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2019-11-02xsk: Restructure/inline XSKMAP lookup/redirect/flushBjörn Töpel
In this commit the XSKMAP entry lookup function used by the XDP redirect code is moved from the xskmap.c file to the xdp_sock.h header, so the lookup can be inlined from, e.g., the bpf_xdp_redirect_map() function. Further the __xsk_map_redirect() and __xsk_map_flush() is moved to the xsk.c, which lets the compiler inline the xsk_rcv() and xsk_flush() functions. Finally, all the XDP socket functions were moved from linux/bpf.h to net/xdp_sock.h, where most of the XDP sockets functions are anyway. This yields a ~2% performance boost for the xdpsock "rx_drop" scenario. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191101110346.15004-4-bjorn.topel@gmail.com
2019-11-02bpf: Implement map_gen_lookup() callback for XSKMAPMaciej Fijalkowski
Inline the xsk_map_lookup_elem() via implementing the map_gen_lookup() callback. This results in emitting the bpf instructions in place of bpf_map_lookup_elem() helper call and better performance of bpf programs. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/20191101110346.15004-3-bjorn.topel@gmail.com
2019-11-02xsk: Store struct xdp_sock as a flexible array member of the XSKMAPBjörn Töpel
Prior this commit, the array storing XDP socket instances were stored in a separate allocated array of the XSKMAP. Now, we store the sockets as a flexible array member in a similar fashion as the arraymap. Doing so, we do less pointer chasing in the lookup. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/20191101110346.15004-2-bjorn.topel@gmail.com
2019-09-25bpf/xskmap: Return ERR_PTR for failure case instead of NULL.Jonathan Lemon
When kzalloc() failed, NULL was returned to the caller, which tested the pointer with IS_ERR(), which didn't match, so the pointer was used later, resulting in a NULL dereference. Return ERR_PTR(-ENOMEM) instead of NULL. Reported-by: syzbot+491c1b7565ba9069ecae@syzkaller.appspotmail.com Fixes: 0402acd683c6 ("xsk: remove AF_XDP socket from map when the socket is released") Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-20bpf: Use PTR_ERR_OR_ZERO in xsk_map_inc()YueHaibing
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-17xsk: support BPF_EXIST and BPF_NOEXIST flags in XSKMAPBjörn Töpel
The XSKMAP did not honor the BPF_EXIST/BPF_NOEXIST flags when updating an entry. This patch addresses that. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-17xsk: remove AF_XDP socket from map when the socket is releasedBjörn Töpel
When an AF_XDP socket is released/closed the XSKMAP still holds a reference to the socket in a "released" state. The socket will still use the netdev queue resource, and block newly created sockets from attaching to that queue, but no user application can access the fill/complete/rx/tx queues. This results in that all applications need to explicitly clear the map entry from the old "zombie state" socket. This should be done automatically. In this patch, the sockets tracks, and have a reference to, which maps it resides in. When the socket is released, it will remove itself from all maps. Suggested-by: Bruce Richardson <bruce.richardson@intel.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-29xskmap: Move non-standard list manipulation to helperToke Høiland-Jørgensen
Add a helper in list.h for the non-standard way of clearing a list that is used in xskmap. This makes it easier to reuse it in the other map types, and also makes sure this usage is not forgotten in any list refactorings in the future. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-10bpf: Allow bpf_map_lookup_elem() on an xskmapJonathan Lemon
Currently, the AF_XDP code uses a separate map in order to determine if an xsk is bound to a queue. Instead of doing this, have bpf_map_lookup_elem() return a xdp_sock. Rearrange some xdp_sock members to eliminate structure holes. Remove selftest - will be added back in later patch. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-04bpf: remove redundant assignment to errColin Ian King
The variable err is assigned with the value -EINVAL that is never read and it is re-assigned a new value later on. The assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-31bpf: move memory size checks to bpf_map_charge_init()Roman Gushchin
Most bpf map types doing similar checks and bytes to pages conversion during memory allocation and charging. Let's unify these checks by moving them into bpf_map_charge_init(). Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-31bpf: rework memlock-based memory accounting for mapsRoman Gushchin
In order to unify the existing memlock charging code with the memcg-based memory accounting, which will be added later, let's rework the current scheme. Currently the following design is used: 1) .alloc() callback optionally checks if the allocation will likely succeed using bpf_map_precharge_memlock() 2) .alloc() performs actual allocations 3) .alloc() callback calculates map cost and sets map.memory.pages 4) map_create() calls bpf_map_init_memlock() which sets map.memory.user and performs actual charging; in case of failure the map is destroyed <map is in use> 1) bpf_map_free_deferred() calls bpf_map_release_memlock(), which performs uncharge and releases the user 2) .map_free() callback releases the memory The scheme can be simplified and made more robust: 1) .alloc() calculates map cost and calls bpf_map_charge_init() 2) bpf_map_charge_init() sets map.memory.user and performs actual charge 3) .alloc() performs actual allocations <map is in use> 1) .map_free() callback releases the memory 2) bpf_map_charge_finish() performs uncharge and releases the user The new scheme also allows to reuse bpf_map_charge_init()/finish() functions for memcg-based accounting. Because charges are performed before actual allocations and uncharges after freeing the memory, no bogus memory pressure can be created. In cases when the map structure is not available (e.g. it's not created yet, or is already destroyed), on-stack bpf_map_memory structure is used. The charge can be transferred with the bpf_map_charge_move() function. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-31bpf: group memory related fields in struct bpf_map_memoryRoman Gushchin
Group "user" and "pages" fields of bpf_map into the bpf_map_memory structure. Later it can be extended with "memcg" and other related information. The main reason for a such change (beside cosmetics) is to pass bpf_map_memory structure to charging functions before the actual allocation of bpf_map. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
net/sched/cls_api.c has overlapping changes to a call to nlmsg_parse(), one (from 'net') added rtm_tca_policy instead of NULL to the 5th argument, and another (from 'net-next') added cb->extack instead of NULL to the 6th argument. net/ipv4/ipmr_base.c is a case of a bug fix in 'net' being done to code which moved (to mr_table_dump)) in 'net-next'. Thanks to David Ahern for the heads up. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-11xsk: do not call synchronize_net() under RCU read lockBjörn Töpel
The XSKMAP update and delete functions called synchronize_net(), which can sleep. It is not allowed to sleep during an RCU read section. Instead we need to make sure that the sock sk_destruct (xsk_destruct) function is asynchronously called after an RCU grace period. Setting the SOCK_RCU_FREE flag for XDP sockets takes care of this. Fixes: fbfc504a24f5 ("bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-09bpf: return EOPNOTSUPP when map lookup isn't supportedPrashant Bhole
Return ERR_PTR(-EOPNOTSUPP) from map_lookup_elem() methods of below map types: - BPF_MAP_TYPE_PROG_ARRAY - BPF_MAP_TYPE_STACK_TRACE - BPF_MAP_TYPE_XSKMAP - BPF_MAP_TYPE_SOCKMAP/BPF_MAP_TYPE_SOCKHASH Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-17bpf: fix redirect to map under tail callsDaniel Borkmann
Commits 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") and 7c3001313396 ("bpf: fix ri->map_owner pointer on bpf_prog_realloc") tried to mitigate that buggy programs using bpf_redirect_map() helper call do not leave stale maps behind. Idea was to add a map_owner cookie into the per CPU struct redirect_info which was set to prog->aux by the prog making the helper call as a proof that the map is not stale since the prog is implicitly holding a reference to it. This owner cookie could later on get compared with the program calling into BPF whether they match and therefore the redirect could proceed with processing the map safely. In (obvious) hindsight, this approach breaks down when tail calls are involved since the original caller's prog->aux pointer does not have to match the one from one of the progs out of the tail call chain, and therefore the xdp buffer will be dropped instead of redirected. A way around that would be to fix the issue differently (which also allows to remove related work in fast path at the same time): once the life-time of a redirect map has come to its end we use it's map free callback where we need to wait on synchronize_rcu() for current outstanding xdp buffers and remove such a map pointer from the redirect info if found to be present. At that time no program is using this map anymore so we simply invalidate the map pointers to NULL iff they previously pointed to that instance while making sure that the redirect path only reads out the map once. Fixes: 97f91a7cf04f ("bpf: add bpf_redirect_map helper routine") Fixes: 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") Reported-by: Sebastiano Miano <sebastiano.miano@polito.it> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-13bpf: decouple btf from seq bpf fs dump and enable more mapsDaniel Borkmann
Commit a26ca7c982cb ("bpf: btf: Add pretty print support to the basic arraymap") and 699c86d6ec21 ("bpf: btf: add pretty print for hash/lru_hash maps") enabled support for BTF and dumping via BPF fs for array and hash/lru map. However, both can be decoupled from each other such that regular BPF maps can be supported for attaching BTF key/value information, while not all maps necessarily need to dump via map_seq_show_elem() callback. The basic sanity check which is a prerequisite for all maps is that key/value size has to match in any case, and some maps can have extra checks via map_check_btf() callback, e.g. probing certain types or indicating no support in general. With that we can also enable retrieving BTF info for per-cpu map types and lpm. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com>
2018-05-18xsk: clean up SPDX headersBjörn Töpel
Clean up SPDX-License-Identifier and removing licensing leftovers. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-04bpf, xskmap: fix crash in xsk_map_alloc error path handlingDaniel Borkmann
If bpf_map_precharge_memlock() did not fail, then we set err to zero. However, any subsequent failure from either alloc_percpu() or the bpf_map_area_alloc() will return ERR_PTR(0) which in find_and_alloc_map() will cause NULL pointer deref. In devmap we have the convention that we return -EINVAL on page count overflow, so keep the same logic here and just set err to -ENOMEM after successful bpf_map_precharge_memlock(). Fixes: fbfc504a24f5 ("bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Björn Töpel <bjorn.topel@intel.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-03bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAPBjörn Töpel
The xskmap is yet another BPF map, very much inspired by dev/cpu/sockmap, and is a holder of AF_XDP sockets. A user application adds AF_XDP sockets into the map, and by using the bpf_redirect_map helper, an XDP program can redirect XDP frames to an AF_XDP socket. Note that a socket that is bound to certain ifindex/queue index will *only* accept XDP frames from that netdev/queue index. If an XDP program tries to redirect from a netdev/queue index other than what the socket is bound to, the frame will not be received on the socket. A socket can reside in multiple maps. v3: Fixed race and simplified code. v2: Removed one indirection in map lookup. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>