Fixes the following sparse warning:
drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c:464:1: warning:
symbol 'mlxsw_sp_qdisc_prio_unoffload' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The check in sctp_sockaddr_af is not robust enough to forbid binding a
v4mapped v6 addr on a v4 socket.
The worse thing is that v4 socket's bind_verify would not convert this
v4mapped v6 addr to a v4 addr. syzbot even reported a crash as the v4
socket bound a v6 addr.
This patch is to fix it by doing the common sa.sa_family check first,
then AF_INET check for v4mapped v6 addrs.
Fixes: 7dab83de50 ("sctp: Support ipv6only AF_INET6 sockets.")
Reported-by: syzbot+7b7b518b1228d2743963@syzkaller.appspotmail.com
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit cea0cc80a6 ("sctp: use the right sk after waking up from
wait_buf sleep"), it may change to lock another sk if the asoc has been
peeled off in sctp_wait_for_sndbuf.
However, the asoc's new sk could be already closed elsewhere, as it's in
the sendmsg context of the old sk that can't avoid the new sk's closing.
If the sk's last one refcnt is held by this asoc, later on after putting
this asoc, the new sk will be freed, while under it's own lock.
This patch is to revert that commit, but fix the old issue by returning
error under the old sk's lock.
Fixes: cea0cc80a6 ("sctp: use the right sk after waking up from wait_buf sleep")
Reported-by: syzbot+ac6ea7baa4432811eb50@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After introducing sctp_stream structure, sctp uses stream->outcnt as the
out stream nums instead of c.sinit_num_ostreams.
However when users use sinit in cmsg, it only updates c.sinit_num_ostreams
in sctp_sendmsg. At that moment, stream->outcnt is still using previous
value. If it's value is not updated, the sinit_num_ostreams of sinit could
not really work.
This patch is to fix it by updating stream->outcnt and reiniting stream
if stream outcnt has been change by sinit in sendmsg.
Fixes: a83863174a ("sctp: prepare asoc stream for stream reconf")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For legacy chips without CLM blob files, kernel with user helper function
returns -EAGAIN when we request_firmware(), and then driver got failed
when bringing up legacy chips. We expect the CLM blob file for legacy chip
is not existence in firmware path, but the -ENOENT error is transferred to
-EAGAIN in firmware_class.c with user helper.
Because of that, we continue with CLM data currently present in firmware
if getting error from doing request_firmware().
Cc: stable@vger.kernel.org # v4.15.y
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Wright Feng <wright.feng@cypress.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Since commit d41e6858ba ("MIPS: Kconfig: Set default MIPS system type
as generic") changed the default MIPS platform to the "generic"
platform, which uses PCI_DRIVERS_GENERIC instead of PCI_DRIVERS_LEGACY,
various files in drivers/ssb/ have failed to build.
This is particularly due to the existence of struct pci_controller being
dependent on PCI_DRIVERS_LEGACY since commit c5611df968 ("MIPS: PCI:
Introduce CONFIG_PCI_DRIVERS_LEGACY"), so add that dependency to Kconfig
to prevent these files being built for the "generic" platform including
all{yes,mod}config builds.
Fixes: c5611df968 ("MIPS: PCI: Introduce CONFIG_PCI_DRIVERS_LEGACY")
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Michael Buesch <m@bues.ch>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-wireless@vger.kernel.org
Cc: linux-mips@linux-mips.org
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Jiri Pirko says:
====================
devlink: Add support for resource abstraction
Arkadi says:
Many of the ASIC's internal resources are limited and are shared between
several hardware procedures. For example, unified hash-based memory can
be used for many lookup purposes, like FDB and LPM. In many cases the user
can provide a partitioning scheme for such a resource in order to perform
fine tuning for his application. In such cases performing driver reload is
needed for the changes to take place, thus this patchset also adds support
for hot reload.
Such an abstraction can be coupled with devlink's dpipe interface, which
models the ASIC's pipeline as a graph of match/action tables. By modeling
the hardware resource object, and by coupling it to several dpipe tables,
further visibility can be achieved in order to debug ASIC-wide issues.
The proposed interface will provide the user the ability to understand the
limitations of the hardware, and receive notification regarding its occupancy.
Furthermore, monitoring the resource occupancy can be done in real-time and
can be useful in many cases.
---
v2->v3
- Mix/Max/Gran attributes.
- Add resource consumption per table.
- Change basic resource unit to 'entry'.
- ABI documentation.
v1->v2
- Add resource size attribute.
- Fix split bug.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add resources ABI documentation.
