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2019-01-02bpf: restrict stack pointer arithmetic for unprivilegedDaniel Borkmann1-22/+41
Restrict stack pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a stack pointer as a destination we simulate a check_stack_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. This is analog to map value pointer arithmetic and needed for masking later on. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-02bpf: restrict map value pointer arithmetic for unprivilegedDaniel Borkmann1-0/+11
Restrict map value pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a map value pointer as a destination it will simulate a check_map_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. We use this later on for masking any pointer arithmetic with the remainder of the map value space. The likelihood of breaking any existing real-world unprivileged eBPF program is very small for this corner case. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-02bpf: enable access to ax register also from verifier rewriteDaniel Borkmann1-0/+20
Right now we are using BPF ax register in JIT for constant blinding as well as in interpreter as temporary variable. Verifier will not be able to use it simply because its use will get overridden from the former in bpf_jit_blind_insn(). However, it can be made to work in that blinding will be skipped if there is prior use in either source or destination register on the instruction. Taking constraints of ax into account, the verifier is then open to use it in rewrites under some constraints. Note, ax register already has mappings in every eBPF JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-02bpf: move tmp variable into ax register in interpreterDaniel Borkmann1-17/+17
This change moves the on-stack 64 bit tmp variable in ___bpf_prog_run() into the hidden ax register. The latter is currently only used in JITs for constant blinding as a temporary scratch register, meaning the BPF interpreter will never see the use of ax. Therefore it is safe to use it for the cases where tmp has been used earlier. This is needed to later on allow restricted hidden use of ax in both interpreter and JITs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-02bpf: move {prev_,}insn_idx into verifier envDaniel Borkmann1-38/+38
Move prev_insn_idx and insn_idx from the do_check() function into the verifier environment, so they can be read inside the various helper functions for handling the instructions. It's easier to put this into the environment rather than changing all call-sites only to pass it along. insn_idx is useful in particular since this later on allows to hold state in env->insn_aux_data[env->insn_idx]. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller7-100/+702
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-12-21 The following pull-request contains BPF updates for your *net-next* tree. There is a merge conflict in test_verifier.c. Result looks as follows: [...] }, { "calls: cross frame pruning", .insns = { [...] .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, .errstr_unpriv = "function calls to other bpf functions are allowed for root only", .result_unpriv = REJECT, .errstr = "!read_ok", .result = REJECT, }, { "jset: functional", .insns = { [...] { "jset: unknown const compare not taken", .insns = { BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32), BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 1), BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), BPF_EXIT_INSN(), }, .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, .errstr_unpriv = "!read_ok", .result_unpriv = REJECT, .errstr = "!read_ok", .result = REJECT, }, [...] { "jset: range", .insns = { [...] }, .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, .result_unpriv = ACCEPT, .result = ACCEPT, }, The main changes are: 1) Various BTF related improvements in order to get line info working. Meaning, verifier will now annotate the corresponding BPF C code to the error log, from Martin and Yonghong. 2) Implement support for raw BPF tracepoints in modules, from Matt. 3) Add several improvements to verifier state logic, namely speeding up stacksafe check, optimizations for stack state equivalence test and safety checks for liveness analysis, from Alexei. 4) Teach verifier to make use of BPF_JSET instruction, add several test cases to kselftests and remove nfp specific JSET optimization now that verifier has awareness, from Jakub. 5) Improve BPF verifier's slot_type marking logic in order to allow more stack slot sharing, from Jiong. 6) Add sk_msg->size member for context access and add set of fixes and improvements to make sock_map with kTLS usable with openssl based applications, from John. 7) Several cleanups and documentation updates in bpftool as well as auto-mount of tracefs for "bpftool prog tracelog" command, from Quentin. 8) Include sub-program tags from now on in bpf_prog_info in order to have a reliable way for user space to get all tags of the program e.g. needed for kallsyms correlation, from Song. 9) Add BTF annotations for cgroup_local_storage BPF maps and implement bpf fs pretty print support, from Roman. 10) Fix bpftool in order to allow for cross-compilation, from Ivan. 11) Update of bpftool license to GPLv2-only + BSD-2-Clause in order to be compatible with libbfd and allow for Debian packaging, from Jakub. 12) Remove an obsolete prog->aux sanitation in dump and get rid of version check for prog load, from Daniel. 13) Fix a memory leak in libbpf's line info handling, from Prashant. 14) Fix cpumap's frame alignment for build_skb() so that skb_shared_info does not get unaligned, from Jesper. 15) Fix test_progs kselftest to work with older compilers which are less smart in optimizing (and thus throwing build error), from Stanislav. 16) Cleanup and simplify AF_XDP socket teardown, from Björn. 17) Fix sk lookup in BPF kselftest's test_sock_addr with regards to netns_id argument, from Andrey. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20bpf/cpumap: make sure frame_size for build_skb is aligned if headroom isn'tJesper Dangaard Brouer1-1/+1
