" is set then "abyWPAIE[0]" is
initialized. To make that work, I changed the test here to say that if
"wpa_ie_len" is set then "wpa_ie" has to be a valid pointer or we return
-EINVAL.
Oddly, we only use the first element of the abyWPAIE[] array. So I
suspect there may be some other issues in this function.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 96d592ed59.
The netfilter hook seems to be misused and may leak skbs in situations
when NF_HOOK returns NF_STOLEN. It may not filter everything as
expected. Also the ethernet bridge tables are not yet capable to
understand batman-adv packet correctly.
It was only added for testing purposes and can be removed again.
Reported-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit d87d9b7d1 ("tty: serial - fix tty referencing in set_ldisc") changed
set_ldisc to take ldisc number as parameter. This patch fixes AMBA PL010 driver
according the new prototype.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If we don't, contributors to musb and any USB OMAP
code will be sending mails to an unexistent inbox.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The TIOCGICOUNT device ioctl in both mos7720.c and mos7840.c allows
unprivileged users to read uninitialized stack memory, because the
"reserved" member of the serial_icounter_struct struct declared on the
stack is not altered or zeroed before being copied back to the user.
This patch takes care of it.
Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 461c317705eca5cac09a360f488715927fd0a927(into 2.6.36-v3)
is put forward to power down phy if no usb cable is connected,
but does introduce the two issues below:
1), phy is not into work state if usb cable is connected
with PC during poweron, so musb device mode is not usable
in such case, follows the reasons:
-twl4030_phy_resume is not called, so
regulators are not enabled
i2c access are not enabled
usb mode not configurated
2), The kernel warings[1] of regulators 'unbalanced disables'
is caused if poweron without usb cable connected
with PC or b-device.
This patch fixes the two issues above:
-power down phy only if no usb cable is connected with PC
and b-device
-do phy initialization(via __twl4030_phy_resume) if usb cable
is connected with PC(vbus event) or another b-device(ID event) in
twl4030_usb_probe.
This patch also doesn't put VUSB3V1 LDO into active mode in
twl4030_usb_ldo_init until VBUS/ID change detected, so we can
save more power consumption than before.
This patch is verified OK on Beagle board either connected with
usb cable or not when poweron.
[1]. warnings of 'unbalanced disables' of regulators.
[root@OMAP3EVM /]# dmesg
------------[ cut here ]------------
WARNING: at drivers/regulator/core.c:1357 _regulator_disable+0x38/0x128()
unbalanced disables for VUSB1V8
Modules linked in:
Backtrace:
[<c0030c48>] (dump_backtrace+0x0/0x110) from [<c034f5a8>] (dump_stack+0x18/0x1c)
r7:c78179d8 r6:c01ed6b8 r5:c0410822 r4:0000054d
[<c034f590>] (dump_stack+0x0/0x1c) from [<c0057da8>] (warn_slowpath_common+0x54/0x6c)
[<c0057d54>] (warn_slowpath_common+0x0/0x6c) from [<c0057e64>] (warn_slowpath_fmt+0x38/0x40)
r9:00000000 r8:00000000 r7:c78e6608 r6:00000000 r5:fffffffb
r4:c78e6c00
[<c0057e2c>] (warn_slowpath_fmt+0x0/0x40) from [<c01ed6b8>] (_regulator_disable+0x38/0x128)
r3:c0410e53 r2:c0410ad5
[<c01ed680>] (_regulator_disable+0x0/0x128) from [<c01ed87c>] (regulator_disable+0x24/0x38)
r7:c78e6608 r6:00000000 r5:c78e6c40 r4:c78e6c00
[<c01ed858>] (regulator_disable+0x0/0x38) from [<c02382dc>] (twl4030_phy_power+0x15c/0x17c)
r5:c78595c0 r4:00000000
[<c0238180>] (twl4030_phy_power+0x0/0x17c) from [<c023831c>] (twl4030_phy_suspend+0x20/0x2c)
r6:00000000 r5:c78595c0 r4:c78595c0
