kernel/include/net/pkt_sched.h, branch linux-5.11.y

net: sched: convert tasklets to use new tasklet_setup() API

2020-11-07T18:41:15Z

In preparation for unconditionally passing the struct tasklet_struct pointer to all tasklet callbacks, switch to using the new tasklet_setup() and from_tasklet() to pass the tasklet pointer explicitly. Signed-off-by: Romain Perier Signed-off-by: Allen Pais Signed-off-by: Jakub Kicinski

net/sched: get rid of qdisc->padded

2020-10-09T15:08:08Z

kmalloc() of sufficiently big portion of memory is cache-aligned in regular conditions. If some debugging options are used, there is no reason qdisc structures would need 64-byte alignment if most other kernel structures are not aligned. This get rid of QDISC_ALIGN and QDISC_ALIGNTO. Addition of privdata field will help implementing the reverse of qdisc_priv() and documents where the private data is. Signed-off-by: Eric Dumazet Cc: Allen Pais Acked-by: Cong Wang Signed-off-by: Jakub Kicinski

sched: consistently handle layer3 header accesses in the presence of VLANs

2020-07-03T21:34:53Z

There are a couple of places in net/sched/ that check skb->protocol and act on the value there. However, in the presence of VLAN tags, the value stored in skb->protocol can be inconsistent based on whether VLAN acceleration is enabled. The commit quoted in the Fixes tag below fixed the users of skb->protocol to use a helper that will always see the VLAN ethertype. However, most of the callers don't actually handle the VLAN ethertype, but expect to find the IP header type in the protocol field. This means that things like changing the ECN field, or parsing diffserv values, stops working if there's a VLAN tag, or if there are multiple nested VLAN tags (QinQ). To fix this, change the helper to take an argument that indicates whether the caller wants to skip the VLAN tags or not. When skipping VLAN tags, we make sure to skip all of them, so behaviour is consistent even in QinQ mode. To make the helper usable from the ECN code, move it to if_vlan.h instead of pkt_sched.h. v3: - Remove empty lines - Move vlan variable definitions inside loop in skb_protocol() - Also use skb_protocol() helper in IP{,6}_ECN_decapsulate() and bpf_skb_ecn_set_ce() v2: - Use eth_type_vlan() helper in skb_protocol() - Also fix code that reads skb->protocol directly - Change a couple of 'if/else if' statements to switch constructs to avoid calling the helper twice Reported-by: Ilya Ponetayev Fixes: d8b9605d2697 ("net: sched: fix skb->protocol use in case of accelerated vlan path") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller

net_sched: add qdisc_watchdog_schedule_range_ns()

2020-03-18T04:16:34Z

Some packet schedulers might want to add a slack when programming hrtimers. This can reduce number of interrupts and increase batch sizes and thus give good xmit_more savings. This commit adds qdisc_watchdog_schedule_range_ns() helper, with an extra delta_ns parameter. Legacy qdisc_watchdog_schedule_n() becomes an inline passing a zero slack. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: sched: Replace zero-length array with flexible-array member

2020-03-01T05:27:02Z

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 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller

Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net

2019-09-17T21:51:10Z

Pull in bug fixes from 'net' tree for the merge window. Signed-off-by: David S. Miller

taprio: Add support for hardware offloading

2019-09-16T19:32:57Z

This allows taprio to offload the schedule enforcement to capable network cards, resulting in more precise windows and less CPU usage. The gate mask acts on traffic classes (groups of queues of same priority), as specified in IEEE 802.1Q-2018, and following the existing taprio and mqprio semantics. It is up to the driver to perform conversion between tc and individual netdev queues if for some reason it needs to make that distinction. Full offload is requested from the network interface by specifying "flags 2" in the tc qdisc creation command, which in turn corresponds to the TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD bit. The important detail here is the clockid which is implicitly /dev/ptpN for full offload, and hence not configurable. A reference counting API is added to support the use case where Ethernet drivers need to keep the taprio offload structure locally (i.e. they are a multi-port switch driver, and configuring a port depends on the settings of other ports as well). The refcount_t variable is kept in a private structure (__tc_taprio_qopt_offload) and not exposed to drivers. In the future, the private structure might also be expanded with a backpointer to taprio_sched *q, to implement the notification system described in the patch (of when admin became oper, or an error occurred, etc, so the offload can be monitored with 'tc qdisc show'). Signed-off-by: Vinicius Costa Gomes Signed-off-by: Voon Weifeng Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net/sched: fix race between deactivation and dequeue for NOLOCK qdisc

2019-09-15T18:35:55Z

The test implemented by some_qdisc_is_busy() is somewhat loosy for NOLOCK qdisc, as we may hit the following scenario: CPU1 CPU2 // in net_tx_action() clear_bit(__QDISC_STATE_SCHED...); // in some_qdisc_is_busy() val = (qdisc_is_running(q) || test_bit(__QDISC_STATE_SCHED, &q->state)); // here val is 0 but... qdisc_run(q) // ... CPU1 is going to run the qdisc next As a conseguence qdisc_run() in net_tx_action() can race with qdisc_reset() in dev_qdisc_reset(). Such race is not possible for !NOLOCK qdisc as both the above bit operations are under the root qdisc lock(). After commit 021a17ed796b ("pfifo_fast: drop unneeded additional lock on dequeue") the race can cause use after free and/or null ptr dereference, but the root cause is likely older. This patch addresses the issue explicitly checking for deactivation under the seqlock for NOLOCK qdisc, so that the qdisc_run() in the critical scenario becomes a no-op. Note that the enqueue() op can still execute concurrently with dev_qdisc_reset(), but that is safe due to the skb_array() locking, and we can't avoid that for NOLOCK qdiscs. Fixes: 021a17ed796b ("pfifo_fast: drop unneeded additional lock on dequeue") Reported-by: Li Shuang Reported-and-tested-by: Davide Caratti Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

net: sched: extend Qdisc with rcu

2018-09-26T03:17:35Z

Currently, Qdisc API functions assume that users have rtnl lock taken. To implement rtnl unlocked classifiers update interface, Qdisc API must be extended with functions that do not require rtnl lock. Extend Qdisc structure with rcu. Implement special version of put function qdisc_put_unlocked() that is called without rtnl lock taken. This function only takes rtnl lock if Qdisc reference counter reached zero and is intended to be used as optimization. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller

net/sched: Add HW offloading capability to ETF

2018-07-04T13:30:27Z

Add infra so etf qdisc supports HW offload of time-based transmission. For hw offload, the time sorted list is still used, so packets are dequeued always in order of txtime. Example: $ tc qdisc replace dev enp2s0 parent root handle 100 mqprio num_tc 3 \ map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@1 2@2 hw 0 $ tc qdisc add dev enp2s0 parent 100:1 etf offload delta 100000 \ clockid CLOCK_REALTIME In this example, the Qdisc will use HW offload for the control of the transmission time through the network adapter. The hrtimer used for packets scheduling inside the qdisc will use the clockid CLOCK_REALTIME as reference and packets leave the Qdisc "delta" (100000) nanoseconds before their transmission time. Because this will be using HW offload and since dynamic clocks are not supported by the hrtimer, the system clock and the PHC clock must be synchronized for this mode to behave as expected. Signed-off-by: Jesus Sanchez-Palencia Signed-off-by: David S. Miller