Signed-off-by: Arkadi Sharhsevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for hot reload. First, all the driver/core resources are
released but the PCI and devlink instances, then reset is performed
through the PCI interface. Finally the driver performs initialization.
In case of reload failure the driver is left in a partially initialized
state. Special care is taken during the driver removal in order to
properly handle this state.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Up until now the KVD partition was static. This patch introduces the
ability to get the resource sizes via devlink. In case the resource is not
available the default configuration is used.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for getting the kvdl occupancy through the resource interface.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Connect current dpipe tables to resources. The tables are connected
in the following fashion:
1. IPv4 host -> KVD hash single
2. IPv6 host -> KVD hash double
3. Adjacency -> KVD linear
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Register the KVD resources with devlink. The KVD is a memory resource
which is subdivided into three partitions which are the linear, hash
single and hash double.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a preparation stage before introducing hot reload. During the
reload process the ASIC should be resetted by accessing the PCI BAR due
to unavailability of the mailbox/emad interfaces.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The hardware processes which are modeled via dpipe commonly use some
internal hardware resources. Such relation can improve the understanding
of hardware limitations. The number of resource's unit consumed per
table's entry are also provided for each table.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for performing driver hot reload.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for hardware resource abstraction over devlink. Each resource
is identified via id, furthermore it contains information regarding its
size and its related sub resources. Each resource can also provide its
current occupancy.
In some cases the sizes of some resources can be changed, yet for those
changes to take place a hot driver reload may be needed. The reload
capability will be introduced in the next patch.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a preparation before introducing resources and hot reload support.
Currently there are two global lock where one protects all devlink access,
and the second one protects devlink port access. This patch adds per devlink
instance lock which protects the internal members which are the sb/dpipe/
resource/ports. By introducing this lock the global devlink port lock can
be discarded.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mips builds with BCMA host mode enabled fail in mainline and -next
with:
In file included from include/linux/bcma/bcma.h:10:0,
from drivers/bcma/bcma_private.h:9,
from drivers/bcma/main.c:8:
include/linux/bcma/bcma_driver_pci.h:218:24: error:
field 'pci_controller' has incomplete type
Bisect points to commit d41e6858ba ("MIPS: Kconfig: Set default MIPS
system type as generic") as the culprit. Analysis shows that the commmit
changes PCI configuration and enables PCI_DRIVERS_GENERIC. This in turn
disables PCI_DRIVERS_LEGACY. 'struct pci_controller' is, however, only
defined if PCI_DRIVERS_LEGACY is enabled.
Ultimately that means that BCMA_DRIVER_PCI_HOSTMODE depends on
PCI_DRIVERS_LEGACY. Add the missing dependency.
Fixes: d41e6858ba ("MIPS: Kconfig: Set default MIPS system type as ...")
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: James Hogan <jhogan@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Make use of the new helpers for paged register access.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that copy_siginfo copies all of the fields this is safe, safer (as
all of the bits are guaranteed to be copied), clearer, and less error
prone than using a structure copy.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
intel_power_domains_init_hw() calls set_init_power, but when using
runtime power management this call is skipped. This prevents hw readout
from taking place.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104172
Link: https://patchwork.freedesktop.org/patch/msgid/20180116155324.75120-1-maarten.lankhorst@linux.intel.com
Fixes: bc87229f32 ("drm/i915/skl: enable PC9/10 power states during suspend-to-idle")
Cc: Nivedita Swaminathan <nivedita.swaminathan@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: <stable@vger.kernel.org> # v4.5+
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reenable the 64-bit window during resume.
Fixes: fa564ad963 ("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)")
Reported-by: Tom St Denis <tom.stdenis@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The Marvell 9128 is the original device generating bug 42679, from which
many other Marvell DMA alias quirks have been sourced, but we didn't have
positive confirmation of the fix on 9128 until now.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=42679
Link: https://www.spinics.net/lists/kvm/msg161459.html
Reported-by: Binarus <lists@binarus.de>
Tested-by: Binarus <lists@binarus.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
With ARM64_SW_TTBR0_PAN enabled, the exception entry code checks the
active ASID to decide whether user access was enabled (non-zero ASID)
when the exception was taken. On return from exception, if user access
was previously disabled, it re-instates TTBR0_EL1 from the per-thread
saved value (updated in switch_mm() or efi_set_pgd()).
Commit 7655abb953 ("arm64: mm: Move ASID from TTBR0 to TTBR1") makes a
TTBR0_EL1 + ASID switching non-atomic. Subsequently, commit 27a921e757
("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN") changes the
__uaccess_ttbr0_disable() function and asm macro to first write the
reserved TTBR0_EL1 followed by the ASID=0 update in TTBR1_EL1. If an
exception occurs between these two, the exception return code will
re-instate a valid TTBR0_EL1. Similar scenario can happen in
cpu_switch_mm() between setting the reserved TTBR0_EL1 and the ASID
update in cpu_do_switch_mm().
