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With binutils-2.26 and before, a weak missing symbol was kept during the
final link, and a missing CRC for an export would lead to that CRC being
treated as zero implicitly. With binutils-2.27, the crc symbol gets
dropped, and any module trying to use it will fail to load.
This sets the weak CRC symbol to zero explicitly, making it defined in
vmlinux, which in turn lets us load the modules referring to that CRC.
The comment above the __CRC_SYMBOL macro suggests that this was always
the intention, although it also seems that all symbols defined in C have
a correct CRC these days, and only the exports that are now done in
assembly need this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Adam Borowski <kilobyte@angband.pl>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The core and the cluster sleep state entry latencies can't be same as
cluster sleep involves more work compared to core level e.g. shared
cache maintenance.
Experiments have shown on an average about 100us more latency for the
cluster sleep state compared to the core level sleep. This patch fixes
the entry latency for the cluster sleep state.
Fixes: 28e10a8f3a03 ("arm64: dts: juno: Add idle-states to device tree")
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: "Jon Medhurst (Tixy)" <tixy@linaro.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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After 326fe02d1ed6 ("net/mlx4_en: protect ring->xdp_prog with rcu_read_lock"),
the rcu_read_lock() in bpf_prog_run_xdp() is superfluous, since callers
need to hold rcu_read_lock() already to make sure BPF program doesn't
get released in the background.
Thus, drop it from bpf_prog_run_xdp(), as it can otherwise be misleading.
Still keeping the bpf_prog_run_xdp() is useful as it allows for grepping
in XDP supported drivers and to keep the typecheck on the context intact.
For mlx4, this means we don't have a double rcu_read_lock() anymore. nfp can
just make use of bpf_prog_run_xdp(), too. For qede, just move rcu_read_lock()
out of the helper. When the driver gets atomic replace support, this will
move to call-sites eventually.
mlx5 needs actual fixing as it has the same issue as described already in
326fe02d1ed6 ("net/mlx4_en: protect ring->xdp_prog with rcu_read_lock"),
that is, we're under RCU bh at this time, BPF programs are released via
call_rcu(), and call_rcu() != call_rcu_bh(), so we need to properly mark
read side as programs can get xchg()'ed in mlx5e_xdp_set() without queue
reset.
Fixes: 86994156c736 ("net/mlx5e: XDP fast RX drop bpf programs support")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Only when ICMP packets are enqueued onto the error queue,
sk_err is also set. Before f5f99309fa74 (sock: do not set sk_err
in sock_dequeue_err_skb), a subsequent error queue read
would set sk_err to the next error on the queue, or 0 if empty.
As no error types other than ICMP set this field, sk_err should
not be modified upon dequeuing them.
Only for ICMP errors, reset the (racy) sk_err. Some applications,
like traceroute, rely on it and go into a futile busy POLLERR
loop otherwise.
In principle, sk_err has to be set while an ICMP error is queued.
Testing is_icmp_err_skb(skb_next) approximates this without
requiring a full queue walk. Applications that receive both ICMP
and other errors cannot rely on this legacy behavior, as other
errors do not set sk_err in the first place.
Fixes: f5f99309fa74 (sock: do not set sk_err in sock_dequeue_err_skb)
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Thomas Graf says:
====================
bpf: BPF for lightweight tunnel encapsulation
This series implements BPF program invocation from dst entries via the
lightweight tunnels infrastructure. The BPF program can be attached to
lwtunnel_input(), lwtunnel_output() or lwtunnel_xmit() and see an L3
skb as context. Programs attached to input and output are read-only.
Programs attached to lwtunnel_xmit() can modify and redirect, push headers
and redirect packets.
The facility can be used to:
- Collect statistics and generate sampling data for a subset of traffic
based on the dst utilized by the packet thus allowing to extend the
existing realms.
- Apply additional per route/dst filters to prohibit certain outgoing
or incoming packets based on BPF filters. In particular, this allows
to maintain per dst custom state across multiple packets in BPF maps
and apply filters based on statistics and behaviour observed over time.
