This time it appears GRO layer can accumulate skb->truesize
adjustments made by drivers when they attach a fragment to skb.
skb_gro_receive() can only subtract from skb->truesize the used part
of a fragment.
I spotted this problem seeing TcpExtPruneCalled and
TcpExtTCPRcvCollapsed that were unexpected with a recent kernel, where
TCP receive window should be sized properly to accept traffic coming
from a driver not overshooting skb->truesize.
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
With the recent changes for how we compute the skb truesize it occurs to me
we are probably going to have a lot of calls to skb_end_pointer -
skb->head. Instead of running all over the place doing that it would make
more sense to just make it a separate inline skb_end_offset(skb) that way
we can return the correct value without having gcc having to do all the
optimization to cancel out skb->head - skb->head.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
the value of itag is a random value from stack, and may not be initiated by
fib_validate_source, which called fib_combine_itag if CONFIG_IP_ROUTE_CLASSID
is not set
This will make the cached dst uncertainty
Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
We drop packet unconditionally when we fail to mirror it. This is not intended
in some cases. Consdier for kvm guest, we may mirror the traffic of the bridge
to a tap device used by a VM. When kernel fails to mirror the packet in
conditions such as when qemu crashes or stop polling the tap, it's hard for the
management software to detect such condition and clean the the mirroring
before. This would lead all packets to the bridge to be dropped and break the
netowrk of other virtual machines.
To solve the issue, the patch does not drop packets when kernel fails to mirror
it, and only drop the redirected packets.
Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Clearing the IFF_ALLMULTI flag on a down interface could cause an allmulti
overflow on the underlying interface.
Attempting the set IFF_ALLMULTI on the underlying interface would cause an
error and the log message:
"allmulti touches root, set allmulti failed."
Signed-off-by: Peter Christensen <pch@ordbogen.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Increment fib_info_cnt in fib_create_info() right after successfuly
alllocating fib_info structure, overwise fib_metrics allocation failure
leads to fib_info_cnt incorrectly decremented in free_fib_info(), called
on error path from fib_create_info().
Signed-off-by: Sergey Popovich <popovich_sergei@mail.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
local_df means 'ignore DF bit if set', so if its set we're
allowed to perform ip fragmentation.
This wasn't noticed earlier because the output path also drops such skbs
(and emits needed icmp error) and because netfilter ip defrag did not
set local_df until couple of days ago.
Only difference is that DF-packets-larger-than MTU now discarded
earlier (f.e. we avoid pointless netfilter postrouting trip).
While at it, drop the repeated test ip_exceeds_mtu, checking it once
is enough...
Fixes: fe6cc55f3a9 ("net: ip, ipv6: handle gso skbs in forwarding path") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b9f47a3aaeab (tcp_cubic: limit delayed_ack ratio to prevent
divide error) try to prevent divide error, but there is still a little
chance that delayed_ack can reach zero. In case the param cnt get
negative value, then ratio+cnt would overflow and may happen to be zero.
As a result, min(ratio, ACK_RATIO_LIMIT) will calculate to be zero.
In some old kernels, such as 2.6.32, there is a bug that would
pass negative param, which then ultimately leads to this divide error.
commit 5b35e1e6e9c (tcp: fix tcp_trim_head() to adjust segment count
with skb MSS) fixed the negative param issue. However,
it's safe that we fix the range of delayed_ack as well,
to make sure we do not hit a divide by zero.
CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Liu Yu <allanyuliu@tencent.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This reverts commit 12a2856b604476c27d85a5f9a57ae1661fc46019.
The commit above doesn't appear to be necessary any more as the
checksums appear to be correctly computed/validated.
Additionally the above commit breaks kvm configurations where
one VM is using a device that support checksum offload (virtio) and
the other VM does not.
In this case, packets leaving virtio device will have CHECKSUM_PARTIAL
set. The packets is forwarded to a macvtap that has offload features
turned off. Since we use CHECKSUM_UNNECESSARY, the host does does not
update the checksum and thus a bad checksum is passed up to
the guest.
CC: Daniel Lezcano <daniel.lezcano@free.fr> CC: Patrick McHardy <kaber@trash.net> CC: Andrian Nord <nightnord@gmail.com> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Michael S. Tsirkin <mst@redhat.com> CC: Jason Wang <jasowang@redhat.com> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 813b3b5db83 (ipv4: Use caller's on-stack flowi as-is
in output route lookups.) introduces another regression which
is very similar to the problem of commit e6b45241c (ipv4: reset
flowi parameters on route connect) wants to fix:
Before we call ip_route_output_key() in sctp_v4_get_dst() to
get a dst that matches a bind address as the source address,
we have already called this function previously and the flowi
parameters have been initialized including flowi4_oif, so when
we call this function again, the process in __ip_route_output_key()
will be different because of the setting of flowi4_oif, and we'll
get a networking device which corresponds to the inputted flowi4_oif
as the output device, this is wrong because we'll never hit this
place if the previously returned source address of dst match one
of the bound addresses.
To reproduce this problem, a vlan setting is enough:
# ifconfig eth0 up
# route del default
# vconfig add eth0 2
# vconfig add eth0 3
# ifconfig eth0.2 10.0.1.14 netmask 255.255.255.0
# route add default gw 10.0.1.254 dev eth0.2
# ifconfig eth0.3 10.0.0.14 netmask 255.255.255.0
# ip rule add from 10.0.0.14 table 4
# ip route add table 4 default via 10.0.0.254 src 10.0.0.14 dev eth0.3
# sctp_darn -H 10.0.0.14 -P 36422 -h 10.1.4.134 -p 36422 -s -I
You'll detect that all the flow are routed to eth0.2(10.0.1.254).
Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com> Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When bridge device is created with IFLA_ADDRESS, we are not calling
br_stp_change_bridge_id(), which leads to incorrect local fdb
management and bridge id calculation, and prevents us from receiving
frames on the bridge device.
Reported-by: Tom Gundersen <teg@jklm.no> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Since 115c9b81928360d769a76c632bae62d15206a94a (rtnetlink: Fix problem with
buffer allocation), RTM_NEWLINK messages only contain the IFLA_VFINFO_LIST
attribute if they were solicited by a GETLINK message containing an
IFLA_EXT_MASK attribute with the RTEXT_FILTER_VF flag.
That was done because some user programs broke when they received more data
than expected - because IFLA_VFINFO_LIST contains information for each VF
it can become large if there are many VFs.
However, the IFLA_VF_PORTS attribute, supplied for devices which implement
ndo_get_vf_port (currently the 'enic' driver only), has the same problem.
It supplies per-VF information and can therefore become large, but it is
not currently conditional on the IFLA_EXT_MASK value.
