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* bpf: sockmap, map_release does not hold refcnt for pinned mapsJohn Fastabend2018-04-241-2/+2
| | | | | | | | | | | | | | | Relying on map_release hook to decrement the reference counts when a map is removed only works if the map is not being pinned. In the pinned case the ref is decremented immediately and the BPF programs released. After this BPF programs may not be in-use which is not what the user would expect. This patch moves the release logic into bpf_map_put_uref() and brings sockmap in-line with how a similar case is handled in prog array maps. Fixes: 3d9e952697de ("bpf: sockmap, fix leaking maps with attached but not detached progs") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* kernel/bpf/syscall: fix warning defined but not usedAnders Roxell2018-04-041-12/+12
| | | | | | | | | | | | | | | | There will be a build warning -Wunused-function if CONFIG_CGROUP_BPF isn't defined, since the only user is inside #ifdef CONFIG_CGROUP_BPF: kernel/bpf/syscall.c:1229:12: warning: ‘bpf_prog_attach_check_attach_type’ defined but not used [-Wunused-function] static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Current code moves function bpf_prog_attach_check_attach_type inside ifdef CONFIG_CGROUP_BPF. Fixes: 5e43f899b03a ("bpf: Check attach type at prog load time") Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Post-hooks for sys_bindAndrey Ignatov2018-03-311-0/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "Post-hooks" are hooks that are called right before returning from sys_bind. At this time IP and port are already allocated and no further changes to `struct sock` can happen before returning from sys_bind but BPF program has a chance to inspect the socket and change sys_bind result. Specifically it can e.g. inspect what port was allocated and if it doesn't satisfy some policy, BPF program can force sys_bind to fail and return EPERM to user. Another example of usage is recording the IP:port pair to some map to use it in later calls to sys_connect. E.g. if some TCP server inside cgroup was bound to some IP:port_n, it can be recorded to a map. And later when some TCP client inside same cgroup is trying to connect to 127.0.0.1:port_n, BPF hook for sys_connect can override the destination and connect application to IP:port_n instead of 127.0.0.1:port_n. That helps forcing all applications inside a cgroup to use desired IP and not break those applications if they e.g. use localhost to communicate between each other. == Implementation details == Post-hooks are implemented as two new attach types `BPF_CGROUP_INET4_POST_BIND` and `BPF_CGROUP_INET6_POST_BIND` for existing prog type `BPF_PROG_TYPE_CGROUP_SOCK`. Separate attach types for IPv4 and IPv6 are introduced to avoid access to IPv6 field in `struct sock` from `inet_bind()` and to IPv4 field from `inet6_bind()` since those fields might not make sense in such cases. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Hooks for sys_connectAndrey Ignatov2018-03-311-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | == The problem == See description of the problem in the initial patch of this patch set. == The solution == The patch provides much more reliable in-kernel solution for the 2nd part of the problem: making outgoing connecttion from desired IP. It adds new attach types `BPF_CGROUP_INET4_CONNECT` and `BPF_CGROUP_INET6_CONNECT` for program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` that can be used to override both source and destination of a connection at connect(2) time. Local end of connection can be bound to desired IP using newly introduced BPF-helper `bpf_bind()`. It allows to bind to only IP though, and doesn't support binding to port, i.e. leverages `IP_BIND_ADDRESS_NO_PORT` socket option. There are two reasons for this: * looking for a free port is expensive and can affect performance significantly; * there is no use-case for port. As for remote end (`struct sockaddr *` passed by user), both parts of it can be overridden, remote IP and remote port. It's useful if an application inside cgroup wants to connect to another application inside same cgroup or to itself, but knows nothing about IP assigned to the cgroup. Support is added for IPv4 and IPv6, for TCP and UDP. IPv4 and IPv6 have separate attach types for same reason as sys_bind hooks, i.e. to prevent reading from / writing to e.g. user_ip6 fields when user passes sockaddr_in since it'd be out-of-bound. == Implementation notes == The patch introduces new field in `struct proto`: `pre_connect` that is a pointer to a function with same signature as `connect` but is called before it. The reason is in some cases BPF hooks should be called way before control is passed to `sk->sk_prot->connect`. Specifically `inet_dgram_connect` autobinds socket before calling `sk->sk_prot->connect` and there is no way to call `bpf_bind()` from hooks from e.g. `ip4_datagram_connect` or `ip6_datagram_connect` since it'd cause double-bind. On the other hand `proto.pre_connect` provides a flexible way to add BPF hooks for connect only for necessary `proto` and call them at desired time before `connect`. Since `bpf_bind()` is allowed to bind only to IP and autobind in `inet_dgram_connect` binds only port there is no chance of double-bind. bpf_bind() sets `force_bind_address_no_port` to bind to only IP despite of value of `bind_address_no_port` socket field. bpf_bind() sets `with_lock` to `false` when calling to __inet_bind() and __inet6_bind() since all call-sites, where bpf_bind() is called, already hold socket lock. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Hooks for sys_bindAndrey Ignatov2018-03-311-8/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | == The problem == There is a use-case when all processes inside a cgroup should use one single IP address on a host that has multiple IP configured. Those processes should use the IP for both ingress and egress, for TCP and UDP traffic. So TCP/UDP servers should be bound to that IP to accept incoming connections on it, and TCP/UDP clients should make outgoing connections from that IP. It should not require changing application code since it's often not possible. Currently it's solved by intercepting glibc wrappers around syscalls such as `bind(2)` and `connect(2)`. It's done by a shared library that is preloaded for every process in a cgroup so that whenever TCP/UDP server calls `bind(2)`, the library replaces IP in sockaddr before passing arguments to syscall. When application calls `connect(2)` the library transparently binds the local end of connection to that IP (`bind(2)` with `IP_BIND_ADDRESS_NO_PORT` to avoid performance penalty). Shared library approach is fragile though, e.g.: * some applications clear env vars (incl. `LD_PRELOAD`); * `/etc/ld.so.preload` doesn't help since some applications are linked with option `-z nodefaultlib`; * other applications don't use glibc and there is nothing to intercept. == The solution == The patch provides much more reliable in-kernel solution for the 1st part of the problem: binding TCP/UDP servers on desired IP. It does not depend on application environment and implementation details (whether glibc is used or not). It adds new eBPF program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` and attach types `BPF_CGROUP_INET4_BIND` and `BPF_CGROUP_INET6_BIND` (similar to already existing `BPF_CGROUP_INET_SOCK_CREATE`). The new program type is intended to be used with sockets (`struct sock`) in a cgroup and provided by user `struct sockaddr`. Pointers to both of them are parts of the context passed to programs of newly added types. The new attach types provides hooks in `bind(2)` system call for both IPv4 and IPv6 so that one can write a program to override IP addresses and ports user program tries to bind to and apply such a program for whole cgroup. == Implementation notes == [1] Separate attach types for `AF_INET` and `AF_INET6` are added intentionally to prevent reading/writing to offsets that don't make sense for corresponding socket family. E.g. if user passes `sockaddr_in` it doesn't make sense to read from / write to `user_ip6[]` context fields. [2] The write access to `struct bpf_sock_addr_kern` is implemented using special field as an additional "register". There are just two registers in `sock_addr_convert_ctx_access`: `src` with value to write and `dst` with pointer to context that can't be changed not to break later instructions. But the fields, allowed to write to, are not available directly and to access them address of corresponding pointer has to be loaded first. To get additional register the 1st not used by `src` and `dst` one is taken, its content is saved to `bpf_sock_addr_kern.tmp_reg`, then the register is used to load address of pointer field, and finally the register's content is restored from the temporary field after writing `src` value. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Check attach type at prog load timeAndrey Ignatov2018-03-311-1/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | == The problem == There are use-cases when a program of some type can be attached to multiple attach points and those attach points must have different permissions to access context or to call helpers. E.g. context structure may have fields for both IPv4 and IPv6 but it doesn't make sense to read from / write to IPv6 field when attach point is somewhere in IPv4 stack. Same applies to BPF-helpers: it may make sense to call some helper from some attach point, but not from other for same prog type. == The solution == Introduce `expected_attach_type` field in in `struct bpf_attr` for `BPF_PROG_LOAD` command. If scenario described in "The problem" section is the case for some prog type, the field will be checked twice: 1) At load time prog type is checked to see if attach type for it must be known to validate program permissions correctly. Prog will be rejected with EINVAL if it's the case and `expected_attach_type` is not specified or has invalid value. 2) At attach time `attach_type` is compared with `expected_attach_type`, if prog type requires to have one, and, if they differ, attach will be rejected with EINVAL. The `expected_attach_type` is now available as part of `struct bpf_prog` in both `bpf_verifier_ops->is_valid_access()` and `bpf_verifier_ops->get_func_proto()` () and can be used to check context accesses and calls to helpers correspondingly. Initially the idea was discussed by Alexei Starovoitov <ast@fb.com> and Daniel Borkmann <daniel@iogearbox.net> here: https://marc.info/?l=linux-netdev&m=152107378717201&w=2 Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: introduce BPF_RAW_TRACEPOINTAlexei Starovoitov2018-03-281-0/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce BPF_PROG_TYPE_RAW_TRACEPOINT bpf program type to access kernel internal arguments of the tracepoints in their raw form. >From bpf program point of view the access to the arguments look like: struct bpf_raw_tracepoint_args { __u64 args[0]; }; int bpf_prog(struct bpf_raw_tracepoint_args *ctx) { // program can read args[N] where N depends on tracepoint // and statically verified at program load+attach time } kprobe+bpf infrastructure allows programs access function arguments. This feature allows programs access raw tracepoint arguments. Similar to proposed 'dynamic ftrace events' there are no abi guarantees to what the tracepoints arguments are and what their meaning is. The program needs to type cast args properly and use bpf_probe_read() helper to access struct fields when argument is a pointer. For every tracepoint __bpf_trace_##call function is prepared. In assembler it looks like: (gdb) disassemble __bpf_trace_xdp_exception Dump of assembler code for function __bpf_trace_xdp_exception: 0xffffffff81132080 <+0>: mov %ecx,%ecx 0xffffffff81132082 <+2>: jmpq 0xffffffff811231f0 <bpf_trace_run3> where TRACE_EVENT(xdp_exception, TP_PROTO(const struct net_device *dev, const struct bpf_prog *xdp, u32 act), The above assembler snippet is casting 32-bit 'act' field into 'u64' to pass into bpf_trace_run3(), while 'dev' and 'xdp' args are passed as-is. All of ~500 of __bpf_trace_*() functions are only 5-10 byte long and in total this approach adds 7k bytes to .text. This approach gives the lowest possible overhead while calling trace_xdp_exception() from kernel C code and transitioning into bpf land. Since tracepoint+bpf are used at speeds of 1M+ events per second this is valuable optimization. The new BPF_RAW_TRACEPOINT_OPEN sys_bpf command is introduced that returns anon_inode FD of 'bpf-raw-tracepoint' object. The user space looks like: // load bpf prog with BPF_PROG_TYPE_RAW_TRACEPOINT type prog_fd = bpf_prog_load(...); // receive anon_inode fd for given bpf_raw_tracepoint with prog attached raw_tp_fd = bpf_raw_tracepoint_open("xdp_exception", prog_fd); Ctrl-C of tracing daemon or cmdline tool that uses this feature will automatically detach bpf program, unload it and unregister tracepoint probe. On the kernel side the __bpf_raw_tp_map section of pointers to tracepoint definition and to __bpf_trace_*() probe function is used to find a tracepoint with "xdp_exception" name and corresponding __bpf_trace_xdp_exception() probe function which are passed to tracepoint_probe_register() to connect probe with tracepoint. Addition of bpf_raw_tracepoint doesn't interfere with ftrace and perf tracepoint mechanisms. perf_event_open() can be used in parallel on the same tracepoint. Multiple bpf_raw_tracepoint_open("xdp_exception", prog_fd) are permitted. Each with its own bpf program. The kernel will execute all tracepoint probes and all attached bpf programs. In the future bpf_raw_tracepoints can be extended with query/introspection logic. __bpf_raw_tp_map section logic was contributed by Steven Rostedt Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: follow idr code conventionShaohua Li2018-03-271-0/+4
| | | | | | | | | | Generally we do a preload before doing idr allocation. This also help improve the allocation success rate in memory pressure. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-03-231-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fun set of conflict resolutions here... For the mac80211 stuff, these were fortunately just parallel adds. Trivially resolved. In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the function phy_disable_interrupts() earlier in the file, whilst in 'net-next' the phy_error() call from this function was removed. In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the 'rt_table_id' member of rtable collided with a bug fix in 'net' that added a new struct member "rt_mtu_locked" which needs to be copied over here. The mlxsw driver conflict consisted of net-next separating the span code and definitions into separate files, whilst a 'net' bug fix made some changes to that moved code. The mlx5 infiniband conflict resolution was quite non-trivial, the RDMA tree's merge commit was used as a guide here, and here are their notes: ==================== Due to bug fixes found by the syzkaller bot and taken into the for-rc branch after development for the 4.17 merge window had already started being taken into the for-next branch, there were fairly non-trivial merge issues that would need to be resolved between the for-rc branch and the for-next branch. This merge resolves those conflicts and provides a unified base upon which ongoing development for 4.17 can be based. Conflicts: drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f9524 (IB/mlx5: Fix cleanup order on unload) added to for-rc and commit b5ca15ad7e61 (IB/mlx5: Add proper representors support) add as part of the devel cycle both needed to modify the init/de-init functions used by mlx5. To support the new representors, the new functions added by the cleanup patch needed to be made non-static, and the init/de-init list added by the representors patch needed to be modified to match the init/de-init list changes made by the cleanup patch. Updates: drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function prototypes added by representors patch to reflect new function names as changed by cleanup patch drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init stage list to match new order from cleanup patch ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf: skip unnecessary capability checkChenbo Feng2018-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The current check statement in BPF syscall will do a capability check for CAP_SYS_ADMIN before checking sysctl_unprivileged_bpf_disabled. This code path will trigger unnecessary security hooks on capability checking and cause false alarms on unprivileged process trying to get CAP_SYS_ADMIN access. This can be resolved by simply switch the order of the statement and CAP_SYS_ADMIN is not required anyway if unprivileged bpf syscall is allowed. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX dataJohn Fastabend2018-03-191-5/+9
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements a BPF ULP layer to allow policy enforcement and monitoring at the socket layer. In order to support this a new program type BPF_PROG_TYPE_SK_MSG is used to run the policy at the sendmsg/sendpage hook. To attach the policy to sockets a sockmap is used with a new program attach type BPF_SK_MSG_VERDICT. Similar to previous sockmap usages when a sock is added to a sockmap, via a map update, if the map contains a BPF_SK_MSG_VERDICT program type attached then the BPF ULP layer is created on the socket and the attached BPF_PROG_TYPE_SK_MSG program is run for every msg in sendmsg case and page/offset in sendpage case. BPF_PROG_TYPE_SK_MSG Semantics/API: BPF_PROG_TYPE_SK_MSG supports only two return codes SK_PASS and SK_DROP. Returning SK_DROP free's the copied data in the sendmsg case and in the sendpage case leaves the data untouched. Both cases return -EACESS to the user. Returning SK_PASS will allow the msg to be sent. In the sendmsg case data is copied into kernel space buffers before running the BPF program. The kernel space buffers are stored in a scatterlist object where each element is a kernel memory buffer. Some effort is made to coalesce data from the sendmsg call here. For example a sendmsg call with many one byte iov entries will likely be pushed into a single entry. The BPF program is run with data pointers (start/end) pointing to the first sg element. In the sendpage case data is not copied. We opt not to copy the data by default here, because the BPF infrastructure does not know what bytes will be needed nor when they will be needed. So copying all bytes may be wasteful. Because of this the initial start/end data pointers are (0,0). Meaning no data can be read or written. This avoids reading data that may be modified by the user. A new helper is added later in this series if reading and writing the data is needed. The helper call will do a copy by default so that the page is exclusively owned by the BPF call. The verdict from the BPF_PROG_TYPE_SK_MSG applies to the entire msg in the sendmsg() case and the entire page/offset in the sendpage case. This avoids ambiguity on how to handle mixed return codes in the sendmsg case. Again a helper is added later in the series if a verdict needs to apply to multiple system calls and/or only a subpart of the currently being processed message. The helper msg_redirect_map() can be used to select the socket to send the data on. This is used similar to existing redirect use cases. This allows policy to redirect msgs. Pseudo code simple example: The basic logic to attach a program to a socket is as follows, // load the programs bpf_prog_load(SOCKMAP_TCP_MSG_PROG, BPF_PROG_TYPE_SK_MSG, &obj, &msg_prog); // lookup the sockmap bpf_map_msg = bpf_object__find_map_by_name(obj, "my_sock_map"); // get fd for sockmap map_fd_msg = bpf_map__fd(bpf_map_msg); // attach program to sockmap bpf_prog_attach(msg_prog, map_fd_msg, BPF_SK_MSG_VERDICT, 0); Adding sockets to the map is done in the normal way, // Add a socket 'fd' to sockmap at location 'i' bpf_map_update_elem(map_fd_msg, &i, fd, BPF_ANY); After the above any socket attached to "my_sock_map", in this case 'fd', will run the BPF msg verdict program (msg_prog) on every sendmsg and sendpage system call. For a complete example see BPF selftests or sockmap samples. Implementation notes: It seemed the simplest, to me at least, to use a refcnt to ensure psock is not lost across the sendmsg copy into the sg, the bpf program running on the data in sg_data, and the final pass to the TCP stack. Some performance testing may show a better method to do this and avoid the refcnt cost, but for now use the simpler method. Another item that will come after basic support is in place is supporting MSG_MORE flag. At the moment we call sendpages even if the MSG_MORE flag is set. An enhancement would be to collect the pages into a larger scatterlist and pass down the stack. Notice that bpf_tcp_sendmsg() could support this with some additional state saved across sendmsg calls. I built the code to support this without having to do refactoring work. Other features TBD include ZEROCOPY and the TCP_RECV_QUEUE/TCP_NO_QUEUE support. This will follow initial series shortly. Future work could improve size limits on the scatterlist rings used here. Currently, we use MAX_SKB_FRAGS simply because this was being used already in the TLS case. Future work could extend the kernel sk APIs to tune this depending on workload. This is a trade-off between memory usage and throughput performance. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Use the IS_FD_ARRAY() macro in map_update_elem()Mickaël Salaün2018-01-251-4/+1
| | | | | | | | | Make the code more readable. Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: offload: report device information about offloaded mapsJakub Kicinski2018-01-181-0/+6
| | | | | | | | | | | Tell user space about device on which the map was created. Unfortunate reality of user ABI makes sharing this code with program offload difficult but the information is the same. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: allow socket_filter programs to use bpf_prog_test_runAlexei Starovoitov2018-01-181-0/+2
| | | | | | | | | | | in order to improve test coverage allow socket_filter program type to be run via bpf_prog_test_run command. Since such programs can be loaded by non-root tighten permissions for bpf_prog_test_run to be root only to avoid surprises. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: add new jited info fields in bpf_dev_offload and bpf_prog_infoJiong Wang2018-01-181-13/+18
| | | | | | | | | | | | | | | | | | | | | | | For host JIT, there are "jited_len"/"bpf_func" fields in struct bpf_prog used by all host JIT targets to get jited image and it's length. While for offload, targets are likely to have different offload mechanisms that these info are kept in device private data fields. Therefore, BPF_OBJ_GET_INFO_BY_FD syscall needs an unified way to get JIT length and contents info for offload targets. One way is to introduce new callback to parse device private data then fill those fields in bpf_prog_info. This might be a little heavy, the other way is to add generic fields which will be initialized by all offload targets. This patch follow the second approach to introduce two new fields in struct bpf_dev_offload and teach bpf_prog_get_info_by_fd about them to fill correct jited_prog_len and jited_prog_insns in bpf_prog_info. Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: offload: add map offload infrastructureJakub Kicinski2018-01-141-6/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | BPF map offload follow similar path to program offload. At creation time users may specify ifindex of the device on which they want to create the map. Map will be validated by the kernel's .map_alloc_check callback and device driver will be called for the actual allocation. Map will have an empty set of operations associated with it (save for alloc and free callbacks). The real device callbacks are kept in map->offload->dev_ops because they have slightly different signatures. Map operations are called in process context so the driver may communicate with HW freely, msleep(), wait() etc. Map alloc and free callbacks are muxed via existing .ndo_bpf, and are always called with rtnl lock held. Maps and programs are guaranteed to be destroyed before .ndo_uninit (i.e. before unregister_netdev() returns). Map callbacks are invoked with bpf_devs_lock *read* locked, drivers must take care of exclusive locking if necessary. All offload-specific branches are marked with unlikely() (through bpf_map_is_dev_bound()), given that branch penalty will be negligible compared to IO anyway, and we don't want to penalize SW path unnecessarily. 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>
* bpf: add helper for copying attrs to struct bpf_mapJakub Kicinski2018-01-141-0/+10
| | | | | | | | | | All map types reimplement the field-by-field copy of union bpf_attr members into struct bpf_map. Add a helper to perform this operation. 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>
* bpf: add map_alloc_check callbackJakub Kicinski2018-01-141-4/+13
| | | | | | | | | | | | | | | .map_alloc callbacks contain a number of checks validating user- -provided map attributes against constraints of a particular map type. For offloaded maps we will need to check map attributes without actually allocating any memory on the host. Add a new callback for validating attributes before any memory is allocated. This callback can be selectively implemented by map types for sharing code with offloads, or simply to separate the logical steps of validation and allocation. 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-01-091-1/+1
|\
| * fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'"Al Viro2018-01-051-1/+1
| | | | | | | | | | | | | | | | | | | | Descriptor table is a shared object; it's not a place where you can stick temporary references to files, especially when we don't need an opened file at all. Cc: stable@vger.kernel.org # v4.14 Fixes: 98589a0998b8 ("netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'") Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | bpf: offload: report device information for offloaded programsJakub Kicinski2017-12-311-0/+6
| | | | | | | | | | | | | | | | | | | | Report to the user ifindex and namespace information of offloaded programs. If device has disappeared return -ENODEV. Specify the namespace using dev/inode combination. CC: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: offload: free program id when device disappearsJakub Kicinski2017-12-311-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | bpf: offload: don't use prog->aux->offload as booleanJakub Kicinski2017-12-311-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | We currently use aux->offload to indicate that program is bound to a specific device. This forces us to keep the offload structure around even after the device is gone. Add a bool member to struct bpf_prog_aux to indicate if offload was requested. 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>
* | bpf: allow for correlation of maps and helpers in dumpDaniel Borkmann2017-12-201-5/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently a dump of an xlated prog (post verifier stage) doesn't correlate used helpers as well as maps. The prog info lists involved map ids, however there's no correlation of where in the program they are used as of today. Likewise, bpftool does not correlate helper calls with the target functions. The latter can be done w/o any kernel changes through kallsyms, and also has the advantage that this works with inlined helpers and BPF calls. Example, via interpreter: # tc filter show dev foo ingress filter protocol all pref 49152 bpf chain 0 filter protocol all pref 49152 bpf chain 0 handle 0x1 foo.o:[ingress] \ direct-action not_in_hw id 1 tag c74773051b364165 <-- prog id:1 * Output before patch (calls/maps remain unclear): # bpftool prog dump xlated id 1 <-- dump prog id:1 0: (b7) r1 = 2 1: (63) *(u32 *)(r10 -4) = r1 2: (bf) r2 = r10 3: (07) r2 += -4 4: (18) r1 = 0xffff95c47a8d4800 6: (85) call unknown#73040 7: (15) if r0 == 0x0 goto pc+18 8: (bf) r2 = r10 9: (07) r2 += -4 10: (bf) r1 = r0 11: (85) call unknown#73040 12: (15) if r0 == 0x0 goto pc+23 [...] * Output after patch: # bpftool prog dump xlated id 1 0: (b7) r1 = 2 1: (63) *(u32 *)(r10 -4) = r1 2: (bf) r2 = r10 3: (07) r2 += -4 4: (18) r1 = map[id:2] <-- map id:2 6: (85) call bpf_map_lookup_elem#73424 <-- helper call 7: (15) if r0 == 0x0 goto pc+18 8: (bf) r2 = r10 9: (07) r2 += -4 10: (bf) r1 = r0 11: (85) call bpf_map_lookup_elem#73424 12: (15) if r0 == 0x0 goto pc+23 [...] # bpftool map show id 2 <-- show/dump/etc map id:2 2: hash_of_maps flags 0x0 key 4B value 4B max_entries 3 memlock 4096B Example, JITed, same prog: # tc filter show dev foo ingress filter protocol all pref 49152 bpf chain 0 filter protocol all pref 49152 bpf chain 0 handle 0x1 foo.o:[ingress] \ direct-action not_in_hw id 3 tag c74773051b364165 jited # bpftool prog show id 3 3: sched_cls tag c74773051b364165 loaded_at Dec 19/13:48 uid 0 xlated 384B jited 257B memlock 4096B map_ids 2 # bpftool prog dump xlated id 3 0: (b7) r1 = 2 1: (63) *(u32 *)(r10 -4) = r1 2: (bf) r2 = r10 3: (07) r2 += -4 4: (18) r1 = map[id:2] <-- map id:2 6: (85) call __htab_map_lookup_elem#77408 <-+ inlined rewrite 7: (15) if r0 == 0x0 goto pc+2 | 8: (07) r0 += 56 | 9: (79) r0 = *(u64 *)(r0 +0) <-+ 10: (15) if r0 == 0x0 goto pc+24 11: (bf) r2 = r10 12: (07) r2 += -4 [...] Example, same prog, but kallsyms disabled (in that case we are also not allowed to pass any relative offsets, etc, so prog becomes pointer sanitized on dump): # sysctl kernel.kptr_restrict=2 kernel.kptr_restrict = 2 # bpftool prog dump xlated id 3 0: (b7) r1 = 2 1: (63) *(u32 *)(r10 -4) = r1 2: (bf) r2 = r10 3: (07) r2 += -4 4: (18) r1 = map[id:2] 6: (85) call bpf_unspec#0 7: (15) if r0 == 0x0 goto pc+2 [...] Example, BPF calls via interpreter: # bpftool prog dump xlated id 1 0: (85) call pc+2#__bpf_prog_run_args32 1: (b7) r0 = 1 2: (95) exit 3: (b7) r0 = 2 4: (95) exit Example, BPF calls via JIT: # sysctl net.core.bpf_jit_enable=1 net.core.bpf_jit_enable = 1 # sysctl net.core.bpf_jit_kallsyms=1 net.core.bpf_jit_kallsyms = 1 # bpftool prog dump xlated id 1 0: (85) call pc+2#bpf_prog_3b185187f1855c4c_F 1: (b7) r0 = 1 2: (95) exit 3: (b7) r0 = 2 4: (95) exit And finally, an example for tail calls that is now working as well wrt correlation: # bpftool prog dump xlated id 2 [...] 10: (b7) r2 = 8 11: (85) call bpf_trace_printk#-41312 12: (bf) r1 = r6 13: (18) r2 = map[id:1] 15: (b7) r3 = 0 16: (85) call bpf_tail_call#12 17: (b7) r1 = 42 18: (6b) *(u16 *)(r6 +46) = r1 19: (b7) r0 = 0 20: (95) exit # bpftool map show id 1 1: prog_array flags 0x0 key 4B value 4B max_entries 1 memlock 4096B Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: fix kallsyms handling for subprogsDaniel Borkmann2017-12-201-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now kallsyms handling is not working with JITed subprogs. The reason is that when in 1c2a088a6626 ("bpf: x64: add JIT support for multi-function programs") in jit_subprogs() they are passed to bpf_prog_kallsyms_add(), then their prog type is 0, which BPF core will think it's a cBPF program as only cBPF programs have a 0 type. Thus, they need to inherit the type from the main prog. Once that is fixed, they are indeed added to the BPF kallsyms infra, but their tag is 0. Therefore, since intention is to add them as bpf_prog_F_<tag>, we need to pass them to bpf_prog_calc_tag() first. And once this is resolved, there is a use-after-free on prog cleanup: we remove the kallsyms entry from the main prog, later walk all subprogs and call bpf_jit_free() on them. However, the kallsyms linkage was never released on them. Thus, do that for all subprogs right in __bpf_prog_put() when refcount hits 0. Fixes: 1c2a088a6626 ("bpf: x64: add JIT support for multi-function programs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: x64: add JIT support for multi-function programsAlexei Starovoitov2017-12-171-1/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Typical JIT does several passes over bpf instructions to compute total size and relative offsets of jumps and calls. With multitple bpf functions calling each other all relative calls will have invalid offsets intially therefore we need to additional last pass over the program to emit calls with correct offsets. For example in case of three bpf functions: main: call foo call bpf_map_lookup exit foo: call bar exit bar: exit We will call bpf_int_jit_compile() indepedently for main(), foo() and bar() x64 JIT typically does 4-5 passes to converge. After these initial passes the image for these 3 functions will be good except call targets, since start addresses of foo() and bar() are unknown when we were JITing main() (note that call bpf_map_lookup will be resolved properly during initial passes). Once start addresses of 3 functions are known we patch call_insn->imm to point to right functions and call bpf_int_jit_compile() again which needs only one pass. Additional safety checks are done to make sure this last pass doesn't produce image that is larger or smaller than previous pass. When constant blinding is on it's applied to all functions at the first pass, since doing it once again at the last pass can change size of the JITed code. Tested on x64 and arm64 hw with JIT on/off, blinding on/off. x64 jits bpf-to-bpf calls correctly while arm64 falls back to interpreter. All other JITs that support normal BPF_CALL will behave the same way since bpf-to-bpf call is equivalent to bpf-to-kernel call from JITs point of view. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: revert report offload info to user spaceJakub Kicinski2017-11-211-5/+0
| | | | | | | | | | | 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>
* bpf: turn bpf_prog_get_type() into a wrapperJakub Kicinski2017-11-211-10/+0
| | | | | | | | | | | | bpf_prog_get_type() is identical to bpf_prog_get_type_dev(), with false passed as attach_drv. Instead of keeping it as an exported symbol turn it into static inline wrapper. 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>
* bpf: offload: move offload device validation out to the driversJakub Kicinski2017-11-211-11/+12
| | | | | | | | | | | | | | | | | | | | | With TC shared block changes we can't depend on correct netdev pointer being available in cls_bpf. Move the device validation to the driver. Core will only make sure that offloaded programs are always attached in the driver (or in HW by the driver). We trust that drivers which implement offload callbacks will perform necessary checks. Moving the checks to the driver is generally a useful thing, in practice the check should be against a switchdev instance, not a netdev, given that most ASICs will probably allow using the same program on many ports. 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> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: offload: rename the ifindex fieldJakub Kicinski2017-11-211-2/+2
| | | | | | | | | | | | | 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>
* bpf, cgroup: implement eBPF-based device controller for cgroup v2Roman Gushchin2017-11-051-0/+7
| | | | | | | | | | | | | | | | | | | | Cgroup v2 lacks the device controller, provided by cgroup v1. This patch adds a new eBPF program type, which in combination of previously added ability to attach multiple eBPF programs to a cgroup, will provide a similar functionality, but with some additional flexibility. This patch introduces a BPF_PROG_TYPE_CGROUP_DEVICE program type. A program takes major and minor device numbers, device type (block/character) and access type (mknod/read/write) as parameters and returns an integer which defines if the operation should be allowed or terminated with -EPERM. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* cls_bpf: allow attaching programs loaded for specific deviceJakub Kicinski2017-11-051-0/+1
| | | | | | | | | | If TC program is loaded with skip_sw flag, we should allow the device-specific programs to be accepted. 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>
* xdp: allow attaching programs loaded for specific deviceJakub Kicinski2017-11-051-4/+29
| | | | | | | | | | | Pass the netdev pointer to bpf_prog_get_type(). This way BPF code can decide whether the device matches what the code was loaded/translated for. 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>
* bpf: report offload info to user spaceJakub Kicinski2017-11-051-0/+5
| | | | | | | | | | | | 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>
* bpf: offload: add infrastructure for loading programs for a specific netdevJakub Kicinski2017-11-051-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* selinux: bpf: Add addtional check for bpf object file receiveChenbo Feng2017-10-201-2/+2
| | | | | | | | | | | | | | | Introduce a bpf object related check when sending and receiving files through unix domain socket as well as binder. It checks if the receiving process have privilege to read/write the bpf map or use the bpf program. This check is necessary because the bpf maps and programs are using a anonymous inode as their shared inode so the normal way of checking the files and sockets when passing between processes cannot work properly on eBPF object. This check only works when the BPF_SYSCALL is configured. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* security: bpf: Add LSM hooks for bpf object related syscallChenbo Feng2017-10-201-2/+32
| | | | | | | | | | | | | | | | Introduce several LSM hooks for the syscalls that will allow the userspace to access to eBPF object such as eBPF programs and eBPF maps. The security check is aimed to enforce a per object security protection for eBPF object so only processes with the right priviliges can read/write to a specific map or use a specific eBPF program. Besides that, a general security hook is added before the multiplexer of bpf syscall to check the cmd and the attribute used for the command. The actual security module can decide which command need to be checked and how the cmd should be checked. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: Add file mode configuration into bpf mapsChenbo Feng2017-10-201-10/+78