- Attachment of L2 headers at transmit where resolving the L2 address
is not required.
- Possibly many more.
v3 -> v4:
- Bumped LWT_BPF_MAX_HEADROOM from 128 to 256 (Alexei)
- Renamed bpf_skb_push() helper to bpf_skb_change_head() to relate to
existing bpf_skb_change_tail() helper (Alexei/Daniel)
- Added check in __bpf_redirect_common() to verify that program added a
link header before redirecting to a l2 device. Adding the check to
lwt-bpf code was considered but dropped due to massive code required
due to retrieval of net_device via per-cpu redirect buffer. A test
case was added to cover the scenario when a program directs to an l2
device without adding an appropriate l2 header.
(Alexei)
- Prohibited access to tc_classid (Daniel)
- Collapsed bpf_verifier_ops instance for lwt in/out as they are
identical (Daniel)
- Some cosmetic changes
v2 -> v3:
- Added real world sample lwt_len_hist_kern.c which demonstrates how to
collect a histogram on packet sizes for all packets flowing through
a number of routes.
- Restricted output to be read-only. Since the header can no longer
be modified, the rerouting functionality has been removed again.
- Added test case which cover destructive modification of packet data.
v1 -> v2:
- Added new BPF_LWT_REROUTE return code for program to indicate
that new route lookup should be performed. Suggested by Tom.
- New sample to illustrate rerouting
- New patch 05: Recursion limit for lwtunnel_output for the case
when user creates circular dst redirection. Also resolves the
issue for ILA.
- Fix to ensure headroom for potential future L2 header is still
guaranteed
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Adds a series of tests to verify the functionality of attaching
BPF programs at LWT hooks.
Also adds a sample which collects a histogram of packet sizes which
pass through an LWT hook.
$ ./lwt_len_hist.sh
Starting netserver with host 'IN(6)ADDR_ANY' port '12865' and family AF_UNSPEC
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.253.2 () port 0 AF_INET : demo
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
87380 16384 16384 10.00 39857.69
1 -> 1 : 0 | |
2 -> 3 : 0 | |
4 -> 7 : 0 | |
8 -> 15 : 0 | |
16 -> 31 : 0 | |
32 -> 63 : 22 | |
64 -> 127 : 98 | |
128 -> 255 : 213 | |
256 -> 511 : 1444251 |******** |
512 -> 1023 : 660610 |*** |
1024 -> 2047 : 535241 |** |
2048 -> 4095 : 19 | |
4096 -> 8191 : 180 | |
8192 -> 16383 : 5578023 |************************************* |
16384 -> 32767 : 632099 |*** |
32768 -> 65535 : 6575 | |
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Registers new BPF program types which correspond to the LWT hooks:
- BPF_PROG_TYPE_LWT_IN => dst_input()
- BPF_PROG_TYPE_LWT_OUT => dst_output()
- BPF_PROG_TYPE_LWT_XMIT => lwtunnel_xmit()
The separate program types are required to differentiate between the
capabilities each LWT hook allows:
* Programs attached to dst_input() or dst_output() are restricted and
may only read the data of an skb. This prevent modification and
possible invalidation of already validated packet headers on receive
and the construction of illegal headers while the IP headers are
still being assembled.
* Programs attached to lwtunnel_xmit() are allowed to modify packet
content as well as prepending an L2 header via a newly introduced
helper bpf_skb_change_head(). This is safe as lwtunnel_xmit() is
invoked after the IP header has been assembled completely.
All BPF programs receive an skb with L3 headers attached and may return
one of the following error codes:
BPF_OK - Continue routing as per nexthop
BPF_DROP - Drop skb and return EPERM
BPF_REDIRECT - Redirect skb to device as per redirect() helper.
