This patch is to improve sctp stream adding events in 2 places:
1. In sctp_process_strreset_addstrm_out(), move up SCTP_MAX_STREAM
and in stream allocation failure checks, as the adding has to
succeed after reconf_timer stops for the in stream adding
request retransmission.
3. In sctp_process_strreset_addstrm_in(), no event should be sent,
as no in or out stream is added here.
Fixes: 50a41591f110 ("sctp: implement receiver-side procedures for the Add Outgoing Streams Request Parameter") Fixes: c5c4ebb3ab87 ("sctp: implement receiver-side procedures for the Add Incoming Streams Request Parameter") Reported-by: Ying Xu <yinxu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When _virtnet_set_queues() failed we did not restore real_num_rx_queues.
Fix this by placing the change of real_num_rx_queues after
_virtnet_set_queues().
This order is also in line with virtnet_set_channels().
Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When napi_tx is enabled, virtnet_poll_cleantx() called
free_old_xmit_skbs() even for xdp send queue.
This is bogus since the queue has xdp_frames, not sk_buffs, thus mangled
device tx bytes counters because skb->len is meaningless value, and even
triggered oops due to general protection fault on freeing them.
Since xdp send queues do not aquire locks, old xdp_frames should be
freed only in virtnet_xdp_xmit(), so just skip free_old_xmit_skbs() for
xdp send queues.
Similarly virtnet_poll_tx() called free_old_xmit_skbs(). This NAPI
handler is called even without calling start_xmit() because cb for tx is
by default enabled. Once the handler is called, it enabled the cb again,
and then the handler would be called again. We don't need this handler
for XDP, so don't enable cb as well as not calling free_old_xmit_skbs().
Also, we need to disable tx NAPI when disabling XDP, so
virtnet_poll_tx() can safely access curr_queue_pairs and
xdp_queue_pairs, which are not atomically updated while disabling XDP.
Fixes: b92f1e6751a6 ("virtio-net: transmit napi") Fixes: 7b0411ef4aa6 ("virtio-net: clean tx descriptors from rx napi") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 4e09ff536284 ("virtio-net: disable NAPI only when enabled during
XDP set") tried to fix inappropriate NAPI enabling/disabling when
!netif_running(), but was not complete.
On error path virtio_net could enable NAPI even when !netif_running().
This can cause enabling NAPI twice on virtnet_open(), which would
trigger BUG_ON() in napi_enable().
Fixes: 4941d472bf95b ("virtio-net: do not reset during XDP set") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the original commit, eswitch instance will not be initialized for
a function which is vport group manager but not eswitch manager such as
host PF on SmartNIC (BlueField) card. This will result in a kernel crash
when such a vport group manager is trying to access vports in its group.
E.g, PF vport manager (not eswitch manager) tries to configure the MAC
of its VF vport, a kernel trace will happen similar as bellow:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
...
RIP: 0010:mlx5_eswitch_get_vport_config+0xc/0x180 [mlx5_core]
...
Fixes: 5f5991f36dce ("net/mlx5e: E-Switch, Initialize eswitch only if eswitch manager") Signed-off-by: Bodong Wang <bodong@mellanox.com> Reported-by: Yuval Avnery <yuvalav@mellanox.com> Reviewed-by: Daniel Jurgens <danielj@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After a timeout event caused by for example a broadcast storm, when
the MAC and PHY are reset, the BQL TX queue needs to be reset as
well. Otherwise, the device will exhibit severe performance issues
even after the storm has ended.
Co-authored-by: David Gounaris <david.gounaris@infinera.com> Signed-off-by: Mathias Thore <mathias.thore@infinera.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Assign a default net namespace to netdevs created by init_dummy_netdev().
Fixes a NULL pointer dereference caused by busy-polling a socket bound to
an iwlwifi wireless device, which bumps the per-net BUSYPOLLRXPACKETS stat
if napi_poll() received packets:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000190
IP: napi_busy_loop+0xd6/0x200
Call Trace:
sock_poll+0x5e/0x80
do_sys_poll+0x324/0x5a0
SyS_poll+0x6c/0xf0
do_syscall_64+0x6b/0x1f0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Fixes: 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id instead of socket") Signed-off-by: Josh Elsasser <jelsasser@appneta.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When an internally generated frame is handled by rose_xmit(),
rose_route_frame() is called:
if (!rose_route_frame(skb, NULL)) {
dev_kfree_skb(skb);
stats->tx_errors++;
return NETDEV_TX_OK;
}
We have the same code sequence in Net/Rom where an internally generated
frame is handled by nr_xmit() calling nr_route_frame(skb, NULL).
However, in this function NULL argument is tested while it is not in
rose_route_frame().
Then kernel panic occurs later on when calling ax25cmp() with a NULL
ax25_cb argument as reported many times and recently with syzbot.
We need to test if ax25 is NULL before using it.
Testing:
Built kernel with CONFIG_ROSE=y.
Signed-off-by: Bernard Pidoux <f6bvp@free.fr> Acked-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: syzbot+1a2c456a1ea08fa5b5f7@syzkaller.appspotmail.com Cc: "David S. Miller" <davem@davemloft.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Bernard Pidoux <f6bvp@free.fr> Cc: linux-hams@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Driver reads the query HCA capabilities without the corresponding masks.
Without the correct masks, the base addresses of the queues are
unaligned. In addition some reserved bits were wrongly read. Using the
correct masks, ensures alignment of the base addresses and allows future
firmware versions safe use of the reserved bits.
Fixes: ab9c17a009ee ("mlx4_core: Modify driver initialization flow to accommodate SRIOV for Ethernet") Fixes: 0ff1fb654bec ("{NET, IB}/mlx4: Add device managed flow steering firmware API") Signed-off-by: Aya Levin <ayal@mellanox.com> Signed-off-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The size of L2TPv2 header with all optional fields is 14 bytes.
l2tp_udp_recv_core only moves 10 bytes to the linear part of a
skb. This may lead to l2tp_recv_common read data outside of a skb.
This patch make sure that there is at least 14 bytes in the linear
part of a skb to meet the maximum need of l2tp_udp_recv_core and
l2tp_recv_common. The minimum size of both PPP HDLC-like frame and
Ethernet frame is larger than 14 bytes, so we are safe to do so.
Also remove L2TP_HDR_SIZE_NOSEQ, it is unused now.
Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jacob Wen <jian.w.wen@oracle.com> Acked-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
skb->cb may contain data from previous layers (in an observed case
IPv4 with L3 Master Device). In the observed scenario, the data in
IPCB(skb)->frags was misinterpreted as IP6CB(skb)->frag_max_size,
eventually caused an unexpected IPv6 fragmentation in ip6_fragment()
through ip6_finish_output().
This patch clears IP6CB(skb), which potentially contains garbage data,
on the SRH ip4ip6 encapsulation.
Fixes: 32d99d0b6702 ("ipv6: sr: add support for ip4ip6 encapsulation") Signed-off-by: Yohei Kanemaru <yohei.kanemaru@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IPv6 does not consider if the socket is bound to a device when binding
to an address. The result is that a socket can be bound to eth0 and then
bound to the address of eth1. If the device is a VRF, the result is that
a socket can only be bound to an address in the default VRF.
