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path: root/kernel/bpf/offload.c
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2017-12-31bpf: offload: free program id when device disappearsJakub Kicinski
Bound programs are quite useless after their device disappears. They are simply waiting for reference count to go to zero, don't list them in BPF_PROG_GET_NEXT_ID by freeing their ID early. Note that orphaned offload programs will return -ENODEV on BPF_OBJ_GET_INFO_BY_FD so user will never see ID 0. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-31bpf: offload: free prog->aux->offload when device disappearsJakub Kicinski
All bpf offload operations should now be under bpf_devs_lock, it's safe to free and clear the entire offload structure, not only the netdev pointer. __bpf_prog_offload_destroy() will no longer be called multiple times. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-31bpf: offload: allow netdev to disappear while verifier is runningJakub Kicinski
To allow verifier instruction callbacks without any extra locking NETDEV_UNREGISTER notification would wait on a waitqueue for verifier to finish. This design decision was made when rtnl lock was providing all the locking. Use the read/write lock instead and remove the workqueue. Verifier will now call into the offload code, so dev_ops are moved to offload structure. Since verifier calls are all under bpf_prog_is_dev_bound() we no longer need static inline implementations to please builds with CONFIG_NET=n. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-31bpf: offload: don't require rtnl for dev list manipulationJakub Kicinski
We don't need the RTNL lock for all operations on offload state. We only need to hold it around ndo calls. The device offload initialization doesn't require it. The soon-to-come querying of the offload info will only need it partially. We will also be able to remove the waitqueue in following patches. Use struct rw_semaphore because map offload will require sleeping with the semaphore held for read. Suggested-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-27bpf: offload: add a license headerJakub Kicinski
I forgot to add a license on kernel/bpf/offload.c. Luckily I'm still the only author so make it explicitly GPLv2. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-21bpf: revert report offload info to user spaceJakub Kicinski
This reverts commit bd601b6ada11 ("bpf: report offload info to user space"). The ifindex by itself is not sufficient, we should provide information on which network namespace this ifindex belongs to. After considering some options we concluded that it's best to just remove this API for now, and rework it in -next. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-21bpf: offload: ignore namespace movesJakub Kicinski
We are currently destroying the device offload state when device moves to another net namespace. This doesn't break with current NFP code, because offload state is not used on program removal, but it's not correct behaviour. Ignore the device unregister notifications on namespace move. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-21bpf: offload: rename the ifindex fieldJakub Kicinski
bpf_target_prog seems long and clunky, rename it to prog_ifindex. We don't want to call this field just ifindex, because maps may need a similar field in the future and bpf_attr members for programs and maps are unnamed. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-21bpf: offload: limit offload to cls_bpf and xdp programs onlyJakub Kicinski
We are currently only allowing attachment of device-bound cls_bpf and XDP programs. Make this restriction explicit in the BPF offload code. This way we can potentially reuse the ifindex field in the future. Since XDP and cls_bpf programs can only be loaded by admin, we can drop the explicit capability check from offload code. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-21bpf: offload: add comment warning developers about double destroyJakub Kicinski
Offload state may get destroyed either because the device for which it was constructed is going away, or because the refcount of bpf program itself has reached 0. In both of those cases we will call __bpf_prog_offload_destroy() to unlink the offload from the device. We may in fact call it twice, which works just fine, but we should make clear this is intended and caution others trying to extend the function. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-05bpf: report offload info to user spaceJakub Kicinski
Extend struct bpf_prog_info to contain information about program being bound to a device. Since the netdev may get destroyed while program still exists we need a flag to indicate the program is loaded for a device, even if the device is gone. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05bpf: offload: add infrastructure for loading programs for a specific netdevJakub Kicinski
The fact that we don't know which device the program is going to be used on is quite limiting in current eBPF infrastructure. We have to reverse or limit the changes which kernel makes to the loaded bytecode if we want it to be offloaded to a networking device. We also have to invent new APIs for debugging and troubleshooting support. Make it possible to load programs for a specific netdev. This helps us to bring the debug information closer to the core eBPF infrastructure (e.g. we will be able to reuse the verifer log in device JIT). It allows device JITs to perform translation on the original bytecode. __bpf_prog_get() when called to get a reference for an attachment point will now refuse to give it if program has a device assigned. Following patches will add a version of that function which passes the expected netdev in. @type argument in __bpf_prog_get() is renamed to attach_type to make it clearer that it's only set on attachment. All calls to ndo_bpf are protected by rtnl, only verifier callbacks are not. We need a wait queue to make sure netdev doesn't get destroyed while verifier is still running and calling its driver. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>