The frame_size passed to build_skb must be aligned, else it is possible that the embedded struct skb_shared_info gets unaligned. For correctness make sure that xdpf->headroom in included in the alignment. No upstream drivers can hit this, as all XDP drivers provide an aligned headroom. This was discovered when playing with implementing XDP support for mvneta, which have a 2 bytes DSA header, and this Marvell ARM64 platform didn't like doing atomic operations on an unaligned skb_shinfo(skb)->dataref addresses. Fixes: 1c601d829ab0 ("bpf: cpumap xdp_buff to skb conversion and allocation") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-9/+25
Lots of conflicts, by happily all cases of overlapping changes, parallel adds, things of that nature. Thanks to Stephen Rothwell, Saeed Mahameed, and others for their guidance in these resolutions. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20bpf: verifier: reorder stack size check with dead code sanitizationJakub Kicinski1-2/+3
Reorder the calls to check_max_stack_depth() and sanitize_dead_code() to separate functions which can rewrite instructions from pure checks. No functional changes. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20bpf: verifier: teach the verifier to reason about the BPF_JSET instructionJakub Kicinski1-0/+20
Some JITs (nfp) try to optimize code on their own. It could make sense in case of BPF_JSET instruction which is currently not interpreted by the verifier, meaning for instance that dead could would not be detected if it was under BPF_JSET branch. Teach the verifier basics of BPF_JSET, JIT optimizations will be removed shortly. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-19bpf: Ensure line_info.insn_off cannot point to insn with zero codeMartin KaFai Lau1-0/+8
This patch rejects a line_info if the bpf insn code referred by line_info.insn_off is 0. F.e. a broken userspace tool might generate a line_info.insn_off that points to the second 8 bytes of a BPF_LD_IMM64. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-19bpf: log struct/union attribute for forward typeYonghong Song1-1/+7
Current btf internal verbose logger logs fwd type as [2] FWD A type_id=0 where A is the type name. Commit 9d5f9f701b18 ("bpf: btf: fix struct/union/fwd types with kind_flag") introduced kind_flag which can be used to distinguish whether a forward type is a struct or union. Also, "type_id=0" does not carry any meaningful information for fwd type as btf_type.type = 0 is simply enforced during btf verification and is not used anywhere else. This commit changed the log to [2] FWD A struct if kind_flag = 0, or [2] FWD A union if kind_flag = 1. Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-18bpf: correct slot_type marking logic to allow more stack slot sharingJiong Wang1-0/+5
Verifier is supposed to support sharing stack slot allocated to ptr with SCALAR_VALUE for privileged program. However this doesn't happen for some cases. The reason is verifier is not clearing slot_type STACK_SPILL for all bytes, it only clears part of them, while verifier is using: slot_type[0] == STACK_SPILL as a convention to check one slot is ptr type. So, the consequence of partial clearing slot_type is verifier could treat a partially overridden ptr slot, which should now be a SCALAR_VALUE slot, still as ptr slot, and rejects some valid programs. Before this patch, test_xdp_noinline.o under bpf selftests, bpf_lxc.o and bpf_netdev.o under Cilium bpf repo, when built with -mattr=+alu32 are rejected due to this issue. After this patch, they all accepted. There is no processed insn number change before and after this patch on Cilium bpf programs. Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-18bpf: support raw tracepoints in modulesMatt Mullins1-3/+8
Distributions build drivers as modules, including network and filesystem drivers which export numerous tracepoints. This enables bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints. Signed-off-by: Matt Mullins <mmullins@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-18bpf: enable cgroup local storage map pretty print with kind_flagYonghong Song2-22/+32
Commit 970289fc0a83 ("bpf: add bpffs pretty print for cgroup local storage maps") added bpffs pretty print for cgroup local storage maps. The commit worked for struct without kind_flag set. This patch refactored and made pretty print also work with kind_flag set for the struct. Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-18bpf: btf: fix struct/union/fwd types with kind_flagYonghong Song1-20/+260
This patch fixed two issues with BTF. One is related to struct/union bitfield encoding and the other is related to forward type. Issue #1 and solution: ====================== Current btf encoding of bitfield follows what pahole generates. For each bitfield, pahole will duplicate the type chain and put the bitfield size at the final int or enum type. Since the BTF enum type cannot encode bit size, pahole workarounds the issue by generating an int type whenever the enum bit size is not 32. For example, -bash-4.4$ cat t.c typedef int ___int; enum A { A1, A2, A3 }; struct t { int a[5]; ___int b:4; volatile enum A c:4; } g; -bash-4.4$ gcc -c -O2 -g t.c The current kernel supports the following BTF encoding: $ pahole -JV t.o [1] TYPEDEF ___int type_id=2 [2] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED [3] ENUM A size=4 vlen=3 A1 val=0 A2 val=1 A3 val=2 [4] STRUCT t size=24 vlen=3 a type_id=5 bits_offset=0 b type_id=9 bits_offset=160 c type_id=11 bits_offset=164 [5] ARRAY (anon) type_id=2 index_type_id=2 nr_elems=5 [6] INT sizetype size=8 bit_offset=0 nr_bits=64 encoding=(none) [7] VOLATILE (anon) type_id=3 [8] INT int size=1 bit_offset=0 nr_bits=4 encoding=(none) [9] TYPEDEF ___int type_id=8 [10] INT (anon) size=1 bit_offset=0 nr_bits=4 encoding=SIGNED [11] VOLATILE (anon) type_id=10 Two issues are in the above: . by changing enum type to int, we lost the original type information and this will not be ideal later when we try to convert BTF to a header file. . the type duplication for bitfields will cause BTF bloat. Duplicated types cannot be deduplicated later if the bitfield size is different. To fix this issue, this patch implemented a compatible change for BTF struct type encoding: . the bit 31 of struct_type->info, previously reserved, now is used to indicate whether bitfield_size is encoded in btf_member or not. . if bit 31 of struct_type->info is set, btf_member->offset will encode like: bit 0 - 23: bit offset bit 24 - 31: bitfield size if bit 31 is not set, the old behavior is preserved: bit 0 - 31: bit offset So if the struct contains a bit field, the maximum bit offset will be reduced to (2^24 - 1) instead of MAX_UINT. The maximum bitfield size will be 256 which is enough for today as maximum bitfield in compiler can be 128 where int128 type is supported. This kernel patch intends to support the new BTF encoding: $ pahole -JV t.o [1] TYPEDEF ___int type_id=2 [2] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED [3] ENUM A size=4 vlen=3 A1 val=0 A2 val=1 A3 val=2 [4] STRUCT t kind_flag=1 size=24 vlen=3 a type_id=5 bitfield_size=0 bits_offset=0 b type_id=1 bitfield_size=4 bits_offset=160 c type_id=7 bitfield_size=4 bits_offset=164 [5] ARRAY (anon) type_id=2 index_type_id=2 nr_elems=5 [6] INT sizetype size=8 bit_offset=0 nr_bits=64 encoding=(none) [7] VOLATILE (anon) type_id=3 Issue #2 and solution: ====================== Current forward type in BTF does not specify whether the original type is struct or union. This will not work for type pretty print and BTF-to-header-file conversion as struct/union must be specified. $ cat tt.c struct t; union u; int foo(struct t *t, union u *u) { return 0; } $ gcc -c -g -O2 tt.c $ pahole -JV tt.o [1] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED [2] FWD t type_id=0 [3] PTR (anon) type_id=2 [4] FWD u type_id=0 [5] PTR (anon) type_id=4 To fix this issue, similar to issue #1, type->info bit 31 is used. If the bit is set, it is union type. Otherwise, it is a struct type. $ pahole -JV tt.o [1] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED [2] FWD t kind_flag=0 type_id=0 [3] PTR (anon) kind_flag=0 type_id=2 [4] FWD u kind_flag=1 type_id=0 [5] PTR (anon) kind_flag=0 type_id=4 Pahole/LLVM change: =================== The new kind_flag functionality has been implemented in pahole and llvm: https://github.com/yonghong-song/pahole/tree/bitfield https://github.com/yonghong-song/llvm/tree/bitfield Note that pahole hasn't implemented func/func_proto kind and .BTF.ext. So to print function signature with bpftool, the llvm compiler should be used. Fixes: 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)") Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-18bpf: btf: refactor btf_int_bits_seq_show()Yonghong Song1-14/+21
Refactor function btf_int_bits_seq_show() by creating function btf_bitfield_seq_show() which has no dependence on btf and btf_type. The function btf_bitfield_seq_show() will be in later patch to directly dump bitfield member values. Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-17bpf: remove useless version check for prog loadDaniel Borkmann1-5/+0
Existing libraries and tracing frameworks work around this kernel version check by automatically deriving the kernel version from uname(3) or similar such that the user does not need to do it manually; these workarounds also make the version check useless at the same time. Moreover, most other BPF tracing types enabling bpf_probe_read()-like functionality have /not/ adapted this check, and in general these days it is well understood anyway that all the tracing programs are not stable with regards to future kernels as kernel internal data structures are subject to change from release to release. Back at last netconf we discussed [0] and agreed to remove this check from bpf_prog_load() and instead document it here in the uapi header that there is no such guarantee for stable API for these programs. [0] http://vger.kernel.org/netconf2018_files/DanielBorkmann_netconf2018.pdf Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-15bpf: add self-check logic to liveness analysisAlexei Starovoitov1-1/+107
Introduce REG_LIVE_DONE to check the liveness propagation and prepare the states for merging. See algorithm description in clean_live_states(). Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-15bpf: improve stacksafe state comparisonAlexei Starovoitov1-6/+7
"if (old->allocated_stack > cur->allocated_stack)" check is too conservative. In some cases explored stack could have allocated more space, but that stack space was not live. The test case improves from 19 to 15 processed insns and improvement on real programs is significant as well: before after bpf_lb-DLB_L3.o 1940 1831 bpf_lb-DLB_L4.o 3089 3029 bpf_lb-DUNKNOWN.o 1065 1064 bpf_lxc-DDROP_ALL.o 28052 26309 bpf_lxc-DUNKNOWN.o 35487 33517 bpf_netdev.o 10864 9713 bpf_overlay.o 6643 6184 bpf_lcx_jit.o 38437 37335 Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Edward Cree <ecree@solarflare.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-15bpf: speed up stacksafe checkAlexei Starovoitov1-1/+3
Don't check the same stack liveness condition 8 times. once is enough. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Edward Cree <ecree@solarflare.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-14bpf: verbose log bpf_line_info in verifierMartin KaFai Lau1-5/+69
This patch adds bpf_line_info during the verifier's verbose. It can give error context for debug purpose. ~~~~~~~~~~ Here is the verbose log for backedge: while (a) { a += bpf_get_smp_processor_id(); bpf_trace_printk(fmt, sizeof(fmt), a); } ~> bpftool prog load ./test_loop.o /sys/fs/bpf/test_loop type tracepoint 13: while (a) { 3: a += bpf_get_smp_processor_id(); back-edge from insn 13 to 3 ~~~~~~~~~~ Here is the verbose log for invalid pkt access: Modification to test_xdp_noinline.c: data = (void *)(long)xdp->data; data_end = (void *)(long)xdp->data_end; /* if (data + 4 > data_end) return XDP_DROP; */ *(u32 *)data = dst->dst; ~> bpftool prog load ./test_xdp_noinline.o /sys/fs/bpf/test_xdp_noinline type xdp ; data = (void *)(long)xdp->data; 224: (79) r2 = *(u64 *)(r10 -112) 225: (61) r2 = *(u32 *)(r2 +0) ; *(u32 *)data = dst->dst; 226: (63) *(u32 *)(r2 +0) = r1 invalid access to packet, off=0 size=4, R2(id=0,off=0,r=0) R2 offset is outside of the packet Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-14bpf: Create a new btf_name_by_offset() for non type name use caseMartin KaFai Lau2-13/+22
The current btf_name_by_offset() is returning "(anon)" type name for the offset == 0 case and "(invalid-name-offset)" for the out-of-bound offset case. It fits well for the internal BTF verbose log purpose which is focusing on type. For example, offset == 0 => "(anon)" => anonymous type/name. Returning non-NULL for the bad offset case is needed during the BTF verification process because the BTF verifier may complain about another field first before discovering the name_off is invalid. However, it may not be ideal for the newer use case which does not necessary mean type name. For example, when logging line_info in the BPF verifier in the next patch, it is better to log an empty src line instead of logging "(anon)". The existing bpf_name_by_offset() is renamed to __bpf_name_by_offset() and static to btf.c. A new bpf_name_by_offset() is added for generic context usage. It returns "\0" for name_off == 0 (note that btf->strings[0] is "\0") and NULL for invalid offset. It allows the caller to decide what is the best output in its context. The new btf_name_by_offset() is overlapped with btf_name_offset_valid(). Hence, btf_name_offset_valid() is removed from btf.h to keep the btf.h API minimal. The existing btf_name_offset_valid() usage in btf.c could also be replaced later. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-13bpf: remove obsolete prog->aux sanitation in bpf_insn_prepare_dumpDaniel Borkmann1-7/+0
This logic is not needed anymore since we got rid of the verifier rewrite that was using prog->aux address in f6069b9aa993 ("bpf: fix redirect to map under tail calls"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-13bpf: verifier: make sure callees don't prune with caller differencesJakub Kicinski1-3/+10
Currently for liveness and state pruning the register parentage chains don't include states of the callee. This makes some sense as the callee can't access those registers. However, this means that READs done after the callee returns will not propagate into the states of the callee. Callee will then perform pruning disregarding differences in caller state. Example: 0: (85) call bpf_user_rnd_u32 1: (b7) r8 = 0 2: (55) if r0 != 0x0 goto pc+1 3: (b7) r8 = 1 4: (bf) r1 = r8 5: (85) call pc+4 6: (15) if r8 == 0x1 goto pc+1 7: (05) *(u64 *)(r9 - 8) = r3 8: (b7) r0 = 0 9: (95) exit 10: (15) if r1 == 0x0 goto pc+0 11: (95) exit Here we acquire unknown state with call to get_random() [1]. Then we store this random state in r8 (either 0 or 1) [1 - 3], and make a call on line 5. Callee does nothing but a trivial conditional jump (to create a pruning point). Upon return caller checks the state of r8 and either performs an unsafe read or not. Verifier will first explore the path with r8 == 1, creating a pruning point at [11]. The parentage chain for r8 will include only callers states so once verifier reaches [6] it will mark liveness only on states in the caller, and not [11]. Now when verifier walks the paths with r8 == 0 it will reach [11] and since REG_LIVE_READ on r8 was not propagated there it will prune the walk entirely (stop walking the entire program, not just the callee). Since [6] was never walked with r8 == 0, [7] will be considered dead and replaced with "goto -1" causing hang at runtime. This patch weaves the callee's explored states onto the callers parentage chain. Rough parentage for r8 would have looked like this before: [0] [1] [2] [3] [4] [5] [10] [11] [6] [7] | | ,---|----. | | | sl0: sl0: / sl0: \ sl0: sl0: sl0: fr0: r8 <-- fr0: r8<+--fr0: r8 `fr0: r8 ,fr0: r8<-fr0: r8 \ fr1: r8 <- fr1: r8 / \__________________/ after: [0] [1] [2] [3] [4] [5] [10] [11] [6] [7] | | | | | | sl0: sl0: sl0: sl0: sl0: sl0: fr0: r8 <-- fr0: r8 <- fr0: r8 <- fr0: r8 <-fr0: r8<-fr0: r8 fr1: r8 <- fr1: r8 Now the mark from instruction 6 will travel through callees states. Note that we don't have to connect r0 because its overwritten by callees state on return and r1 - r5 because those are not alive any more once a call is made. v2: - don't connect the callees registers twice (Alexei: suggestion & code) - add more details to the comment (Ed & Alexei) v1: don't unnecessarily link caller saved regs (Jiong) Fixes: f4d7e40a5b71 ("bpf: introduce function calls (verification)") Reported-by: David Beckett <david.beckett@netronome.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-13bpf: include sub program tags in bpf_prog_infoSong Liu1-0/+22
Changes v2 -> v3: 1. remove check for bpf_dump_raw_ok(). Changes v1 -> v2: 1. Fix error path as Martin suggested. This patch adds nr_prog_tags and prog_tags to bpf_prog_info. This is a reliable way for user space to get tags of all sub programs. Before this patch, user space need to find sub program tags via kallsyms. This feature will be used in BPF introspection, where user space queries information about BPF programs via sys_bpf. Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-13bpf: Remove bpf_dump_raw_ok() check for func_info and line_infoMartin KaFai Lau1-20/+12
The func_info and line_info have the bpf insn offset but they do not contain kernel address. They will still be useful for the userspace tool to annotate the xlated insn. This patch removes the bpf_dump_raw_ok() guard for the func_info and line_info during bpf_prog_get_info_by_fd(). The guard stays for jited_line_info which contains the kernel address. Although this bpf_dump_raw_ok() guard behavior has started since the earlier func_info patch series, I marked the Fixes tag to the latest line_info patch series which contains both func_info and line_info and this patch is fixing for both of them. Fixes: c454a46b5efd ("bpf: Add bpf_line_info support") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-12bpf: add bpffs pretty print for cgroup local storage mapsRoman Gushchin2-1/+114
Implement bpffs pretty printing for cgroup local storage maps (both shared and per-cpu). Output example (captured for tools/testing/selftests/bpf/netcnt_prog.c): Shared: $ cat /sys/fs/bpf/map_2 # WARNING!! The output is for debug purpose only # WARNING!! The output format will change {4294968594,1}: {9999,1039896} Per-cpu: $ cat /sys/fs/bpf/map_1 # WARNING!! The output is for debug purpose only # WARNING!! The output format will change {4294968594,1}: { cpu0: {0,0,0,0,0} cpu1: {0,0,0,0,0} cpu2: {1,104,0,0,0} cpu3: {0,0,0,0,0} } Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-12bpf: pass struct btf pointer to the map_check_btf() callbackRoman Gushchin3-1/+4
If key_type or value_type are of non-trivial data types (e.g. structure or typedef), it's not possible to check them without the additional information, which can't be obtained without a pointer to the btf structure. So, let's pass btf pointer to the map_check_btf() callbacks. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-11bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64KDaniel Borkmann1-6/+15
Michael and Sandipan report: Commit ede95a63b5 introduced a bpf_jit_limit tuneable to limit BPF JIT allocations. At compile time it defaults to PAGE_SIZE * 40000, and is adjusted again at init time if MODULES_VADDR is defined. For ppc64 kernels, MODULES_VADDR isn't defined, so we're stuck with the compile-time default at boot-time, which is 0x9c400000 when using 64K page size. This overflows the signed 32-bit bpf_jit_limit value: root@ubuntu:/tmp# cat /proc/sys/net/core/bpf_jit_limit -1673527296 and can cause various unexpected failures throughout the network stack. In one case `strace dhclient eth0` reported: setsockopt(5, SOL_SOCKET, SO_ATTACH_FILTER, {len=11, filter=0x105dd27f8}, 16) = -1 ENOTSUPP (Unknown error 524) and similar failures can be seen with tools like tcpdump. This doesn't always reproduce however, and I'm not sure why. The more consistent failure I've seen is an Ubuntu 18.04 KVM guest booted on a POWER9 host would time out on systemd/netplan configuring a virtio-net NIC with no noticeable errors in the logs. Given this and also given that in near future some architectures like arm64 will have a custom area for BPF JIT image allocations we should get rid of the BPF_JIT_LIMIT_DEFAULT fallback / default entirely. For 4.21, we have an overridable bpf_jit_alloc_exec(), bpf_jit_free_exec() so therefore add another overridable bpf_jit_alloc_exec_limit() helper function which returns the possible size of the memory area for deriving the default heuristic in bpf_jit_charge_init(). Like bpf_jit_alloc_exec() and bpf_jit_free_exec(), the new bpf_jit_alloc_exec_limit() assumes that module_alloc() is the default JIT memory provider, and therefore in case archs implement their custom module_alloc() we use MODULES_{END,_VADDR} for limits and otherwise for vmalloc_exec() cases like on ppc64 we use VMALLOC_{END,_START}. Additionally, for archs supporting large page sizes, we should change the sysctl to be handled as long to not run into sysctl restrictions in future. Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations") Reported-by: Sandipan Das <sandipan@linux.ibm.com> Reported-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller4-99/+458
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-12-11 The following pull-request contains BPF updates for your *net-next* tree. It has three minor merge conflicts, resolutions: 1) tools/testing/selftests/bpf/test_verifier.c Take first chunk with alignment_prevented_execution. 2) net/core/filter.c [...] case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): case bpf_ctx_range(struct __sk_buff, wire_len): return false; [...] 3) include/uapi/linux/bpf.h Take the second chunk for the two cases each. The main changes are: 1) Add support for BPF line info via BTF and extend libbpf as well as bpftool's program dump to annotate output with BPF C code to facilitate debugging and introspection, from Martin. 2) Add support for BPF_ALU | BPF_ARSH | BPF_{K,X} in interpreter and all JIT backends, from Jiong. 3) Improve BPF test coverage on archs with no efficient unaligned access by adding an "any alignment" flag to the BPF program load to forcefully disable verifier alignment checks, from David. 4) Add a new bpf_prog_test_run_xattr() API to libbpf which allows for proper use of BPF_PROG_TEST_RUN with data_out, from Lorenz. 5) Extend tc BPF programs to use a new __sk_buff field called wire_len for more accurate accounting of packets going to wire, from Petar. 6) Improve bpftool to allow dumping the trace pipe from it and add several improvements in bash completion and map/prog dump, from Quentin. 7) Optimize arm64 BPF JIT to always emit movn/movk/movk sequence for kernel addresses and add a dedicated BPF JIT backend allocator, from Ard. 8) Add a BPF helper function for IR remotes to report mouse movements, from Sean. 9) Various cleanups in BPF prog dump e.g. to make UAPI bpf_prog_info member naming consistent with existing conventions, from Yonghong and Song. 10) Misc cleanups and improvements in allowing to pass interface name via cmdline for xdp1 BPF example, from Matteo. 11) Fix a potential segfault in BPF sample loader's kprobes handling, from Daniel T. 12) Fix SPDX license in libbpf's README.rst, from Andrey. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-10bpf: rename *_info_cnt to nr_*_info in bpf_prog_infoYonghong Song1-19/+19
In uapi bpf.h, currently we have the following fields in the struct bpf_prog_info: __u32 func_info_cnt; __u32 line_info_cnt; __u32 jited_line_info_cnt; The above field names "func_info_cnt" and "line_info_cnt" also appear in union bpf_attr for program loading. The original intention is to keep the names the same between bpf_prog_info and bpf_attr so it will imply what we returned to user space will be the same as what the user space passed to the kernel. Such a naming convention in bpf_prog_info is not consistent with other fields like: __u32 nr_jited_ksyms; __u32 nr_jited_func_lens; This patch made this adjustment so in bpf_prog_info newly introduced *_info_cnt becomes nr_*_info. Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-10bpf: clean up bpf_prog_get_info_by_fd()Song Liu1-2/+2
info.nr_jited_ksyms and info.nr_jited_func_lens cannot be 0 in these two statements, so we don't need to check them. Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-10bpf: relax verifier restriction on BPF_MOV | BPF_ALUJiong Wang1-4/+12
Currently, the destination register is marked as unknown for 32-bit sub-register move (BPF_MOV | BPF_ALU) whenever the source register type is SCALAR_VALUE. This is too conservative that some valid cases will be rejected. Especially, this may turn a constant scalar value into unknown value that could break some assumptions of verifier. For example, test_l4lb_noinline.c has the following C code: struct real_definition *dst 1: if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6)) 2: return TC_ACT_SHOT; 3: 4: if (dst->flags & F_IPV6) { get_packet_dst is responsible for initializing "dst" into valid pointer and return true (1), otherwise return false (0). The compiled instruction sequence using alu32 will be: 412: (54) (u32) r7 &= (u32) 1 413: (bc) (u32) r0 = (u32) r7 414: (95) exit insn 413, a BPF_MOV | BPF_ALU, however will turn r0 into unknown value even r7 contains SCALAR_VALUE 1. This causes trouble when verifier is walking the code path that hasn't initialized "dst" inside get_packet_dst, for which case 0 is returned and we would then expect verifier concluding line 1 in the above C code pass the "if" check, therefore would skip fall through path starting at line 4. Now, because r0 returned from callee has became unknown value, so verifier won't skip analyzing path starting at line 4 and "dst->flags" requires dereferencing the pointer "dst" which actually hasn't be initialized for this path. This patch relaxed the code marking sub-register move destination. For a SCALAR_VALUE, it is safe to just copy the value from source then truncate it into 32-bit. A unit test also included to demonstrate this issue. This test will fail before this patch. This relaxation could let verifier skipping more paths for conditional comparison against immediate. It also let verifier recording a more accurate/strict value for one register at one state, if this state end up with going through exit without rejection and it is used for state comparison later, then it is possible an inaccurate/permissive value is better. So the real impact on verifier processed insn number is complex. But in all, without this fix, valid program could be rejected. >From real benchmarking on kernel selftests and Cilium bpf tests, there is no impact on processed instruction number when tests ares compiled with default compilation options. There is slightly improvements when they are compiled with -mattr=+alu32 after this patch. Also, test_xdp_noinline/-mattr=+alu32 now passed verification. It is rejected before this fix. Insn processed before/after this patch: default -mattr=+alu32 Kernel selftest === test_xdp.o 371/371 369/369 test_l4lb.o 6345/6345 5623/5623 test_xdp_noinline.o 2971/2971 rejected/2727 test_tcp_estates.o 429/429 430/430 Cilium bpf === bpf_lb-DLB_L3.o: 2085/2085 1685/1687 bpf_lb-DLB_L4.o: 2287/2287 1986/1982 bpf_lb-DUNKNOWN.o: 690/690 622/622 bpf_lxc.o: 95033/95033 N/A bpf_netdev.o: 7245/7245 N/A bpf_overlay.o: 2898/2898 3085/2947 NOTE: - bpf_lxc.o and bpf_netdev.o compiled by -mattr=+alu32 are rejected by verifier due to another issue inside verifier on supporting alu32 binary. - Each cilium bpf program could generate several processed insn number, above number is sum of them. v1->v2: - Restrict the change on SCALAR_VALUE. - Update benchmark numbers on Cilium bpf tests. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-14/+146
Several conflicts, seemingly all over the place. I used Stephen Rothwell's sample resolutions for many of these, if not just to double check my own work, so definitely the credit largely goes to him. The NFP conflict consisted of a bug fix (moving operations past the rhashtable operation) while chaning the initial argument in the function call in the moved code. The net/dsa/master.c conflict had to do with a bug fix intermixing of making dsa_master_set_mtu() static with the fixing of the tagging attribute location. cls_flower had a conflict because the dup reject fix from Or overlapped with the addition of port range classifiction. __set_phy_supported()'s conflict was relatively easy to resolve because Andrew fixed it in both trees, so it was just a matter of taking the net-next copy. Or at least I think it was :-) Joe Stringer's fix to the handling of netns id 0 in bpf_sk_lookup() intermixed with changes on how the sdif and caller_net are calculated in these code paths in net-next. The remaining BPF conflicts were largely about the addition of the __bpf_md_ptr stuff in 'net' overlapping with adjustments and additions to the relevant data structure where the MD pointer macros are used. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-09bpf: Add bpf_line_info supportMartin KaFai Lau4-33/+368
This patch adds bpf_line_info support. It accepts an array of bpf_line_info objects during BPF_PROG_LOAD. The "line_info", "line_info_cnt" and "line_info_rec_size" are added to the "union bpf_attr". The "line_info_rec_size" makes bpf_line_info extensible in the future. The new "check_btf_line()" ensures the userspace line_info is valid for the kernel to use. When the verifier is translating/patching the bpf_prog (through "bpf_patch_insn_single()"), the line_infos' insn_off is also adjusted by the newly added "bpf_adj_linfo()". If the bpf_prog is jited, this patch also provides the jited addrs (in aux->jited_linfo) for the corresponding line_info.insn_off. "bpf_prog_fill_jited_linfo()" is added to fill the aux->jited_linfo. It is currently called by the x86 jit. Other jits can also use "bpf_prog_fill_jited_linfo()" and it will be done in the followup patches. In the future, if it deemed necessary, a particular jit could also provide its own "bpf_prog_fill_jited_linfo()" implementation. A few "*line_info*" fields are added to the bpf_prog_info such that the user can get the xlated line_info back (i.e. the line_info with its insn_off reflecting the translated prog). The jited_line_info is available if the prog is jited. It is an array of __u64. If the prog is not jited, jited_line_info_cnt is 0. The verifier's verbose log with line_info will be done in a follow up patch. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-07bpf: verifier remove the rejection on BPF_ALU | BPF_ARSHJiong Wang1-5/+0
This patch remove the rejection on BPF_ALU | BPF_ARSH as we have supported them on interpreter and all JIT back-ends Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-07bpf: interpreter support BPF_ALU | BPF_ARSHJiong Wang1-22/+30
This patch implements interpreting BPF_ALU | BPF_ARSH. Do arithmetic right shift on low 32-bit sub-register, and zero the high 32 bits. Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-05bpf: Change insn_offset to insn_off in bpf_func_infoMartin KaFai Lau1-9/+9
The later patch will introduce "struct bpf_line_info" which has member "line_off" and "file_off" referring back to the string section in btf. The line_"off" and file_"off" are more consistent to the naming convention in btf.h that means "offset" (e.g. name_off in "struct btf_type"). The to-be-added "struct bpf_line_info" also has another member, "insn_off" which is the same as the "insn_offset" in "struct bpf_func_info". Hence, this patch renames "insn_offset" to "insn_off" for "struct bpf_func_info". Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-05bpf: Improve the info.func_info and info.func_info_rec_size behaviorMartin KaFai Lau2-27/+21
1) When bpf_dump_raw_ok() == false and the kernel can provide >=1 func_info to the userspace, the current behavior is setting the info.func_info_cnt to 0 instead of setting info.func_info to 0. It is different from the behavior in jited_func_lens/nr_jited_func_lens, jited_ksyms/nr_jited_ksyms...etc. This patch fixes it. (i.e. set func_info to 0 instead of func_info_cnt to 0 when bpf_dump_raw_ok() == false). 2) When the userspace passed in info.func_info_cnt == 0, the kernel will set the expected func_info size back to the info.func_info_rec_size. It is a way for the userspace to learn the kernel expected func_info_rec_size introduced in commit 838e96904ff3 ("bpf: Introduce bpf_func_info"). An exception is the kernel expected size is not set when func_info is not available for a bpf_prog. This makes the returned info.func_info_rec_size has different values depending on the returned value of info.func_info_cnt. This patch sets the kernel expected size to info.func_info_rec_size independent of the info.func_info_cnt. 3) The current logic only rejects invalid func_info_rec_size if func_info_cnt is non zero. This patch also rejects invalid nonzero info.func_info_rec_size and not equal to the kernel expected size. 4) Set info.btf_id as long as prog->aux->btf != NULL. That will setup the later copy_to_user() codes look the same as others which then easier to understand and maintain. prog->aux->btf is not NULL only if prog->aux->func_info_cnt > 0. Breaking up info.btf_id from prog->aux->func_info_cnt is needed for the later line info patch anyway. A similar change is made to bpf_get_prog_name(). Fixes: 838e96904ff3 ("bpf: Introduce bpf_func_info") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-05bpf: add __weak hook for allocating executable memoryArd Biesheuvel1-2/+12
By default, BPF uses module_alloc() to allocate executable memory, but this is not necessary on all arches and potentially undesirable on some of them. So break out the module_alloc() and module_memfree() calls into __weak functions to allow them to be overridden in arch code. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-04bpf: add per-insn complexity limitAlexei Starovoitov1-1/+6
malicious bpf program may try to force the verifier to remember a lot of distinct verifier states. Put a limit to number of per-insn 'struct bpf_verifier_state'. Note that hitting the limit doesn't reject the program. It potentially makes the verifier do more steps to analyze the program. It means that malicious programs will hit BPF_COMPLEXITY_LIMIT_INSNS sooner instead of spending cpu time walking long link list. The limit of BPF_COMPLEXITY_LIMIT_STATES==64 affects cilium progs with slight increase in number of "steps" it takes to successfully verify the programs: before after bpf_lb-DLB_L3.o 1940 1940 bpf_lb-DLB_L4.o 3089 3089 bpf_lb-DUNKNOWN.o 1065 1065 bpf_lxc-DDROP_ALL.o 28052 | 28162 bpf_lxc-DUNKNOWN.o 35487 | 35541 bpf_netdev.o 10864 10864 bpf_overlay.o 6643 6643 bpf_lcx_jit.o 38437 38437 But it also makes malicious program to be rejected in 0.4 seconds vs 6.5 Hence apply this limit to unprivileged programs only. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-04bpf: improve verifier branch analysisAlexei Starovoitov1-13/+80
pathological bpf programs may try to force verifier to explode in the number of branch states: 20: (d5) if r1 s<= 0x24000028 goto pc+0 21: (b5) if r0 <= 0xe1fa20 goto pc+2 22: (d5) if r1 s<= 0x7e goto pc+0 23: (b5) if r0 <= 0xe880e000 goto pc+0 24: (c5) if r0 s< 0x2100ecf4 goto pc+0 25: (d5) if r1 s<= 0xe880e000 goto pc+1 26: (c5) if r0 s< 0xf4041810 goto pc+0 27: (d5) if r1 s<= 0x1e007e goto pc+0 28: (b5) if r0 <= 0xe86be000 goto pc+0 29: (07) r0 += 16614 30: (c5) if r0 s< 0x6d0020da goto pc+0 31: (35) if r0 >= 0x2100ecf4 goto pc+0 Teach verifier to recognize always taken and always not taken branches. This analysis is already done for == and != comparison. Expand it to all other branches. It also helps real bpf programs to be verified faster: before after bpf_lb-DLB_L3.o 2003 1940 bpf_lb-DLB_L4.o 3173 3089 bpf_lb-DUNKNOWN.o 1080 1065 bpf_lxc-DDROP_ALL.o 29584 28052 bpf_lxc-DUNKNOWN.o 36916 35487 bpf_netdev.o 11188 10864 bpf_overlay.o 6679 6643 bpf_lcx_jit.o 39555 38437 Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-04bpf: check pending signals while verifying programsAlexei Starovoitov1-0/+3
Malicious user space may try to force the verifier to use as much cpu time and memory as possible. Hence check for pending signals while verifying the program. Note that suspend of sys_bpf(PROG_LOAD) syscall will lead to EAGAIN, since the kernel has to release the resources used for program verification. Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-02bpf: Fix memleak in aux->func_info and aux->btfMartin KaFai Lau1-0/+2
The aux->func_info and aux->btf are leaked in the error out cases during bpf_prog_load(). This patch fixes it. Fixes: ba64e7d85252 ("bpf: btf: support proper non-jit func info") Cc: Yonghong Song <yhs@fb.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-30bpf: Add BPF_F_ANY_ALIGNMENT.David Miller2-1/+8
Often we want to write tests cases that check things like bad context offset accesses. And one way to do this is to use an odd offset on, for example, a 32-bit load. This unfortunately triggers the alignment checks first on platforms that do not set CONFIG_EFFICIENT_UNALIGNED_ACCESS. So the test case see the alignment failure rather than what it was testing for. It is often not completely possible to respect the original intention of the test, or even test the same exact thing, while solving the alignment issue. Another option could have been to check the alignment after the context and other validations are performed by the verifier, but that is a non-trivial change to the verifier. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller3-43/+48
Daniel Borkmann says: ==================== bpf-next 2018-11-30 The following pull-request contains BPF updates for your *net-next* tree. (Getting out bit earlier this time to pull in a dependency from bpf.) The main changes are: 1) Add libbpf ABI versioning and document API naming conventions as well as ABI versioning process, from Andrey. 2) Add a new sk_msg_pop_data() helper for sk_msg based BPF programs that is used in conjunction with sk_msg_push_data() for adding / removing meta data to the msg data, from John. 3) Optimize convert_bpf_ld_abs() for 0 offset and fix various lib and testsuite build failures on 32 bit, from David. 4) Make BPF prog dump for !JIT identical to how we dump subprogs when JIT is in use, from Yonghong. 5) Rename btf_get_from_id() to make it more conform with libbpf API naming conventions, from Martin. 6) Add a missing BPF kselftest config item, from Naresh. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller4-10/+45
Trivial conflict in net/core/filter.c, a locally computed 'sdif' is now an argument to the function. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-28bpf: btf: check name validity for various typesYonghong Song1-0/+57
This patch added name checking for the following types: . BTF_KIND_PTR, BTF_KIND_ARRAY, BTF_KIND_VOLATILE, BTF_KIND_CONST, BTF_KIND_RESTRICT: the name must be null . BTF_KIND_STRUCT, BTF_KIND_UNION: the struct/member name is either null or a valid identifier . BTF_KIND_ENUM: the enum type name is either null or a valid identifier; the enumerator name must be a valid identifier. . BTF_KIND_FWD: the name must be a valid identifier . BTF_KIND_TYPEDEF: the name must be a valid identifier For those places a valid name is required, the name must be a valid C identifier. This can be relaxed later if we found use cases for a different (non-C) frontend. Fixes: 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)") Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-28bpf: btf: implement btf_name_valid_identifier()Yonghong Song1-0/+25
Function btf_name_valid_identifier() have been implemented in bpf-next commit 2667a2626f4d ("bpf: btf: Add BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO"). Backport this function so later patch can use it. Fixes: 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>