[<c02382fc>] (twl4030_phy_suspend+0x0/0x2c) from [<c0238638>] (twl4030_usb_irq+0x11c/0x16c)
r5:c78595c0 r4:00000040
[<c023851c>] (twl4030_usb_irq+0x0/0x16c) from [<c034ec18>] (twl4030_usb_probe+0x2c4/0x32c)
r6:00000000 r5:00000000 r4:c78595c0
[<c034e954>] (twl4030_usb_probe+0x0/0x32c) from [<c02152a0>] (platform_drv_probe+0x20/0x24)
r7:00000000 r6:c047d49c r5:c78e6608 r4:c047d49c
[<c0215280>] (platform_drv_probe+0x0/0x24) from [<c0214244>] (driver_probe_device+0xd0/0x190)
[<c0214174>] (driver_probe_device+0x0/0x190) from [<c02143d4>] (__device_attach+0x44/0x48)
r7:00000000 r6:c78e6608 r5:c78e6608 r4:c047d49c
[<c0214390>] (__device_attach+0x0/0x48) from [<c0213694>] (bus_for_each_drv+0x50/0x90)
r5:c0214390 r4:00000000
[<c0213644>] (bus_for_each_drv+0x0/0x90) from [<c0214474>] (device_attach+0x70/0x94)
r6:c78e663c r5:c78e6608 r4:c78e6608
[<c0214404>] (device_attach+0x0/0x94) from [<c02134fc>] (bus_probe_device+0x2c/0x48)
r7:00000000 r6:00000002 r5:c78e6608 r4:c78e6600
[<c02134d0>] (bus_probe_device+0x0/0x48) from [<c0211e48>] (device_add+0x340/0x4b4)
[<c0211b08>] (device_add+0x0/0x4b4) from [<c021597c>] (platform_device_add+0x110/0x16c)
[<c021586c>] (platform_device_add+0x0/0x16c) from [<c0220cb0>] (add_numbered_child+0xd8/0x118)
r7:00000000 r6:c045f15c r5:c78e6600 r4:00000000
[<c0220bd8>] (add_numbered_child+0x0/0x118) from [<c001c618>] (twl_probe+0x3a4/0x72c)
[<c001c274>] (twl_probe+0x0/0x72c) from [<c02601ac>] (i2c_device_probe+0x7c/0xa4)
[<c0260130>] (i2c_device_probe+0x0/0xa4) from [<c0214244>] (driver_probe_device+0xd0/0x190)
r5:c7856e20 r4:c047c860
[<c0214174>] (driver_probe_device+0x0/0x190) from [<c02143d4>] (__device_attach+0x44/0x48)
r7:c7856e04 r6:c7856e20 r5:c7856e20 r4:c047c860
[<c0214390>] (__device_attach+0x0/0x48) from [<c0213694>] (bus_for_each_drv+0x50/0x90)
r5:c0214390 r4:00000000
[<c0213644>] (bus_for_each_drv+0x0/0x90) from [<c0214474>] (device_attach+0x70/0x94)
r6:c7856e54 r5:c7856e20 r4:c7856e20
[<c0214404>] (device_attach+0x0/0x94) from [<c02134fc>] (bus_probe_device+0x2c/0x48)
r7:c7856e04 r6:c78fd048 r5:c7856e20 r4:c7856e20
[<c02134d0>] (bus_probe_device+0x0/0x48) from [<c0211e48>] (device_add+0x340/0x4b4)
[<c0211b08>] (device_add+0x0/0x4b4) from [<c0211fd8>] (device_register+0x1c/0x20)
[<c0211fbc>] (device_register+0x0/0x20) from [<c0260aa8>] (i2c_new_device+0xec/0x150)
r5:c7856e00 r4:c7856e20
[<c02609bc>] (i2c_new_device+0x0/0x150) from [<c0260dc0>] (i2c_register_adapter+0xa0/0x1c4)
r7:00000000 r6:c78fd078 r5:c78fd048 r4:c781d5c0
[<c0260d20>] (i2c_register_adapter+0x0/0x1c4) from [<c0260f80>] (i2c_add_numbered_adapter+0x9c/0xb4)
r7:00000a28 r6:c04600a8 r5:c78fd048 r4:00000000
[<c0260ee4>] (i2c_add_numbered_adapter+0x0/0xb4) from [<c034efa4>] (omap_i2c_probe+0x324/0x3e8)
r5:00000000 r4:c78fd000
[<c034ec80>] (omap_i2c_probe+0x0/0x3e8) from [<c02152a0>] (platform_drv_probe+0x20/0x24)
[<c0215280>] (platform_drv_probe+0x0/0x24) from [<c0214244>] (driver_probe_device+0xd0/0x190)
[<c0214174>] (driver_probe_device+0x0/0x190) from [<c021436c>] (__driver_attach+0x68/0x8c)
r7:c78b2140 r6:c047e214 r5:c04600e4 r4:c04600b0
[<c0214304>] (__driver_attach+0x0/0x8c) from [<c021399c>] (bus_for_each_dev+0x50/0x84)
r7:c78b2140 r6:c047e214 r5:c0214304 r4:00000000
[<c021394c>] (bus_for_each_dev+0x0/0x84) from [<c0214068>] (driver_attach+0x20/0x28)
r6:c047e214 r5:c047e214 r4:c00270d0
[<c0214048>] (driver_attach+0x0/0x28) from [<c0213274>] (bus_add_driver+0xa8/0x228)
[<c02131cc>] (bus_add_driver+0x0/0x228) from [<c02146a4>] (driver_register+0xb0/0x13c)
[<c02145f4>] (driver_register+0x0/0x13c) from [<c0215744>] (platform_driver_register+0x4c/0x60)
r9:00000000 r8:c001f688 r7:00000013 r6:c005b6fc r5:c00083dc
r4:c00270d0