Worse, it interacts badly with the existing EXT_MASK handling. When
IFLA_EXT_MASK is not supplied, the buffer for netlink replies is fixed at
NLMSG_GOODSIZE. If the information for IFLA_VF_PORTS exceeds this, then
rtnl_fill_ifinfo() returns -EMSGSIZE on the first message in a packet.
netlink_dump() will misinterpret this as having finished the listing and
omit data for this interface and all subsequent ones. That can cause
getifaddrs(3) to enter an infinite loop.
This patch addresses the problem by only supplying IFLA_VF_PORTS when
IFLA_EXT_MASK is supplied with the RTEXT_FILTER_VF flag set.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Without IFLA_EXT_MASK specified, the information reported for a single
interface in response to RTM_GETLINK is expected to fit within a netlink
packet of NLMSG_GOODSIZE.
If it doesn't, however, things will go badly wrong, When listing all
interfaces, netlink_dump() will incorrectly treat -EMSGSIZE on the first
message in a packet as the end of the listing and omit information for
that interface and all subsequent ones. This can cause getifaddrs(3) to
enter an infinite loop.
This patch won't fix the problem, but it will WARN_ON() making it easier to
track down what's going wrong.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The patch fixes a problem with dropped jumbo frames after usage of
'ethtool -G ... rx'.
Scenario:
1. ip link set eth0 up
2. ethtool -G eth0 rx N # <- This zeroes rx-jumbo
3. ip link set mtu 9000 dev eth0
The ethtool command set rx_jumbo_pending to zero so any received jumbo
packets are dropped and you need to use 'ethtool -G eth0 rx-jumbo N'
to workaround the issue.
The patch changes the logic so rx_jumbo_pending value is changed only if
jumbo frames are enabled (MTU > 1500).
Signed-off-by: Ivan Vecera <ivecera@redhat.com> Acked-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The BPF_S_ANC_NLATTR and BPF_S_ANC_NLATTR_NEST extensions fail to check
for a minimal message length before testing the supplied offset to be
within the bounds of the message. This allows the subtraction of the nla
header to underflow and therefore -- as the data type is unsigned --
allowing far to big offset and length values for the search of the
netlink attribute.
The remainder calculation for the BPF_S_ANC_NLATTR_NEST extension is
also wrong. It has the minuend and subtrahend mixed up, therefore
calculates a huge length value, allowing to overrun the end of the
message while looking for the netlink attribute.
The following three BPF snippets will trigger the bugs when attached to
a UNIX datagram socket and parsing a message with length 1, 2 or 3.
,-[ PoC for missing size check in BPF_S_ANC_NLATTR ]--
| ld #0x87654321
| ldx #42
| ld #nla
| ret a
`---
,-[ PoC for the same bug in BPF_S_ANC_NLATTR_NEST ]--
| ld #0x87654321
| ldx #42
| ld #nlan
| ret a
`---
,-[ PoC for wrong remainder calculation in BPF_S_ANC_NLATTR_NEST ]--
| ; (needs a fake netlink header at offset 0)
| ld #0
| ldx #42
| ld #nlan
| ret a
`---
Fix the first issue by ensuring the message length fulfills the minimal
size constrains of a nla header. Fix the second bug by getting the math
for the remainder calculation right.
Fixes: 4738c1db15 ("[SKFILTER]: Add SKF_ADF_NLATTR instruction") Fixes: d214c7537b ("filter: add SKF_AD_NLATTR_NEST to look for nested..") Cc: Patrick McHardy <kaber@trash.net> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Mathias Krause <minipli@googlemail.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Fix misplacement of the first check due to a bug in the patch program] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Plug a group_info refcount leak in ping_init.
group_info is only needed during initialization and
the code failed to release the reference on exit.
While here move grabbing the reference to a place
where it is actually needed.
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> Signed-off-by: Zhang Dongxing <dongxing.zhang@intel.com> Signed-off-by: xiaoming wang <xiaoming.wang@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Francois reported that setting big mtu on loopback device could prevent
tcp sessions making progress.
We do not support (yet ?) IPv6 Jumbograms and cook corrupted packets.
We must limit the IPv6 MTU to (65535 + 40) bytes in theory.
Tested:
ifconfig lo mtu 70000
netperf -H ::1
Before patch : Throughput : 0.05 Mbits
After patch : Throughput : 35484 Mbits
Reported-by: Francois WELLENREITER <f.wellenreiter@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Remove the bonding debug_fs entries when the
module initialization fails. The debug_fs
entries should be removed together with all other
already allocated resources.
Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Signed-off-by: Jay Vosburgh <j.vosburgh@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
For UFO (udp fragmentation offloading) skbs, gso_size is the fragment
payload size, i.e. we must not account for udp header size.
Otherwise, when using virtio drivers, a to-be-forwarded UFO GSO packet
will be needlessly fragmented in the forward path, because we think its
individual segments are too large for the outgoing link.
Fixes: fe6cc55f3a9a053 ("net: ip, ipv6: handle gso skbs in forwarding path") Cc: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Tobias Brunner <tobias@strongswan.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When l2tp driver tries to get PMTU for the tunnel destination, it uses
the pointer to struct sock that represents PPPoX socket, while it
should use the pointer that represents UDP socket of the tunnel.
Signed-off-by: Dmitry Petukhov <dmgenp@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
All xtables variants suffer from the defect that the copy_to_user()
to copy the counters to user memory may fail after the table has
already been exchanged and thus exposed. Return an error at this
point will result in freeing the already exposed table. Any
subsequent packet processing will result in a kernel panic.
We can't copy the counters before exposing the new tables as we
want provide the counter state after the old table has been
unhooked. Therefore convert this into a silent error.
Cc: Florian Westphal <fw@strlen.de> Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Mode setting in the TGA driver is broken for these reasons:
- info->fix.line_length is set just once in tgafb_init_fix function. If
we change videomode, info->fix.line_length is not recalculated - so
the video mode is changed but the screen is corrupted because of wrong
info->fix.line_length.
- info->fix.smem_len is set in tgafb_init_fix to the size of the default
video mode (640x480). If we set a higher resolution,
info->fix.smem_len is smaller than the current screen size, preventing
the userspace program from mapping the framebuffer.
This patch fixes it:
- info->fix.line_length initialization is moved to tgafb_set_par so that
it is recalculated with each mode change.
- info->fix.smem_len is set to a fixed value representing the real
amount of video ram (the values are taken from xfree86 driver).
- add a check to tgafb_check_var to prevent us from setting a videomode
that doesn't fit into videoram.
- in tgafb_register, tgafb_init_fix is moved upwards, to be called
before fb_find_mode (because fb_find_mode already needs the videoram
size set in tgafb_init_fix).
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vga.kernel.org Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Address a regression caused by commit ad332c8a4533:
(ACPI / EC: Clear stale EC events on Samsung systems)
After the earlier patch, there was found to be a race condition on some
earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was
sometimes discarding a new EC event before its GPE was triggered by the
system. In the case of these systems, this meant that the "lid open"
event was not registered on resume if that was the cause of the wake,
leading to problems when attempting to close the lid to suspend again.
After testing on a number of Samsung systems, both those affected by the
previous EC bug and those affected by the race condition, it seemed that
the best course of action was to process rather than discard the events.
On Samsung systems which accumulate stale EC events, there does not seem
to be any adverse side-effects of running the associated _Q methods.
This patch adds an argument to the static function acpi_ec_sync_query so
that it may be used within the acpi_ec_clear loop in place of
acpi_ec_query_unlocked which was used previously.
With thanks to Stefan Biereigel for reporting the issue, and for all the
people who helped test the new patch on affected systems.
Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems)
References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de
References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173 Reported-by: Stefan Biereigel <stefan@biereigel.de> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Stefan Biereigel <stefan@biereigel.de> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Nicolas Porcel <nicolasporcel06@gmail.com> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Giannis Koutsou <giannis.koutsou@gmail.com> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc)
continue to log events during sleep (lid open/close, AC plug/unplug,
battery level change), which accumulate in the EC until a buffer fills.
After the buffer is full (tests suggest it holds 8 events), GPEs stop
being triggered for new events. This state persists on wake or even on
power cycle, and prevents new events from being registered until the EC
is manually polled.
This is the root cause of a number of bugs, including AC not being
detected properly, lid close not triggering suspend, and low ambient
light not triggering the keyboard backlight. The bug also seemed to be
responsible for performance issues on at least one user's machine.
Juan Manuel Cabo found the cause of bug and the workaround of polling
the EC manually on wake.
The loop which clears the stale events is based on an earlier patch by
Lan Tianyu (see referenced attachment).
This patch:
- Adds a function acpi_ec_clear() which polls the EC for stale _Q
events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is
logged if this limit is reached.
- Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI
system vendor is Samsung. This check could be replaced by several
more specific DMI vendor/product pairs, but it's likely that the bug
affects more Samsung products than just the five series mentioned
above. Further, it should not be harmful to run acpi_ec_clear() on
systems without the bug; it will return immediately after finding no
data waiting.
- Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add()
- Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions()
References: https://bugzilla.kernel.org/show_bug.cgi?id=44161
References: https://bugzilla.kernel.org/show_bug.cgi?id=45461
References: https://bugzilla.kernel.org/show_bug.cgi?id=57271
References: https://bugzilla.kernel.org/attachment.cgi?id=126801 Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Reviewed-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Kieran Clancy <clancy.kieran@gmail.com> Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com> Tested-by: Dennis Jansen <dennis.jansen@web.de> Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com> Tested-by: San Zamoyski <san@plusnet.pl> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2:
- Adjust context
- acpi_ec::mutex was called lock] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size. They are needed for the raid6 altivec support.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Do not leak kernel-only floppy_raw_cmd structure members to userspace.
This includes the linked-list pointer and the pointer to the allocated
DMA space.
Signed-off-by: Matthew Daley <mattd@bugfuzz.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Always clear out these floppy_raw_cmd struct members after copying the
entire structure from userspace so that the in-kernel version is always
valid and never left in an interdeterminate state.
Signed-off-by: Matthew Daley <mattd@bugfuzz.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The tty atomic_write_lock does not provide an exclusion guarantee for
the tty driver if the termios settings are LECHO & !OPOST. And since
it is unexpected and not allowed to call TTY buffer helpers like
tty_insert_flip_string concurrently, this may lead to crashes when
concurrect writers call pty_write. In that case the following two
writers:
* the ECHOing from a workqueue and
* pty_write from the process
race and can overflow the corresponding TTY buffer like follows.
If we look into tty_insert_flip_string_fixed_flag, there is:
int space = __tty_buffer_request_room(port, goal, flags);
struct tty_buffer *tb = port->buf.tail;
...
memcpy(char_buf_ptr(tb, tb->used), chars, space);
...
tb->used += space;
so the race of the two can result in something like this:
A B
__tty_buffer_request_room
__tty_buffer_request_room
memcpy(buf(tb->used), ...)
tb->used += space;
memcpy(buf(tb->used), ...) ->BOOM
B's memcpy is past the tty_buffer due to the previous A's tb->used
increment.
Since the N_TTY line discipline input processing can output
concurrently with a tty write, obtain the N_TTY ldisc output_lock to
serialize echo output with normal tty writes. This ensures the tty
buffer helper tty_insert_flip_string is not called concurrently and
everything is fine.
Note that this is nicely reproducible by an ordinary user using
forkpty and some setup around that (raw termios + ECHO). And it is
present in kernels at least after commit d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty layer to
use the normal buffering logic) in 2.6.31-rc3.
js: add more info to the commit log
js: switch to bool
js: lock unconditionally
js: lock only the tty->ops->write call
References: CVE-2014-0196 Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: output_lock is a member of struct tty_struct] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Ben Hutchings [Sat, 19 Apr 2014 13:36:43 +0000 (14:36 +0100)]
rtl8192ce: Fix null dereference in watchdog
Dmitry Semyonov reported that after upgrading from 3.2.54 to
3.2.57 the rtl8192ce driver will crash when its interface is brought
up. The oops message shows:
Disassembly of rtl92ce_update_hal_rate_tbl() shows that the 'sta'
parameter was null. None of the changes to the rtlwifi family between
3.2.54 and 3.2.57 seem to directly cause this, and reverting commit f78bccd79ba3 ('rtlwifi: rtl8192ce: Fix too long disable of IRQs')
doesn't fix it.
rtl92c_dm_watchdog() calls rtl92ce_update_hal_rate_tbl() via
rtl92c_dm_refresh_rate_adaptive_mask(), which does not appear in the
call trace as it was inlined. That function has been completely
removed upstream which may explain why this crash wasn't seen there.
I'm not sure that it is sensible to completely remove
rtl92c_dm_refresh_rate_adaptive_mask() without making other
compensating changes elsewhere, so try to work around this for 3.2 by
checking for a null pointer in rtl92c_dm_refresh_rate_adaptive_mask()
and then skipping the call to rtl92ce_update_hal_rate_tbl().
References: https://bugs.debian.org/745137
References: https://bugs.debian.org/745462 Reported-by: Dmitry Semyonov <linulin@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Larry Finger <Larry.Finger@lwfinger.net> Cc: Chaoming Li <chaoming_li@realsil.com.cn>
During firmware download the device expects memory addresses in
big-endian byte order. As the wIndex parameter which hold the address is
sent in little-endian byte order regardless of host byte order, we need
to use swab16 rather than cpu_to_be16.
Also make sure to handle the struct ti_i2c_desc size parameter which is
returned in little-endian byte order.