| | | | | | | | | | | | | | | Introduce the map read/write flags to the eBPF syscalls that returns the map fd. The flags is used to set up the file mode when construct a new file descriptor for bpf maps. To not break the backward capability, the f_flags is set to O_RDWR if the flag passed by syscall is 0. Otherwise it should be O_RDONLY or O_WRONLY. When the userspace want to modify or read the map content, it will check the file mode to see if it is allowed to make the change. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: remove the verifier ops from program structureJakub Kicinski2017-10-181-10/+0
| | | | | | | | | | | Since the verifier ops don't have to be associated with the program for its entire lifetime we can move it to verifier's struct bpf_verifier_env. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: split verifier and program opsJakub Kicinski2017-10-181-3/+13
| | | | | | | | | | | | | | struct bpf_verifier_ops contains both verifier ops and operations used later during program's lifetime (test_run). Split the runtime ops into a different structure. BPF_PROG_TYPE() will now append ## _prog_ops or ## _verifier_ops to the names. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAPJesper Dangaard Brouer2017-10-181-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'cpumap' is primarily used as a backend map for XDP BPF helper call bpf_redirect_map() and XDP_REDIRECT action, like 'devmap'. This patch implement the main part of the map. It is not connected to the XDP redirect system yet, and no SKB allocation are done yet. The main concern in this patch is to ensure the datapath can run without any locking. This adds complexity to the setup and tear-down procedure, which assumptions are extra carefully documented in the code comments. V2: - make sure array isn't larger than NR_CPUS - make sure CPUs added is a valid possible CPU V3: fix nitpicks from Jakub Kicinski <kubakici@wp.pl> V5: - Restrict map allocation to root / CAP_SYS_ADMIN - WARN_ON_ONCE if queue is not empty on tear-down - Return -EPERM on memlock limit instead of -ENOMEM - Error code in __cpu_map_entry_alloc() also handle ptr_ring_cleanup() - Moved cpu_map_enqueue() to next patch V6: all notice by Daniel Borkmann - Fix err return code in cpu_map_alloc() introduced in V5 - Move cpu_possible() check after max_entries boundary check - Forbid usage initially in check_map_func_compatibility() V7: - Fix alloc error path spotted by Daniel Borkmann - Did stress test adding+removing CPUs from the map concurrently - Fixed refcnt issue on cpu_map_entry, kthread started too soon - Make sure packets are flushed during tear-down, involved use of rcu_barrier() and kthread_run only exit after queue is empty - Fix alloc error path in __cpu_map_entry_alloc() for ptr_ring V8: - Nitpicking comments and gramma by Edward Cree - Fix missing semi-colon introduced in V7 due to rebasing - Move struct bpf_cpu_map_entry members cpu+map_id to tracepoint patch Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0Martin KaFai Lau2017-10-071-3/+2
| | | | | | | | | | | | | | | | | | During get_info_by_fd, the prog/map name is memcpy-ed. It depends on the prog->aux->name and map->name to be zero initialized. bpf_prog_aux is easy to guarantee that aux->name is zero init. The name in bpf_map may be harder to be guaranteed in the future when new map type is added. Hence, this patch makes bpf_obj_name_cpy() to always zero init the prog/map name. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: introduce BPF_PROG_QUERY commandAlexei Starovoitov2017-10-041-0/+34
| | | | | | | | | | | | | introduce BPF_PROG_QUERY command to retrieve a set of either attached programs to given cgroup or a set of effective programs that will execute for events within a cgroup Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: multi program support for cgroup+bpfAlexei Starovoitov2017-10-041-11/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | introduce BPF_F_ALLOW_MULTI flag that can be used to attach multiple bpf programs to a cgroup. The difference between three possible flags for BPF_PROG_ATTACH command: - NONE(default): No further bpf programs allowed in the subtree. - BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program, the program in this cgroup yields to sub-cgroup program. - BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program, that cgroup program gets run in addition to the program in this cgroup. NONE and BPF_F_ALLOW_OVERRIDE existed before. This patch doesn't change their behavior. It only clarifies the semantics in relation to new flag. Only one program is allowed to be attached to a cgroup with NONE or BPF_F_ALLOW_OVERRIDE flag. Multiple programs are allowed to be attached to a cgroup with BPF_F_ALLOW_MULTI flag. They are executed in FIFO order (those that were attached first, run first) The programs of sub-cgroup are executed first, then programs of this cgroup and then programs of parent cgroup. All eligible programs are executed regardless of return code from earlier programs. To allow efficient execution of multiple programs attached to a cgroup and to avoid penalizing cgroups without any programs attached introduce 'struct bpf_prog_array' which is RCU protected array of pointers to bpf programs. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: Fix compiler warning on info.map_ids for 32bit platformMartin KaFai Lau2017-10-011-1/+1
| | | | | | | | | | This patch uses u64_to_user_ptr() to cast info.map_ids to a userspace ptr. It also tags the user_map_ids with '__user' for sparse check. Fixes: cb4d2b3f03d8 ("bpf: Add name, load_time, uid and map_ids to bpf_prog_info") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: Add map_name to bpf_map_infoMartin KaFai Lau2017-09-291-1/+6