[<c02156f8>] (platform_driver_register+0x0/0x60) from [<c001f69c>] (omap_i2c_init_driver+0x14/0x1c)
[<c001f688>] (omap_i2c_init_driver+0x0/0x1c) from [<c002c460>] (do_one_initcall+0xd0/0x1a4)
[<c002c390>] (do_one_initcall+0x0/0x1a4) from [<c0008478>] (kernel_init+0x9c/0x154)
[<c00083dc>] (kernel_init+0x0/0x154) from [<c005b6fc>] (do_exit+0x0/0x688)
r5:c00083dc r4:00000000
---[ end trace 1b75b31a2719ed1d ]---
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Felipe Balbi <me@felipebalbi.com>
Cc: Anand Gadiyar <gadiyar@ti.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We have to do so due to HW limitation.
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
seq_files use the private_data field of a file struct for storing a seq_file structure,
data should be stored in seq_file's own private field (e.g. file->private_data->private)
Otherwise seq_release() will free the private data when the file is closed.
Signed-off-by: Mathias Nyman <mathias.nyman@nokia.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
During heavy aperture thrashing we may be forced to wait upon several active
objects during eviction. The active list may be the last reference to
these objects and so the action of waiting upon one of them may cause
another to be freed (and itself unbound). To prevent the object
disappearing underneath us, we need to acquire and hold a reference
whilst unbinding.
This should fix the reported page refcount OOPS:
kernel BUG at drivers/gpu/drm/i915/i915_gem.c:1444!
...
RIP: 0010:[<ffffffffa0093026>] [<ffffffffa0093026>] i915_gem_object_put_pages+0x25/0xf5 [i915]
Call Trace:
[<ffffffffa009481d>] i915_gem_object_unbind+0xc5/0x1a7 [i915]
[<ffffffffa0098ab2>] i915_gem_evict_something+0x3bd/0x409 [i915]
[<ffffffffa0027923>] ? drm_gem_object_lookup+0x27/0x57 [drm]
[<ffffffffa0093bc3>] i915_gem_object_bind_to_gtt+0x1d3/0x279 [i915]
[<ffffffffa0095b30>] i915_gem_object_pin+0xa3/0x146 [i915]
[<ffffffffa0027948>] ? drm_gem_object_lookup+0x4c/0x57 [drm]
[<ffffffffa00961bc>] i915_gem_do_execbuffer+0x50d/0xe32 [i915]
Reported-by: Shawn Starr <shawn.starr@rogers.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=18902
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
We need to make sure that only the first do_signal() to be handled on
the way out syscall will bother with syscall restarts; additionally, the
check on the "signal has user handler" path had been wrong - compare
with restart prevention in sigreturn()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_signal() should place the syscall number in gr7, not gr8 when
handling ERESTART_WOULDBLOCK.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use force_sigsegv() rather than force_sig(SIGSEGV, ...) as the former
resets the SEGV handler pointer which will kill the process, rather than
leaving it open to an infinite loop if the SEGV handler itself caused a
SEGV signal.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
a) sa_handler might be maliciously set to point to kernel memory;
blindly dereferencing it in FDPIC case is a Bad Idea(tm).
b) I'm not sure you need that set_fs(USER_DS) there at all, but if you
do, you'd better do it *before* checking the frame you've decided to
use with access_ok(), lest sigaltstack() becomes a convenient
roothole.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reset restart_block.fn on executing a sigreturn such that any currently
pending system call restarts will be forced to return -EINTR.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 4969c1192d ("mm: fix swapin race condition") is now agreed to
be incomplete. There's a race, not very much less likely than the
original race envisaged, in which it is further necessary to check that
the swapcache page's swap has not changed.