This patch reverts the entry.S check for ASID == 0 to TTBR0_EL1 and
disables the interrupts around the TTBR0_EL1 and ASID switching code in
__uaccess_ttbr0_disable(). It also ensures that, when returning from the
EFI runtime services, efi_set_pgd() doesn't leave a non-zero ASID in
TTBR1_EL1 by using uaccess_ttbr0_{enable,disable}.
The accesses to current_thread_info()->ttbr0 are updated to use
READ_ONCE/WRITE_ONCE.
As a safety measure, __uaccess_ttbr0_enable() always masks out any
existing non-zero ASID TTBR1_EL1 before writing in the new ASID.
Fixes: 27a921e757 ("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN")
Acked-by: Will Deacon <will.deacon@arm.com>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Co-developed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.
Signed-off-by: Luis de Bethencourt <luisbg@kernel.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Heiner Kallweit says:
====================
phy: add helpers for setting/clearing bits in PHY registers
Based on the recent introduction of phy_modify add helpers for setting
and clearing bits in PHY registers. First user is phylib.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Use new helpers phy_set_bits / phy_clear_bits in phylib.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on the recent introduction of phy_modify add helpers for setting
and clearing bits in PHY registers.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
KVM doesn't follow the SMCCC when it comes to unimplemented calls,
and inject an UNDEF instead of returning an error. Since firmware
calls are now used for security mitigation, they are becoming more
common, and the undef is counter productive.
Instead, let's follow the SMCCC which states that -1 must be returned
to the caller when getting an unknown function number.
Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Commit fbcab13d2e ("selftests: silence test output by default")
changed the run_tests logic as well as the logic to generate
run_kselftests.sh to redirect test output away from the console.
As discussed on the list and at kernel summit, this is not a desirable
default as it means in order to debug a failure the console output is
not sufficient, you also need access to the test machine to get the
full test logs. Additionally it's impolite to write directly to
/tmp/$TEST_NAME on shared systems.
The change to the run_tests logic was reverted in commit
a323335e62 ("selftests: lib.mk: print individual test results to
console by default"), and instead a summary option was added so that
quiet output could be requested.
However the change to run_kselftests.sh was left as-is.
This commit applies the same logic to the run_kselftests.sh code, ie.
the script now takes a "--summary" option which suppresses the output,
but shows all output by default.
Additionally instead of writing to /tmp/$TEST_NAME the output is
redirected to the directory where the generated test script is
located.
Fixes: fbcab13d2e ("selftests: silence test output by default")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Current multiple-kprobe testcase only tries to add
kprobe events on first 256 text symbols. However
kprobes fails to probe on some text symbols (like
blacklisted symbols). Thus in the worst case,
the test can not add any kprobe events.
To avoid that, continue to try adding kprobe events
until 256 events. Also it confirms the number of
registered kprobe events.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Fix to pick text symbols for multiple kprobe testcase.
kallsyms shows text symbols with " t " or " T " but
current testcase picks all symbols including "t",
so it picks data symbols if it includes 't' (e.g. "str").
This fixes it to find symbol lines with " t " or " T "
(including spaces).
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Russell King <linux@armlinux.org.uk>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Due to architecture limitations, the IBM VNIC client driver is unable
to perform MAC address changes unless the device has "logged in" to
its backing device. Currently, pending MAC changes are handled before
login, resulting in an error and failure to change the MAC address.
Moving that chunk to the end of the ibmvnic_login function, when we are
sure that it was successful, fixes that.
The MAC address can be changed when the device is up or down, so
only check if the device is in a "PROBED" state before setting the
MAC address.
Fixes: c26eba03e4 ("ibmvnic: Update reset infrastructure to support tunable parameters")
Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Reviewed-by: John Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch, basically, reverts commit 6b97a20d3a ("printk:
set may_schedule for some of console_trylock() callers").
That commit was a mistake, it introduced a big dependency
on the scheduler, by enabling preemption under console_sem
in printk()->console_unlock() path, which is rather too
critical. The patch did not significantly reduce the
possibilities of printk() lockups, but made it possible to
stall printk(), as has been reported by Tetsuo Handa [1].
Another issues is that preemption under console_sem also
messes up with Steven Rostedt's hand off scheme, by making
it possible to sleep with console_sem both in console_unlock()
and in vprintk_emit(), after acquiring the console_sem
ownership (anywhere between printk_safe_exit_irqrestore() in
console_trylock_spinning() and printk_safe_enter_irqsave()
in console_unlock()). This makes hand off less likely and,
at the same time, may result in a significant amount of
pending logbuf messages. Preempted console_sem owner makes
it impossible for other CPUs to emit logbuf messages, but
does not make it impossible for other CPUs to append new
messages to the logbuf.
Reinstate the old behavior and make printk() non-preemptible.
Should any printk() lockup reports arrive they must be handled
in a different way.
[1] http://lkml.kernel.org/r/201603022101.CAH73907.OVOOMFHFFtQJSL%20()%20I-love%20!%20SAKURA%20!%20ne%20!%20jp
Fixes: 6b97a20d3a ("printk: set may_schedule for some of console_trylock() callers")
Link: http://lkml.kernel.org/r/20180116044716.GE6607@jagdpanzerIV
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: akpm@linux-foundation.org
Cc: linux-mm@kvack.org
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
The commit ("printk: Add console owner and waiter logic to load balance
console writes") made vprintk_emit() and console_unlock() even more
complicated.
This patch extracts the new code into 3 helper functions. They should
help to keep it rather self-contained. It will be easier to use and
maintain.
This patch just shuffles the existing code. It does not change
the functionality.
Link: http://lkml.kernel.org/r/20180112160837.GD24497@linux.suse
Cc: akpm@linux-foundation.org
Cc: linux-mm@kvack.org
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: rostedt@home.goodmis.org
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
This patch implements what I discussed in Kernel Summit. I added
lockdep annotation (hopefully correctly), and it hasn't had any splats
(since I fixed some bugs in the first iterations). It did catch
problems when I had the owner covering too much. But now that the owner
is only set when actively calling the consoles, lockdep has stayed
quiet.
Here's the design again:
I added a "console_owner" which is set to a task that is actively
writing to the consoles. It is *not* the same as the owner of the
console_lock. It is only set when doing the calls to the console
functions. It is protected by a console_owner_lock which is a raw spin
lock.
There is a console_waiter. This is set when there is an active console
owner that is not current, and waiter is not set. This too is protected
by console_owner_lock.
In printk() when it tries to write to the consoles, we have:
if (console_trylock())
console_unlock();
Now I added an else, which will check if there is an active owner, and
no current waiter. If that is the case, then console_waiter is set, and
the task goes into a spin until it is no longer set.
When the active console owner finishes writing the current message to
the consoles, it grabs the console_owner_lock and sees if there is a
waiter, and clears console_owner.
If there is a waiter, then it breaks out of the loop, clears the waiter
flag (because that will release the waiter from its spin), and exits.
Note, it does *not* release the console semaphore. Because it is a
semaphore, there is no owner. Another task may release it. This means
that the waiter is guaranteed to be the new console owner! Which it
becomes.
Then the waiter calls console_unlock() and continues to write to the
consoles.
If another task comes along and does a printk() it too can become the
new waiter, and we wash rinse and repeat!
By Petr Mladek about possible new deadlocks:
The thing is that we move console_sem only to printk() call
that normally calls console_unlock() as well. It means that
the transferred owner should not bring new type of dependencies.
As Steven said somewhere: "If there is a deadlock, it was
there even before."
We could look at it from this side. The possible deadlock would
look like:
CPU0 CPU1
console_unlock()
console_owner = current;
spin_lockA()
printk()
spin = true;
while (...)
call_console_drivers()
spin_lockA()
This would be a deadlock. CPU0 would wait for the lock A.
While CPU1 would own the lockA and would wait for CPU0
to finish calling the console drivers and pass the console_sem
owner.
But if the above is true than the following scenario was
already possible before:
CPU0
spin_lockA()
printk()
console_unlock()
call_console_drivers()
spin_lockA()
By other words, this deadlock was there even before. Such
deadlocks are prevented by using printk_deferred() in
the sections guarded by the lock A.
By Steven Rostedt:
To demonstrate the issue, this module has been shown to lock up a
system with 4 CPUs and a slow console (like a serial console). It is
also able to lock up a 8 CPU system with only a fast (VGA) console, by
passing in "loops=100". The changes in this commit prevent this module
from locking up the system.
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/hrtimer.h>
static bool stop_testing;
static unsigned int loops = 1;
static void preempt_printk_workfn(struct work_struct *work)
{
int i;
while (!READ_ONCE(stop_testing)) {
for (i = 0; i < loops && !READ_ONCE(stop_testing); i++) {
preempt_disable();
pr_emerg("%5d%-75s\n", smp_processor_id(),
" XXX NOPREEMPT");
preempt_enable();
}
msleep(1);
}
}
static struct work_struct __percpu *works;
static void finish(void)
{
int cpu;
WRITE_ONCE(stop_testing, true);
for_each_online_cpu(cpu)
flush_work(per_cpu_ptr(works, cpu));
free_percpu(works);
}
static int __init test_init(void)
{
int cpu;
works = alloc_percpu(struct work_struct);
if (!works)
return -ENOMEM;
/*
* This is just a test module. This will break if you
* do any CPU hot plugging between loading and
* unloading the module.
*/
for_each_online_cpu(cpu) {
struct work_struct *work = per_cpu_ptr(works, cpu);
INIT_WORK(work, &preempt_printk_workfn);
schedule_work_on(cpu, work);
}
return 0;
}
static void __exit test_exit(void)
{
finish();
}
module_param(loops, uint, 0);
module_init(test_init);
module_exit(test_exit);
MODULE_LICENSE("GPL");
Link: http://lkml.kernel.org/r/20180110132418.7080-2-pmladek@suse.com
Cc: akpm@linux-foundation.org
Cc: linux-mm@kvack.org
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[pmladek@suse.com: Commit message about possible deadlocks]
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Clean up: Code review suggested that a common bit of code can be
placed into a helper function, and this gives us fewer places to
stick an "I DMA unmapped something" trace point.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: struct rpcrdma_mw was named after Memory Windows, but
xprtrdma no longer supports a Memory Window registration mode.
Rename rpcrdma_mw and its fields to reduce confusion and make
the code more sensible to read.
Renaming "mw" was suggested by Tom Talpey, the author of the
original xprtrdma implementation. It's a good idea, but I haven't
done this until now because it's a huge diffstat for no benefit
other than code readability.
However, I'm about to introduce static trace points that expose
a few of xprtrdma's internal data structures. They should make sense
in the trace report, and it's reasonable to treat trace points as a
kernel API contract which might be difficult to change later.
While I'm churning things up, two additional changes:
- rename variables unhelpfully called "r" to "mr", to improve code
clarity, and
- rename the MR-related helper functions using the form
"rpcrdma_mr_<verb>", to be consistent with other areas of the
code.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: Over time, the industry has adopted the term "frwr"
instead of "frmr". The term "frwr" is now more widely recognized.
For the past couple of years I've attempted to add new code using
"frwr" , but there still remains plenty of older code that still
uses "frmr". Replace all usage of "frmr" to avoid confusion.
While we're churning code, rename variables unhelpfully called "f"
to "frwr", to improve code clarity.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
No need for the overhead of atomically setting and clearing this bit
flag for every use of a pre-allocated backchannel rpc_rqst. These
are a distinct pool of rpc_rqsts that are used only for callback
operations, so it is safe to simply leave the bit set.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up. @rqst is set up differently for backchannel Replies. For
example, rqst->rq_task and task->tk_client are both NULL. So it is
easier to understand and maintain this code path if it is separated.
Also, we can get rid of the confusing rl_connect_cookie hack in
rpcrdma_bc_receive_call.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Since commit 5a6d1db455 ("SUNRPC: Add a transport-specific private
field in rpc_rqst"), the rpc_rqst's for RPC-over-RDMA backchannel
operations leave rq_buffer set to NULL.
xprt_release does not invoke ->op->buf_free when rq_buffer is NULL.
The RPCRDMA_REQ_F_BACKCHANNEL check in xprt_rdma_free is therefore
redundant because xprt_rdma_free is not invoked for backchannel
requests.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up. This logic is related to marshaling the request, and I'd
like to keep everything that touches req->rl_registered close
together, for CPU cache efficiency.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up a harmless oversight. xprtrdma's ->set_port method has
never properly supported IPv6.
This issue has never been a problem because NFS/RDMA mounts have
always required "port=20049", thus so far, rpcbind is not invoked
for these mounts.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Save more space in struct rpcrdma_xprt by removing the redundant
"addr" field from struct rpcrdma_create_data_internal. Wherever
we have rpcrdma_xprt, we also have the rpc_xprt, which has a
sockaddr_storage field with the same content.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This makes the address strings available for debugging messages in
earlier stages of transport set up.
The first benefit is to get rid of the single-use rep_remote_addr
field, saving 128+ bytes in struct rpcrdma_ep.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up. Remove fields that should have been removed by
commit b3221d6a53 ("xprtrdma: Remove logic that constructs
RDMA_MSGP type calls").
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up.
Commit b5f0afbea4 ("xprtrdma: Per-connection pad optimization")
should have removed this.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