(Only valid in lwtunnel_xmit() context)
The return codes are binary compatible with their TC_ACT_
relatives to ease compatibility.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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A route on the output path hitting a RTN_LOCAL route will keep the dst
associated on its way through the loopback device. On the receive path,
the dst_input() call will thus invoke the input handler of the route
created in the output path. Thus, lwt redirection for input must be done
for dsts allocated in the otuput path as well.
Also, if a route is cached in the input path, the allocated dst should
respect lwtunnel configuration on the nexthop as well.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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orig_output for IPv4 was only set for dsts which hit an input route.
Set it consistently for locally generated traffic as well to allow
lwt to continue the dst_output() path as configured by the nexthop.
Fixes: 2536862311d ("lwt: Add support to redirect dst.input")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Saeed Mahameed says:
====================
Mellanox 100G mlx5 updates 2016-11-29
The following series from Tariq and Roi, provides some critical fixes
and updates for the mlx5e driver.
From Tariq:
- Fix driver coherent memory huge allocation issues by fragmenting
completion queues, in a way that is transparent to the netdev driver by
providing a new buffer type "mlx5_frag_buf" with the same access API.
- Create UMR MKey per RQ to have better scalability.
From Roi:
- Some fixes for the encap-decap support and tc flower added lately to the
mlx5e driver.
v1->v2:
- Fix start index in error flow of mlx5_frag_buf_alloc_node, pointed out by Eric.
This series was generated against commit:
31ac1c19455f ("geneve: fix ip_hdr_len reserved for geneve6 tunnel.")
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Handling flow encap entry should be inside tc del flow
and is only relevant for offloaded eswitch TC rules.
Fixes: 11a457e9b6c1 ("net/mlx5e: Add basic TC tunnel set action for SRIOV offloads")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Change the function that deletes offloaded TC rule to get
struct mlx5e_tc_flow instance which contains both the flow
handle and flow attributes. This is a cleanup needed for
downstream patches, it doesn't change any functionality.
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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According to the reverse unwinding principle, on delete time we should
first handle deletion of the steering rule and later handle the vlan
deletion from the eswitch.
Fixes: 8b32580df1cb ("net/mlx5e: Add TC vlan action for SRIOV offloads")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We will never find a flow with the same cookie as cls_flower always
allocates a new flow and the cookie is the allocated memory address.
Fixes: e3a2b7ed018e ("net/mlx5e: Support offload cls_flower with drop action")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In Striding RQ implementation, we used a single UMR
(User-Mode Memory Registration) memory key for all RQs.
When the product of RQs number*size gets high, we hit a
limitation of u16 field size in FW.
Here we move to using a UMR memory key per RQ, so we can
scale to any number of rings, with the maximum buffer
size in each.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In next patch we are going to create a UMR MKey per RQ, we need
mlx5e_create_umr_mkey declared before mlx5e_create_rq.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add new type of struct mlx5_frag_buf which is used to allocate fragmented
buffers rather than contiguous, and make the Completion Queues (CQs) use
it as they are big (default of 2MB per CQ in Striding RQ).
This fixes the failures of type:
"mlx5e_open_locked: mlx5e_open_channels failed, -12"
due to dma_zalloc_coherent insufficient contiguous coherent memory to
satisfy the driver's request when the user tries to setup more or larger
rings.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Johan Hovold says:
====================
net: stmmac: fix probe error handling and phydev leaks
This series fixes a number of issues with the stmmac-driver probe error
handling, which for example left clocks enabled after probe failures.
The final patch fixes a failure to deregister and free any fixed-link
PHYs that were registered during probe on probe errors and on driver
unbind. It also fixes a related of-node leak on late probe errors.
This series depends on the of_phy_deregister_fixed_link() helper that
was just merged to net.
As mentioned earlier, one staging driver also suffers from a similar
leak and can be fixed up once the above mentioned helper hits mainline.
Note that these patches have only been compile tested.
====================
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make sure to deregister and free any fixed-link phy registered during
probe on probe errors and on driver unbind by adding a new glue helper
function.