Resolve by considering the device if sk_bound_dev_if is set.
This problem exists from the beginning of git history.
Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix "net: ipv4: do not handle duplicate fragments as overlapping"
ade446403bfb ("net: ipv4: do not handle duplicate fragments as
overlapping") was backported to many stable trees, but it had a problem
that was "accidentally" fixed by the upstream commit 0ff89efb5246 ("ip:
fail fast on IP defrag errors")
This is the fixup for that problem as we do not want the larger patch in
the older stable trees.
Fixes: ade446403bfb ("net: ipv4: do not handle duplicate fragments as overlapping") Reported-by: Ivan Babrou <ivan@cloudflare.com> Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At the time of forced unmount we place the running replace to
BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state, so when the system comes
back and expect the target device is missing.
Then let the replace state continue to be in
BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state instead of
BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED as there isn't any matching scrub
running as part of replace.
Fixes: e93c89c1aaaa ("Btrfs: add new sources for device replace code") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we fail to start a transaction in btrfs_dev_replace_start, we leave
dev_replace->replace_start set to STARTED but clear ->srcdev and
->tgtdev. Later, that can result in an Oops in
btrfs_dev_replace_progress when having state set to STARTED or SUSPENDED
implies that ->srcdev is valid.
Also fix error handling when the state is already STARTED or SUSPENDED
while starting. That, too, will clear ->srcdev and ->tgtdev even though
it doesn't own them. This should be an impossible case to hit since we
should be protected by the BTRFS_FS_EXCL_OP bit being set. Let's add an
ASSERT there while we're at it.
Fixes: e93c89c1aaaaa (Btrfs: add new sources for device replace code) CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function truncate_node frees the page with f2fs_put_page. However,
the page index is read after that. So, the patch reads the index before
freeing the page.
Fixes: bf39c00a9a7f ("f2fs: drop obsolete node page when it is truncated") Cc: <stable@vger.kernel.org> Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable'
sched_clock() interface") broke Xen guest time handling across
migration:
[ 187.249951] Freezing user space processes ... (elapsed 0.001 seconds) done.
[ 187.251137] OOM killer disabled.
[ 187.251137] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[ 187.252299] suspending xenstore...
[ 187.266987] xen:grant_table: Grant tables using version 1 layout
[18446743811.706476] OOM killer enabled.
[18446743811.706478] Restarting tasks ... done.
[18446743811.720505] Setting capacity to 16777216
Fix that by setting xen_sched_clock_offset at resume time to ensure a
monotonic clock value.
[boris: replaced pr_info() with pr_info_once() in xen_callback_vector()
to avoid printing with incorrect timestamp during resume (as we
haven't re-adjusted the clock yet)]
Fixes: f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") Cc: <stable@vger.kernel.org> # 4.11 Reported-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is expected for sched_clock() to output data from 0, when system boots.
Add an offset xen_sched_clock_offset (similarly how it is done in other
hypervisors i.e. kvm_sched_clock_offset) to count sched_clock() from 0,
when time is first initialized.
In order to support pvclock vdso on xen we need to setup the time
info page for vcpu 0 and register the page with Xen using the
VCPUOP_register_vcpu_time_memory_area hypercall. This hypercall
will also forcefully update the pvti which will set some of the
necessary flags for vdso. Afterwards we check if it supports the
PVCLOCK_TSC_STABLE_BIT flag which is mandatory for having
vdso/vsyscall support. And if so, it will set the cpu 0 pvti that
will be later on used when mapping the vdso image.
The xen headers are also updated to include the new hypercall for
registering the secondary vcpu_time_info struct.
Specifically check for PVCLOCK_TSC_STABLE_BIT and if this bit is set,
then set it too on pvclock flags. This allows Xen clocksource to use it
and thus speeding up xen_clocksource_read() callers (i.e. sched_clock())
Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Right now there is only a pvclock_pvti_cpu0_va() which is defined
on kvmclock since:
commit dac16fba6fc5
("x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap")
The only user of this interface so far is kvm. This commit adds a
setter function for the pvti page and moves pvclock_pvti_cpu0_va
to pvclock, which is a more generic place to have it; and would
allow other PV clocksources to use it, such as Xen.
While moving pvclock_pvti_cpu0_va into pvclock, rename also this
function to pvclock_get_pvti_cpu0_va (including its call sites)
to be symmetric with the setter (pvclock_set_pvti_cpu0_va).
Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the event of moving pvclock_pvti_cpu0_va() definition to common
pvclock code, this function would return a value on non KVM guests.
Later on this would fail with a GPF on ptp_kvm_init when running on a
Xen guest. Therefore, ptp_kvm_init() should check whether it is running
in a KVM guest.
Ensure that the shared_hcd pointer is valid when calling usb_put_hcd()
The shared_hcd is removed and freed in xhci by first calling
usb_remove_hcd(xhci->shared_hcd), and later
usb_put_hcd(xhci->shared_hcd)
Afer commit fe190ed0d602 ("xhci: Do not halt the host until both HCD have
disconnected their devices.") the shared_hcd was never properly put as
xhci->shared_hcd was set to NULL before usb_put_hcd(xhci->shared_hcd) was
called.
shared_hcd (USB3) is removed before primary hcd (USB2).
While removing the primary hcd we might need to handle xhci interrupts
to cleanly remove last USB2 devices, therefore we need to set
xhci->shared_hcd to NULL before removing the primary hcd to let xhci
interrupt handler know shared_hcd is no longer available.
xhci-plat.c, xhci-histb.c and xhci-mtk first create both their hcd's before
adding them. so to keep the correct reverse removal order use a temporary
shared_hcd variable for them.
For more details see commit 4ac53087d6d4 ("usb: xhci: plat: Create both
HCDs before adding them")
Fixes: fe190ed0d602 ("xhci: Do not halt the host until both HCD have disconnected their devices.") Cc: Joel Stanley <joel@jms.id.au> Cc: Chunfeng Yun <chunfeng.yun@mediatek.com> Cc: Thierry Reding <treding@nvidia.com> Cc: Jianguo Sun <sunjianguo1@huawei.com> Cc: <stable@vger.kernel.org> Reported-by: Jack Pham <jackp@codeaurora.org> Tested-by: Jack Pham <jackp@codeaurora.org> Tested-by: Peter Chen <peter.chen@nxp.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
OUT endpoint requests may somtimes have this flag set when
preparing to be submitted to HW indicating that there is an
additional TRB chained to the request for alignment purposes.
If that request is removed before the controller can execute the
transfer (e.g. ep_dequeue/ep_disable), the request will not go
through the dwc3_gadget_ep_cleanup_completed_request() handler
and will not have its needs_extra_trb flag cleared when
dwc3_gadget_giveback() is called. This same request could be
later requeued for a new transfer that does not require an
extra TRB and if it is successfully completed, the cleanup
and TRB reclamation will incorrectly process the additional TRB
which belongs to the next request, and incorrectly advances the
TRB dequeue pointer, thereby messing up calculation of the next
requeust's actual/remaining count when it completes.
The right thing to do here is to ensure that the flag is cleared
before it is given back to the function driver. A good place
to do that is in dwc3_gadget_del_and_unmap_request().
Fixes: c6267a51639b ("usb: dwc3: gadget: align transfers to wMaxPacketSize") Cc: stable@vger.kernel.org Signed-off-by: Jack Pham <jackp@codeaurora.org> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
[jackp: backport to <= 4.20: replaced 'needs_extra_trb' with 'unaligned'
and 'zero' members in patch and reworded commit text] Signed-off-by: Jack Pham <jackp@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Under heavy load if we don't have any pre-allocated rsps left, we
dynamically allocate a rsp, but we are not actually allocating memory
for nvme_completion (rsp->req.rsp). In such a case, accessing pointer
fields (req->rsp->status) in nvmet_req_init() will result in crash.
To fix this, allocate the memory for nvme_completion by calling
nvmet_rdma_alloc_rsp()
Fixes: 8407879c("nvmet-rdma:fix possible bogus dereference under heavy load") Cc: <stable@vger.kernel.org> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Raju Rangoju <rajur@chelsio.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When calling smp_call_ipl_cpu() from the IPL CPU, we will try to read
from pcpu_devices->lowcore. However, due to prefixing, that will result
in reading from absolute address 0 on that CPU. We have to go via the
actual lowcore instead.
This means that right now, we will read lc->nodat_stack == 0 and
therfore work on a very wrong stack.
This BUG essentially broke rebooting under QEMU TCG (which will report
a low address protection exception). And checking under KVM, it is
also broken under KVM. With 1 VCPU it can be easily triggered.
KVM: x86: Fix a 4.14 backport regression related to userspace/guest FPU
Upstream commit:
f775b13eedee ("x86,kvm: move qemu/guest FPU switching out to vcpu_run")
introduced a bug, which was later fixed by upstream commit:
5663d8f9bbe4 ("kvm: x86: fix WARN due to uninitialized guest FPU state")
For reasons unknown, both commits were initially passed-over for
inclusion in the 4.14 stable branch despite being tagged for stable.
Eventually, someone noticed that the fixup, commit 5663d8f9bbe4, was
missing from stable[1], and so it was queued up for 4.14 and included in
release v4.14.79.
Even later, the original buggy patch, commit f775b13eedee, was also
applied to the 4.14 stable branch. Through an unlucky coincidence, the
incorrect ordering did not generate a conflict between the two patches,
and led to v4.14.94 and later releases containing a spurious call to
kvm_load_guest_fpu() in kvm_arch_vcpu_ioctl_run(). As a result, KVM may
reload stale guest FPU state, e.g. after accepting in INIT event. This
can manifest as crashes during boot, segfaults, failed checksums and so
on and so forth.
Remove the unwanted kvm_{load,put}_guest_fpu() calls, i.e. make
kvm_arch_vcpu_ioctl_run() look like commit 5663d8f9bbe4 was backported
after commit f775b13eedee.
Currently we are using all the available fifo size in RQS and
TQS fields. This will not work correctly in multi-queues IP's
because total fifo size must be splitted to the enabled queues.
Correct this by computing the available fifo size per queue and
setting the right value in TQS and RQS fields.
Signed-off-by: Jose Abreu <joabreu@synopsys.com> Cc: David S. Miller <davem@davemloft.net> Cc: Joao Pinto <jpinto@synopsys.com> Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Niklas Cassel <niklas.cassel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
libdwfl parses an ELF file itself and creates mappings for the
individual sections. perf on the other hand sees raw mmap events which
represent individual sections. When we encounter an address pointing
into a mapping with pgoff != 0, we must take that into account and
report the file at the non-offset base address.
This fixes unwinding with libdwfl in some cases. E.g. for a file like:
```
using namespace std;
mutex g_mutex;
double worker()
{
lock_guard<mutex> guard(g_mutex);
uniform_real_distribution<double> uniform(-1E5, 1E5);
default_random_engine engine;
double s = 0;
for (int i = 0; i < 1000; ++i) {
s += norm(complex<double>(uniform(engine), uniform(engine)));
}
cout << s << endl;
return s;
}
int main()
{
vector<std::future<double>> results;
for (int i = 0; i < 10000; ++i) {
results.push_back(async(launch::async, worker));
}
return 0;
}
```
Compile it with `g++ -g -O2 -lpthread cpp-locking.cpp -o cpp-locking`,
then record it with `perf record --call-graph dwarf -e
sched:sched_switch`.
When you analyze it with `perf script` and libunwind, you should see:
Note that the backtrace is still stopping too early, when compared to
the nice results obtained via libunwind. It's unclear so far what the
reason for that is.
Committer note:
Further comment by Milian on the thread started on the Link: tag below:
---
The remaining issue is due to a bug in elfutils:
Path passed to libdw for unwinding doesn't include symfs path
if specified, so unwinding fails because ELF file is not found.
Similar to unwinding with libunwind, pass symsrc_filename instead
of long_name. If there is no symsrc_filename, fallback to long_name.
Signed-off-by: Martin Vuille <jpmv27@aim.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20180211212420.18388-1-jpmv27@aim.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Kyungtae Kim detected a potential integer overflow in bcm_[rx|tx]_setup()
when the conversion into ktime multiplies the given value with NSEC_PER_USEC
(1000).
Add a check for the given tv_usec, so that the value stays below one second.
Additionally limit the tv_sec value to a reasonable value for CAN related
use-cases of 400 days and ensure all values to be positive.
Reported-by: Kyungtae Kim <kt0755@gmail.com> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Cc: linux-stable <stable@vger.kernel.org> # >= 2.6.26 Tested-by: Kyungtae Kim <kt0755@gmail.com> Acked-by: Andre Naujoks <nautsch2@gmail.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch revert commit 7da11ba5c506
("can: dev: __can_get_echo_skb(): print error message, if trying to echo non existing skb")
After introduction of this change we encountered following new error
message on various i.MX plattforms (flexcan):
| flexcan 53fc8000.can can0: __can_get_echo_skb: BUG! Trying to echo non
| existing skb: can_priv::echo_skb[0]
The introduction of the message was a mistake because
priv->echo_skb[idx] = NULL is a perfectly valid in following case: If
CAN_RAW_LOOPBACK is disabled (setsockopt) in applications, the pkt_type
of the tx skb's given to can_put_echo_skb is set to PACKET_LOOPBACK. In
this case can_put_echo_skb will not set priv->echo_skb[idx]. It is
therefore kept NULL.
As additional argument for revert: The order of check and usage of idx
was changed. idx is used to access an array element before checking it's
boundaries.
Signed-off-by: Manfred Schlaegl <manfred.schlaegl@ginzinger.com> Fixes: 7da11ba5c506 ("can: dev: __can_get_echo_skb(): print error message, if trying to echo non existing skb") Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The way we allocate events works fine in most cases, except
when multiple PCI devices share an ITS-visible DevID, and that
one of them is trying to use MultiMSI allocation.
In that case, our allocation is not guaranteed to be zero-based
anymore, and we have to make sure we allocate it on a boundary
that is compatible with the PCI Multi-MSI constraints.
Fix this by allocating the full region upfront instead of iterating
over the number of MSIs. MSI-X are always allocated one by one,
so this shouldn't change anything on that front.
The recent commit which prevented a division by 0 issue in the alarm timer
code broke posix CPU timers as an unwanted side effect.
The reason is that the common rearm code checks for timer->it_interval
being 0 now. What went unnoticed is that the posix cpu timer setup does not
initialize timer->it_interval as it stores the interval in CPU timer
specific storage. The reason for the separate storage is historical as the
posix CPU timers always had a 64bit nanoseconds representation internally
while timer->it_interval is type ktime_t which used to be a modified
timespec representation on 32bit machines.
Instead of reverting the offending commit and fixing the alarmtimer issue
in the alarmtimer code, store the interval in timer->it_interval at CPU
timer setup time so the common code check works. This also repairs the
existing inconistency of the posix CPU timer code which kept a single shot
timer armed despite of the interval being 0.
The separate storage can be removed in mainline, but that needs to be a
separate commit as the current one has to be backported to stable kernels.
Fixes: 0e334db6bb4b ("posix-timers: Fix division by zero bug") Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190111133500.840117406@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There was a bug where the per-mm pkey state was not being preserved across
fork() in the child. fork() is performed in the pkey selftests, but all of
the pkey activity is performed in the parent. The child does not perform
any actions sensitive to pkey state.
To make the test more sensitive to these kinds of bugs, add a fork() where
the parent exits, and execution continues in the child.
To achieve this let the key exhaustion test not terminate at the first
allocation failure and fork after 2*NR_PKEYS loops and continue in the
child.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: hpa@zytor.com Cc: peterz@infradead.org Cc: mpe@ellerman.id.au Cc: will.deacon@arm.com Cc: luto@kernel.org Cc: jroedel@suse.de Cc: stable@vger.kernel.org Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Will Deacon <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/20190102215657.585704B7@viggo.jf.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Memory protection key behavior should be the same in a child as it was
in the parent before a fork. But, there is a bug that resets the
state in the child at fork instead of preserving it.
The creation of new mm's is a bit convoluted. At fork(), the code
does:
1. memcpy() the parent mm to initialize child
2. mm_init() to initalize some select stuff stuff
3. dup_mmap() to create true copies that memcpy() did not do right
For pkeys two bits of state need to be preserved across a fork:
'execute_only_pkey' and 'pkey_allocation_map'.
Those are preserved by the memcpy(), but mm_init() invokes
init_new_context() which overwrites 'execute_only_pkey' and
'pkey_allocation_map' with "new" values.
The author of the code erroneously believed that init_new_context is *only*
called at execve()-time. But, alas, init_new_context() is used at execve()
and fork().
The result is that, after a fork(), the child's pkey state ends up looking
like it does after an execve(), which is totally wrong. pkeys that are
already allocated can be allocated again, for instance.
To fix this, add code called by dup_mmap() to copy the pkey state from
parent to child explicitly. Also add a comment above init_new_context() to
make it more clear to the next poor sod what this code is used for.
Fixes: e8c24d3a23a ("x86/pkeys: Allocation/free syscalls") Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: hpa@zytor.com Cc: peterz@infradead.org Cc: mpe@ellerman.id.au Cc: will.deacon@arm.com Cc: luto@kernel.org Cc: jroedel@suse.de Cc: stable@vger.kernel.org Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Will Deacon <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/20190102215655.7A69518C@viggo.jf.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The single-step debugging of KVM guests on x86 is broken: if we run
gdb 'stepi' command at the breakpoint when the guest interrupts are
enabled, RIP always jumps to native_apic_mem_write(). Then other
nasty effects follow.
Long investigation showed that on Jun 7, 2017 the
commit c8401dda2f0a00cd25c0 ("KVM: x86: fix singlestepping over syscall")
introduced the kvm_run.debug corruption: kvm_vcpu_do_singlestep() can
be called without X86_EFLAGS_TF set.
Let's fix it. Please consider that for -stable.
Signed-off-by: Alexander Popov <alex.popov@linux.com> Cc: stable@vger.kernel.org Fixes: c8401dda2f0a00cd25c0 ("KVM: x86: fix singlestepping over syscall") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dm-crypt cipher specification in a mapping table is defined as:
cipher[:keycount]-chainmode-ivmode[:ivopts]
or (new crypt API format):
capi:cipher_api_spec-ivmode[:ivopts]
For ESSIV, the parameter includes hash specification, for example:
aes-cbc-essiv:sha256
The implementation expected that additional IV option to never include
another dash '-' character.
But, with SHA3, there are names like sha3-256; so the mapping table
parser fails:
Commit 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next
stage processing") changed process_prepared_discard_passdown_pt1() to
increment all the blocks being discarded until after the passdown had
completed to avoid them being prematurely reused.
IO issued to a thin device that breaks sharing with a snapshot, followed
by a discard issued to snapshot(s) that previously shared the block(s),
results in passdown_double_checking_shared_status() being called to
iterate through the blocks double checking their reference count is zero
and issuing the passdown if so. So a side effect of commit 00a0ea33b495
is passdown_double_checking_shared_status() was broken.
Fix this by checking if the block reference count is greater than 1.
Also, rename dm_pool_block_is_used() to dm_pool_block_is_shared().
Fixes: 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next stage processing") Cc: stable@vger.kernel.org # 4.9+ Reported-by: ryan.p.norwood@gmail.com Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The _DSM function number validation only happens to succeed when the
generic Linux command number translation corresponds with a
DSM-family-specific function number. This breaks NVDIMM-N
implementations that correctly implement _LSR, _LSW, and _LSI, but do
not happen to publish support for DSM function numbers 4, 5, and 6.
Recall that the support for _LS{I,R,W} family of methods results in the
DIMM being marked as supporting those command numbers at
acpi_nfit_register_dimms() time. The DSM function mask is only used for
ND_CMD_CALL support of non-NVDIMM_FAMILY_INTEL devices.
In preparation for using function number 0 as an error value, prevent it
from being considered a valid function value by acpi_nfit_ctl().
Cc: <stable@vger.kernel.org> Cc: stuart hayes <stuart.w.hayes@gmail.com> Fixes: e02fb7264d8a ("nfit: add Microsoft NVDIMM DSM command set...") Reported-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An integer overflow may arise in uinput_validate_absinfo() if "max - min"
can't be represented by an "int". We should check for overflow before
trying to use the result.
Reported-by: Kyungtae Kim <kt0755@gmail.com> Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds wrappers for the __builtin overflow checkers present in gcc
5.1+ as well as fallback implementations for earlier compilers. It's not
that easy to implement the fully generic __builtin_X_overflow(T1 a, T2
b, T3 *d) in macros, so the fallback code assumes that T1, T2 and T3 are
the same. We obviously don't want the wrappers to have different
semantics depending on $GCC_VERSION, so we also insist on that even when
using the builtins.
There are a few problems with the 'a+b < a' idiom for checking for
overflow: For signed types, it relies on undefined behaviour and is
not actually complete (it doesn't check underflow;
e.g. INT_MIN+INT_MIN == 0 isn't caught). Due to type promotion it
is wrong for all types (signed and unsigned) narrower than
int. Similarly, when a and b does not have the same type, there are
subtle cases like
u32 a;
if (a + sizeof(foo) < a)
return -EOVERFLOW;
a += sizeof(foo);
where the test is always false on 64 bit platforms. Add to that that it
is not always possible to determine the types involved at a glance.
The new overflow.h is somewhat bulky, but that's mostly a result of
trying to be type-generic, complete (e.g. catching not only overflow
but also signed underflow) and not relying on undefined behaviour.
Linus is of course right [1] that for unsigned subtraction a-b, the
right way to check for overflow (underflow) is "b > a" and not
"__builtin_sub_overflow(a, b, &d)", but that's just one out of six cases
covered here, and included mostly for completeness.
So is it worth it? I think it is, if nothing else for the documentation
value of seeing
if (check_add_overflow(a, b, &d))
return -EGOAWAY;
do_stuff_with(d);
instead of the open-coded (and possibly wrong and/or incomplete and/or
UBsan-tickling)
if (a+b < a)
return -EGOAWAY;
do_stuff_with(a+b);
While gcc does recognize the 'a+b < a' idiom for testing unsigned add
overflow, it doesn't do nearly as good for unsigned multiplication
(there's also no single well-established idiom). So using
check_mul_overflow in kcalloc and friends may also make gcc generate
slightly better code.
Add support for the SteelSeries Stratus Duo, a wireless Xbox 360
controller. The Stratus Duo ships with a USB dongle to enable wireless
connectivity, but it can also function as a wired controller by connecting
it directly to a PC via USB, hence the need for two USD PIDs. 0x1430 is the
dongle, and 0x1431 is the controller.
When executing add_credits() we currently call cifs_reconnect()
if the number of credits is zero and there are no requests in
flight. In this case we may call cifs_reconnect() recursively
twice and cause memory corruption given the following sequence
of functions:
Fix this by avoiding to call cifs_reconnect() in add_credits()
and checking for zero credits in the demultiplex thread.
Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We do need to account for credits received in error responses
to read requests on encrypted sessions.
Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently we mark MID as malformed if we get an error from server
in a read response. This leads to not properly processing credits
in the readv callback. Fix this by marking such a response as
normal received response and process it appropriately.
Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When doing MTU i/o we need to leave some credits for
possible reopen requests and other operations happening
in parallel. Currently we leave 1 credit which is not
enough even for reopen only: we need at least 2 credits
if durable handle reconnect fails. Also there may be
other operations at the same time including compounding
ones which require 3 credits at a time each. Fix this
by leaving 8 credits which is big enough to cover most
scenarios.
Was able to reproduce this when server was configured
to give out fewer credits than usual.
The proper fix would be to reconnect a file handle first
and then obtain credits for an MTU request but this leads
to bigger code changes and should happen in other patches.
Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fc96df16a1ce is good and can already fix the "return stack garbage" issue,
but let's also improve hv_ringbuffer_get_debuginfo(), which would silently
return stack garbage, if people forget to check channel->state or
ring_info->ring_buffer, when using the function in the future.
Having an error check in the function would eliminate the potential risk.
Add a Fixes tag to indicate the patch depdendency.
Fixes: fc96df16a1ce ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels") Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use
128M. To deal with it we implement partial section onlining by registering
custom page onlining callback (hv_online_page()). Later, when more memory
arrives we try to online the 'tail' (see hv_bring_pgs_online()).
It was found that in some cases this 'tail' onlining causes issues:
Turns out that we now have deferred struct page initialization for memory
hotplug so e.g. memory_block_action() in drivers/base/memory.c does
pages_correctly_probed() check and in that check it avoids inspecting
struct pages and checks sections instead. But in Hyper-V balloon driver we
do PageReserved(pfn_to_page()) check and this is now wrong.
Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user
call while current is TASK_INTERRUPTIBLE. This is a false positive
since the code path does not depend on current state remaining
TASK_INTERRUPTIBLE. The loop breaks out and sets TASK_RUNNING after
calling copy_to_user.
This patch supresses the warning by setting TASK_RUNNING before calling
copy_to_user.
We were experiencing a crash similar to the one reported as part of
commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and
uart_shutdown()") in our testbed as well. We continue to observe the same
crash after integrating the commit a5ba1d95e46e ("uart: fix race between
uart_put_char() and uart_shutdown()")
On reviewing the change, the port lock should be taken prior to checking for
if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer
uart_state->xmit.
Traceback:
[11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference
at virtual address 0000003b
Some tty line disciplines do not have a receive buf callback, so
properly check for that before calling it. If they do not have this
callback, just eat the character quietly, as we can't fail this call.
Fix this by sanitizing ipcnum before using it to index pDrvData->IPCs.
Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].
smp_rescan_cpus() is called without the device_hotplug_lock, which can lead
to a dedlock when a new CPU is found and immediately set online by a udev
rule.
This was observed on an older kernel version, where the cpu_hotplug_begin()
loop was still present, and it resulted in hanging chcpu and systemd-udev
processes. This specific deadlock will not show on current kernels. However,
there may be other possible deadlocks, and since smp_rescan_cpus() can still
trigger a CPU hotplug operation, the device_hotplug_lock should be held.
For reference, this was the deadlock with the old cpu_hotplug_begin() loop:
chcpu (rescan) systemd-udevd
echo 1 > /sys/../rescan
-> smp_rescan_cpus()
-> (*) get_online_cpus()
(increases refcount)
-> smp_add_present_cpu()
(new CPU found)
-> register_cpu()
-> device_add()
-> udev "add" event triggered -----------> udev rule sets CPU online
-> echo 1 > /sys/.../online
-> lock_device_hotplug_sysfs()
(this is missing in rescan path)
-> device_online()
-> (**) device_lock(new CPU dev)
-> cpu_up()
-> cpu_hotplug_begin()
(loops until refcount == 0)
-> deadlock with (*)
-> bus_probe_device()
-> device_attach()
-> device_lock(new CPU dev)
-> deadlock with (**)
Fix this by taking the device_hotplug_lock in the CPU rescan path.
Right now the early machine detection code check stsi 3.2.2 for "KVM"
and set MACHINE_IS_VM if this is different. As the console detection
uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux
early for any non z/VM system that sets a different value than KVM.
So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR,
MACHINE_IS_VM, or MACHINE_IS_KVM.
CC: stable@vger.kernel.org Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So far we've mapped branches to "ijmp" which also counts conditional
branches NOT taken. This makes us different from other architectures
such as ARM which seem to be counting only taken branches.
So use "ijmptak" hardware condition which only counts (all jump
instructions that are taken)
'ijmptak' event is available on both ARCompact and ARCv2 ISA based
cores.
In setup_arch_memory we reserve the memory area wherein the kernel
is located. Current implementation may reserve more memory than
it actually required in case of CONFIG_LINUX_LINK_BASE is not
equal to CONFIG_LINUX_RAM_BASE. This happens because we calculate
start of the reserved region relatively to the CONFIG_LINUX_RAM_BASE
and end of the region relatively to the CONFIG_LINUX_RAM_BASE.
For example in case of HSDK board we wasted 256MiB of physical memory:
------------------->8------------------------------
Memory: 770416K/1048576K available (5496K kernel code,
240K rwdata, 1064K rodata, 2200K init, 275K bss,
278160K reserved, 0K cma-reserved)
------------------->8------------------------------
Fix that.
Fixes: 9ed68785f7f2b ("ARC: mm: Decouple RAM base address from kernel link addr") Cc: stable@vger.kernel.org #4.14+ Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARCv2 optimized memset uses PREFETCHW instruction for prefetching the
next cache line but doesn't ensure that the line is not past the end of
the buffer. PRETECHW changes the line ownership and marks it dirty,
which can cause issues in SMP config when next line was already owned by
other core. Fix the issue by avoiding the PREFETCHW
Some more details:
The current code has 3 logical loops (ignroing the unaligned part)
(a) Big loop for doing aligned 64 bytes per iteration with PREALLOC
(b) Loop for 32 x 2 bytes with PREFETCHW
(c) any left over bytes
loop (a) was already eliding the last 64 bytes, so PREALLOC was
safe. The fix was removing PREFETCW from (b).
Another potential issue (applicable to configs with 32 or 128 byte L1
cache line) is that PREALLOC assumes 64 byte cache line and may not do
the right thing specially for 32b. While it would be easy to adapt,
there are no known configs with those lie sizes, so for now, just
compile out PREALLOC in such cases.
Setting the low threshold to 0 has no effect on frags allocation,
we need to clear high_thresh instead.
The code was pre-existent to commit 648700f76b03 ("inet: frags:
use rhashtables for reassembly units"), but before the above,
such assignment had a different role: prevent concurrent eviction
from the worker and the netns cleanup helper.
Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1. In response to events in the netdev and inetaddr notification chains
2. When a network namespace is being dismantled
In both cases only routes associated with a dead nexthop group are
flushed. However, a nexthop group will only be marked as dead in case it
is populated with actual nexthops using a nexthop device. This is not
the case when the route in question is an error route (e.g.,
'blackhole', 'unreachable').
Therefore, when a network namespace is being dismantled such routes are
not flushed and leaked [1].
To reproduce:
# ip netns add blue
# ip -n blue route add unreachable 192.0.2.0/24
# ip netns del blue
Fix this by not skipping error routes that are not marked with
RTNH_F_DEAD when flushing the routing tables.
To prevent the flushing of such routes in case #1, add a parameter to
fib_table_flush() that indicates if the table is flushed as part of
namespace dismantle or not.
Note that this problem does not exist in IPv6 since error routes are
associated with the loopback device.
Vhost dirty page logging API is designed to sync through GPA. But we
try to log GIOVA when device IOTLB is enabled. This is wrong and may
lead to missing data after migration.
To solve this issue, when logging with device IOTLB enabled, we will:
1) reuse the device IOTLB translation result of GIOVA->HVA mapping to
get HVA, for writable descriptor, get HVA through iovec. For used
ring update, translate its GIOVA to HVA
2) traverse the GPA->HVA mapping to get the possible GPA and log
through GPA. Pay attention this reverse mapping is not guaranteed
to be unique, so we should log each possible GPA in this case.
This fix the failure of scp to guest during migration. In -next, we
will probably support passing GIOVA->GPA instead of GIOVA->HVA.
Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API") Reported-by: Jintack Lim <jintack@cs.columbia.edu> Cc: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For nested and variable attributes, the expected length of an attribute
is not known and marked by a negative number. This results in an OOB
read when the expected length is later used to check if the attribute is
all zeros. Fix this by using the actual length of the attribute rather
than the expected length.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Martin reported a set of filters don't work after changing
from reclassify to continue. Looking into the code, it
looks like skb protocol is not always fetched for each
iteration of the filters. But, as demonstrated by Martin,
TC actions could modify skb->protocol, for example act_vlan,
this means we have to refetch skb protocol in each iteration,
rather than using the one we fetch in the beginning of the loop.
This bug is _not_ introduced by commit 3b3ae880266d
("net: sched: consolidate tc_classify{,_compat}"), technically,
if act_vlan is the only action that modifies skb protocol, then
it is commit c7e2b9689ef8 ("sched: introduce vlan action") which
introduced this bug.
Reported-by: Martin Olsson <martin.olsson+netdev@sentorsecurity.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current code in __mdiobus_register() doesn't properly handle
failures returned by the devm_gpiod_get_optional() call: it returns
immediately, without unregistering the device that was added by the
call to device_register() earlier in the function.
This leaves a stale device, which then causes a NULL pointer
dereference in the code that handles deferred probing:
The actual error that we had from devm_gpiod_get_optional() was
-EPROBE_DEFER, due to the GPIO being provided by a driver that is
probed later than the Ethernet controller driver.
To fix this, we simply add the missing device_del() invocation in the
error path.
Fixes: 69226896ad636 ("mdio_bus: Issue GPIO RESET to PHYs") Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In certain cases, pskb_trim_rcsum() may change skb pointers.
Reinitialize header pointers afterwards to avoid potential
use-after-frees. Add a note in the documentation of
pskb_trim_rcsum(). Found by KASAN.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The skb header should be set to ethernet header before using
is_skb_forwardable. Because the ethernet header length has been
considered in is_skb_forwardable(including dev->hard_header_len
length).
To reproduce the issue:
1, add 2 ports on linux bridge br using following commands:
$ brctl addbr br
$ brctl addif br eth0
$ brctl addif br eth1
2, the MTU of eth0 and eth1 is 1500
3, send a packet(Data 1480, UDP 8, IP 20, Ethernet 14, VLAN 4)
from eth0 to eth1
So the expect result is packet larger than 1500 cannot pass through
eth0 and eth1. But currently, the packet passes through success, it
means eth1's MTU limit doesn't take effect.
Fixes: f6367b4660dd ("bridge: use is_skb_forwardable in forward path") Cc: bridge@lists.linux-foundation.org Cc: Nkolay Aleksandrov <nikolay@cumulusnetworks.com> Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The XGBE hardware has support for performing MDIO operations using an
MDIO command request. The driver mistakenly uses the mdio port address
as the MDIO command request device address instead of the MDIO command
request port address. Additionally, the driver does not properly check
for and create a clause 45 MDIO command.
Check the supplied MDIO register to determine if the request is a clause
45 operation (MII_ADDR_C45). For a clause 45 operation, extract the device
address and register number from the supplied MDIO register and use them
to set the MDIO command request device address and register number fields.
For a clause 22 operation, the MDIO request device address is set to zero
and the MDIO command request register number is set to the supplied MDIO
register. In either case, the supplied MDIO port address is used as the
MDIO command request port address.
Fixes: 732f2ab7afb9 ("amd-xgbe: Add support for MDIO attached PHYs") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Tested-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The write to the status register is really an ACK for the HW,
and should be treated as such by the driver. Let's move it to the
irq_ack() callback, which will prevent people from moving it around
in order to paper over other bugs.
Fixes: 8c934095fa2f ("PCI: dwc: Clear MSI interrupt status after it is handled,
not before") Fixes: 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains
hierarchical API") Link: https://lore.kernel.org/linux-pci/20181113225734.8026-1-marc.zyngier@arm.com/ Reported-by: Trent Piepho <tpiepho@impinj.com> Tested-by: Niklas Cassel <niklas.cassel@linaro.org> Tested-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> Tested-by: Stanimir Varbanov <svarbanov@mm-sol.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is to fix missed mmap range check on vGPU bar2 region
and only allow to map vGPU allocated GMADDR range, which means
user space should support sparse mmap to get proper offset for
mmap vGPU aperture. And this takes care of actual pgoff in mmap
request as original code always does from beginning of vGPU
aperture.
Fixes: 659643f7d814 ("drm/i915/gvt/kvmgt: add vfio/mdev support to KVMGT") Cc: "Monroy, Rodrigo Axel" <rodrigo.axel.monroy@intel.com> Cc: "Orrala Contreras, Alfredo" <alfredo.orrala.contreras@intel.com> Cc: stable@vger.kernel.org # v4.10+ Reviewed-by: Hang Yuan <hang.yuan@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
allow disabling cifs (SMB1 ie vers=1.0) and vers=2.0 in the
config for the build of cifs.ko if want to always prevent mounting
with these less secure dialects.
Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Jeremy Allison <jra@samba.org> Cc: Alakesh Haloi <alakeshh@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Realtek has some sort of "Virtual" IPMI device on the PCI bus as a
KCS controller, but whatever it is, it's not one. Ignore it if seen.
[ Commit 13d0b35c (ipmi_si: Move PCI setup to another file) from Linux
4.15-rc1 has not been back ported, so the PCI code is still in
`drivers/char/ipmi/ipmi_si_intf.c`, requiring to apply the commit
manually.
This fixes a 100 s boot delay on the HP EliteDesk 705 G4 MT with Linux
4.14.94. ]
Reported-by: Chris Chiu <chiu@endlessm.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Tested-by: Daniel Drake <drake@endlessm.com> Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The following deadlock can occur between a process waiting for a client
to initialize in while walking the client list during nfsv4 server trunking
detection and another process waiting for the nfs_clid_init_mutex so it
can initialize that client:
Process 1 Process 2
--------- ---------
spin_lock(&nn->nfs_client_lock);
list_add_tail(&CLIENTA->cl_share_link,
&nn->nfs_client_list);
spin_unlock(&nn->nfs_client_lock);
spin_lock(&nn->nfs_client_lock);
list_add_tail(&CLIENTB->cl_share_link,
&nn->nfs_client_list);
spin_unlock(&nn->nfs_client_lock);
mutex_lock(&nfs_clid_init_mutex);
nfs41_walk_client_list(clp, result, cred);
nfs_wait_client_init_complete(CLIENTA);
(waiting for nfs_clid_init_mutex)
Make sure nfs_match_client() only evaluates clients that have completed
initialization in order to prevent that deadlock.
This patch also fixes v4.0 trunking behavior by not marking the client
NFS_CS_READY until the clientid has been confirmed.
Signed-off-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Qian Lu <luqia@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch series "THP eligibility reporting via proc".
This series of three patches aims at making THP eligibility reporting much
more robust and long term sustainable. The trigger for the change is a
regression report [2] and the long follow up discussion. In short the
specific application didn't have good API to query whether a particular
mapping can be backed by THP so it has used VMA flags to workaround that.
These flags represent a deep internal state of VMAs and as such they
should be used by userspace with a great deal of caution.
A similar has happened for [3] when users complained that VM_MIXEDMAP is
no longer set on DAX mappings. Again a lack of a proper API led to an
abuse.
The first patch in the series tries to emphasise that that the semantic of
flags might change and any application consuming those should be really
careful.
The remaining two patches provide a more suitable interface to address [2]
and provide a consistent API to query the THP status both for each VMA and
process wide as well. [1]
Even though vma flags exported via /proc/<pid>/smaps are explicitly
documented to be not guaranteed for future compatibility the warning
doesn't go far enough because it doesn't mention semantic changes to those
flags. And they are important as well because these flags are a deep
implementation internal to the MM code and the semantic might change at
any time.
Let's consider two recent examples:
http://lkml.kernel.org/r/20181002100531.GC4135@quack2.suse.cz
: commit e1fb4a086495 "dax: remove VM_MIXEDMAP for fsdax and device dax" has
: removed VM_MIXEDMAP flag from DAX VMAs. Now our testing shows that in the
: mean time certain customer of ours started poking into /proc/<pid>/smaps
: and looks at VMA flags there and if VM_MIXEDMAP is missing among the VMA
: flags, the application just fails to start complaining that DAX support is
: missing in the kernel.
http://lkml.kernel.org/r/alpine.DEB.2.21.1809241054050.224429@chino.kir.corp.google.com
: Commit 1860033237d4 ("mm: make PR_SET_THP_DISABLE immediately active")
: introduced a regression in that userspace cannot always determine the set
: of vmas where thp is ineligible.
: Userspace relies on the "nh" flag being emitted as part of /proc/pid/smaps
: to determine if a vma is eligible to be backed by hugepages.
: Previous to this commit, prctl(PR_SET_THP_DISABLE, 1) would cause thp to
: be disabled and emit "nh" as a flag for the corresponding vmas as part of
: /proc/pid/smaps. After the commit, thp is disabled by means of an mm
: flag and "nh" is not emitted.
: This causes smaps parsing libraries to assume a vma is eligible for thp
: and ends up puzzling the user on why its memory is not backed by thp.
In both cases userspace was relying on a semantic of a specific VMA flag.
The primary reason why that happened is a lack of a proper interface.
While this has been worked on and it will be fixed properly, it seems that
our wording could see some refinement and be more vocal about semantic
aspect of these flags as well.
Link: http://lkml.kernel.org/r/20181211143641.3503-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Dan Williams <dan.j.williams@intel.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Paul Oppenheimer <bepvte@gmail.com> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Since a2468cc9bfdf ("swap: choose swap device according to numa node"),
avail_lists field of swap_info_struct is changed to an array with
MAX_NUMNODES elements. This made swap_info_struct size increased to 40KiB
and needs an order-4 page to hold it.
This is not optimal in that:
1 Most systems have way less than MAX_NUMNODES(1024) nodes so it
is a waste of memory;
2 It could cause swapon failure if the swap device is swapped on
after system has been running for a while, due to no order-4
page is available as pointed out by Vasily Averin.
Solve the above two issues by using nr_node_ids(which is the actual
possible node number the running system has) for avail_lists instead of
MAX_NUMNODES.
nr_node_ids is unknown at compile time so can't be directly used when
declaring this array. What I did here is to declare avail_lists as zero
element array and allocate space for it when allocating space for
swap_info_struct. The reason why keep using array but not pointer is
plist_for_each_entry needs the field to be part of the struct, so pointer
will not work.
This patch is on top of Vasily Averin's fix commit. I think the use of
kvzalloc for swap_info_struct is still needed in case nr_node_ids is
really big on some systems.
Link: http://lkml.kernel.org/r/20181115083847.GA11129@intel.com Signed-off-by: Aaron Lu <aaron.lu@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
write_cache_pages() is used in both background and integrity writeback
scenarios by various filesystems. Background writeback is mostly
concerned with cleaning a certain number of dirty pages based on various
mm heuristics. It may not write the full set of dirty pages or wait for
I/O to complete. Integrity writeback is responsible for persisting a set
of dirty pages before the writeback job completes. For example, an
fsync() call must perform integrity writeback to ensure data is on disk
before the call returns.
write_cache_pages() unconditionally breaks out of its processing loop in
the event of a ->writepage() error. This is fine for background
writeback, which had no strict requirements and will eventually come
around again. This can cause problems for integrity writeback on
filesystems that might need to clean up state associated with failed page
writeouts. For example, XFS performs internal delayed allocation
accounting before returning a ->writepage() error, where applicable. If
the current writeback happens to be associated with an unmount and
write_cache_pages() completes the writeback prematurely due to error, the
filesystem is unmounted in an inconsistent state if dirty+delalloc pages
still exist.
To handle this problem, update write_cache_pages() to always process the
full set of pages for integrity writeback regardless of ->writepage()
errors. Save the first encountered error and return it to the caller once
complete. This facilitates XFS (or any other fs that expects integrity
writeback to process the entire set of dirty pages) to clean up its
internal state completely in the event of persistent mapping errors.
Background writeback continues to exit on the first error encountered.
[akpm@linux-foundation.org: fix typo in comment] Link: http://lkml.kernel.org/r/20181116134304.32440-1-bfoster@redhat.com Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
mount.ocfs2 ignore the inconsistent error that journal is clean but
local alloc is unrecovered. After mount, local alloc not empty, then
reserver cluster didn't alloc a new local alloc window, reserveration
map is empty(ocfs2_reservation_map.m_bitmap_len = 0), that triggered the
following panic.
and was advised to fixed during mount. But this is a very unusual
inconsistent state, usually journal dirty flag should be cleared at the
last stage of umount until every other things go right. We may need do
further debug to check that. Any way to avoid possible futher
corruption, mount should be abort and fsck should be run.
This is because when populating Driver Map using firmware raid map, all
non-existing VDs set their ldTgtIdToLd to 0xff, so it can be skipped later.
From drivers/scsi/megaraid/megaraid_sas_base.c ,
memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);
From drivers/scsi/megaraid/megaraid_sas_fp.c ,
/* For non existing VDs, iterate to next VD*/
if (ld >= (MAX_LOGICAL_DRIVES_EXT - 1))
continue;
However, there are a few places that failed to skip those non-existing VDs
due to off-by-one errors. Then, those 0xff leaked into MR_LdRaidGet(0xff,
map) and triggered the out-of-bound accesses.
Fixes: 51087a8617fe ("megaraid_sas : Extended VD support") Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Sumit Saxena <sumit.saxena@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
1. smartpqi is built as module, not built-in;
2. We have a disk connected to smartpqi card;
3. Both kexec's 1st and 2nd kernels use this disk as Rootfs' mount point.
Signed-off-by: Yanjiang Jin <yanjiang.jin@hxt-semitech.com> Acked-by: Don Brace <don.brace@microsemi.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Problem:
The Linux kernel takes a logical volume offline after a LUN reset. This is
generally accompanied by this message in the dmesg output:
Device offlined - not ready after error recovery
Root Cause:
The root cause is a "quirk" in the timeout handling in the Linux SCSI
layer. The Linux kernel places a 30-second timeout on most media access
commands (reads and writes) that it send to device drivers. When a media
access command times out, the Linux kernel goes into error recovery mode
for the LUN that was the target of the command that timed out. Every
command that timed out is kept on a list inside of the Linux kernel to be
retried later. The kernel attempts to recover the command(s) that timed out
by issuing a LUN reset followed by a TEST UNIT READY. If the LUN reset and
TEST UNIT READY commands are successful, the kernel retries the command(s)
that timed out.
Each SCSI command issued by the kernel has a result field associated with
it. This field indicates the final result of the command (success or
error). When a command times out, the kernel places a value in this result
field indicating that the command timed out.
The "quirk" is that after the LUN reset and TEST UNIT READY commands are
completed, the kernel checks each command on the timed-out command list
before retrying it. If the result field is still "timed out", the kernel
treats that command as not having been successfully recovered for a
retry. If the number of commands that are in this state are greater than
two, the kernel takes the LUN offline.
Fix:
When our RAIDStack receives a LUN reset, it simply waits until all
outstanding commands complete. Generally, all of these outstanding commands
complete successfully. Therefore, the fix in the smartpqi driver is to
always set the command result field to indicate success when a request
completes successfully. This normally isn’t necessary because the result
field is always initialized to success when the command is submitted to the
driver. So when the command completes successfully, the result field is
left untouched. But in this case, the kernel changes the result field
behind the driver’s back and then expects the field to be changed by the
driver as the commands that timed-out complete.
Reviewed-by: Dave Carroll <david.carroll@microsemi.com> Reviewed-by: Scott Teel <scott.teel@microsemi.com> Signed-off-by: Kevin Barnett <kevin.barnett@microsemi.com> Signed-off-by: Don Brace <don.brace@microsemi.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit moves the usdev_lock acquisition after the rtnl lock has been
released.
This is safe to do because usdev_lock is not protecting anything being
accessed in ib_get_eth_speed(). Hence, the correct order of holding locks
(rtnl -> usdev_lock) is not violated.
This is the much more correct fix for my earlier attempt at:
https://lkml.org/lkml/2018/12/10/118
Short recap:
- There's not actually a locking issue, it's just lockdep being a bit
too eager to complain about a possible deadlock.
- Contrary to what I claimed the real problem is recursion on
kn->count. Greg pointed me at sysfs_break_active_protection(), used
by the scsi subsystem to allow a sysfs file to unbind itself. That
would be a real deadlock, which isn't what's happening here. Also,
breaking the active protection means we'd need to manually handle
all the lifetime fun.
- With Rafael we discussed the task_work approach, which kinda works,
but has two downsides: It's a functional change for a lockdep
annotation issue, and it won't work for the bind file (which needs
to get the errno from the driver load function back to userspace).
- Greg also asked why this never showed up: To hit this you need to
unregister a 2nd driver from the unload code of your first driver. I
guess only gpus do that. The bug has always been there, but only
with a recent patch series did we add more locks so that lockdep
built a chain from unbinding the snd-hda driver to the
acpi_video_unregister call.
Looking around I've noticed that usb and i2c already handle similar
recursion problems, where a sysfs file can unbind the same type of
sysfs somewhere else in the hierarchy. Relevant commits are: