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2020-09-02xsk: Fix possible segfault at xskmap entry insertionMagnus Karlsson1-5/+0
Fix possible segfault when entry is inserted into xskmap. This can happen if the socket is in a state where the umem has been set up, the Rx ring created but it has yet to be bound to a device. In this case the pool has not yet been created and we cannot reference it for the existence of the fill ring. Fix this by removing the whole xsk_is_setup_for_bpf_map function. Once upon a time, it was used to make sure that the Rx and fill rings where set up before the driver could call xsk_rcv, since there are no tests for the existence of these rings in the data path. But these days, we have a state variable that we test instead. When it is XSK_BOUND, everything has been set up correctly and the socket has been bound. So no reason to have the xsk_is_setup_for_bpf_map function anymore. Fixes: 7361f9c3d719 ("xsk: Move fill and completion rings to buffer pool") Reported-by: syzbot+febe51d44243fbc564ee@syzkaller.appspotmail.com Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/1599037569-26690-1-git-send-email-magnus.karlsson@intel.com
2020-08-28bpf: Relax max_entries check for most of the inner map typesMartin KaFai Lau1-1/+8
Most of the maps do not use max_entries during verification time. Thus, those map_meta_equal() do not need to enforce max_entries when it is inserted as an inner map during runtime. The max_entries check is removed from the default implementation bpf_map_meta_equal(). The prog_array_map and xsk_map are exception. Its map_gen_lookup uses max_entries to generate inline lookup code. Thus, they will implement its own map_meta_equal() to enforce max_entries. Since there are only two cases now, the max_entries check is not refactored and stays in its own .c file. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200828011813.1970516-1-kafai@fb.com
2020-08-28bpf: Add map_meta_equal map opsMartin KaFai Lau1-0/+1
Some properties of the inner map is used in the verification time. When an inner map is inserted to an outer map at runtime, bpf_map_meta_equal() is currently used to ensure those properties of the inserting inner map stays the same as the verification time. In particular, the current bpf_map_meta_equal() checks max_entries which turns out to be too restrictive for most of the maps which do not use max_entries during the verification time. It limits the use case that wants to replace a smaller inner map with a larger inner map. There are some maps do use max_entries during verification though. For example, the map_gen_lookup in array_map_ops uses the max_entries to generate the inline lookup code. To accommodate differences between maps, the map_meta_equal is added to bpf_map_ops. Each map-type can decide what to check when its map is used as an inner map during runtime. Also, some map types cannot be used as an inner map and they are currently black listed in bpf_map_meta_alloc() in map_in_map.c. It is not unusual that the new map types may not aware that such blacklist exists. This patch enforces an explicit opt-in and only allows a map to be used as an inner map if it has implemented the map_meta_equal ops. It is based on the discussion in [1]. All maps that support inner map has its map_meta_equal points to bpf_map_meta_equal in this patch. A later patch will relax the max_entries check for most maps. bpf_types.h counts 28 map types. This patch adds 23 ".map_meta_equal" by using coccinelle. -5 for BPF_MAP_TYPE_PROG_ARRAY BPF_MAP_TYPE_(PERCPU)_CGROUP_STORAGE BPF_MAP_TYPE_STRUCT_OPS BPF_MAP_TYPE_ARRAY_OF_MAPS BPF_MAP_TYPE_HASH_OF_MAPS The "if (inner_map->inner_map_meta)" check in bpf_map_meta_alloc() is moved such that the same error is returned. [1]: https://lore.kernel.org/bpf/20200522022342.899756-1-kafai@fb.com/ Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200828011806.1970400-1-kafai@fb.com
2020-06-22bpf: Set map_btf_{name, id} for all map typesAndrey Ignatov1-0/+3
Set map_btf_name and map_btf_id for all map types so that map fields can be accessed by bpf programs. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/a825f808f22af52b018dbe82f1c7d29dab5fc978.1592600985.git.rdna@fb.com
2020-05-22xsk: Move xskmap.c to net/xdp/Björn Töpel1-0/+267
The XSKMAP is partly implemented by net/xdp/xsk.c. Move xskmap.c from kernel/bpf/ to net/xdp/, which is the logical place for AF_XDP related code. Also, move AF_XDP struct definitions, and function declarations only used by AF_XDP internals into net/xdp/xsk.h. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-3-bjorn.topel@gmail.com