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2024-02-02net/sched: Load modules via their aliasMichal Koutný
The cls_,sch_,act_ modules may be loaded lazily during network configuration but without user's awareness and control. Switch the lazy loading from canonical module names to a module alias. This allows finer control over lazy loading, the precedent from commit 7f78e0351394 ("fs: Limit sys_mount to only request filesystem modules.") explains it already: Using aliases means user space can control the policy of which filesystem^W net/sched modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. By default, nothing changes. However, if a specific module is blacklisted (its canonical name), it won't be modprobe'd when requested under its alias (i.e. kernel auto-loading). It would appear as if the given module was unknown. The module can still be loaded under its canonical name, which is an explicit (privileged) user action. Signed-off-by: Michal Koutný <mkoutny@suse.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240201130943.19536-4-mkoutny@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-07net/sched: simplify tc_action_load_ops parametersPedro Tammela
Instead of using two bools derived from a flags passed as arguments to the parent function of tc_action_load_ops, just pass the flags itself to tc_action_load_ops to simplify its parameters. Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-03net/sched: introduce ACT_P_BOUND return codePedro Tammela
Bound actions always return '0' and as of today we rely on '0' being returned in order to properly skip bound actions in tcf_idr_insert_many. In order to further improve maintainability, introduce the ACT_P_BOUND return code. Actions are updated to return 'ACT_P_BOUND' instead of plain '0'. tcf_idr_insert_many is then updated to check for 'ACT_P_BOUND'. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20231229132642.1489088-1-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-20net: sched: Add initial TC error skb drop reasonsVictor Nogueira
Continue expanding Daniel's patch by adding new skb drop reasons that are idiosyncratic to TC. More specifically: - SKB_DROP_REASON_TC_COOKIE_ERROR: An error occurred whilst processing a tc ext cookie. - SKB_DROP_REASON_TC_CHAIN_NOTFOUND: tc chain lookup failed. - SKB_DROP_REASON_TC_RECLASSIFY_LOOP: tc exceeded max reclassify loop iterations Signed-off-by: Victor Nogueira <victor@mojatatu.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-20net: sched: Move drop_reason to struct tc_skb_cbVictor Nogueira
Move drop_reason from struct tcf_result to skb cb - more specifically to struct tc_skb_cb. With that, we'll be able to also set the drop reason for the remaining qdiscs (aside from clsact) that do not have access to tcf_result when time comes to set the skb drop reason. Signed-off-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-13net/sched: act_api: skip idr replace on bound actionsPedro Tammela
tcf_idr_insert_many will replace the allocated -EBUSY pointer in tcf_idr_check_alloc with the real action pointer, exposing it to all operations. This operation is only needed when the action pointer is created (ACT_P_CREATED). For actions which are bound to (returned 0), the pointer already resides in the idr making such operation a nop. Even though it's a nop, it's still not a cheap operation as internally the idr code walks the idr and then does a replace on the appropriate slot. So if the action was bound, better skip the idr replace entirely. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Vlad Buslov <vladbu@nvidia.com> Link: https://lore.kernel.org/r/20231211181807.96028-3-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-13net/sched: act_api: rely on rcu in tcf_idr_check_allocPedro Tammela
Instead of relying only on the idrinfo->lock mutex for bind/alloc logic, rely on a combination of rcu + mutex + atomics to better scale the case where multiple rtnl-less filters are binding to the same action object. Action binding happens when an action index is specified explicitly and an action exists which such index exists. Example: tc actions add action drop index 1 tc filter add ... matchall action drop index 1 tc filter add ... matchall action drop index 1 tc filter add ... matchall action drop index 1 tc filter ls ... filter protocol all pref 49150 matchall chain 0 filter protocol all pref 49150 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 filter protocol all pref 49151 matchall chain 0 filter protocol all pref 49151 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 filter protocol all pref 49152 matchall chain 0 filter protocol all pref 49152 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 When no index is specified, as before, grab the mutex and allocate in the idr the next available id. In this version, as opposed to before, it's simplified to store the -EBUSY pointer instead of the previous alloc + replace combination. When an index is specified, rely on rcu to find if there's an object in such index. If there's none, fallback to the above, serializing on the mutex and reserving the specified id. If there's one, it can be an -EBUSY pointer, in which case we just try again until it's an action, or an action. Given the rcu guarantees, the action found could be dead and therefore we need to bump the refcount if it's not 0, handling the case it's in fact 0. As bind and the action refcount are already atomics, these increments can happen without the mutex protection while many tcf_idr_check_alloc race to bind to the same action instance. In case binding encounters a parallel delete or add, it will return -EAGAIN in order to try again. Both filter and action apis already have the retry machinery in-place. In case it's an unlocked filter it retries under the rtnl lock. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Vlad Buslov <vladbu@nvidia.com> Link: https://lore.kernel.org/r/20231211181807.96028-2-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-11net/sched: act_api: conditional notification of eventsPedro Tammela
As of today tc-action events are unconditionally built and sent to RTNLGRP_TC. As with the introduction of rtnl_notify_needed we can check before-hand if they are really needed. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20231208192847.714940-6-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-11net/sched: act_api: don't open code max()Pedro Tammela
Use max() in a couple of places that are open coding it with the ternary operator. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20231208192847.714940-5-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-05net/sched: act_api: use tcf_act_for_each_action in tcf_idr_insert_manyPedro Tammela
The actions array is contiguous, so stop processing whenever a NULL is found. This is already the assumption for tcf_action_destroy[1], which is called from tcf_actions_init. [1] https://elixir.bootlin.com/linux/v6.7-rc3/source/net/sched/act_api.c#L1115 Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-12-05net/sched: act_api: stop loop over ops array on NULL in tcf_action_initPedro Tammela
The ops array is contiguous, so stop processing whenever a NULL is found Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-12-05net/sched: act_api: avoid non-contiguous action arrayPedro Tammela
In tcf_action_add, when putting the reference for the bound actions it assigns NULLs to just created actions passing a non contiguous array to tcf_action_put_many. Refactor the code so the actions array is always contiguous. Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-12-05net/sched: act_api: use tcf_act_for_each_actionPedro Tammela
Use the auxiliary macro tcf_act_for_each_action in all the functions that expect a contiguous action array Suggested-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-11-06net, sched: Fix SKB_NOT_DROPPED_YET splat under debug configJamal Hadi Salim
Getting the following splat [1] with CONFIG_DEBUG_NET=y and this reproducer [2]. Problem seems to be that classifiers clear 'struct tcf_result::drop_reason', thereby triggering the warning in __kfree_skb_reason() due to reason being 'SKB_NOT_DROPPED_YET' (0). Fixed by disambiguating a legit error from a verdict with a bogus drop_reason [1] WARNING: CPU: 0 PID: 181 at net/core/skbuff.c:1082 kfree_skb_reason+0x38/0x130 Modules linked in: CPU: 0 PID: 181 Comm: mausezahn Not tainted 6.6.0-rc6-custom-ge43e6d9582e0 #682 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014 RIP: 0010:kfree_skb_reason+0x38/0x130 [...] Call Trace: <IRQ> __netif_receive_skb_core.constprop.0+0x837/0xdb0 __netif_receive_skb_one_core+0x3c/0x70 process_backlog+0x95/0x130 __napi_poll+0x25/0x1b0 net_rx_action+0x29b/0x310 __do_softirq+0xc0/0x29b do_softirq+0x43/0x60 </IRQ> [2] ip link add name veth0 type veth peer name veth1 ip link set dev veth0 up ip link set dev veth1 up tc qdisc add dev veth1 clsact tc filter add dev veth1 ingress pref 1 proto all flower dst_mac 00:11:22:33:44:55 action drop mausezahn veth0 -a own -b 00:11:22:33:44:55 -q -c 1 Ido reported: [...] getting the following splat [1] with CONFIG_DEBUG_NET=y and this reproducer [2]. Problem seems to be that classifiers clear 'struct tcf_result::drop_reason', thereby triggering the warning in __kfree_skb_reason() due to reason being 'SKB_NOT_DROPPED_YET' (0). [...] [1] WARNING: CPU: 0 PID: 181 at net/core/skbuff.c:1082 kfree_skb_reason+0x38/0x130 Modules linked in: CPU: 0 PID: 181 Comm: mausezahn Not tainted 6.6.0-rc6-custom-ge43e6d9582e0 #682 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014 RIP: 0010:kfree_skb_reason+0x38/0x130 [...] Call Trace: <IRQ> __netif_receive_skb_core.constprop.0+0x837/0xdb0 __netif_receive_skb_one_core+0x3c/0x70 process_backlog+0x95/0x130 __napi_poll+0x25/0x1b0 net_rx_action+0x29b/0x310 __do_softirq+0xc0/0x29b do_softirq+0x43/0x60 </IRQ> [2] #!/bin/bash ip link add name veth0 type veth peer name veth1 ip link set dev veth0 up ip link set dev veth1 up tc qdisc add dev veth1 clsact tc filter add dev veth1 ingress pref 1 proto all flower dst_mac 00:11:22:33:44:55 action drop mausezahn veth0 -a own -b 00:11:22:33:44:55 -q -c 1 What happens is that inside most classifiers the tcf_result is copied over from a filter template e.g. *res = f->res which then implicitly overrides the prior SKB_DROP_REASON_TC_{INGRESS,EGRESS} default drop code which was set via sch_handle_{ingress,egress}() for kfree_skb_reason(). Commit text above copied verbatim from Daniel. The general idea of the patch is not very different from what Ido originally posted but instead done at the cls_api codepath. Fixes: 54a59aed395c ("net, sched: Make tc-related drop reason more flexible") Reported-by: Ido Schimmel <idosch@idosch.org> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/netdev/ZTjY959R+AFXf3Xy@shredder Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-10net: sched: Replace strlcpy with strscpyAzeem Shaikh
strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). Direct replacement is safe here since return value of -errno is used to check for truncation instead of sizeof(dest). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-23net/sched: act_api: use the correct TCA_ACT attributes in dumpPedro Tammela
4 places in the act api code are using 'TCA_' definitions where they should be using 'TCA_ACT_', which is confusing for the reader, although functionally they are equivalent. Cc: Hangbin Liu <haliu@redhat.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Hangbin Liu <haliu@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-16net/sched: act_api: add specific EXT_WARN_MSG for tc actionHangbin Liu
In my previous commit 0349b8779cc9 ("sched: add new attr TCA_EXT_WARN_MSG to report tc extact message") I didn't notice the tc action use different enum with filter. So we can't use TCA_EXT_WARN_MSG directly for tc action. Let's add a TCA_ROOT_EXT_WARN_MSG for tc action specifically and put this param before going to the TCA_ACT_TAB nest. Fixes: 0349b8779cc9 ("sched: add new attr TCA_EXT_WARN_MSG to report tc extact message") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-16Revert "net/sched: act_api: move TCA_EXT_WARN_MSG to the correct hierarchy"Hangbin Liu
This reverts commit 923b2e30dc9cd05931da0f64e2e23d040865c035. This is not a correct fix as TCA_EXT_WARN_MSG is not a hierarchy to TCA_ACT_TAB. I didn't notice the TC actions use different enum when adding TCA_EXT_WARN_MSG. To fix the difference I will add a new WARN enum in TCA_ROOT_MAX as Jamal suggested. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-27net/sched: act_api: move TCA_EXT_WARN_MSG to the correct hierarchyPedro Tammela
TCA_EXT_WARN_MSG is currently sitting outside of the expected hierarchy for the tc actions code. It should sit within TCA_ACT_TAB. Fixes: 0349b8779cc9 ("sched: add new attr TCA_EXT_WARN_MSG to report tc extact message") Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-20net/sched: cls_api: Support hardware miss to tc actionPaul Blakey
For drivers to support partial offload of a filter's action list, add support for action miss to specify an action instance to continue from in sw. CT action in particular can't be fully offloaded, as new connections need to be handled in software. This imposes other limitations on the actions that can be offloaded together with the CT action, such as packet modifications. Assign each action on a filter's action list a unique miss_cookie which drivers can then use to fill action_miss part of the tc skb extension. On getting back this miss_cookie, find the action instance with relevant cookie and continue classifying from there. Signed-off-by: Paul Blakey <paulb@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-20net/sched: Rename user cookie and act cookiePaul Blakey
struct tc_action->act_cookie is a user defined cookie, and the related struct flow_action_entry->act_cookie is used as an handle similar to struct flow_cls_offload->cookie. Rename tc_action->act_cookie to user_cookie, and flow_action_entry->act_cookie to cookie so their names would better fit their usage. Signed-off-by: Paul Blakey <paulb@nvidia.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-14net/sched: support per action hw statsOz Shlomo
There are currently two mechanisms for populating hardware stats: 1. Using flow_offload api to query the flow's statistics. The api assumes that the same stats values apply to all the flow's actions. This assumption breaks when action drops or jumps over following actions. 2. Using hw_action api to query specific action stats via a driver callback method. This api assures the correct action stats for the offloaded action, however, it does not apply to the rest of the actions in the flow's actions array. Extend the flow_offload stats callback to indicate that a per action stats update is required. Use the existing flow_offload_action api to query the action's hw stats. In addition, currently the tc action stats utility only updates hw actions. Reuse the existing action stats cb infrastructure to query any action stats. Signed-off-by: Oz Shlomo <ozsh@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-14net/sched: introduce flow_offload action cookieOz Shlomo
Currently a hardware action is uniquely identified by the <id, hw_index> tuple. However, the id is set by the flow_act_setup callback and tc core cannot enforce this, and it is possible that a future change could break this. In addition, <id, hw_index> are not unique across network namespaces. Uniquely identify the action by setting an action cookie by the tc core. Use the unique action cookie to query the action's hardware stats. Signed-off-by: Oz Shlomo <ozsh@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-14net/sched: optimize action stats api callsOz Shlomo