Drop the of-node reference taken in the same path also on late probe
errors (and not just on driver unbind) by moving the put from
stmmac_dvr_remove() to the new helper.
Fixes: 277323814e49 ("stmmac: add fixed-link device-tree support")
Fixes: 4613b279bee7 ("ethernet: stmicro: stmmac: add missing of_node_put
after calling of_parse_phandle")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Fix the OF-helper function header to reflect that the function no longer
has a platform-data parameter.
Fixes: b0003ead75f3 ("stmmac: make stmmac_probe_config_dt return the
platform data struct")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make sure to disable clocks before returning on late probe errors.
Fixes: 566e82516253 ("net: stmmac: add a glue driver for the Amlogic
Meson 8b / GXBB DWMAC")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make sure to call any exit() callback to undo the effect of init()
before returning on late probe errors.
Fixes: cf3f047b9af4 ("stmmac: move hw init in the probe (v2)")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make sure to disable runtime PM, power down the PHY, and disable clocks
before returning on late probe errors.
Fixes: 27ffefd2d109 ("stmmac: dwmac-rk: create a new probe function")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make sure to disable clocks before returning on late probe errors.
Fixes: 8387ee21f972 ("stmmac: dwmac-sti: turn setup callback into a
probe function")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make sure to call stmmac_dvr_remove() before returning on late probe
errors so that memory is freed, clocks are disabled, and the netdev is
deregistered before its resources go away.
Fixes: 3c201b5a84ed ("net: stmmac: socfpga: Remove re-registration of
reset controller")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Neill Whillans says:
====================
net: Add support for SGMII PCS on Altera TSE MAC
These patches were created as part of work to add support for SGMII
PCS functionality to the Altera TSE MAC. Patches are based on 4.9-rc6
git tree.
The first patch in the series adds support for the VSC8572 dual-port
Gigabit Ethernet transceiver, used in integration testing.
The second patch adds support for the SGMII PCS functionality to the
Altera TSE driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add support for the (optional) SGMII PCS functionality of the Altera
TSE MAC. If the phy-mode is set to 'sgmii' then we attempt to discover
and initialise the PCS so that the MAC can communicate to the PHY.
The PCS IP block provides a scratch register for testing presence of
the PCS, which is mapped into one of the two MDIO spaces present in
the MAC's register space. Once we have determined that the scratch
register is functioning, we attempt to initialise the PCS to
auto-negotiate an SGMII link with the PHY. There is no need to monitor
or manage the SGMII link beyond this, since the normal PHY MDIO will
then be used to monitor the media layer.
The Altera TSE MAC has only one way in which it can be configured with an
SGMII PCS, and as such, this patch only looks to the phy-mode to select
whether or not to attempt to initialise the PCS registers. During
initialisation, we report the PCS's equivalent of a PHY ID register.
This can be parameterised during the IP instantiation and is often left
as '0x00000000' which is not an error.
Signed-off-by: Neill Whillans <neill.whillans@codethink.co.uk>
Reviewed-by: Daniel Silverstone <daniel.silverstone@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add support for the Vitesse VSC8572 which is functionally equivalent to
the already supported VSC8574. As such, all the same handling functions
are used since the VSC8572 merely has half the number of phy blocks
internally.
Signed-off-by: Stephen Agate <stephen.agate@uk.thalesgroup.com>
Signed-off-by: Neill Whillans <neill.whillans@codethink.co.uk>
Reviewed-by: Daniel Silverstone <daniel.silverstone@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Use the correct attribute constant names IFLA_GSO_MAX_{SEGS,SIZE}
instead of IFLA_MAX_GSO_{SEGS,SIZE} for the comments int nlmsg_size().
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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rt_mutex_proxy_unlock()/init_proxy_locked()
While debugging the unlock vs. dequeue race which resulted in state
corruption of futexes the lockless nature of rt_mutex_proxy_unlock()
caused some confusion.
Add commentry to explain why it is safe to do this lockless. Add matching
comments to rt_mutex_init_proxy_locked() for completeness sake.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20161130210030.591941927@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This is a left over from the original rtmutex implementation which used
both bit0 and bit1 in the owner pointer. Commit:
8161239a8bcc ("rtmutex: Simplify PI algorithm and make highest prio task get lock")
... removed the usage of bit1, but kept the extra mask around. This is
confusing at best.
Remove it and just use RT_MUTEX_HAS_WAITERS for the masking.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20161130210030.509567906@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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While debugging the rtmutex unlock vs. dequeue race Will suggested to use
READ_ONCE() in rt_mutex_owner() as it might race against the
cmpxchg_release() in unlock_rt_mutex_safe().
Will: "It's a minor thing which will most likely not matter in practice"
Careful search did not unearth an actual problem in todays code, but it's
better to be safe than surprised.
Suggested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20161130210030.431379999@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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David reported a futex/rtmutex state corruption. It's caused by the
following problem:
CPU0 CPU1 CPU2
l->owner=T1
rt_mutex_lock(l)
lock(l->wait_lock)
l->owner = T1 | HAS_WAITERS;
enqueue(T2)
boost()
unlock(l->wait_lock)
schedule()
rt_mutex_lock(l)
lock(l->wait_lock)
l->owner = T1 | HAS_WAITERS;
enqueue(T3)
boost()
unlock(l->wait_lock)
schedule()
signal(->T2) signal(->T3)
lock(l->wait_lock)
dequeue(T2)
deboost()
unlock(l->wait_lock)
lock(l->wait_lock)
dequeue(T3)
===> wait list is now empty
deboost()
unlock(l->wait_lock)
lock(l->wait_lock)
fixup_rt_mutex_waiters()
if (wait_list_empty(l)) {
owner = l->owner & ~HAS_WAITERS;
l->owner = owner
==> l->owner = T1
}
lock(l->wait_lock)
rt_mutex_unlock(l) fixup_rt_mutex_waiters()
if (wait_list_empty(l)) {
owner = l->owner & ~HAS_WAITERS;
cmpxchg(l->owner, T1, NULL)
===> Success (l->owner = NULL)
l->owner = owner
==> l->owner = T1
}
That means the problem is caused by fixup_rt_mutex_waiters() which does the
RMW to clear the waiters bit unconditionally when there are no waiters in
the rtmutexes rbtree.
This can be fatal: A concurrent unlock can release the rtmutex in the
fastpath because the waiters bit is not set. If the cmpxchg() gets in the
middle of the RMW operation then the previous owner, which just unlocked
the rtmutex is set as the owner again when the write takes place after the
successfull cmpxchg().
The solution is rather trivial: verify that the owner member of the rtmutex
has the waiters bit set before clearing it. This does not require a
cmpxchg() or other atomic operations because the waiters bit can only be
set and cleared with the rtmutex wait_lock held. It's also safe against the
fast path unlock attempt. The unlock attempt via cmpxchg() will either see
the bit set and take the slowpath or see the bit cleared and release it
atomically in the fastpath.
It's remarkable that the test program provided by David triggers on ARM64
and MIPS64 really quick, but it refuses to reproduce on x86-64, while the
problem exists there as well. That refusal might explain that this got not
discovered earlier despite the bug existing from day one of the rtmutex
implementation more than 10 years ago.
Thanks to David for meticulously instrumenting the code and providing the
information which allowed to decode this subtle problem.
Reported-by: David Daney <ddaney@caviumnetworks.com>
Tested-by: David Daney <david.daney@cavium.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Fixes: 23f78d4a03c5 ("[PATCH] pi-futex: rt mutex core")
Link: http://lkml.kernel.org/r/20161130210030.351136722@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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batadv_tt_prepare_tvlv_local_data can fail to allocate the memory for the
new TVLV block. The caller is informed about this problem with the returned
length of 0. Not checking this value results in an invalid memory access
when either tt_data or tt_change is accessed.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Support AArch64 in the 'annotate' code, native/local and
cross-arch/remote (Kim Phillips)
- Allow considering just events in a given time interval, via the
'--time start.s.ms,end.s.ms' command line, added to 'perf kmem',
'perf report', 'perf sched timehist' and 'perf script' (David Ahern)
- Add option to stop printing a callchain at one of a given group of
symbol names (David Ahern)
- Handle CPU migration events in 'perf sched timehist' (David Ahern)
- Track memory freed in 'perf kmem stat' (David Ahern)
Infrastructure:
- Add initial support (and perf test entry) for tooling hooks, starting with
'record_start' and 'record_end', that will have as its initial user the
eBPF infrastructure, where perf_ prefixed functions will be JITed and
run when such hooks are called (Wang Nan)
- Remove redundant "test" and similar strings from 'perf test' descriptions
(Arnaldo Carvalho de Melo)
- Implement assorted libbpf improvements (Wang Nan)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI fixes from Bjorn Helgaas:
"PCI fixes:
- Fix Read Completion Boundary setting, which fixes a boot failure on
IBM x3850 with Mellanox MT27500 ConnectX-3
- Update some MAINTAINERS entries and email addresses"
* tag 'pci-v4.9-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX)
PCI: Export pcie_find_root_port
PCI: designware-plat: Update author email
PCI: designware: Change maintainer to Joao Pinto
MAINTAINERS: Add devicetree binding to PCI i.MX6 entry
MAINTAINERS: Update Richard Zhu's email address
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Install the callbacks via the state machine.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Scott Wood <oss@buserror.net>
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: rt@linutronix.de
Cc: Roy Pledge <roy.pledge@nxp.com>
Link: http://lkml.kernel.org/r/20161126231350.10321-21-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Scott Wood <oss@buserror.net>
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: rt@linutronix.de
Cc: Roy Pledge <roy.pledge@nxp.com>
Link: http://lkml.kernel.org/r/20161126231350.10321-20-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine with multi instance support and let
the core invoke the callbacks on the already online CPUs.
[bigeasy: wire up the multi instance stuff]
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: rt@linutronix.de
Cc: Nitin Gupta <ngupta@vflare.org>
Link: http://lkml.kernel.org/r/20161126231350.10321-19-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: kvm-ppc@vger.kernel.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: rt@linutronix.de
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alexander Graf <agraf@suse.com>
Link: http://lkml.kernel.org/r/20161126231350.10321-18-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: rt@linutronix.de
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20161126231350.10321-17-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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There is no requirement to keep the sysfs files around until the CPU is
completely dead. Remove them during the DOWN_PREPARE notification. This is
a preparatory patch for converting to the hotplug state machine.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: rt@linutronix.de
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20161126231350.10321-16-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine. Should the hotplug init fail then
no threads are spawned.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-mm@kvack.org
Cc: rt@linutronix.de
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20161126231350.10321-15-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org
Cc: rt@linutronix.de
Cc: David Woodhouse <dwmw2@infradead.org>
Link: http://lkml.kernel.org/r/20161126231350.10321-14-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine. Multi state is used to address the
per-pool notifier. Uppon adding of the intance the callback is invoked for all
online CPUs so the manual init can go.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-mm@kvack.org
Cc: Seth Jennings <sjenning@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161126231350.10321-13-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-mm@kvack.org
Cc: Seth Jennings <sjenning@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161126231350.10321-12-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-mm@kvack.org
Cc: Minchan Kim <minchan@kernel.org>
Cc: rt@linutronix.de
Cc: Nitin Gupta <ngupta@vflare.org>
Link: http://lkml.kernel.org/r/20161126231350.10321-11-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine, but do not invoke them as we
can initialize the node state without calling the callbacks on all online
CPUs.
start_shepherd_timer() is now called outside the get_online_cpus() block
which is safe as it only operates on cpu possible mask.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: rt@linutronix.de
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20161129145221.ffc3kg3hd7lxiwj6@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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