Here's the reasoning: cast in terms of reuse_swap_page(), but probably
could be reformulated to rely on try_to_free_swap() instead, or on
swapoff+swapon.
A, faults into do_swap_page(): does page1 = lookup_swap_cache(swap1) and
comes through the lock_page(page1).
B, a racing thread of the same process, faults on the same address: does
page1 = lookup_swap_cache(swap1) and now waits in lock_page(page1), but
for whatever reason is unlucky not to get the lock any time soon.
A carries on through do_swap_page(), a write fault, but cannot reuse the
swap page1 (another reference to swap1). Unlocks the page1 (but B
doesn't get it yet), does COW in do_wp_page(), page2 now in that pte.
C, perhaps the parent of A+B, comes in and write faults the same swap
page1 into its mm, reuse_swap_page() succeeds this time, swap1 is freed.
kswapd comes in after some time (B still unlucky) and swaps out some
pages from A+B and C: it allocates the original swap1 to page2 in A+B,
and some other swap2 to the original page1 now in C. But does not
immediately free page1 (actually it couldn't: B holds a reference),
leaving it in swap cache for now.
B at last gets the lock on page1, hooray! Is PageSwapCache(page1)? Yes.
Is pte_same(*page_table, orig_pte)? Yes, because page2 has now been
given the swap1 which page1 used to have. So B proceeds to insert page1
into A+B's page_table, though its content now belongs to C, quite
different from what A wrote there.
B ought to have checked that page1's swap was still swap1.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha-2.6:
alpha: deal with multiple simultaneously pending signals
alpha: fix a 14 years old bug in sigreturn tracing
alpha: unb0rk sigsuspend() and rt_sigsuspend()
alpha: belated ERESTART_RESTARTBLOCK race fix
alpha: Shift perf event pending work earlier in timer interrupt
alpha: wire up fanotify and prlimit64 syscalls
alpha: kill big kernel lock
alpha: fix build breakage in asm/cacheflush.h
alpha: remove unnecessary cast from void* in assignment.
alpha: Use static const char * const where possible
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
dca: disable dca on IOAT ver.3.0 multiple-IOH platforms
netpoll: Disable IRQ around RCU dereference in netpoll_rx
sctp: Do not reset the packet during sctp_packet_config().
net/llc: storing negative error codes in unsigned short
MAINTAINERS: move atlx discussions to netdev
drivers/net/cxgb3/cxgb3_main.c: prevent reading uninitialized stack memory
drivers/net/eql.c: prevent reading uninitialized stack memory
drivers/net/usb/hso.c: prevent reading uninitialized memory
xfrm: dont assume rcu_read_lock in xfrm_output_one()
r8169: Handle rxfifo errors on 8168 chips
3c59x: Remove atomic context inside vortex_{set|get}_wol
tcp: Prevent overzealous packetization by SWS logic.
net: RPS needs to depend upon USE_GENERIC_SMP_HELPERS
phylib: fix PAL state machine restart on resume
net: use rcu_barrier() in rollback_registered_many
bonding: correctly process non-linear skbs
ipv4: enable getsockopt() for IP_NODEFRAG
ipv4: force_igmp_version ignored when a IGMPv3 query received
ppp: potential NULL dereference in ppp_mp_explode()
net/llc: make opt unsigned in llc_ui_setsockopt()
...
Coda's REQ_* defines were renamed to avoid clashes with the block layer
(commit 4aeefdc69f: "coda: fixup clash with block layer REQ_*
defines").
However one was missed and response messages are no longer matched with
requests and waiting threads are no longer woken up. This patch fixes
this.
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
[ Also fixed up whitespace while at it -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Unlike the other targets, alpha sets _one_ sigframe and
buggers off until the next syscall/interrupt, even if
more signals are pending. It leads to quite a few unpleasant
inconsistencies, starting with SIGSEGV potentially arriving
not where it should and including e.g. mess with sigsuspend();
consider two pending signals blocked until sigsuspend()
unblocks them. We pick the first one; then, if we are hit
by interrupt while in the handler, we process the second one
as well. If we are not, and if no syscalls had been made,
we get out of the first handler and leave the second signal
pending; normally sigreturn() would've picked it anyway, but
here it starts with restoring the original mask and voila -
the second signal is blocked again. On everything else we
get both delivered consistently.
It's actually easy to fix; the only thing to watch out for
is prevention of double syscall restart. Fortunately, the
idea I've nicked from arm fix by rmk works just fine...
Testcase demonstrating the behaviour in question; on alpha
we get one or both flags set (usually one), on everything
else both are always set.
#include <signal.h>
#include <stdio.h>
int had1, had2;
void f1(int sig) { had1 = 1; }
void f2(int sig) { had2 = 1; }
main()
{
sigset_t set1, set2;
sigemptyset(&set1);
sigemptyset(&set2);
sigaddset(&set2, 1);
sigaddset(&set2, 2);
signal(1, f1);
signal(2, f2);
sigprocmask(SIG_SETMASK, &set2, NULL);
raise(1);
raise(2);
sigsuspend(&set1);
printf("had1:%d had2:%d\n", had1, had2);
}
Tested-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL,
all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support.
What happens is direct return to ret_from_syscall, in order to bypass
mangling of a3 (error indicator) and prevent other mutilations of
registers (e.g. by syscall restart). That's fine, but... the entire
TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall
stopping/notifying the tracer is after the syscall. And the normal
path we are forcibly switching to doesn't have it.
So we end up with *one* stop in traced sigreturn() vs. two in other
syscalls. And yes, strace is visibly broken by that; try to strace
the following
#include <signal.h>
#include <stdio.h>
void f(int sig) {}
main()
{
signal(SIGHUP, f);
raise(SIGHUP);
write(1, "eeeek\n", 6);
}
and watch the show. The
close(1) = 405
in the end of strace output is coming from return value of write() (6 ==
__NR_close on alpha) and syscall number of exit_group() (__NR_exit_group ==
405 there).
The fix is fairly simple - the only thing we end up missing is the call
of syscall_trace() and we can tell whether we'd been called from the
SYSCALL_TRACE path by checking ra value. Since we are setting the
switch_stack up (that's what sys_sigreturn() does), we have the right
environment for calling syscall_trace() - just before we call
undo_switch_stack() and return. Since undo_switch_stack() will overwrite
s0 anyway, we can use it to store the result of "has it been called from
SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn().
Tested-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Old code used to set regs->r0 and regs->r19 to force the right
return value. Leaving that after switch to ERESTARTNOHAND
was a Bad Idea(tm), since now that screws the restart - if we
hit the case when get_signal_to_deliver() returns 0, we will
step back to syscall insn, with v0 set to EINTR and a3 to 1.
The latter won't matter, since EINTR is 4, aka __NR_write.
Testcase:
#include <signal.h>
#define _GNU_SOURCE
#include <unistd.h>
#include <sys/syscall.h>
main()
{
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGCONT);
sigprocmask(SIG_SETMASK, &mask, NULL);
kill(0, SIGCONT);
syscall(__NR_sigsuspend, 1, "b0rken\n", 7);
}
results on alpha in immediate message to stdout...
Fix is obvious; moreover, since we don't need regs anymore, we can
switch to normal prototypes for these guys and lose the wrappers.
Even better, rt_sigsuspend() is identical to generic version in
kernel/signal.c now.
Tested-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
same thing as had been done on other targets back in 2003 -
move setting ->restart_block.fn into {rt_,}sigreturn().
Tested-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Pending work from the performance event subsystem is executed in
the timer interrupt. This patch shifts the call to
perf_event_do_pending() before the call to update_process_times()
as the latter may call back into the perf event subsystem and it
is prudent to have the pending work executed first.
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Matt Turner <mattst88@gmail.com>
The 2.6.36-rc kernel added three new system calls:
fanotify_init, fanotify_mark, and prlimit64. This
patch wires them up on Alpha.
Built and booted on an XP900. Untested beyond that.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Matt Turner <mattst88@gmail.com>
All uses of the BKL on alpha are totally bogus, nothing
is really protected by this. Remove the remaining users
so we don't have to mark alpha as 'depends on BKL'.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: Matt Turner <mattst88@gmail.com>
Alpha SMP flush_icache_user_range() is implemented as an inline
function inside include/asm/cacheflush.h. It dereferences @current
but doesn't include linux/sched.h and thus causes build failure if
linux/sched.h wasn't included previously. Fix it by including the
needed header file explicitly.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Matt Turner <mattst88@gmail.com>