Currently the hw action stats update is called from tcf_exts_hw_stats_update, when a tc filter is dumped, and from tcf_action_copy_stats, when a hw action is dumped. However, the tcf_action_copy_stats is also called from tcf_action_dump. As such, the hw action stats update cb is called 3 times for every tc flower filter dump. Move the tc action hw stats update from tcf_action_copy_stats to tcf_dump_walker to update the hw action stats when tc action is dumped. Signed-off-by: Oz Shlomo <ozsh@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-01-17sched: add new attr TCA_EXT_WARN_MSG to report tc extact messageHangbin Liu
We will report extack message if there is an error via netlink_ack(). But if the rule is not to be exclusively executed by the hardware, extack is not passed along and offloading failures don't get logged. In commit 81c7288b170a ("sched: cls: enable verbose logging") Marcelo made cls could log verbose info for offloading failures, which helps improving Open vSwitch debuggability when using flower offloading. It would also be helpful if userspace monitor tools, like "tc monitor", could log this kind of message, as it doesn't require vswitchd log level adjusment. Let's add a new tc attributes to report the extack message so the monitor program could receive the failures. e.g. # tc monitor added chain dev enp3s0f1np1 parent ffff: chain 0 added filter dev enp3s0f1np1 ingress protocol all pref 49152 flower chain 0 handle 0x1 ct_state +trk+new not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 1 bind 1 Warning: mlx5_core: matching on ct_state +new isn't supported. In this patch I only report the extack message on add/del operations. It doesn't look like we need to report the extack message on get/dump operations. Note this message not only reporte to multicast groups, it could also be reported unicast, which may affect the current usersapce tool's behaivor. Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20230113034353.2766735-1-liuhangbin@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-12-09net/sched: avoid indirect act functions on retpoline kernelsPedro Tammela
Expose the necessary tc act functions and wire up act_api to use direct calls in retpoline kernels. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-09net: sched: act_api: implement generic walker and search for tc actionZhengchao Shao
Being able to get tc_action_net by using net_id stored in tc_action_ops and execute the generic walk/search function, add __tcf_generic_walker() and __tcf_idr_search() helpers. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-27net/sched: act_api: Notify user space if any actions were flushed before errorVictor Nogueira
If during an action flush operation one of the actions is still being referenced, the flush operation is aborted and the kernel returns to user space with an error. However, if the kernel was able to flush, for example, 3 actions and failed on the fourth, the kernel will not notify user space that it deleted 3 actions before failing. This patch fixes that behaviour by notifying user space of how many actions were deleted before flush failed and by setting extack with a message describing what happened. Fixes: 55334a5db5cd ("net_sched: act: refuse to remove bound action outside") Signed-off-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-08net/sched: act_api: Add extack to offload_act_setup() callbackIdo Schimmel
The callback is used by various actions to populate the flow action structure prior to offload. Pass extack to this callback so that the various actions will be able to report accurate error messages to user space. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-02flow_offload: improve extack msg for user when adding invalid filterBaowen Zheng
Add extack message to return exact message to user when adding invalid filter with conflict flags for TC action. In previous implement we just return EINVAL which is confusing for user. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Reviewed-by: Roi Dayan <roid@nvidia.com> Link: https://lore.kernel.org/r/1646191769-17761-1-git-send-email-baowen.zheng@corigine.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-23net: sched: avoid newline at end of message in NL_SET_ERR_MSG_MODWan Jiabing
Fix following coccicheck warning: ./net/sched/act_api.c:277:7-49: WARNING avoid newline at end of message in NL_SET_ERR_MSG_MOD Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-16net: sched: limit TC_ACT_REPEAT loopsEric Dumazet
We have been living dangerously, at the mercy of malicious users, abusing TC_ACT_REPEAT, as shown by this syzpot report [1]. Add an arbitrary limit (32) to the number of times an action can return TC_ACT_REPEAT. v2: switch the limit to 32 instead of 10. Use net_warn_ratelimited() instead of pr_err_once(). [1] (C repro available on demand) rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=021/1/0x4000000000000000 softirq=5592/5592 fqs=0 (t=10502 jiffies g=5305 q=190) rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g5305 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=3527 rcu: rcu_preempt kthread starved for 10505 jiffies! g5305 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:29344 pid: 14 ppid: 2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4db0 kernel/sched/core.c:6295 schedule+0xd2/0x260 kernel/sched/core.c:6368 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3646 Comm: syz-executor358 Not tainted 5.17.0-rc3-syzkaller-00149-gbf8e59fd315f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:437 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3b8/0xb40 kernel/locking/qspinlock.c:508 Code: 48 89 eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c <f3> 90 41 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 RSP: 0018:ffffc9000283f1b0 EFLAGS: 00000206 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffff1100fc0071e RDX: 0000000000000001 RSI: 0000000000000201 RDI: 0000000000000000 RBP: ffff88807e0038f0 R08: 0000000000000001 R09: ffffffff8ffbf9ff R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000004c1e R13: ffffed100fc0071e R14: 0000000000000001 R15: ffff8880b9c3aa80 FS: 00005555562bf300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdbfef12b8 CR3: 00000000723c2000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:354 [inline] sch_tree_lock include/net/sch_generic.h:610 [inline] sch_tree_lock include/net/sch_generic.h:605 [inline] prio_tune+0x3b9/0xb50 net/sched/sch_prio.c:211 prio_init+0x5c/0x80 net/sched/sch_prio.c:244 qdisc_create.constprop.0+0x44a/0x10f0 net/sched/sch_api.c:1253 tc_modify_qdisc+0x4c5/0x1980 net/sched/sch_api.c:1660 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5594 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7ee98aae99 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdbfef12d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ffdbfef1300 RCX: 00007f7ee98aae99 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d R10: 000000000000000d R11: 0000000000000246 R12: 00007ffdbfef12f0 R13: 00000000000f4240 R14: 000000000004ca47 R15: 00007ffdbfef12e4 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.293 msecs NMI backtrace for cpu 1 CPU: 1 PID: 3260 Comm: kworker/1:3 Not tainted 5.17.0-rc3-syzkaller-00149-gbf8e59fd315f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: mld mld_ifc_work Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xc/0x70 kernel/kcov.c:286 Code: 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b c3 0f 1f 80 00 00 00 00 41 89 f8 bf 03 00 00 00 4c 8b 14 24 <89> f1 65 48 8b 34 25 00 70 02 00 e8 14 f9 ff ff 84 c0 74 4b 48 8b RSP: 0018:ffffc90002c5eea8 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff88801c625800 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffff8880137d3100 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff874fcd88 R11: 0000000000000000 R12: ffff88801d692dc0 R13: ffff8880137d3104 R14: 0000000000000000 R15: ffff88801d692de8 tcf_police_act+0x358/0x11d0 net/sched/act_police.c:256 tcf_action_exec net/sched/act_api.c:1049 [inline] tcf_action_exec+0x1a6/0x530 net/sched/act_api.c:1026 tcf_exts_exec include/net/pkt_cls.h:326 [inline] route4_classify+0xef0/0x1400 net/sched/cls_route.c:179 __tcf_classify net/sched/cls_api.c:1549 [inline] tcf_classify+0x3e8/0x9d0 net/sched/cls_api.c:1615 prio_classify net/sched/sch_prio.c:42 [inline] prio_enqueue+0x3a7/0x790 net/sched/sch_prio.c:75 dev_qdisc_enqueue+0x40/0x300 net/core/dev.c:3668 __dev_xmit_skb net/core/dev.c:3756 [inline] __dev_queue_xmit+0x1f61/0x3660 net/core/dev.c:4081 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0x14dc/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 iptunnel_xmit+0x628/0xa50 net/ipv4/ip_tunnel_core.c:82 geneve_xmit_skb drivers/net/geneve.c:966 [inline] geneve_xmit+0x10c8/0x3530 drivers/net/geneve.c:1077 __netdev_start_xmit include/linux/netdevice.h:4683 [inline] netdev_start_xmit include/linux/netdevice.h:4697 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 __dev_queue_xmit+0x2985/0x3660 net/core/dev.c:4116 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip6_finish_output2+0xf7a/0x14f0 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] mld_sendpack+0x9a3/0xe40 net/ipv6/mcast.c:1826 mld_send_cr net/ipv6/mcast.c:2127 [inline] mld_ifc_work+0x71c/0xdc0 net/ipv6/mcast.c:2659 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> ---------------- Code disassembly (best guess): 0: 48 89 eb mov %rbp,%rbx 3: c6 45 01 01 movb $0x1,0x1(%rbp) 7: 41 bc 00 80 00 00 mov $0x8000,%r12d d: 48 c1 e9 03 shr $0x3,%rcx 11: 83 e3 07 and $0x7,%ebx 14: 41 be 01 00 00 00 mov $0x1,%r14d 1a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 21: fc ff df 24: 4c 8d 2c 01 lea (%rcx,%rax,1),%r13 28: eb 0c jmp 0x36 * 2a: f3 90 pause <-- trapping instruction 2c: 41 83 ec 01 sub $0x1,%r12d 30: 0f 84 72 04 00 00 je 0x4a8 36: 41 0f b6 45 00 movzbl 0x0(%r13),%eax 3b: 38 d8 cmp %bl,%al 3d: 7f 08 jg 0x47 3f: 84 .byte 0x84 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Reported-by: syzbot <syzkaller@googlegroups.com> Link: https://lore.kernel.org/r/20220215235305.3272331-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-23flow_offload: fix suspicious RCU usage when offloading tc actionBaowen Zheng
Fix suspicious rcu_dereference_protected() usage when offloading tc action. We should hold tcfa_lock to offload tc action in action initiation. Without these changes, the following warning will be observed: WARNING: suspicious RCU usage 5.16.0-rc5-net-next-01504-g7d1f236dcffa-dirty #50 Tainted: G I ----------------------------- include/net/tc_act/tc_tunnel_key.h:33 suspicious rcu_dereference_protected() usage! 1 lock held by tc/12108: CPU: 4 PID: 12108 Comm: tc Tainted: G Hardware name: Dell Inc. PowerEdge R740/07WCGN, BIOS 1.6.11 11/20/2018 Call Trace: <TASK> dump_stack_lvl+0x49/0x5e dump_stack+0x10/0x12 lockdep_rcu_suspicious+0xed/0xf8 tcf_tunnel_key_offload_act_setup+0x1de/0x300 [act_tunnel_key] tcf_action_offload_add_ex+0xc0/0x1f0 tcf_action_init+0x26a/0x2f0 tcf_action_add+0xa9/0x1f0 tc_ctl_action+0xfb/0x170 rtnetlink_rcv_msg+0x169/0x510 ? sched_clock+0x9/0x10 ? rtnl_newlink+0x70/0x70 netlink_rcv_skb+0x55/0x100 rtnetlink_rcv+0x15/0x20 netlink_unicast+0x1a8/0x270 netlink_sendmsg+0x245/0x490 sock_sendmsg+0x65/0x70 ____sys_sendmsg+0x219/0x260 ? __import_iovec+0x2c/0x150 ___sys_sendmsg+0xb7/0x100 ? __lock_acquire+0x3d5/0x1f40 ? __this_cpu_preempt_check+0x13/0x20 ? lock_is_held_type+0xe4/0x140 ? sched_clock+0x9/0x10 ? ktime_get_coarse_real_ts64+0xbe/0xd0 ? __this_cpu_preempt_check+0x13/0x20 ? lockdep_hardirqs_on+0x7e/0x100 ? ktime_get_coarse_real_ts64+0xbe/0xd0 ? trace_hardirqs_on+0x2a/0xf0 __sys_sendmsg+0x5a/0xa0 ? syscall_trace_enter.constprop.0+0x1dd/0x220 __x64_sys_sendmsg+0x1f/0x30 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4db7bb7a60 Fixes: 8cbfe939abe9 ("flow_offload: allow user to offload tc action to net device") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Louis Peens <louis.peens@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-19flow_offload: validate flags of filter and actionsBaowen Zheng
Add process to validate flags of filter and actions when adding a tc filter. We need to prevent adding filter with flags conflicts with its actions. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Louis Peens <louis.peens@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-19flow_offload: add reoffload process to update hw_countBaowen Zheng
Add reoffload process to update hw_count when driver is inserted or removed. We will delete the action if it is with skip_sw flag and not offloaded to any hardware in reoffload process. When reoffloading actions, we still offload the actions that are added independent of filters. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Louis Peens <louis.peens@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-19net: sched: save full flags for tc actionBaowen Zheng
Save full action flags and return user flags when return flags to user space. Save full action flags to distinguish if the action is created independent from classifier. We made this change mainly for further patch to reoffload tc actions. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-19flow_offload: add process to update action stats from hardwareBaowen Zheng
When collecting stats for actions update them using both hardware and software counters. Stats update process should not run in context of preempt_disable. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Louis Peens <louis.peens@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-19flow_offload: add skip_hw and skip_sw to control if offload the actionBaowen Zheng
We add skip_hw and skip_sw for user to control if offload the action to hardware. We also add in_hw_count for user to indicate if the action is offloaded to any hardware. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-19flow_offload: allow user to offload tc action to net deviceBaowen Zheng
Use flow_indr_dev_register/flow_indr_dev_setup_offload to offload tc action. We need to call tc_cleanup_flow_action to clean up tc action entry since in tc_setup_action, some actions may hold dev refcnt, especially the mirror action. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Louis Peens <louis.peens@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18net: sched: Remove Qdisc::running sequence counterAhmed S. Darwish
The Qdisc::running sequence counter has two uses: 1. Reliably reading qdisc's tc statistics while the qdisc is running (a seqcount read/retry loop at gnet_stats_add_basic()). 2. As a flag, indicating whether the qdisc in question is running (without any retry loops). For the first usage, the Qdisc::running sequence counter write section, qdisc_run_begin() => qdisc_run_end(), covers a much wider area than what is actually needed: the raw qdisc's bstats update. A u64_stats sync point was thus introduced (in previous commits) inside the bstats structure itself. A local u64_stats write section is then started and stopped for the bstats updates. Use that u64_stats sync point mechanism for the bstats read/retry loop at gnet_stats_add_basic(). For the second qdisc->running usage, a __QDISC_STATE_RUNNING bit flag, accessed with atomic bitops, is sufficient. Using a bit flag instead of a sequence counter at qdisc_run_begin/end() and qdisc_is_running() leads to the SMP barriers implicitly added through raw_read_seqcount() and write_seqcount_begin/end() getting removed. All call sites have been surveyed though, and no required ordering was identified. Now that the qdisc->running sequence counter is no longer used, remove it. Note, using u64_stats implies no sequence counter protection for 64-bit architectures. This can lead to the qdisc tc statistics "packets" vs. "bytes" values getting out of sync on rare occasions. The individual values will still be valid. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data typesAhmed S. Darwish
The only factor differentiating per-CPU bstats data type (struct gnet_stats_basic_cpu) from the packed non-per-CPU one (struct gnet_stats_basic_packed) was a u64_stats sync point inside the former. The two data types are now equivalent: earlier commits added a u64_stats sync point to the latter. Combine both data types into "struct gnet_stats_basic_sync". This eliminates redundancy and simplifies the bstats read/write APIs. Use u64_stats_t for bstats "packets" and "bytes" data types. On 64-bit architectures, u64_stats sync points do not use sequence counter protection. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18net: sched: Protect Qdisc::bstats with u64_statsAhmed S. Darwish
The not-per-CPU variant of qdisc tc (traffic control) statistics, Qdisc::gnet_stats_basic_packed bstats, is protected with Qdisc::running sequence counter. This sequence counter is used for reliably protecting bstats reads from parallel writes. Meanwhile, the seqcount's write section covers a much wider area than bstats update: qdisc_run_begin() => qdisc_run_end(). That read/write section asymmetry can lead to needless retries of the read section. To prepare for removing the Qdisc::running sequence counter altogether, introduce a u64_stats sync point inside bstats instead. Modify _bstats_update() to start/end the bstats u64_stats write section. For bisectability, and finer commits granularity, the bstats read section is still protected with a Qdisc::running read/retry loop and qdisc_run_begin/end() still starts/ends that seqcount write section. Once all call sites are modified to use _bstats_update(), the Qdisc::running seqcount will be removed and bstats read/retry loop will be modified to utilize the internal u64_stats sync point. Note, using u64_stats implies no sequence counter protection for 64-bit architectures. This can lead to the statistics "packets" vs. "bytes" values getting out of sync on rare occasions. The individual values will still be valid. [bigeasy: Minor commit message edits, init all gnet_stats_basic_packed.] Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-02net_sched: refactor TC action init APICong Wang
TC action ->init() API has 10 parameters, it becomes harder to read. Some of them are just boolean and can be replaced by flags. Similarly for the internal API tcf_action_init() and tcf_exts_validate(). This patch converts them to flags and fold them into the upper 16 bits of "flags", whose lower 16 bits are still reserved for user-space. More specifically, the following kernel flags are introduced: TCA_ACT_FLAGS_POLICE replace 'name' in a few contexts, to distinguish whether it is compatible with policer. TCA_ACT_FLAGS_BIND replaces 'bind', to indicate whether this action is bound to a filter. TCA_ACT_FLAGS_REPLACE replaces 'ovr' in most contexts, means we are replacing an existing action. TCA_ACT_FLAGS_NO_RTNL replaces 'rtnl_held' but has the opposite meaning, because we still hold RTNL in most cases. The only user-space flag TCA_ACT_FLAGS_NO_PERCPU_STATS is untouched and still stored as before. I have tested this patch with tdc and I do not see any failure related to this patch. Tested-by: Vlad Buslov <vladbu@nvidia.com> Acked-by: Jamal Hadi Salim<jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-16net/sched: Remove unnecessary if statementYajun Deng
It has been deal with the 'if (err' statement in rtnetlink_send() and rtnl_unicast(). so remove unnecessary if statement. v2: use the raw name rtnetlink_send(). Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17net: sched: fix error return code in tcf_del_walker()Yang Yingliang
When nla_put_u32() fails, 'ret' could be 0, it should return error code in tcf_del_walker(). Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-08net: sched: fix err handler in tcf_action_init()Vlad Buslov
With recent changes that separated action module load from action initialization tcf_action_init() function error handling code was modified to manually release the loaded modules if loading/initialization of any further action in same batch failed. For the case when all modules successfully loaded and some of the actions were initialized before one of them failed in init handler. In this case for all previous actions the module will be released twice by the error handler: First time by the loop that manually calls module_put() for all ops, and second time by the action destroy code that puts the module after destroying the action. Reproduction: $ sudo tc actions add action simple sdata \"2\" index 2 $ sudo tc actions add action simple sdata \"1\" index 1 \ action simple sdata \"2\" index 2 RTNETLINK answers: File exists We have an error talking to the kernel $ sudo tc actions ls action simple total acts 1 action order 0: Simple <"2"> index 2 ref 1 bind 0 $ sudo tc actions flush action simple $ sudo tc actions ls action simple $ sudo tc actions add action simple sdata \"2\" index 2 Error: Failed to load TC action module. We have an error talking to the kernel $ lsmod | grep simple act_simple 20480 -1 Fix the issue by modifying module reference counting handling in action initialization code: - Get module reference in tcf_idr_create() and put it in tcf_idr_release() instead of taking over the reference held by the caller. - Modify users of tcf_action_init_1() to always release the module reference which they obtain before calling init function instead of assuming that created action takes over the reference. - Finally, modify tcf_action_init_1() to not release the module reference when overwriting existing action as this is no longer necessary since both upper and lower layers obtain and manage their own module references independently. Fixes: d349f9976868 ("net_sched: fix RTNL deadlock again caused by request_module()") Suggested-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Vlad Buslov <vladbu@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-08net: sched: fix action overwrite reference countingVlad Buslov
Action init code increments reference counter when it changes an action. This is the desired behavior for cls API which needs to obtain action reference for every classifier that points to action. However, act API just needs to change the action and releases the reference before returning. This sequence breaks when the requested action doesn't exist, which causes act API init code to create new action with specified index, but action is still released before returning and is deleted (unless it was referenced concurrently by cls API). Reproduction: $ sudo tc actions ls action gact $ sudo tc actions change action gact drop index 1 $ sudo tc actions ls action gact Extend tcf_action_init() to accept 'init_res' array and initialize it with action->ops->init() result. In tcf_action_add() remove pointers to created actions from actions array before passing it to tcf_action_put_many(). Fixes: cae422f379f3 ("net: sched: use reference counting action init") Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Vlad Buslov <vladbu@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-08Revert "net: sched: bump refcount for new action in ACT replace mode"Vlad Buslov
This reverts commit 6855e8213e06efcaf7c02a15e12b1ae64b9a7149. Following commit in series fixes the issue without introducing regression in error rollback of tcf_action_destroy(). Signed-off-by: Vlad Buslov <vladbu@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-30net: sched: bump refcount for new action in ACT replace modeKumar Kartikeya Dwivedi
Currently, action creation using ACT API in replace mode is buggy. When invoking for non-existent action index 42, tc action replace action bpf obj foo.o sec <xyz> index 42 kernel creates the action, fills up the netlink response, and then just deletes the action after notifying userspace. tc action show action bpf doesn't list the action. This happens due to the following sequence when ovr = 1 (replace mode) is enabled: tcf_idr_check_alloc is used to atomically check and either obtain reference for existing action at index, or reserve the index slot using a dummy entry (ERR_PTR(-EBUSY)). This is necessary as pointers to these actions will be held after dropping the idrinfo lock, so bumping the reference count is necessary as we need to insert the actions, and notify userspace by dumping their attributes. Finally, we drop the reference we took using the tcf_action_put_many call in tcf_action_add. However, for the case where a new action is created due to free index, its refcount remains one. This when paired with the put_many call leads to the kernel setting up the action, notifying userspace of its creation, and then tearing it down. For existing actions, the refcount is still held so they remain unaffected. Fortunately due to rtnl_lock serialization requirement, such an action with refcount == 1 will not be concurrently deleted by anything else, at best CLS API can move its refcount up and down by binding to it after it has been published from tcf_idr_insert_many. Since refcount is atleast one until put_many call, CLS API cannot delete it. Also __tcf_action_put release path already ensures deterministic outcome (either new action will be created or existing action will be reused in case CLS API tries to bind to action concurrently) due to idr lock serialization. We fix this by making refcount of newly created actions as 2 in ACT API replace mode. A relaxed store will suffice as visibility is ensured only after the tcf_idr_insert_many call. Note that in case of creation or overwriting using CLS API only (i.e. bind = 1), overwriting existing action object is not allowed, and any such request is silently ignored (without error). The refcount bump that occurs in tcf_idr_check_alloc call there for existing action will pair with tcf_exts_destroy call made from the owner module for the same action. In case of action creation, there is no existing action, so no tcf_exts_destroy callback happens. This means no code changes for CLS API. Fixes: cae422f379f3 ("net: sched: use reference counting action init") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller