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* bpf, ppc64: generalize fetching subprog into bpf_jit_get_func_addrDaniel Borkmann2018-11-261-0/+34
| | | | | | | | | | | | | | | | | | | Make fetching of the BPF call address from ppc64 JIT generic. ppc64 was using a slightly different variant rather than through the insns' imm field encoding as the target address would not fit into that space. Therefore, the target subprog number was encoded into the insns' offset and fetched through fp->aux->func[off]->bpf_func instead. Given there are other JITs with this issue and the mechanism of fetching the address is JIT-generic, move it into the core as a helper instead. On the JIT side, we get information on whether the retrieved address is a fixed one, that is, not changing through JIT passes, or a dynamic one. For the former, JITs can optimize their imm emission because this doesn't change jump offsets throughout JIT process. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Sandipan Das <sandipan@linux.ibm.com> Tested-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix integer overflow in queue_stack_mapAlexei Starovoitov2018-11-221-8/+8
| | | | | | | | | | | | | | Fix the following issues: - allow queue_stack_map for root only - fix u32 max_entries overflow - disallow value_size == 0 Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Reported-by: Wei Wu <ww9210@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Mauricio Vasquez B <mauricio.vasquez@polito.it> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: allocate local storage buffers using GFP_ATOMICRoman Gushchin2018-11-161-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Naresh reported an issue with the non-atomic memory allocation of cgroup local storage buffers: [ 73.047526] BUG: sleeping function called from invalid context at /srv/oe/build/tmp-rpb-glibc/work-shared/intel-corei7-64/kernel-source/mm/slab.h:421 [ 73.060915] in_atomic(): 1, irqs_disabled(): 0, pid: 3157, name: test_cgroup_sto [ 73.068342] INFO: lockdep is turned off. [ 73.072293] CPU: 2 PID: 3157 Comm: test_cgroup_sto Not tainted 4.20.0-rc2-next-20181113 #1 [ 73.080548] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.0b 07/27/2017 [ 73.088018] Call Trace: [ 73.090463] dump_stack+0x70/0xa5 [ 73.093783] ___might_sleep+0x152/0x240 [ 73.097619] __might_sleep+0x4a/0x80 [ 73.101191] __kmalloc_node+0x1cf/0x2f0 [ 73.105031] ? cgroup_storage_update_elem+0x46/0x90 [ 73.109909] cgroup_storage_update_elem+0x46/0x90 cgroup_storage_update_elem() (as well as other update map update callbacks) is called with disabled preemption, so GFP_ATOMIC allocation should be used: e.g. alloc_htab_elem() in hashtab.c. Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix off-by-one error in adjust_subprog_startsEdward Cree2018-11-161-1/+1
| | | | | | | | | | | | | When patching in a new sequence for the first insn of a subprog, the start of that subprog does not change (it's the first insn of the sequence), so adjust_subprog_starts should check start <= off (rather than < off). Also added a test to test_verifier.c (it's essentially the syz reproducer). Fixes: cc8b0b92a169 ("bpf: introduce function calls (function boundaries)") Reported-by: syzbot+4fc427c7af994b0948be@syzkaller.appspotmail.com Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix bpf_prog_get_info_by_fd to return 0 func_lens for unprivDaniel Borkmann2018-11-021-0/+1
| | | | | | | | | | | | | | | While dbecd7388476 ("bpf: get kernel symbol addresses via syscall") zeroed info.nr_jited_ksyms in bpf_prog_get_info_by_fd() for queries from unprivileged users, commit 815581c11cc2 ("bpf: get JITed image lengths of functions via syscall") forgot about doing so and therefore returns the #elems of the user set up buffer which is incorrect. It also needs to indicate a info.nr_jited_func_lens of zero. Fixes: 815581c11cc2 ("bpf: get JITed image lengths of functions via syscall") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Sandipan Das <sandipan@linux.vnet.ibm.com> Cc: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: show main program address and length in bpf_prog_infoSong Liu2018-11-021-9/+24
| | | | | | | | | | Currently, when there is no subprog (prog->aux->func_cnt == 0), bpf_prog_info does not return any jited_ksyms or jited_func_lens. This patch adds main program address (prog->bpf_func) and main program length (prog->jited_len) to bpf_prog_info. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: show real jited address in bpf_prog_info->jited_ksymsSong Liu2018-11-021-1/+0