| | | | | | | | | | | | | This patch allows userspace to specify a name for a map during BPF_MAP_CREATE. The map's name can later be exported to user space via BPF_OBJ_GET_INFO_BY_FD. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: Add name, load_time, uid and map_ids to bpf_prog_infoMartin KaFai Lau2017-09-291-1/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch adds name and load_time to struct bpf_prog_aux. They are also exported to bpf_prog_info. The bpf_prog's name is passed by userspace during BPF_PROG_LOAD. The kernel only stores the first (BPF_PROG_NAME_LEN - 1) bytes and the name stored in the kernel is always \0 terminated. The kernel will reject name that contains characters other than isalnum() and '_'. It will also reject name that is not null terminated. The existing 'user->uid' of the bpf_prog_aux is also exported to the bpf_prog_info as created_by_uid. The existing 'used_maps' of the bpf_prog_aux is exported to the newly added members 'nr_map_ids' and 'map_ids' of the bpf_prog_info. On the input, nr_map_ids tells how big the userspace's map_ids buffer is. On the output, nr_map_ids tells the exact user_map_cnt and it will only copy up to the userspace's map_ids buffer is allowed. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: do not disable/enable BH in bpf_map_free_id()Eric Dumazet2017-09-191-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzkaller reported following splat [1] Since hard irq are disabled by the caller, bpf_map_free_id() should not try to enable/disable BH. Another solution would be to change htab_map_delete_elem() to defer the free_htab_elem() call after raw_spin_unlock_irqrestore(&b->lock, flags), but this might be not enough to cover other code paths. [1] WARNING: CPU: 1 PID: 8052 at kernel/softirq.c:161 __local_bh_enable_ip +0x1e/0x160 kernel/softirq.c:161 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 8052 Comm: syz-executor1 Not tainted 4.13.0-next-20170915+ #23 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x417 kernel/panic.c:181 __warn+0x1c4/0x1d9 kernel/panic.c:542 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:261 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905 RIP: 0010:__local_bh_enable_ip+0x1e/0x160 kernel/softirq.c:161 RSP: 0018:ffff8801cdcd7748 EFLAGS: 00010046 RAX: 0000000000000082 RBX: 0000000000000201 RCX: 0000000000000000 RDX: 1ffffffff0b5933c RSI: 0000000000000201 RDI: ffffffff85ac99e0 RBP: ffff8801cdcd7758 R08: ffffffff85b87158 R09: 1ffff10039b9aec6 R10: ffff8801c99f24c0 R11: 0000000000000002 R12: ffffffff817b0b47 R13: dffffc0000000000 R14: ffff8801cdcd77e8 R15: 0000000000000001 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:361 [inline] bpf_map_free_id kernel/bpf/syscall.c:197 [inline] __bpf_map_put+0x267/0x320 kernel/bpf/syscall.c:227 bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:235 bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96 free_htab_elem+0xc3/0x1b0 kernel/bpf/hashtab.c:658 htab_map_delete_elem+0x74d/0x970 kernel/bpf/hashtab.c:1063 map_delete_elem kernel/bpf/syscall.c:633 [inline] SYSC_bpf kernel/bpf/syscall.c:1479 [inline] SyS_bpf+0x2188/0x46a0 kernel/bpf/syscall.c:1451 entry_SYSCALL_64_fastpath+0x1f/0xbe Fixes: f3f1c054c288 ("bpf: Introduce bpf_map ID") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: add support for sockmap detach programsJohn Fastabend2017-09-081-10/+17
| | | | | | | | | | | | | | | | | | | The bpf map sockmap supports adding programs via attach commands. This patch adds the detach command to keep the API symmetric and allow users to remove previously added programs. Otherwise the user would have to delete the map and re-add it to get in this state. This also adds a series of additional tests to capture detach operation and also attaching/detaching invalid prog types. API note: socks will run (or not run) programs depending on the state of the map at the time the sock is added. We do not for example walk the map and remove programs from previously attached socks. Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: fix numa_node validationEric Dumazet2017-09-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzkaller reported crashes in bpf map creation or map update [1] Problem is that nr_node_ids is a signed integer, NUMA_NO_NODE is also an integer, so it is very tempting to declare numa_node as a signed integer. This means the typical test to validate a user provided value : if (numa_node != NUMA_NO_NODE && (numa_node >= nr_node_ids || !node_online(numa_node))) must be written : if (numa_node != NUMA_NO_NODE && ((unsigned int)numa_node >= nr_node_ids || !node_online(numa_node))) [1] kernel BUG at mm/slab.c:3256! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 2946 Comm: syzkaller916108 Not tainted 4.13.0-rc7+ #35 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d2bc60c0 task.stack: ffff8801c0c90000 RIP: 0010:____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292 RSP: 0018:ffff8801c0c97638 EFLAGS: 00010096 RAX: ffffffffffff8b7b RBX: 0000000001080220 RCX: 0000000000000000 RDX: 00000000ffff8b7b RSI: 0000000001080220 RDI: ffff8801dac00040 RBP: ffff8801c0c976c0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8801c0c97620 R11: 0000000000000001 R12: ffff8801dac00040 R13: ffff8801dac00040 R14: 0000000000000000 R15: 00000000ffff8b7b FS: 0000000002119940(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001fec CR3: 00000001d2980000 CR4: 00000000001406f0 Call Trace: __do_kmalloc_node mm/slab.c:3688 [inline] __kmalloc_node+0x33/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:535 [inline] alloc_htab_elem+0x2a8/0x480 kernel/bpf/hashtab.c:740 htab_map_update_elem+0x740/0xb80 kernel/bpf/hashtab.c:820 map_update_elem kernel/bpf/syscall.c:587 [inline] SYSC_bpf kernel/bpf/syscall.c:1468 [inline] SyS_bpf+0x20c5/0x4c40 kernel/bpf/syscall.c:1443 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x440409 RSP: 002b:00007ffd1f1792b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440409 RDX: 0000000000000020 RSI: 0000000020006000 RDI: 0000000000000002 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401d70 R13: 0000000000401e00 R14: 0000000000000000 R15: 0000000000000000 Code: 83 c2 01 89 50 18 4c 03 70 08 e8 38 f4 ff ff 4d 85 f6 0f 85 3e ff ff ff 44 89 fe 4c 89 ef e8 94 fb ff ff 49 89 c6 e9 2b ff ff ff <0f> 0b 0f 0b 0f 0b 66 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 RIP: ____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292 RSP: ffff8801c0c97638 ---[ end trace d745f355da2e33ce ]--- Kernel panic - not syncing: Fatal exception Fixes: 96eabe7a40aa ("bpf: Allow selecting numa node during map creation") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-13 09:30:56 +0000