Unifies adjusted and unadjusted register value types (e.g. FRAME_POINTER is
now just a PTR_TO_STACK with zero offset).
Tracks value alignment by means of tracking known & unknown bits. This
also replaces the 'reg->imm' (leading zero bits) calculations for (what
were) UNKNOWN_VALUEs.
If pointer leaks are allowed, and adjust_ptr_min_max_vals returns -EACCES,
treat the pointer as an unknown scalar and try again, because we might be
able to conclude something about the result (e.g. pointer & 0x40 is either
0 or 0x40).
Verifier hooks in the netronome/nfp driver were changed to match the new
data structures.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Fix checkpatch.pl error:
ERROR: space prohibited before open square bracket '['.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by <linux/usb.h> work with
const usb_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add extack error messages for failure paths creating vrf devices. Once
extack support is added to iproute2, we go from the unhelpful:
$ ip li add foobar type vrf
RTNETLINK answers: Invalid argument
to:
$ ip li add foobar type vrf
Error: VRF table id is missing
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Declare this structure as const as it is only used during a copy
operation.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Arkadi Sharshevsky says:
====================
Update DSA's FDB API and perform switchdev cleanup
The patchset adds support for configuring static FDB entries via the
switchdev notification chain. The current method for FDB configuration
uses the switchdev's bridge bypass implementation. In order to support
this legacy way and to perform the switchdev cleanup, the implementation
is moved inside DSA.
The DSA drivers cannot sync the software bridge with hardware learned
entries and use the switchdev's implementation of bypass FDB dumping.
Because they are the only ones using this functionality, the fdb_dump
implementation is moved from switchdev code into DSA.
Finally after this changes a major cleanup in switchdev can be done.
Please see individual patches for patch specific change logs.
v1->v2
- Split MDB/vlan dump removal into core/driver removal.
v2->v3
- The self implementation for FDB add/del is moved inside DSA.
====================
Tested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the bridge port flags, vlans, FDBs and MDBs can be offloaded
through the bridge code, making the switchdev's SELF bridge bypass
implementation to be redundant. This implies several changes:
- No need for dump infra in switchdev, DSA's special case is handled
privately.
- Remove obj_dump from switchdev_ops.
- FDBs are removed from obj_add/del routines, due to the fact that they
are offloaded through the bridge notification chain.
- The switchdev_port_bridge_xx() and switchdev_port_fdb_xx() functions
can be removed.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
At this point no driver supports FDB add/del through switchdev object
but rather via notification chain, thus, it is removed.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
>From all switchdev devices only DSA requires special FDB dump. This is due
to lack of ability for syncing the hardware learned FDBs with the bridge.
Due to this it is removed from switchdev and moved inside DSA.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the MDB HW database is synced with the bridge's one, thus,
There is no need to support special dump functionality.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is done as a preparation before removing support for MDB dump from
DSA core. The MDBs are synced with the bridge and thus there is no
need for special dump operation support.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridge port attributes/vlan for DSA devices should be set only
from bridge code. Furthermore, The vlans are synced totally with the
bridge so there is no need for special dump support.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is done as a preparation before removing support for vlan dump from
DSA core. The vlans are synced with the bridge and thus there is no
need for special dump operation support.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The DSA drivers do not support bridge flags offload. Yet, this attribute
should be added in order for the bridge to fail when one tries set a
flag on the port, as explained in commit dc0ecabd62 ("net: switchdev:
Add support for querying supported bridge flags by hardware").
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently DSA uses switchdev's implementation of FDB add/del ndos. This
patch moves the implementation inside DSA in order to support the legacy
way for static FDB configuration.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for learning FDB through notification. The driver defers
the hardware update via ordered work queue. In case of a successful
FDB add a notification is sent back to bridge.
In case of hw FDB del failure the static FDB will be deleted from
the bridge, thus, the interface is moved to down state in order to
indicate inconsistent situation.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, the switchdev objects are embedded inside the DSA notifier
info. This patch removes this dependency. This is done as a preparation
stage before adding support for learning FDB through the switchdev
notification chain.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The prepare phase for FDB add is unneeded because most of DSA devices
can have failures during bus transactions (SPI, I2C, etc.), thus, the
prepare phase cannot guarantee success of the commit stage.
The support for learning FDB through notification chain, which will be
introduced in the following patches, will provide the ability to notify
back the bridge about successful offload.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to support FDB add/del to be on a notifier chain the slave
API need to be changed to be switchdev independent.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make hdlcdrv_ops structures const as they are only passed to
hdlcdrv_register function. The corresponding argument is of type const,
so make the structures const.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Quoting Ilan Tayari:
1. Set up a host-to-host IPSec tunnel (or transport, doesn't matter)
2. Ping over IPSec, or do something to populate the pcpu cache
3. Join a MC group, then leave MC group
4. Try to ping again using same CPU as before -> traffic
doesn't egress the machine at all
Ilan debugged the problem down to the fact that one of the path dsts
devices point to lo due to earlier dst_dev_put().
In this case, dst is marked as DEAD and we cannot reuse the bundle.
The cache only asserted that the requested policy and that of the cached
bundle match, but its not enough - also verify the path is still valid.
Fixes: ec30d78c14 ("xfrm: add xdst pcpu cache")
Reported-by: Ayham Masood <ayhamm@mellanox.com>
Tested-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vivien Didelot says:
====================
net: dsa: remove useless arguments
Several DSA core setup functions take many arguments, mostly because of
the legacy code. This patch series removes the useless args of these
functions, where either the dsa_switch or dsa_port argument is enough.
Changes in v2:
- ds->dev is already assigned by dsa_switch_alloc
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
dsa_slave_create currently takes 4 arguments while it only needs the
related dsa_port and its name. Remove all other arguments.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dsa_cpu_dsa_setup currently takes 4 arguments but they are all available
from the dsa_port argument. Remove all others.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dsa_switch_alloc() already assigns ds-dev, which can be used in
dsa_switch_setup_one and dsa_cpu_dsa_setups instead of requiring an
additional struct device argument.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trivial fix to spelling mistake in dev_err error message and also
split overly long line to avoid a checkpatch warning.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Egil Hjelmeland says:
====================
Refactor lan9303_xxx_packet_processing
This series is purely non functional.
It changes the lan9303_enable_packet_processing,
lan9303_disable_packet_processing() to pass port number (0,1,2) as
parameter instead of port offset. This aligns them with
other functions in the module, and makes it possible to simplify the code.
The lan9303_enable_packet_processing, lan9303_disable_packet_processing
functions operate on port. Therefore rename the functions to reflect that
as well.
Reviewer pointed out lan9303_get_ethtool_stats would be better off with
the use of a lan9303_read_switch_port(). So that was added to the series.
Changes v3 -> v4:
- Whitespace adjustments.
Changes v2 -> v3:
- Patch 1: Removed the change in lan9303_get_ethtool_stats
- Added patch 4: rename lan9303_xxx_packet_processing
- Added patch 5: refactor lan9303_get_ethtool_stats
Changes v1 -> v2:
- introduced lan9303_write_switch_port() in first patch
- inserted LAN9303_NUM_PORTS patch
- Use LAN9303_NUM_PORTS in last patch. Plus whitespace change.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In lan9303_get_ethtool_stats: Get rid of 0x400 constant magic
by using new lan9303_read_switch_reg() inside loop.
Reduced scope of two variables.
Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The lan9303_enable_packet_processing, lan9303_disable_packet_processing
functions operate on port, so the names should reflect that.
And to align with lan9303_disable_processing(), rename:
lan9303_enable_packet_processing -> lan9303_enable_processing_port
lan9303_disable_packet_processing -> lan9303_disable_processing_port
Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Simplify usage of lan9303_enable_packet_processing,
lan9303_disable_packet_processing()
Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Will be used instead of '3' in upcomming patches.
Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lan9303_enable_packet_processing, lan9303_disable_packet_processing()
Pass port number (0,1,2) as parameter instead of port offset.
Because other functions in the module pass port numbers.
And to enable simplifications in following patch.
Introduce lan9303_write_switch_port().
Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David Lebrun says:
====================
ipv6: sr: add support for advanced local segment processing
v2: use EXPORT_SYMBOL_GPL
The current implementation of IPv6 SR supports SRH insertion/encapsulation
and basic segment endpoint behavior (i.e., processing of an SRH contained in
a packet whose active segment (IPv6 DA) is routed to the local node). This
behavior simply consists of updating the DA to the next segment and forwarding
the packet accordingly. This processing is realised for all such packets,
regardless of the active segment.
The most recent specifications of IPv6 SR [1] [2] extend the SRH processing
features as follows. Each segment endpoint defines a MyLocalSID table.
This table maps segments to operations to perform. For each ingress IPv6
packet whose DA is part of a given prefix, the segment endpoint looks
up the active segment (i.e., the IPv6 DA) in the MyLocalSID table and
applies the corresponding operation. Such specifications enable to specify
arbitrary operations besides the basic SRH processing and allow for a more
fine-grained classification.
This patch series implements those extended specifications by leveraging
a new type of lightweight tunnel, seg6local. The MyLocalSID table is
simply an arbitrary routing table (using CONFIG_IPV6_MULTIPLE_TABLES). The
following commands would assign the prefix fc00::/64 to the MyLocalSID
table, map the segment fc00::42 to the regular SRH processing function
(named "End"), and drop all packets received with an undefined active
segment:
ip -6 rule add fc00::/64 lookup 100
ip -6 route add fc00::42 encap seg6local action End dev eth0 table 100
ip -6 route add blackhole default table 100
As another example, the following command would assign the segment
fc00::1234 to the regular SRH processing function, except that the
processed packet must be forwarded to the next-hop fc42::1 (this operation
is named "End.X"):
ip -6 route add fc00::1234 encap seg6local action End.X nh6 fc42::1 dev eth0 table 100
Those two basic operations (End and End.X) are defined in [1]. A more
extensive list of advanced operations is defined in [2].
The first two patches of the series are preliminary work that remove an
assumption about initial SRH format, and export the two functions used to
insert and encapsulate an SRH onto packets. The third patch defines the
new seg6local lightweight tunnel and implement the core functions. The
fourth patch implements the operations needed to handle the newly defined
rtnetlink attributes. The fifth patch implements a few SRH processing
operations, including End and End.X.
[1] https://tools.ietf.org/html/draft-ietf-6man-segment-routing-header-07
[2] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements the following seg6local actions.
- SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet
is updated to the next segment and forwarded accordingly.
- SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is
forwarded to the specified IPv6 next-hop.
- SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to
inner IPv6 packet to the specified IPv6 next-hop.
- SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after
the IPv6 header of the packet.
- SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within
an outer IPv6 header, containing the specified SRH.
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the necessary functions to parse, fill, and compare
seg6local rtnetlink attributes, for all defined action parameters.
- The SRH parameter defines an SRH to be inserted or encapsulated.
- The TABLE parameter defines the table to use for the route lookup of
the next segment or the inner decapsulated packet.
- The NH4 parameter defines the IPv4 next-hop for an inner decapsulated
IPv4 packet.
- The NH6 parameter defines the IPv6 next-hop for the next segment or
for an inner decapsulated IPv6 packet
- The IIF parameter defines an ingress interface index.
- The OIF parameter defines an egress interface index.
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements a new type of lightweight tunnel named seg6local.
A seg6local lwt is defined by a type of action and a set of parameters.
The action represents the operation to perform on the packets matching the
lwt's route, and is not necessarily an encapsulation. The set of parameters
are arguments for the processing function.
Each action is defined in a struct seg6_action_desc within
seg6_action_table[]. This structure contains the action, mandatory
attributes, the processing function, and a static headroom size required by
the action. The mandatory attributes are encoded as a bitmask field. The
static headroom is set to a non-zero value when the processing function
always add a constant number of bytes to the skb (e.g. the header size for
encapsulations).
To facilitate rtnetlink-related operations such as parsing, fill_encap,
and cmp_encap, each type of action parameter is associated to three
function pointers, in seg6_action_params[].
All actions defined in seg6_local.h are detailed in [1].
[1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch exports the seg6_do_srh_encap() and seg6_do_srh_inline()
functions. It also removes the CONFIG_IPV6_SEG6_INLINE knob
that enabled the compilation of seg6_do_srh_inline(). This function
is now built-in.
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
The seg6_validate_srh() function only allows SRHs whose active segment is
the first segment of the path. However, an application may insert an SRH
whose active segment is not the first one. Such an application might be
for example an SR-aware Virtual Network Function.
This patch enables to insert SRHs with an arbitrary active segment.
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Originally we used a mutex to protect concurrent devmap update
and delete operations from racing with netdev unregister notifier
callbacks.
The notifier hook is needed because we increment the netdev ref
count when a dev is added to the devmap. This ensures the netdev
reference is valid in the datapath. However, we don't want to block
unregister events, hence the initial mutex and notifier handler.
The concern was in the notifier hook we search the map for dev
entries that hold a refcnt on the net device being torn down. But,
in order to do this we require two steps,
(i) dereference the netdev: dev = rcu_dereference(map[i])
(ii) test ifindex: dev->ifindex == removing_ifindex
and then finally we can swap in the NULL dev in the map via an
xchg operation,
xchg(map[i], NULL)
The danger here is a concurrent update could run a different
xchg op concurrently leading us to replace the new dev with a
NULL dev incorrectly.
CPU 1 CPU 2
notifier hook bpf devmap update
dev = rcu_dereference(map[i])
dev = rcu_dereference(map[i])
xchg(map[i]), new_dev);
rcu_call(dev,...)
xchg(map[i], NULL)
The above flow would create the incorrect state with the dev
reference in the update path being lost. To resolve this the
original code used a mutex around the above block. However,
updates, deletes, and lookups occur inside rcu critical sections
so we can't use a mutex in this context safely.
Fortunately, by writing slightly better code we can avoid the
mutex altogether. If CPU 1 in the above example uses a cmpxchg
and _only_ replaces the dev reference in the map when it is in
fact the expected dev the race is removed completely. The two
cases being illustrated here, first the race condition,
CPU 1 CPU 2
notifier hook bpf devmap update
dev = rcu_dereference(map[i])
dev = rcu_dereference(map[i])
xchg(map[i]), new_dev);
rcu_call(dev,...)
odev = cmpxchg(map[i], dev, NULL)
Now we can test the cmpxchg return value, detect odev != dev and
abort. Or in the good case,
CPU 1 CPU 2
notifier hook bpf devmap update
dev = rcu_dereference(map[i])
odev = cmpxchg(map[i], dev, NULL)
[...]
Now 'odev == dev' and we can do proper cleanup.
And viola the original race we tried to solve with a mutex is
corrected and the trace noted by Sasha below is resolved due
to removal of the mutex.
Note: When walking the devmap and removing dev references as needed
we depend on the core to fail any calls to dev_get_by_index() using
the ifindex of the device being removed. This way we do not race with
the user while searching the devmap.
Additionally, the mutex was also protecting list add/del/read on
the list of maps in-use. This patch converts this to an RCU list
and spinlock implementation. This protects the list from concurrent
alloc/free operations. The notifier hook walks this list so it uses
RCU read semantics.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747
in_atomic(): 1, irqs_disabled(): 0, pid: 16315, name: syz-executor1
1 lock held by syz-executor1/16315:
#0: (rcu_read_lock){......}, at: [<ffffffff8c363bc2>] map_delete_elem kernel/bpf/syscall.c:577 [inline]
#0: (rcu_read_lock){......}, at: [<ffffffff8c363bc2>] SYSC_bpf kernel/bpf/syscall.c:1427 [inline]
#0: (rcu_read_lock){......}, at: [<ffffffff8c363bc2>] SyS_bpf+0x1d32/0x4ba0 kernel/bpf/syscall.c:1388
Fixes: 2ddf71e23c ("net: add notifier hooks for devmap bpf map")
Reported-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cong Wang says:
====================
net_sched: clean up filter handle
This patchset sits in my local branch for a long time, it is time to
send it out. It cleans up the ambiguous use of 'unsigned long fh',
please see each of them for details.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Edward Cree