| | | | | | | | | | | | | | Currently, jited_ksyms in bpf_prog_info shows page addresses of jited bpf program. The main reason here is to not expose randomized start address. However, this is not ideal for detailed profiling (find hot instructions from stack traces). This patch replaces the page address with real prog start address. This change is OK because bpf_prog_get_info_by_fd() is only available to root. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: show real jited prog address in /proc/kallsymsSong Liu2018-11-021-3/+1
| | | | | | | | | | | | | | | Currently, /proc/kallsyms shows page address of jited bpf program. The main reason here is to not expose randomized start address. However, This is not ideal for detailed profiling (find hot instructions from stack traces). This patch replaces the page address with real prog start address. This change is OK because these addresses are still protected by sysctl kptr_restrict (see kallsyms_show_value()), and only programs loaded by root are added to kallsyms (see bpf_prog_kallsyms_add()). Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: don't set id on after map lookup with ptr_to_map_val returnDaniel Borkmann2018-10-311-5/+6
| | | | | | | | | | | | | | In the verifier there is no such semantics where registers with PTR_TO_MAP_VALUE type have an id assigned to them. This is only used in PTR_TO_MAP_VALUE_OR_NULL and later on nullified once the test against NULL has been pattern matched and type transformed into PTR_TO_MAP_VALUE. Fixes: 3e6a4b3e0289 ("bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Roman Gushchin <guro@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix partial copy of map_ptr when dst is scalarDaniel Borkmann2018-10-311-4/+6
| | | | | | | | | | | | | | | | ALU operations on pointers such as scalar_reg += map_value_ptr are handled in adjust_ptr_min_max_vals(). Problem is however that map_ptr and range in the register state share a union, so transferring state through dst_reg->range = ptr_reg->range is just buggy as any new map_ptr in the dst_reg is then truncated (or null) for subsequent checks. Fix this by adding a raw member and use it for copying state over to dst_reg. Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Edward Cree <ecree@solarflare.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add bpf_jit_limit knob to restrict unpriv allocationsDaniel Borkmann2018-10-251-3/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rick reported that the BPF JIT could potentially fill the entire module space with BPF programs from unprivileged users which would prevent later attempts to load normal kernel modules or privileged BPF programs, for example. If JIT was enabled but unsuccessful to generate the image, then before commit 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config") we would always fall back to the BPF interpreter. Nowadays in the case where the CONFIG_BPF_JIT_ALWAYS_ON could be set, then the load will abort with a failure since the BPF interpreter was compiled out. Add a global limit and enforce it for unprivileged users such that in case of BPF interpreter compiled out we fail once the limit has been reached or we fall back to BPF interpreter earlier w/o using module mem if latter was compiled in. In a next step, fair share among unprivileged users can be resolved in particular for the case where we would fail hard once limit is reached. Fixes: 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config") Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64") Co-Developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: LKML <linux-kernel@vger.kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: make direct packet write unclone more robustDaniel Borkmann2018-10-251-1/+5
| | | | | | | | | | | | | | Given this seems to be quite fragile and can easily slip through the cracks, lets make direct packet write more robust by requiring that future program types which allow for such write must provide a prologue callback. In case of XDP and sk_msg it's noop, thus add a generic noop handler there. The latter starts out with NULL data/data_end unconditionally when sg pages are shared. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix leaking uninitialized memory on pop/peek helpersDaniel Borkmann2018-10-251-0/+2
| | | | | | | | | | | | | | | | | | | Commit f1a2e44a3aec ("bpf: add queue and stack maps") added helpers with ARG_PTR_TO_UNINIT_MAP_VALUE. Meaning, the helper is supposed to fill the map value buffer with data instead of reading from it like in other helpers such as map update. However, given the buffer is allowed to be uninitialized (since we fill it in the helper anyway), it also means that the helper is obliged to wipe the memory in case of an error in order to not allow for leaking uninitialized memory. Given pop/peek is both handled inside __{stack,queue}_map_get(), lets wipe it there on error case, that is, empty stack/queue. Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Mauricio Vasquez B<mauricio.vasquez@polito.it> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix direct packet write into pop/peek helpersDaniel Borkmann2018-10-251-2/+0
| | | | | | | | | | | | | | Commit f1a2e44a3aec ("bpf: add queue and stack maps") probably just copy-pasted .pkt_access for bpf_map_{pop,peek}_elem() helpers, but this is buggy in this context since it would allow writes into cloned skbs which is invalid. Therefore, disable .pkt_access for the two. Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Mauricio Vasquez B<mauricio.vasquez@polito.it> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix cg_skb types to hint access type in may_access_direct_pkt_dataDaniel Borkmann2018-10-251-0/+1
| | | | | | | | | | | | | | | | | | Commit b39b5f411dcf ("bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB") added direct packet access for skbs in cg_skb program types, however allowed access type was not added to the may_access_direct_pkt_data() helper. Therefore the latter always returns false. This is not directly an issue, it just means writes are unconditionally disabled (which is correct) but also reads. Latter is relevant in this function when BPF helpers may read direct packet data which is unconditionally disabled then. Fix it by properly adding BPF_PROG_TYPE_CGROUP_SKB to may_access_direct_pkt_data(). Fixes: b39b5f411dcf ("bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix direct packet access for flow dissector progsDaniel Borkmann2018-10-251-2/+4
| | | | | | | | | | | | | | | | | Commit d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") added direct packet access for skbs in may_access_direct_pkt_data() function where this enables read and write access to the skb->data. This is buggy because without a prologue generator such as bpf_unclone_prologue() we would allow for writing into cloned skbs. Original intention might have been to only allow read access where this is not needed (similar as the flow_dissector_func_proto() indicates which enables only bpf_skb_load_bytes() as well), therefore this patch fixes it to restrict to read-only. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Petar Penkov <ppenkov@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf, btf: fix a missing check bug in btf_parseMartin Lau2018-10-261-33/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Wenwen Wang reported: In btf_parse(), the header of the user-space btf data 'btf_data' is firstly parsed and verified through btf_parse_hdr(). In btf_parse_hdr(), the header is copied from user-space 'btf_data' to kernel-space 'btf->hdr' and then verified. If no error happens during the verification process, the whole data of 'btf_data', including the header, is then copied to 'data' in btf_parse(). It is obvious that the header is copied twice here. More importantly, no check is enforced after the second copy to make sure the headers obtained in these two copies are same. Given that 'btf_data' resides in the user space, a malicious user can race to modify the header between these two copies. By doing so, the user can inject inconsistent data, which can cause undefined behavior of the kernel and introduce potential security risk. This issue is similar to the one fixed in commit 8af03d1ae2e1 ("bpf: btf: Fix a missing check bug"). To fix it, this patch copies the user 'btf_data' *before* parsing / verifying the BTF header. Fixes: 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Co-developed-by: Wenwen Wang <wang6495@umn.edu> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: devmap: fix wrong interface selection in notifier_callTaehee Yoo2018-10-261-2/+1
| | | | | | | | | | | | | | | | The dev_map_notification() removes interface in devmap if unregistering interface's ifindex is same. But only checking ifindex is not enough because other netns can have same ifindex. so that wrong interface selection could occurred. Hence netdev pointer comparison code is added. v2: compare netdev pointer instead of using net_eq() (Daniel Borkmann) v1: Initial patch Fixes: 2ddf71e23cc2 ("net: add notifier hooks for devmap bpf map") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2018-10-218-20/+500
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2018-10-21 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Implement two new kind of BPF maps, that is, queue and stack map along with new peek, push and pop operations, from Mauricio. 2) Add support for MSG_PEEK flag when redirecting into an ingress psock sk_msg queue, and add a new helper bpf_msg_push_data() for insert data into the message, from John. 3) Allow for BPF programs of type BPF_PROG_TYPE_CGROUP_SKB to use direct packet access for __skb_buff, from Song. 4) Use more lightweight barriers for walking perf ring buffer for libbpf and perf tool as well. Also, various fixes and improvements from verifier side, from Daniel. 5) Add per-symbol visibility for DSO in libbpf and hide by default global symbols such as netlink related functions, from Andrey. 6) Two improvements to nfp's BPF offload to check vNIC capabilities in case prog is shared with multiple vNICs and to protect against mis-initializing atomic counters, from Jakub. 7) Fix for bpftool to use 4 context mode for the nfp disassembler, also from Jakub. 8) Fix a return value comparison in test_libbpf.sh and add several bpftool improvements in bash completion, documentation of bpf fs restrictions and batch mode summary print, from Quentin. 9) Fix a file resource leak in BPF selftest's load_kallsyms() helper, from Peng. 10) Fix an unused variable warning in map_lookup_and_delete_elem(), from Alexei. 11) Fix bpf_skb_adjust_room() signature in BPF UAPI helper doc, from Nicolas. 12) Add missing executables to .gitignore in BPF selftests, from Anders. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf, verifier: avoid retpoline for map push/pop/peek operationDaniel Borkmann2018-10-201-1/+24
| | | | | | | | | | | | | | | | | | | | Extend prior work from 09772d92cd5a ("bpf: avoid retpoline for lookup/update/delete calls on maps") to also apply to the recently added map helpers that perform push/pop/peek operations so that the indirect call can be avoided. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf, verifier: remove unneeded flow key in check_helper_mem_accessDaniel Borkmann2018-10-201-2/+0
| | | | | | | | | | | | | | | | They PTR_TO_FLOW_KEYS is not used today to be passed into a helper as memory, so it can be removed from check_helper_mem_access(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf, verifier: reject xadd on flow key memoryDaniel Borkmann2018-10-201-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We should not enable xadd operation for flow key memory if not needed there anyway. There is no such issue as described in the commit f37a8cb84cce ("bpf: reject stores into ctx via st and xadd") since there's no context rewriter for flow keys today, but it also shouldn't become part of the user facing behavior to allow for it. After patch: 0: (79) r7 = *(u64 *)(r1 +144) 1: (b7) r3 = 4096 2: (db) lock *(u64 *)(r7 +0) += r3 BPF_XADD stores into R7 flow_keys is not allowed Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf, verifier: fix register type dump in xadd and stDaniel Borkmann2018-10-201-6/+13
| | | | | | | | | | | | | | | | | | | | | | Using reg_type_str[insn->dst_reg] is incorrect since insn->dst_reg contains the register number but not the actual register type. Add a small reg_state() helper and use it to get to the type. Also fix up the test_verifier test cases that have an incorrect errstr. Fixes: 9d2be44a7f33 ("bpf: Reuse canonical string formatter for ctx errs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: remove unused variableAlexei Starovoitov2018-10-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | fix the following warning ../kernel/bpf/syscall.c: In function ‘map_lookup_and_delete_elem’: ../kernel/bpf/syscall.c:1010:22: warning: unused variable ‘ptr’ [-Wunused-variable] void *key, *value, *ptr; ^~~ Fixes: bd513cd08f10 ("bpf: add MAP_LOOKUP_AND_DELETE_ELEM syscall") Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKBSong Liu2018-10-191-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | BPF programs of BPF_PROG_TYPE_CGROUP_SKB need to access headers in the skb. This patch enables direct access of skb for these programs. Two helper functions bpf_compute_and_save_data_end() and bpf_restore_data_end() are introduced. There are used in __cgroup_bpf_run_filter_skb(), to compute proper data_end for the BPF program, and restore original data afterwards. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: add MAP_LOOKUP_AND_DELETE_ELEM syscallMauricio Vasquez B2018-10-191-0/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | The previous patch implemented a bpf queue/stack maps that provided the peek/pop/push functions. There is not a direct relationship between those functions and the current maps syscalls, hence a new MAP_LOOKUP_AND_DELETE_ELEM syscall is added, this is mapped to the pop operation in the queue/stack maps and it is still to implement in other kind of maps. Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: add queue and stack mapsMauricio Vasquez B2018-10-196-2/+359
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Queue/stack maps implement a FIFO/LIFO data storage for ebpf programs. These maps support peek, pop and push operations that are exposed to eBPF programs through the new bpf_map[peek/pop/push] helpers. Those operations are exposed to userspace applications through the already existing syscalls in the following way: BPF_MAP_LOOKUP_ELEM -> peek BPF_MAP_LOOKUP_AND_DELETE_ELEM -> pop BPF_MAP_UPDATE_ELEM -> push Queue/stack maps are implemented using a buffer, tail and head indexes, hence BPF_F_NO_PREALLOC is not supported. As opposite to other maps, queue and stack do not use RCU for protecting maps values, the bpf_map[peek/pop] have a ARG_PTR_TO_UNINIT_MAP_VALUE argument that is a pointer to a memory zone where to save the value of a map. Basically the same as ARG_PTR_TO_UNINIT_MEM, but the size has not be passed as an extra argument. Our main motivation for implementing queue/stack maps was to keep track of a pool of elements, like network ports in a SNAT, however we forsee other use cases, like for exampling saving last N kernel events in a map and then analysing from userspace. Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf/verifier: add ARG_PTR_TO_UNINIT_MAP_VALUEMauricio Vasquez B2018-10-191-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ARG_PTR_TO_UNINIT_MAP_VALUE argument is a pointer to a memory zone used to save the value of a map. Basically the same as ARG_PTR_TO_UNINIT_MEM, but the size has not be passed as an extra argument. This will be used in the following patch that implements some new helpers that receive a pointer to be filled with a map value. Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf/syscall: allow key to be null in map functionsMauricio Vasquez B2018-10-191-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds the required logic to allow key being NULL in case the key_size of the map is 0. A new __bpf_copy_key function helper only copies the key from userpsace when key_size != 0, otherwise it enforces that key must be null. Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: rename stack trace map operationsMauricio Vasquez B2018-10-191-1/+1
| | | | | | | | | | | | | | | | | | | | In the following patches queue and stack maps (FIFO and LIFO datastructures) will be implemented. In order to avoid confusion and a possible name clash rename stack_map_ops to stack_trace_map_ops Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-10-191-8/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | 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>
| * xsk: do not call synchronize_net() under RCU read lockBjörn Töpel2018-10-111-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | bpf, sockmap: convert to generic sk_msg interfaceDaniel Borkmann2018-10-154-2620/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a generic sk_msg layer, and convert current sockmap and later kTLS over to make use of it. While sk_buff handles network packet representation from netdevice up to socket, sk_msg handles data representation from application to socket layer. This means that sk_msg framework spans across ULP users in the kernel, and enables features such as introspection or filtering of data with the help of BPF programs that operate on this data structure. Latter becomes in particular useful for kTLS where data encryption is deferred into the kernel, and as such enabling the kernel to perform L7 introspection and policy based on BPF for TLS connections where the record is being encrypted after BPF has run and came to a verdict. In order to get there, first step is to transform open coding of scatter-gather list handling into a common core framework that subsystems can use. The code itself has been split and refactored into three bigger pieces: i) the generic sk_msg API which deals with managing the scatter gather ring, providing helpers for walking and mangling, transferring application data from user space into it, and preparing it for BPF pre/post-processing, ii) the plain sock map itself where sockets can be attached to or detached from; these bits are independent of i) which can now be used also without sock map, and iii) the integration with plain TCP as one protocol to be used for processing L7 application data (later this could e.g. also be extended to other protocols like UDP). The semantics are the same with the old sock map code and therefore no change of user facing behavior or APIs. While pursuing this work it also helped finding a number of bugs in the old sockmap code that we've fixed already in earlier commits. The test_sockmap kselftest suite passes through fine as well. Joint work with John. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | tcp, ulp: remove ulp bits from sockmapDaniel Borkmann2018-10-151-29/+10
