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138 Commits
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f2e2857b35 |
net: switchdev: Add a helper to replay objects on a bridge port
When a front panel joins a bridge via another netdevice (typically a LAG), the driver needs to learn about the objects configured on the bridge port. When the bridge port is offloaded by the driver for the first time, this can be achieved by passing a notifier to switchdev_bridge_port_offload(). The notifier is then invoked for the individual objects (such as VLANs) configured on the bridge, and can look for the interesting ones. Calling switchdev_bridge_port_offload() when the second port joins the bridge lower is unnecessary, but the replay is still needed. To that end, add a new function, switchdev_bridge_port_replay(), which does only the replay part of the _offload() function in exactly the same way as that function. Cc: Jiri Pirko <jiri@resnulli.us> Cc: Ivan Vecera <ivecera@redhat.com> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: Nikolay Aleksandrov <razor@blackwall.org> Cc: bridge@lists.linux-foundation.org Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Danielle Ratson <danieller@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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d62607c3fe |
net: rename reference+tracking helpers
Netdev reference helpers have a dev_ prefix for historic reasons. Renaming the old helpers would be too much churn but we can rename the tracking ones which are relatively recent and should be the default for new code. Rename: dev_hold_track() -> netdev_hold() dev_put_track() -> netdev_put() dev_replace_track() -> netdev_ref_replace() Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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ec638740fc |
net: switchdev: remove lag_mod_cb from switchdev_handle_fdb_event_to_device
When the switchdev_handle_fdb_event_to_device() event replication helper was created, my original thought was that FDB events on LAG interfaces should most likely be special-cased, not just replicated towards all switchdev ports beneath that LAG. So this replication helper currently does not recurse through switchdev lower interfaces of LAG bridge ports, but rather calls the lag_mod_cb() if that was provided. No switchdev driver uses this helper for FDB events on LAG interfaces yet, so that was an assumption which was yet to be tested. It is certainly usable for that purpose, as my RFC series shows: https://patchwork.kernel.org/project/netdevbpf/cover/20220210125201.2859463-1-vladimir.oltean@nxp.com/ however this approach is slightly convoluted because: - the switchdev driver gets a "dev" that isn't its own net device, but rather the LAG net device. It must call switchdev_lower_dev_find(dev) in order to get a handle of any of its own net devices (the ones that pass check_cb). - in order for FDB entries on LAG ports to be correctly refcounted per the number of switchdev ports beneath that LAG, we haven't escaped the need to iterate through the LAG's lower interfaces. Except that is now the responsibility of the switchdev driver, because the replication helper just stopped half-way. So, even though yes, FDB events on LAG bridge ports must be special-cased, in the end it's simpler to let switchdev_handle_fdb_* just iterate through the LAG port's switchdev lowers, and let the switchdev driver figure out that those physical ports are under a LAG. The switchdev_handle_fdb_event_to_device() helper takes a "foreign_dev_check" callback so it can figure out whether @dev can autonomously forward to @foreign_dev. DSA fills this method properly: if the LAG is offloaded by another port in the same tree as @dev, then it isn't foreign. If it is a software LAG, it is foreign - forwarding happens in software. Whether an interface is foreign or not decides whether the replication helper will go through the LAG's switchdev lowers or not. Since the lan966x doesn't properly fill this out, FDB events on software LAG uppers will get called. By changing lan966x_foreign_dev_check(), we can suppress them. Whereas DSA will now start receiving FDB events for its offloaded LAG uppers, so we need to return -EOPNOTSUPP, since we currently don't do the right thing for them. Cc: Horatiu Vultur <horatiu.vultur@microchip.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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acd8df5880 |
net: switchdev: avoid infinite recursion from LAG to bridge with port object handler
The logic from switchdev_handle_port_obj_add_foreign() is directly
adapted from switchdev_handle_fdb_event_to_device(), which already
detects events on foreign interfaces and reoffloads them towards the
switchdev neighbors.
However, when we have a simple br0 <-> bond0 <-> swp0 topology and the
switchdev_handle_port_obj_add_foreign() gets called on bond0, we get
stuck into an infinite recursion:
1. bond0 does not pass check_cb(), so we attempt to find switchdev
neighbor interfaces. For that, we recursively call
__switchdev_handle_port_obj_add() for bond0's bridge, br0.
2. __switchdev_handle_port_obj_add() recurses through br0's lowers,
essentially calling __switchdev_handle_port_obj_add() for bond0
3. Go to step 1.
This happens because switchdev_handle_fdb_event_to_device() and
switchdev_handle_port_obj_add_foreign() are not exactly the same.
The FDB event helper special-cases LAG interfaces with its lag_mod_cb(),
so this is why we don't end up in an infinite loop - because it doesn't
attempt to treat LAG interfaces as potentially foreign bridge ports.
The problem is solved by looking ahead through the bridge's lowers to
see whether there is any switchdev interface that is foreign to the @dev
we are currently processing. This stops the recursion described above at
step 1: __switchdev_handle_port_obj_add(bond0) will not create another
call to __switchdev_handle_port_obj_add(br0). Going one step upper
should only happen when we're starting from a bridge port that has been
determined to be "foreign" to the switchdev driver that passes the
foreign_dev_check_cb().
Fixes:
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c4076cdd21 |
net: switchdev: introduce switchdev_handle_port_obj_{add,del} for foreign interfaces
The switchdev_handle_port_obj_add() helper is good for replicating a
port object on the lower interfaces of @dev, if that object was emitted
on a bridge, or on a bridge port that is a LAG.
However, drivers that use this helper limit themselves to a box from
which they can no longer intercept port objects notified on neighbor
ports ("foreign interfaces").
One such driver is DSA, where software bridging with foreign interfaces
such as standalone NICs or Wi-Fi APs is an important use case. There, a
VLAN installed on a neighbor bridge port roughly corresponds to a
forwarding VLAN installed on the DSA switch's CPU port.
To support this use case while also making use of the benefits of the
switchdev_handle_* replication helper for port objects, introduce a new
variant of these functions that crawls through the neighbor ports of
@dev, in search of potentially compatible switchdev ports that are
interested in the event.
The strategy is identical to switchdev_handle_fdb_event_to_device():
if @dev wasn't a switchdev interface, then go one step upper, and
recursively call this function on the bridge that this port belongs to.
At the next recursion step, __switchdev_handle_port_obj_add() will
iterate through the bridge's lower interfaces. Among those, some will be
switchdev interfaces, and one will be the original @dev that we came
from. To prevent infinite recursion, we must suppress reentry into the
original @dev, and just call the @add_cb for the switchdev_interfaces.
It looks like this:
br0
/ | \
/ | \
/ | \
swp0 swp1 eth0
1. __switchdev_handle_port_obj_add(eth0)
-> check_cb(eth0) returns false
-> eth0 has no lower interfaces
-> eth0's bridge is br0
-> switchdev_lower_dev_find(br0, check_cb, foreign_dev_check_cb))
finds br0
2. __switchdev_handle_port_obj_add(br0)
-> check_cb(br0) returns false
-> netdev_for_each_lower_dev
-> check_cb(swp0) returns true, so we don't skip this interface
3. __switchdev_handle_port_obj_add(swp0)
-> check_cb(swp0) returns true, so we call add_cb(swp0)
(back to netdev_for_each_lower_dev from 2)
-> check_cb(swp1) returns true, so we don't skip this interface
4. __switchdev_handle_port_obj_add(swp1)
-> check_cb(swp1) returns true, so we call add_cb(swp1)
(back to netdev_for_each_lower_dev from 2)
-> check_cb(eth0) returns false, so we skip this interface to
avoid infinite recursion
Note: eth0 could have been a LAG, and we don't want to suppress the
recursion through its lowers if those exist, so when check_cb() returns
false, we still call switchdev_lower_dev_find() to estimate whether
there's anything worth a recursion beneath that LAG. Using check_cb()
and foreign_dev_check_cb(), switchdev_lower_dev_find() not only figures
out whether the lowers of the LAG are switchdev, but also whether they
actively offload the LAG or not (whether the LAG is "foreign" to the
switchdev interface or not).
The port_obj_info->orig_dev is preserved across recursive calls, so
switchdev drivers still know on which device was this notification
originally emitted.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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7b465f4cf3 |
net: switchdev: rename switchdev_lower_dev_find to switchdev_lower_dev_find_rcu
switchdev_lower_dev_find() assumes RCU read-side critical section calling context, since it uses netdev_walk_all_lower_dev_rcu(). Rename it appropriately, in preparation of adding a similar iterator that assumes writer-side rtnl_mutex protection. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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d8c2858181 |
net/switchdev: use struct_size over open coded arithmetic
Replace zero-length array with flexible-array member and make use
of the struct_size() helper in kmalloc(). For example:
struct switchdev_deferred_item {
...
unsigned long data[];
};
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
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4fc003fe03 |
net: switchdev: add net device refcount tracker
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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716a30a97a |
net: switchdev: merge switchdev_handle_fdb_{add,del}_to_device
To reduce code churn, the same patch makes multiple changes, since they all touch the same lines: 1. The implementations for these two are identical, just with different function pointers. Reduce duplications and name the function pointers "mod_cb" instead of "add_cb" and "del_cb". Pass the event as argument. 2. Drop the "const" attribute from "orig_dev". If the driver needs to check whether orig_dev belongs to itself and then call_switchdev_notifiers(orig_dev, SWITCHDEV_FDB_OFFLOADED), it can't, because call_switchdev_notifiers takes a non-const struct net_device *. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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957e2235e5 |
net: make switchdev_bridge_port_{,unoffload} loosely coupled with the bridge
With the introduction of explicit offloading API in switchdev in commit |
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2b0a568849 |
net: switchdev: fix FDB entries towards foreign ports not getting propagated to us
The newly introduced switchdev_handle_fdb_{add,del}_to_device helpers
solved a problem but introduced another one. They have a severe design
bug: they do not propagate FDB events on foreign interfaces to us, i.e.
this use case:
br0
/ \
/ \
/ \
/ \
swp0 eno0
(switchdev) (foreign)
when an address is learned on eno0, what is supposed to happen is that
this event should also be propagated towards swp0. Somehow I managed to
convince myself that this did work correctly, but obviously it does not.
The trouble with foreign interfaces is that we must reach a switchdev
net_device pointer through a foreign net_device that has no direct
upper/lower relationship with it. So we need to do exploratory searching
through the lower interfaces of the foreign net_device's bridge upper
(to reach swp0 from eno0, we must check its upper, br0, for lower
interfaces that pass the check_cb and foreign_dev_check_cb). This is
something that the previous code did not do, it just assumed that "dev"
will become a switchdev interface at some point, somehow, probably by
magic.
With this patch, assisted address learning on the CPU port works again
in DSA:
ip link add br0 type bridge
ip link set swp0 master br0
ip link set eno0 master br0
ip link set br0 up
[ 46.708929] mscc_felix 0000:00:00.5 swp0: Adding FDB entry towards eno0, addr 00:04:9f:05:f4:ab vid 0 as host address
Fixes:
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71f4f89a03 |
net: switchdev: recurse into __switchdev_handle_fdb_del_to_device
The difference between __switchdev_handle_fdb_del_to_device and
switchdev_handle_del_to_device is that the former takes an extra
orig_dev argument, while the latter starts with dev == orig_dev.
We should recurse into the variant that does not lose the orig_dev along
the way. This is relevant when deleting FDB entries pointing towards a
bridge (dev changes to the lower interfaces, but orig_dev shouldn't).
The addition helper already recurses properly, just the deletion one
doesn't.
Fixes:
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8ca07176ab |
net: switchdev: introduce a fanout helper for SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE
Currently DSA has an issue with FDB entries pointing towards the bridge
in the presence of br_fdb_replay() being called at port join and leave
time.
In particular, each bridge port will ask for a replay for the FDB
entries pointing towards the bridge when it joins, and for another
replay when it leaves.
This means that for example, a bridge with 4 switch ports will notify
DSA 4 times of the bridge MAC address.
But if the MAC address of the bridge changes during the normal runtime
of the system, the bridge notifies switchdev [ once ] of the deletion of
the old MAC address as a local FDB towards the bridge, and of the
insertion [ again once ] of the new MAC address as a local FDB.
This is a problem, because DSA keeps the old MAC address as a host FDB
entry with refcount 4 (4 ports asked for it using br_fdb_replay). So the
old MAC address will not be deleted. Additionally, the new MAC address
will only be installed with refcount 1, and when the first switch port
leaves the bridge (leaving 3 others as still members), it will delete
with it the new MAC address of the bridge from the local FDB entries
kept by DSA (because the br_fdb_replay call on deletion will bring the
entry's refcount from 1 to 0).
So the problem, really, is that the number of br_fdb_replay() calls is
not matched with the refcount that a host FDB is offloaded to DSA during
normal runtime.
An elegant way to solve the problem would be to make the switchdev
notification emitted by br_fdb_change_mac_address() result in a host FDB
kept by DSA which has a refcount exactly equal to the number of ports
under that bridge. Then, no matter how many DSA ports join or leave that
bridge, the host FDB entry will always be deleted when there are exactly
zero remaining DSA switch ports members of the bridge.
To implement the proposed solution, we remember that the switchdev
objects and port attributes have some helpers provided by switchdev,
which can be optionally called by drivers:
switchdev_handle_port_obj_{add,del} and switchdev_handle_port_attr_set.
These helpers:
- fan out a switchdev object/attribute emitted for the bridge towards
all the lower interfaces that pass the check_cb().
- fan out a switchdev object/attribute emitted for a bridge port that is
a LAG towards all the lower interfaces that pass the check_cb().
In other words, this is the model we need for the FDB events too:
something that will keep an FDB entry emitted towards a physical port as
it is, but translate an FDB entry emitted towards the bridge into N FDB
entries, one per physical port.
Of course, there are many differences between fanning out a switchdev
object (VLAN) on 3 lower interfaces of a LAG and fanning out an FDB
entry on 3 lower interfaces of a LAG. Intuitively, an FDB entry towards
a LAG should be treated specially, because FDB entries are unicast, we
can't just install the same address towards 3 destinations. It is
imaginable that drivers might want to treat this case specifically, so
create some methods for this case and do not recurse into the LAG lower
ports, just the bridge ports.
DSA also listens for FDB entries on "foreign" interfaces, aka interfaces
bridged with us which are not part of our hardware domain: think an
Ethernet switch bridged with a Wi-Fi AP. For those addresses, DSA
installs host FDB entries. However, there we have the same problem
(those host FDB entries are installed with a refcount of only 1) and an
even bigger one which we did not have with FDB entries towards the
bridge:
br_fdb_replay() is currently not called for FDB entries on foreign
interfaces, just for the physical port and for the bridge itself.
So when DSA sniffs an address learned by the software bridge towards a
foreign interface like an e1000 port, and then that e1000 leaves the
bridge, DSA remains with the dangling host FDB address. That will be
fixed separately by replaying all FDB entries and not just the ones
towards the port and the bridge.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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69bfac968a |
net: switchdev: add a context void pointer to struct switchdev_notifier_info
In the case where the driver asks for a replay of a certain type of event (port object or attribute) for a bridge port that is a LAG, it may do so because this port has just joined the LAG. But there might already be other switchdev ports in that LAG, and it is preferable that those preexisting switchdev ports do not act upon the replayed event. The solution is to add a context to switchdev events, which is NULL most of the time (when the bridge layer initiates the call) but which can be set to a value controlled by the switchdev driver when a replay is requested. The driver can then check the context to figure out if all ports within the LAG should act upon the switchdev event, or just the ones that match the context. We have to modify all switchdev_handle_* helper functions as well as the prototypes in the drivers that use these helpers too, because these helpers hide the underlying struct switchdev_notifier_info from us and there is no way to retrieve the context otherwise. The context structure will be populated and used in later patches. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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dcbdf1350e |
net: bridge: propagate extack through switchdev_port_attr_set
The benefit is the ability to propagate errors from switchdev drivers for the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING and SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL attributes. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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4c08c586ff |
net: switchdev: propagate extack to port attributes
When a struct switchdev_attr is notified through switchdev, there is no way to report informational messages, unlike for struct switchdev_obj. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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c358f95205 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/can/dev.c |
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20776b465c |
net: switchdev: don't set port_obj_info->handled true when -EOPNOTSUPP
It's not true that switchdev_port_obj_notify() only inspects the ->handled field of "struct switchdev_notifier_port_obj_info" if call_switchdev_blocking_notifiers() returns 0 - there's a WARN_ON() triggering for a non-zero return combined with ->handled not being true. But the real problem here is that -EOPNOTSUPP is not being properly handled. The wrapper functions switchdev_handle_port_obj_add() et al change a return value of -EOPNOTSUPP to 0, and the treatment of ->handled in switchdev_port_obj_notify() seems to be designed to change that back to -EOPNOTSUPP in case nobody actually acted on the notifier (i.e., everybody returned -EOPNOTSUPP). Currently, as soon as some device down the stack passes the check_cb() check, ->handled gets set to true, which means that switchdev_port_obj_notify() cannot actually ever return -EOPNOTSUPP. This, for example, means that the detection of hardware offload support in the MRP code is broken: switchdev_port_obj_add() used by br_mrp_switchdev_send_ring_test() always returns 0, so since the MRP code thinks the generation of MRP test frames has been offloaded, no such frames are actually put on the wire. Similarly, br_mrp_switchdev_set_ring_role() also always returns 0, causing mrp->ring_role_offloaded to be set to 1. To fix this, continue to set ->handled true if any callback returns success or any error distinct from -EOPNOTSUPP. But if all the callbacks return -EOPNOTSUPP, make sure that ->handled stays false, so the logic in switchdev_port_obj_notify() can propagate that information. Fixes: |
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bae33f2b5a |
net: switchdev: remove the transaction structure from port attributes
Since the introduction of the switchdev API, port attributes were transmitted to drivers for offloading using a two-step transactional model, with a prepare phase that was supposed to catch all errors, and a commit phase that was supposed to never fail. Some classes of failures can never be avoided, like hardware access, or memory allocation. In the latter case, merely attempting to move the memory allocation to the preparation phase makes it impossible to avoid memory leaks, since commit |
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cf6def51ba |
net: switchdev: delete switchdev_port_obj_add_now
After the removal of the transactional model inside switchdev_port_obj_add_now, it has no added value and we can just call switchdev_port_obj_notify directly, bypassing this function. Let's delete it. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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ffb68fc58e |
net: switchdev: remove the transaction structure from port object notifiers
Since the introduction of the switchdev API, port objects were
transmitted to drivers for offloading using a two-step transactional
model, with a prepare phase that was supposed to catch all errors, and a
commit phase that was supposed to never fail.
Some classes of failures can never be avoided, like hardware access, or
memory allocation. In the latter case, merely attempting to move the
memory allocation to the preparation phase makes it impossible to avoid
memory leaks, since commit
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ea6754aef2 |
net: switchdev: Fixed kerneldoc warning
Update kernel-doc line comments to fix warnings reported by make W=1. net/switchdev/switchdev.c:413: warning: Function parameter or member 'extack' not described in 'call_switchdev_notifiers' Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Acked-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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c8af73f0b2 |
net: switchdev: kerneldoc fixes
Simple fixes which require no deep knowledge of the code. Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> |
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07c6f9805f |
net: switchdev: do not propagate bridge updates across bridges
When configuring a tree of independent bridges, propagating changes from the upper bridge across a bridge master to the lower bridge ports brings surprises. For example, a lower bridge may have vlan filtering enabled. It may have a vlan interface attached to the bridge master, which may then be incorporated into another bridge. As soon as the lower bridge vlan interface is attached to the upper bridge, the lower bridge has vlan filtering disabled. This occurs because switchdev recursively applies its changes to all lower devices no matter what. Reviewed-by: Ido Schimmel <idosch@mellanox.com> Tested-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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fbfc8502af |
net: switchdev: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit
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