Reported-by: Ludovic Drolez <ldrolez@debian.org> Tested-by: Ludovic Drolez <ldrolez@debian.org> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When CONFIG_PCI and CONFIG_PM are not selected, xhci.c gets this
warning:
drivers/usb/host/xhci.c:409:13: warning: ‘xhci_msix_sync_irqs’ defined
but not used [-Wunused-function]
Instead of creating nested #ifdefs, this patch fixes it by defining the
xHCI PCI stubs as inline.
This warning has been in since 3.2 kernel and was
caused by commit 421aa841a134f6a743111cf44d0c6d3b45e3cf8c
"usb/xhci: hide MSI code behind PCI bars", but wasn't noticed
until 3.13 when a configuration with these options was tried
Signed-off-by: David Cohen <david.a.cohen@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
We have observed a rare cycle state desync bug after Set TR Dequeue
Pointer commands on Intel LynxPoint xHCs (resulting in an endpoint that
doesn't fetch new TRBs and thus an unresponsive USB device). It always
triggers when a previous Set TR Dequeue Pointer command has set the
pointer to the final Link TRB of a segment, and then another URB gets
enqueued and cancelled again before it can be completed. Further
investigation showed that the xHC had returned the Link TRB in the TRB
Pointer field of the Transfer Event (CC == Stopped -- Length Invalid),
but when xhci_find_new_dequeue_state() later accesses the Endpoint
Context's TR Dequeue Pointer field it is set to the first TRB of the
next segment.
The driver expects those two values to be the same in this situation,
and uses the cycle state of the latter together with the address of the
former. This should be fine according to the XHCI specification, since
the endpoint ring should be stopped when returning the Transfer Event
and thus should not advance over the Link TRB before it gets restarted.
However, real-world XHCI implementations apparently don't really care
that much about these details, so the driver should follow a more
defensive approach to try to work around HC spec violations.
This patch removes the stopped_trb variable that had been used to store
the TRB Pointer from the last Transfer Event of a stopped TRB. Instead,
xhci_find_new_dequeue_state() now relies only on the Endpoint Context,
requiring a small amount of additional processing to find the virtual
address corresponding to the TR Dequeue Pointer. Some other parts of the
function were slightly rearranged to better fit into this model.
This patch should be backported to kernels as old as 2.6.31 that contain
the commit ae636747146ea97efa18e04576acd3416e2514f5 "USB: xhci: URB
cancellation support."
Signed-off-by: Julius Werner <jwerner@chromium.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Due to an off-by-one error, it is possible to reproduce a bug
when the inode cache is used.
The same inode number is assigned twice, the second time this
leads to an EEXIST in btrfs_insert_empty_items().
The issue can happen when a file is removed right after a subvolume
is created and then a new inode number is created before the
inodes in free_inode_pinned are processed.
unlink() calls btrfs_return_ino() which calls start_caching() in this
case which adds [highest_ino + 1, BTRFS_LAST_FREE_OBJECTID] by
searching for the highest inode (which already cannot find the
unlinked one anymore in btrfs_find_free_objectid()). So if this
unlinked inode's number is equal to the highest_ino + 1 (or >= this value
instead of > this value which was the off-by-one error), we mustn't add
the inode number to free_ino_pinned (caching_thread() does it right).
In this case we need to try directly to add the number to the inode_cache
which will fail in this case.
When this inode number is allocated while it is still in free_ino_pinned,
it is allocated and still added to the free inode cache when the
pinned inodes are processed, thus one of the following inode number
allocations will get an inode that is already in use and fail with EEXIST
in btrfs_insert_empty_items().
One example which was created with the reproducer below:
Create a snapshot, work in the newly created snapshot for the rest.
In unlink(inode 34284) call btrfs_return_ino() which calls start_caching().
start_caching() calls add_free_space [34284, 18446744073709517077].
In btrfs_return_ino(), call start_caching pinned [34284, 1] which is wrong.
mkdir() call btrfs_find_ino_for_alloc() which returns the number 34284.
btrfs_unpin_free_ino calls add_free_space [34284, 1].
mkdir() call btrfs_find_ino_for_alloc() which returns the number 34284.
EEXIST when the new inode is inserted.
One possible reproducer is this one:
#!/bin/sh
# preparation
TEST_DEV=/dev/sdc1
TEST_MNT=/mnt
umount ${TEST_MNT} 2>/dev/null || true
mkfs.btrfs -f ${TEST_DEV}
mount ${TEST_DEV} ${TEST_MNT} -o \
rw,relatime,compress=lzo,space_cache,inode_cache
btrfs subv create ${TEST_MNT}/s1
for i in `seq 34027`; do touch ${TEST_MNT}/s1/${i}; done
btrfs subv snap ${TEST_MNT}/s1 ${TEST_MNT}/s2
FILENAME=`find ${TEST_MNT}/s1/ -inum 4085 | sed 's|^.*/\([^/]*\)$|\1|'`
rm ${TEST_MNT}/s2/$FILENAME
touch ${TEST_MNT}/s2/$FILENAME
# the following steps can be repeated to reproduce the issue again and again
[ -e ${TEST_MNT}/s3 ] && btrfs subv del ${TEST_MNT}/s3
btrfs subv snap ${TEST_MNT}/s2 ${TEST_MNT}/s3
rm ${TEST_MNT}/s3/$FILENAME
touch ${TEST_MNT}/s3/$FILENAME
ls -alFi ${TEST_MNT}/s?/$FILENAME
touch ${TEST_MNT}/s3/_1 || logger FAILED
ls -alFi ${TEST_MNT}/s?/_1
touch ${TEST_MNT}/s3/_2 || logger FAILED
ls -alFi ${TEST_MNT}/s?/_2
touch ${TEST_MNT}/s3/__1 || logger FAILED
ls -alFi ${TEST_MNT}/s?/__1
touch ${TEST_MNT}/s3/__2 || logger FAILED
ls -alFi ${TEST_MNT}/s?/__2
# if the above is not enough, add the following loop:
for i in `seq 3 9`; do touch ${TEST_MNT}/s3/__${i} || logger FAILED; done
#for i in `seq 3 34027`; do touch ${TEST_MNT}/s3/__${i} || logger FAILED; done
# one of the touch(1) calls in s3 fail due to EEXIST because the inode is
# already in use that btrfs_find_ino_for_alloc() returns.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fix driver new_id sysfs-attribute removal deadlock by making sure to
not hold any locks that the attribute operations grab when removing the
attribute.
Specifically, usb_serial_deregister holds the table mutex when
deregistering the driver, which includes removing the new_id attribute.
This can lead to a deadlock as writing to new_id increments the
attribute's active count before trying to grab the same mutex in
usb_serial_probe.
The deadlock can easily be triggered by inserting a sleep in
usb_serial_deregister and writing the id of an unbound device to new_id
during module unload.
As the table mutex (in this case) is used to prevent subdriver unload
during probe, it should be sufficient to only hold the lock while
manipulating the usb-serial driver list during deregister. A racing
probe will then either fail to find a matching subdriver or fail to get
the corresponding module reference.
Since v3.15-rc1 this also triggers the following lockdep warning:
======================================================
[ INFO: possible circular locking dependency detected ]
3.15.0-rc2 #123 Tainted: G W
-------------------------------------------------------
modprobe/190 is trying to acquire lock:
(s_active#4){++++.+}, at: [<c0167aa0>] kernfs_remove_by_name_ns+0x4c/0x94
but task is already holding lock:
(table_lock){+.+.+.}, at: [<bf004d84>] usb_serial_deregister+0x3c/0x78 [usbserial]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
When viewed ftrace records, it will call the do_div(n, base) function, which achieved arch/arm/include/asm/div64.h in. When n = 10000000, base = 1000000, in do_div(n, base) will execute "umull %Q0, %R0, %1, %Q2".
Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Alex Wu <wuquanming@huawei.com> Signed-off-by: Xiangyu Lu <luxiangyu@huawei.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
fixup_user_fault() is used by the futex code when the direct user access
fails, and the futex code wants it to either map in the page in a usable
form or return an error. It relied on handle_mm_fault() to map the
page, and correctly checked the error return from that, but while that
does map the page, it doesn't actually guarantee that the page will be
mapped with sufficient permissions to be then accessed.
So do the appropriate tests of the vma access rights by hand.
[ Side note: arguably handle_mm_fault() could just do that itself, but
we have traditionally done it in the caller, because some callers -
notably get_user_pages() - have been able to access pages even when
they are mapped with PROT_NONE. Maybe we should re-visit that design
decision, but in the meantime this is the minimal patch. ]
Found by Dave Jones running his trinity tool.
Reported-by: Dave Jones <davej@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
We expect that all the Haswell series will need such quirks, sigh.
The T431s seems to be T430 hardware in a T440s case, using the T440s touchpad,
with the same min/max issue.
The X1 Carbon 3rd generation name says 2nd while it is a 3rd generation.
The X1 and T431s share a PnPID with the T540p, but the reported ranges are
closer to those of the T440s.
HdG: Squashed 5 quirk patches into one. T431s + L440 + L540 are written by me,
S1 Yoga and X1 are written by Benjamin Tissoires.
Hdg: Standardized S1 Yoga and X1 values, Yoga uses the same touchpad as the
X240, X1 uses the same touchpad as the T440.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
dmi_match() considers a substring match to be a successful match. This is
not always sufficient to distinguish between DMI data for different
systems. Add support for exact string matching using strcmp() in addition
to the substring matching using strstr().
The specific use case in the i915 driver is to allow us to use an exact
match for D510MO, without also incorrectly matching D510MOV:
soft lockup in freeing gigantic hugepage fixed in commit 55f67141a892 "mm:
hugetlb: fix softlockup when a large number of hugepages are freed." can
happen in return_unused_surplus_pages(), so let's fix it.
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The AHCI spec allows implementations to issue commands in tag order
rather than FIFO order:
5.3.2.12 P:SelectCmd
HBA sets pSlotLoc = (pSlotLoc + 1) mod (CAP.NCS + 1)
or HBA selects the command to issue that has had the
PxCI bit set to '1' longer than any other command
pending to be issued.
The result is that commands posted sequentially (time-wise) may play out
of sequence when issued by hardware.
This behavior has likely been hidden by drives that arrange for commands
to complete in issue order. However, it appears recent drives (two from
different vendors that we have found so far) inflict out-of-order
completions as a matter of course. So, we need to take care to maintain
ordered submission, otherwise we risk triggering a drive to fall out of
sequential-io automation and back to random-io processing, which incurs
large latency and degrades throughput.
This issue was found in simple benchmarks where QD=2 seq-write
performance was 30-50% *greater* than QD=32 seq-write performance.
Tagging for -stable and making the change globally since it has a low
risk-to-reward ratio. Also, word is that recent versions of an unnamed
OS also does it this way now. So, drives in the field are already
experienced with this tag ordering scheme.
Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ed Ciechanowski <ed.ciechanowski@intel.com> Reviewed-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
...otherwise the logic in the timeout handling doesn't work correctly.
Spotted-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[bwh: Backported to 3.2: max_cb_time() takes no parameters] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
By specifying NO_UNION_NORMAL the ACM driver does only use the first two
USB interfaces (modem data & control). The AT Port, Diagnostic and NMEA
interfaces are left to the USB serial driver.
Signed-off-by: Michael Ulbricht <michael.ulbricht@systec-electronic.com> Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Oliver Neukum <oliver@neukum.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Zero-initializing ether_type masked that the ether type would never be
obtained for 8021x packets and the comparison against eapol_type
would always fail.
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This was part of a patch by Alexander Guller from Mellanox in 2011,
but it still isn't upstream.
Signed-off-by: Chris Mason <clm@fb.com> Acked-By: Amir Vadai <amirv@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
A fl->fl_break_time of 0 has a special meaning to the lease break code
that basically means "never break the lease". knfsd uses this to ensure
that leases don't disappear out from under it.
Unfortunately, the code in __break_lease can end up passing this value
to wait_event_interruptible as a timeout, which prevents it from going
to sleep at all. This makes __break_lease to spin in a tight loop and
causes soft lockups.
Fix this by ensuring that we pass a minimum value of 1 as a timeout
instead.
Cc: J. Bruce Fields <bfields@fieldses.org> Reported-by: Terry Barnaby <terry1@beam.ltd.uk> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ext4_end_bio() currently throws away the error that it receives. Chances
are this is part of a spate of errors, one of which will end up getting
the error returned to userspace somehow, but we shouldn't take that risk.
Also print out the errno to aid in debug.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When we try to get 2^32-1 block of the file which has the extent
(ee_block=2^32-2, ee_len=1) with FIBMAP ioctl, it causes BUG_ON
in ext4_ext_put_gap_in_cache().
To avoid the problem, ext4_map_blocks() needs to check the file logical block
number. ext4_ext_put_gap_in_cache() called via ext4_map_blocks() cannot
handle 2^32-1 because the maximum file logical block number is 2^32-2.
Note that ext4_ind_map_blocks() returns -EIO when the block number is invalid.
So ext4_map_blocks() should also return the same errno.
Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: Dan Williams <dan.j.williams@intel.com>
This patch reorders reported frequencies from the highest to the lowest,
just like in other frequency drivers.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: cpu_frequency_table::driver_data is called index] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The powernow-k6 driver used to read the initial multiplier from the
powernow register. However, there is a problem with this:
* If there was a frequency transition before, the multiplier read from the
register corresponds to the current multiplier.
* If there was no frequency transition since reset, the field in the
register always reads as zero, regardless of the current multiplier that
is set using switches on the mainboard and that the CPU is running at.
The zero value corresponds to multiplier 4.5, so as a consequence, the
powernow-k6 driver always assumes multiplier 4.5.
For example, if we have 550MHz CPU with bus frequency 100MHz and
multiplier 5.5, the powernow-k6 driver thinks that the multiplier is 4.5
and bus frequency is 122MHz. The powernow-k6 driver then sets the
multiplier to 4.5, underclocking the CPU to 450MHz, but reports the
current frequency as 550MHz.
There is no reliable way how to read the initial multiplier. I modified
the driver so that it contains a table of known frequencies (based on
parameters of existing CPUs and some common overclocking schemes) and sets
the multiplier according to the frequency. If the frequency is unknown
(because of unusual overclocking or underclocking), the user must supply
the bus speed and maximum multiplier as module parameters.
This patch should be backported to all stable kernels. If it doesn't
apply cleanly, change it, or ask me to change it.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2:
- Adjust context
- s/driver_data/index/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
I found out that a system with k6-3+ processor is unstable during network
server load. The system locks up or the network card stops receiving. The
reason for the instability is the CPU frequency scaling.
During frequency transition the processor is in "EPM Stop Grant" state.
The documentation says that the processor doesn't respond to inquiry
requests in this state. Consequently, coherency of processor caches and
bus master devices is not maintained, causing the system instability.
This patch flushes the cache during frequency transition. It fixes the
instability.
Other minor changes:
* u64 invalue changed to unsigned long because the variable is 32-bit
* move the logic to set the multiplier to a separate function
powernow_k6_set_cpu_multiplier
* preserve lower 5 bits of the powernow port instead of 4 (the voltage
field has 5 bits)
* mask interrupts when reading the multiplier, so that the port is not
open during other activity (running other kernel code with the port open
shouldn't cause any misbehavior, but we should better be safe and keep
the port closed)
This patch should be backported to all stable kernels. If it doesn't
apply cleanly, change it, or ask me to change it.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This patch is based on an earlier patch by Eric Paris, he describes
the problem below:
"If an inode is accessed before policy load it will get placed on a
list of inodes to be initialized after policy load. After policy
load we call inode_doinit() which calls inode_doinit_with_dentry()
on all inodes accessed before policy load. In the case of inodes
in procfs that means we'll end up at the bottom where it does:
/* Default to the fs superblock SID. */
isec->sid = sbsec->sid;
if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
if (opt_dentry) {
isec->sclass = inode_mode_to_security_class(...)
rc = selinux_proc_get_sid(opt_dentry,
isec->sclass,
&sid);
if (rc)
goto out_unlock;
isec->sid = sid;
}
}
Since opt_dentry is null, we'll never call selinux_proc_get_sid()
and will leave the inode labeled with the label on the superblock.
I believe a fix would be to mimic the behavior of xattrs. Look
for an alias of the inode. If it can't be found, just leave the
inode uninitialized (and pick it up later) if it can be found, we
should be able to call selinux_proc_get_sid() ..."
On a system exhibiting this problem, you will notice a lot of files in
/proc with the generic "proc_t" type (at least the ones that were
accessed early in the boot), for example:
Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
unsigned char i;
...
bt->read_data[0] = BMC2HOST;
bt->read_count = bt->read_data[0];
...
for (i = 1; i <= bt->read_count; i++)
bt->read_data[i] = BMC2HOST;
If bt->read_data[0] == bt->read_count == 255, we loop infinitely in the
'for' loop. Make 'i' an 'int' instead of 'char' to get rid of the
overflow and finish the loop after 255 iterations every time.
drivers: hv: additional switch to use mb() instead of smp_mb()
commit e4af376d04b0(drivers: hv: switch to use mb() instead of smp_mb()),
the adjustment mistakenly dropped the change in hv_ringbuffer_read,
so add it.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ft_del_tpg checks tpg->tport is set before unlinking the tpg from the
tport when the tpg is being removed. Set this pointer in ft_tport_create,
or the unlinking won't happen in ft_del_tpg and tport->tpg will reference
a deleted object.
This patch sets tpg->tport in ft_tport_create, because that's what
ft_del_tpg checks, and is the only way to get back to the tport to
clear tport->tpg.
The bug was occuring when:
- lport created, tport (our per-lport, per-provider context) is
allocated.
tport->tpg = NULL
- tpg created
- a PRLI is received. ft_tport_create is called, tpg is found and
tport->tpg is set
- tpg removed. ft_tpg is freed in ft_del_tpg. Since tpg->tport was not
set, tport->tpg is not cleared and points at freed memory
- Future calls to ft_tport_create return tport via first conditional,
instead of searching for new tpg by calling ft_lport_find_tpg.
tport->tpg is still invalid, and will access freed memory.
see https://bugzilla.redhat.com/show_bug.cgi?id=1071340
Signed-off-by: Andy Grover <agrover@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The IRET instruction, when returning to a 16-bit segment, only
restores the bottom 16 bits of the user space stack pointer. We have
a software workaround for that ("espfix") for the 32-bit kernel, but
it relies on a nonzero stack segment base which is not available in
32-bit mode.
Since 16-bit support is somewhat crippled anyway on a 64-bit kernel
(no V86 mode), and most (if not quite all) 64-bit processors support
virtualization for the users who really need it, simply reject
attempts at creating a 16-bit segment when running on top of a 64-bit
kernel.
Register B43_MMIO_PSM_PHY_HDR is 16 bit one, so accessing it with 32b
functions isn't safe. On my machine it causes delayed (!) CPU exception:
Disabling lock debugging due to kernel taint
mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 4: b200000000070f0f
mce: [Hardware Error]: TSC 164083803dc
mce: [Hardware Error]: PROCESSOR 2:20fc2 TIME 1396650505 SOCKET 0 APIC 0 microcode 0
mce: [Hardware Error]: Run the above through 'mcelog --ascii'
mce: [Hardware Error]: Machine check: Processor context corrupt
Kernel panic - not syncing: Fatal machine check on current CPU
Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff)
Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Acked-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
I got a bug report yesterday from Laszlo Ersek in which he states that
his kvm instance fails to suspend. Laszlo bisected it down to this
commit 1cf7e9c68fe8 ("virtio_blk: blk-mq support") where virtio-blk is
converted to use the blk-mq infrastructure.
After digging a bit, it became clear that the issue was with the queue
drain. blk-mq tracks queue usage in a percpu counter, which is
incremented on request alloc and decremented when the request is freed.
The initial hunt was for an inconsistency in blk-mq, but everything
seemed fine. In fact, the counter only returned crazy values when
suspend was in progress.
When a CPU is unplugged, the percpu counters merges that CPU state with
the general state. blk-mq takes care to register a hotcpu notifier with
the appropriate priority, so we know it runs after the percpu counter
notifier. However, the percpu counter notifier only merges the state
when the CPU is fully gone. This leaves a state transition where the
CPU going away is no longer in the online mask, yet it still holds
private values. This means that in this state, percpu_counter_sum()
returns invalid results, and the suspend then hangs waiting for
abs(dead-cpu-value) requests to complete which of course will never
happen.