| | | | | | | | | | | | | | | | | | | | | | | | In order to prepare sockmap logic to be used in combination with kTLS we need to detangle it from ULP, and further split it in later commits into a generic API. Joint work with John. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: wait for running BPF programs when updating map-in-mapDaniel Colascione2018-10-121-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The map-in-map frequently serves as a mechanism for atomic snapshotting of state that a BPF program might record. The current implementation is dangerous to use in this way, however, since userspace has no way of knowing when all programs that might have retrieved the "old" value of the map may have completed. This change ensures that map update operations on map-in-map map types always wait for all references to the old map to drop before returning to userspace. Signed-off-by: Daniel Colascione <dancol@google.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: return EOPNOTSUPP when map lookup isn't supportedPrashant Bhole2018-10-094-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | bpf: error handling when map_lookup_elem isn't supportedPrashant Bhole2018-10-091-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The error value returned by map_lookup_elem doesn't differentiate whether lookup was failed because of invalid key or lookup is not supported. Lets add handling for -EOPNOTSUPP return value of map_lookup_elem() method of map, with expectation from map's implementation that it should return -EOPNOTSUPP if lookup is not supported. The errno for bpf syscall for BPF_MAP_LOOKUP_ELEM command will be set to EOPNOTSUPP if map lookup is not supported. 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>
* | bpf: btf: Fix a missing check bugWenwen Wang2018-10-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In btf_parse_hdr(), the length of the btf data header is firstly copied from the user space to 'hdr_len' and checked to see whether it is larger than 'btf_data_size'. If yes, an error code EINVAL is returned. Otherwise, the whole header is copied again from the user space to 'btf->hdr'. However, after the second copy, there is no check between 'btf->hdr->hdr_len' and 'hdr_len' to confirm that the two copies get the same value. Given that the btf data is in the user space, a malicious user can race to change the data between the two copies. By doing so, the user can provide malicious data to the kernel and cause undefined behavior. This patch adds a necessary check after the second copy, to make sure 'btf->hdr->hdr_len' has the same value as 'hdr_len'. Otherwise, an error code EINVAL will be returned. Signed-off-by: Wenwen Wang <wang6495@umn.edu> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2018-10-087-184/+767
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2018-10-08 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) sk_lookup_[tcp|udp] and sk_release helpers from Joe Stringer which allow BPF programs to perform lookups for sockets in a network namespace. This would allow programs to determine early on in processing whether the stack is expecting to receive the packet, and perform some action (eg drop, forward somewhere) based on this information. 2) per-cpu cgroup local storage from Roman Gushchin. Per-cpu cgroup local storage is very similar to simple cgroup storage except all the data is per-cpu. The main goal of per-cpu variant is to implement super fast counters (e.g. packet counters), which don't require neither lookups, neither atomic operations in a fast path. The example of these hybrid counters is in selftests/bpf/netcnt_prog.c 3) allow HW offload of programs with BPF-to-BPF function calls from Quentin Monnet 4) support more than 64-byte key/value in HW offloaded BPF maps from Jakub Kicinski 5) rename of libbpf interfaces from Andrey Ignatov. libbpf is maturing as a library and should follow good practices in library design and implementation to play well with other libraries. This patch set brings consistent naming convention to global symbols. 6) relicense libbpf as LGPL-2.1 OR BSD-2-Clause from Alexei Starovoitov to let Apache2 projects use libbpf 7) various AF_XDP fixes from Björn and Magnus ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * | bpf: allow offload of programs with BPF-to-BPF function callsQuentin Monnet2018-10-081-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that there is at least one driver supporting BPF-to-BPF function calls, lift the restriction, in the verifier, on hardware offload of eBPF programs containing such calls. But prevent jit_subprogs(), still in the verifier, from being run for offloaded programs. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: add verifier callback to get stack usage info for offloaded progsQuentin Monnet2018-10-082-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for BPF-to-BPF calls in offloaded programs, add a new function attribute to the struct bpf_prog_offload_ops so that drivers supporting eBPF offload can hook at the end of program verification, and potentially extract information collected by the verifier. Implement a minimal callback (returning 0) in the drivers providing the structs, namely netdevsim and nfp. This will be useful in the nfp driver, in later commits, to extract the number of subprograms as well as the stack depth for those subprograms. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Add helper to retrieve socket in BPFJoe Stringer2018-10-031-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds new BPF helper functions, bpf_sk_lookup_tcp() and bpf_sk_lookup_udp() which allows BPF programs to find out if there is a socket listening on this host, and returns a socket pointer which the BPF program can then access to determine, for instance, whether to forward or drop traffic. bpf_sk_lookup_xxx() may take a reference on the socket, so when a BPF program makes use of this function, it must subsequently pass the returned pointer into the newly added sk_release() to return the reference. By way of example, the following pseudocode would filter inbound connections at XDP if there is no corresponding service listening for the traffic: struct bpf_sock_tuple tuple; struct bpf_sock_ops *sk; populate_tuple(ctx, &tuple); // Extract the 5tuple from the packet sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof tuple, netns, 0); if (!sk) { // Couldn't find a socket listening for this traffic. Drop. return TC_ACT_SHOT; } bpf_sk_release(sk, 0); return TC_ACT_OK; Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Add reference tracking to verifierJoe Stringer2018-10-031-19/+287
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow helper functions to acquire a reference and return it into a register. Specific pointer types such as the PTR_TO_SOCKET will implicitly represent such a reference. The verifier must ensure that these references are released exactly once in each path through the program. To achieve this, this commit assigns an id to the pointer and tracks it in the 'bpf_func_state', then when the function or program exits, verifies that all of the acquired references have been freed. When the pointer is passed to a function that frees the reference, it is removed from the 'bpf_func_state` and all existing copies of the pointer in registers are marked invalid. Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Macrofy stack state copyJoe Stringer2018-10-031-46/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An upcoming commit will need very similar copy/realloc boilerplate, so refactor the existing stack copy/realloc functions into macros to simplify it. Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Add PTR_TO_SOCKET verifier typeJoe Stringer2018-10-031-14/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach the verifier a little bit about a new type of pointer, a PTR_TO_SOCKET. This pointer type is accessed from BPF through the 'struct bpf_sock' structure. Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Generalize ptr_or_null regs checkJoe Stringer2018-10-031-18/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | This check will be reused by an upcoming commit for conditional jump checks for sockets. Refactor it a bit to simplify the later commit. Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Reuse canonical string formatter for ctx errsJoe Stringer2018-10-031-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The array "reg_type_str" provides canonical formatting of register types, however a couple of places would previously check whether a register represented the context and write the name "context" directly. An upcoming commit will add another pointer type to these statements, so to provide more accurate error messages in the verifier, update these error messages to use "reg_type_str" instead. Signed-off-by: Joe Stringer <joe@wand.net.nz> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Simplify ptr_min_max_vals adjustmentJoe Stringer2018-10-031-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | An upcoming commit will add another two pointer types that need very similar behaviour, so generalise this function now. Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: Add iterator for spilled registersJoe Stringer2018-10-031-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add this iterator for spilled registers, it concentrates the details of how to get the current frame's spilled registers into a single macro while clarifying the intention of the code which is calling the macro. Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: don't allow create maps of per-cpu cgroup local storagesRoman Gushchin2018-10-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Explicitly forbid creating map of per-cpu cgroup local storages. This behavior matches the behavior of shared cgroup storages. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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