Fix this by clearing the state earlier, so we never have a case where
the CPU isn't in online mask but still holds private state. This bug
has been there since forever, I guess we don't have a lot of users where
percpu counters needs to be reliable during the suspend cycle.
wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and
drops tasklist_lock. If this task is not the natural child and it is
traced, we change its state back to EXIT_ZOMBIE for ->real_parent.
The last transition is racy, this is even documented in 50b8d257486a
"ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE
race". wait_consider_task() tries to detect this transition and clear
->notask_error but we can't rely on ptrace_reparented(), debugger can
exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE.
And there is another problem which were missed before: this transition
can also race with reparent_leader() which doesn't reset >exit_signal if
EXIT_DEAD, assuming that this task must be reaped by someone else. So
the tracee can be re-parented with ->exit_signal != SIGCHLD, and if
/sbin/init doesn't use __WALL it becomes unreapable.
Change reparent_leader() to update ->exit_signal even if EXIT_DEAD.
Note: this is the simple temporary hack for -stable, it doesn't try to
solve all problems, it will be reverted by the next changes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Reported-by: Michal Schmidt <mschmidt@redhat.com> Tested-by: Michal Schmidt <mschmidt@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When I decrease the value of nr_hugepage in procfs a lot, softlockup
happens. It is because there is no chance of context switch during this
process.
On the other hand, when I allocate a large number of hugepages, there is
some chance of context switch. Hence softlockup doesn't happen during
this process. So it's necessary to add the context switch in the
freeing process as same as allocating process to avoid softlockup.
When I freed 12 TB hugapages with kernel-2.6.32-358.el6, the freeing
process occupied a CPU over 150 seconds and following softlockup message
appeared twice or more.
BUG: soft lockup - CPU#16 stuck for 67s! [sh:12883] ...
Pid: 12883, comm: sh Not tainted 2.6.32-358.el6.x86_64 #1
Call Trace:
free_pool_huge_page+0xb8/0xd0
set_max_huge_pages+0x128/0x190
hugetlb_sysctl_handler_common+0x113/0x140
hugetlb_sysctl_handler+0x1e/0x20
proc_sys_call_handler+0x97/0xd0
proc_sys_write+0x14/0x20
vfs_write+0xb8/0x1a0
sys_write+0x51/0x90
__audit_syscall_exit+0x265/0x290
system_call_fastpath+0x16/0x1b
I have not confirmed this problem with upstream kernels because I am not
able to prepare the machine equipped with 12TB memory now. However I
confirmed that the amount of decreasing hugepages was directly
proportional to the amount of required time.
I measured required times on a smaller machine. It showed 130-145
hugepages decreased in a millisecond.
A BUG_ON(!PageLocked) was triggered in mlock_vma_page() by Sasha Levin
fuzzing with trinity. The call site try_to_unmap_cluster() does not lock
the pages other than its check_page parameter (which is already locked).
The BUG_ON in mlock_vma_page() is not documented and its purpose is
somewhat unclear, but apparently it serializes against page migration,
which could otherwise fail to transfer the PG_mlocked flag. This would
not be fatal, as the page would be eventually encountered again, but
NR_MLOCK accounting would become distorted nevertheless. This patch adds
a comment to the BUG_ON in mlock_vma_page() and munlock_vma_page() to that
effect.
The call site try_to_unmap_cluster() is fixed so that for page !=
check_page, trylock_page() is attempted (to avoid possible deadlocks as we
already have check_page locked) and mlock_vma_page() is performed only
upon success. If the page lock cannot be obtained, the page is left
without PG_mlocked, which is again not a problem in the whole unevictable
memory design.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Bob Liu <bob.liu@oracle.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Michel Lespinasse <walken@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This patch fixes a long-standing bug in iscsit_build_conn_drop_async_message()
where during ERL=2 connection recovery, a bogus conn_p pointer could
end up being used to send the ISCSI_OP_ASYNC_EVENT + DROPPING_CONNECTION
notifying the initiator that cmd->logout_cid has failed.
The bug was manifesting itself as an OOPs in iscsit_allocate_cmd() with
a bogus conn_p pointer in iscsit_build_conn_drop_async_message().
Reported-by: Arshad Hussain <arshad.hussain@calsoftinc.com> Reported-by: santosh kulkarni <santosh.kulkarni@calsoftinc.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Do not put bh when buffer_uptodate failed in ocfs2_write_block and
ocfs2_write_super_or_backup, because it will put bh in b_end_io.
Otherwise it will hit a warning "VFS: brelse: Trying to free free
buffer".
Signed-off-by: Alex Chen <alex.chen@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Mark Fasheh <mfasheh@suse.com> Acked-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
There is a race window in dlm_do_recovery() between dlm_remaster_locks()
and dlm_reset_recovery() when the recovery master nearly finish the
recovery process for a dead node. After the master sends FINALIZE_RECO
message in dlm_remaster_locks(), another node may become the recovery
master for another dead node, and then send the BEGIN_RECO message to
all the nodes included the old master, in the handler of this message
dlm_begin_reco_handler() of old master, dlm->reco.dead_node and
dlm->reco.new_master will be set to the second dead node and the new
master, then in dlm_reset_recovery(), these two variables will be reset
to default value. This will cause new recovery master can not finish
the recovery process and hung, at last the whole cluster will hung for
recovery.
old recovery master: new recovery master:
dlm_remaster_locks()
become recovery master for
another dead node.
dlm_send_begin_reco_message()
dlm_begin_reco_handler()
{
if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
return -EAGAIN;
}
dlm_set_reco_master(dlm, br->node_idx);
dlm_set_reco_dead_node(dlm, br->dead_node);
}
dlm_reset_recovery()
{
dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
}
will hang in dlm_remaster_locks() for
request dlm locks info
Before send FINALIZE_RECO message, recovery master should set
DLM_RECO_STATE_FINALIZE for itself and clear it after the recovery done,
this can break the race windows as the BEGIN_RECO messages will not be
handled before DLM_RECO_STATE_FINALIZE flag is cleared.
A similar race may happen between new recovery master and normal node
which is in dlm_finalize_reco_handler(), also fix it.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This issue was introduced by commit 800deef3f6f8 ("ocfs2: use
list_for_each_entry where benefical") in 2007 where it replaced
list_for_each with list_for_each_entry. The variable "lock" will point
to invalid data if "tmpq" list is empty and a panic will be triggered
due to this. Sunil advised reverting it back, but the old version was
also not right. At the end of the outer for loop, that
list_for_each_entry will also set "lock" to an invalid data, then in the
next loop, if the "tmpq" list is empty, "lock" will be an stale invalid
data and cause the panic. So reverting the list_for_each back and reset
"lock" to NULL to fix this issue.
Another concern is that this seemes can not happen because the "tmpq"
list should not be empty. Let me describe how.
old lock resource owner(node 1): migratation target(node 2):
image there's lockres with a EX lock from node 2 in
granted list, a NR lock from node x with convert_type
EX in converting list.
dlm_empty_lockres() {
dlm_pick_migration_target() {
pick node 2 as target as its lock is the first one
in granted list.
}
dlm_migrate_lockres() {
dlm_mark_lockres_migrating() {
res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
//after the above code, we can not dirty lockres any more,
// so dlm_thread shuffle list will not run
downconvert lock from EX to NR
upconvert lock from NR to EX
<<< migration may schedule out here, then
<<< node 2 send down convert request to convert type from EX to
<<< NR, then send up convert request to convert type from NR to
<<< EX, at this time, lockres granted list is empty, and two locks
<<< in the converting list, node x up convert lock followed by
<<< node 2 up convert lock.
// will set lockres RES_MIGRATING flag, the following
// lock/unlock can not run
dlm_lockres_release_ast(dlm, res);
}
dlm_send_one_lockres()
dlm_process_recovery_data()
for (i=0; i<mres->num_locks; i++)
if (ml->node == dlm->node_num)
for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
list_for_each_entry(lock, tmpq, list)
if (lock) break; <<< lock is invalid as grant list is empty.
}
if (lock->ml.node != ml->node)
BUG() >>> crash here
}
I see the above locks status from a vmcore of our internal bug.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arch/sh/kernel/dumpstack.c: In function 'print_trace_address':
arch/sh/kernel/dumpstack.c:118:2: error: format not a string literal and no format arguments [-Werror=format-security]
Use the "%s" format so that it's impossible to interpret 'data' as a
format string.
Signed-off-by: Matt Fleming <matt.fleming@intel.com> Reported-by: Kees Cook <keescook@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This needs to be done to update some of the fields in
the connector structure used by the audio code.
Noticed by several users on irc.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Christian König <christian.koenig@amd.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Previously, the vmwgfx_fb driver would allow users to call FBIOSET_VINFO, but it would not adjust
the FINFO properly, resulting in distorted screen rendering. The patch corrects that behaviour.
See https://bugs.gentoo.org/show_bug.cgi?id=494794 for examples.
Signed-off-by: Christopher Friedt <chrisfriedt@gmail.com> Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
jdm-20004 reiserfs_delete_xattrs: Couldn't delete all xattrs (-2)
The -ENOENT is due to readdir calling dir_emit on the same entry twice.
If the dir_emit callback sleeps and the tree is changed underneath us,
we won't be able to trust deh_offset(deh) anymore. We need to save
next_pos before we might sleep so we can find the next entry.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The original MIPS hibernate code flushes cache and TLB entries in
swsusp_arch_resume(). But they are removed in Commit 44eeab67416711
(MIPS: Hibernation: Remove SMP TLB and cacheflushing code.). A cross-
CPU flush is surely unnecessary because all but the local CPU have
already been disabled. But a local flush (at least the TLB flush) is
needed. When we do hibernation on Loongson-3 with an E1000E NIC, it is
very easy to produce a kernel panic (kernel page fault, or unaligned
access). The root cause is E1000E driver use vzalloc_node() to allocate
pages, the stale TLB entries of the booting kernel will be misused by
the resumed target kernel.
Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6643/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If unable to ensure_next_mapping() we must add the current bio, which
was removed from the @bios list via bio_list_pop, back to the
deferred_bios list before all the remaining @bios.
Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
drm/i915: Don't set up the TV port if it isn't in the BIOS table.
The commit does not check for all TV device types that might be present
in the VBT, disabling TV out for the missing ones. Add composite
S-video.
Reported-and-tested-by: Matthew Khouzam <matthew.khouzam@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=73362 Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[bwh: Backported to 3.2: s/old\.device_type/device_type/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Looks like this bug has been here since these write counts were
introduced, not sure why it was just noticed now.
Thanks also to Jan Kara for pointing out the problem.
Reported-by: Matthew Rahtz <mrahtz@rapitasystems.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This patch bypass the timer_irq_works() check for hyperv guest since:
- It was guaranteed to work.
- timer_irq_works() may fail sometime due to the lpj calibration were inaccurate
in a hyperv guest or a buggy host.
In the future, we should get the tsc frequency from hypervisor and use preset
lpj instead.
[ hpa: I would prefer to not defer things to "the future" in the future... ]
Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: http://lkml.kernel.org/r/1393558229-14755-1-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The scenario here is that someone calls enable_irq_wake() from somewhere
in the code. This will result in the lockdep producing a backtrace as can
be seen below. In my case, this problem is triggered when using the wl1271
(TI WlCore) driver found in drivers/net/wireless/ti/ .
The problem cause is rather obvious from the backtrace, but let's outline
the dependency. enable_irq_wake() grabs the IRQ buslock in irq_set_irq_wake(),
which in turns calls mxs_gpio_set_wake_irq() . But mxs_gpio_set_wake_irq()
calls enable_irq_wake() again on the one-level-higher IRQ , thus it tries to
grab the IRQ buslock again in irq_set_irq_wake() . Because the spinlock in
irq_set_irq_wake()->irq_get_desc_buslock()->__irq_get_desc_lock() is not
marked as recursive, lockdep will spew the stuff below.
We know we can safely re-enter the lock, so use IRQ_GC_INIT_NESTED_LOCK to
fix the spew.
=============================================
[ INFO: possible recursive locking detected ] 3.10.33-00012-gf06b763-dirty #61 Not tainted
---------------------------------------------
kworker/0:1/18 is trying to acquire lock:
(&irq_desc_lock_class){-.-...}, at: [<c00685f0>] __irq_get_desc_lock+0x48/0x88
but task is already holding lock:
(&irq_desc_lock_class){-.-...}, at: [<c00685f0>] __irq_get_desc_lock+0x48/0x88
other info that might help us debug this:
Possible unsafe locking scenario:
Zach found this deadlock that would happen like this
btrfs_end_transaction <- reduce trans->use_count to 0
btrfs_run_delayed_refs
btrfs_cow_block
find_free_extent
btrfs_start_transaction <- increase trans->use_count to 1
allocate chunk
btrfs_end_transaction <- decrease trans->use_count to 0
btrfs_run_delayed_refs
lock tree block we are cowing above ^^
We need to only decrease trans->use_count if it is above 1, otherwise leave it
alone. This will make nested trans be the only ones who decrease their added
ref, and will let us get rid of the trans->use_count++ hack if we have to commit
the transaction. Thanks,
Reported-by: Zach Brown <zab@redhat.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Tested-by: Zach Brown <zab@redhat.com> Signed-off-by: Chris Mason <clm@fb.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
projects / thirdparty / kernel / stable.git / log
