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| | * | | bpf: silence warning messages in coreValdis Klētnieks2019-06-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compiling kernel/bpf/core.c with W=1 causes a flood of warnings: kernel/bpf/core.c:1198:65: warning: initialized field overwritten [-Woverride-init] 1198 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true | ^~~~ kernel/bpf/core.c:1087:2: note: in expansion of macro 'BPF_INSN_3_TBL' 1087 | INSN_3(ALU, ADD, X), \ | ^~~~~~ kernel/bpf/core.c:1202:3: note: in expansion of macro 'BPF_INSN_MAP' 1202 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), | ^~~~~~~~~~~~ kernel/bpf/core.c:1198:65: note: (near initialization for 'public_insntable[12]') 1198 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true | ^~~~ kernel/bpf/core.c:1087:2: note: in expansion of macro 'BPF_INSN_3_TBL' 1087 | INSN_3(ALU, ADD, X), \ | ^~~~~~ kernel/bpf/core.c:1202:3: note: in expansion of macro 'BPF_INSN_MAP' 1202 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), | ^~~~~~~~~~~~ 98 copies of the above. The attached patch silences the warnings, because we *know* we're overwriting the default initializer. That leaves bpf/core.c with only 6 other warnings, which become more visible in comparison. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * | | bpf: Allow bpf_map_lookup_elem() on an xskmapJonathan Lemon2019-06-102-2/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the AF_XDP code uses a separate map in order to determine if an xsk is bound to a queue. Instead of doing this, have bpf_map_lookup_elem() return a xdp_sock. Rearrange some xdp_sock members to eliminate structure holes. Remove selftest - will be added back in later patch. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * | | bpf: remove redundant assignment to errColin Ian King2019-06-042-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The variable err is assigned with the value -EINVAL that is never read and it is re-assigned a new value later on. The assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | | xdp: page_pool related fix to cpumapJesper Dangaard Brouer2019-06-191-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When converting an xdp_frame into an SKB, and sending this into the network stack, then the underlying XDP memory model need to release associated resources, because the network stack don't have callbacks for XDP memory models. The only memory model that needs this is page_pool, when a driver use the DMA-mapping feature. Introduce page_pool_release_page(), which basically does the same as page_pool_unmap_page(). Add xdp_release_frame() as the XDP memory model interface for calling it, if the memory model match MEM_TYPE_PAGE_POOL, to save the function call overhead for others. Have cpumap call xdp_release_frame() before xdp_scrub_frame(). Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-06-1711-80/+36
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Honestly all the conflicts were simple overlapping changes, nothing really interesting to report. Signed-off-by: David S. Miller <davem@davemloft.net>
| * \ \ \ \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-06-078-33/+8
| |\ \ \ \ \ | | |_|/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some ISDN files that got removed in net-next had some changes done in mainline, take the removals. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | bpf: move memory size checks to bpf_map_charge_init()Roman Gushchin2019-05-3111-56/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most bpf map types doing similar checks and bytes to pages conversion during memory allocation and charging. Let's unify these checks by moving them into bpf_map_charge_init(). Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: rework memlock-based memory accounting for mapsRoman Gushchin2019-05-3111-82/+100
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to unify the existing memlock charging code with the memcg-based memory accounting, which will be added later, let's rework the current scheme. Currently the following design is used: 1) .alloc() callback optionally checks if the allocation will likely succeed using bpf_map_precharge_memlock() 2) .alloc() performs actual allocations 3) .alloc() callback calculates map cost and sets map.memory.pages 4) map_create() calls bpf_map_init_memlock() which sets map.memory.user and performs actual charging; in case of failure the map is destroyed <map is in use> 1) bpf_map_free_deferred() calls bpf_map_release_memlock(), which performs uncharge and releases the user 2) .map_free() callback releases the memory The scheme can be simplified and made more robust: 1) .alloc() calculates map cost and calls bpf_map_charge_init() 2) bpf_map_charge_init() sets map.memory.user and performs actual charge 3) .alloc() performs actual allocations <map is in use> 1) .map_free() callback releases the memory 2) bpf_map_charge_finish() performs uncharge and releases the user The new scheme also allows to reuse bpf_map_charge_init()/finish() functions for memcg-based accounting. Because charges are performed before actual allocations and uncharges after freeing the memory, no bogus memory pressure can be created. In cases when the map structure is not available (e.g. it's not created yet, or is already destroyed), on-stack bpf_map_memory structure is used. The charge can be transferred with the bpf_map_charge_move() function. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: group memory related fields in struct bpf_map_memoryRoman Gushchin2019-05-3111-25/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Group "user" and "pages" fields of bpf_map into the bpf_map_memory structure. Later it can be extended with "memcg" and other related information. The main reason for a such change (beside cosmetics) is to pass bpf_map_memory structure to charging functions before the actual allocation of bpf_map. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: add memlock precharge check for cgroup_local_storageRoman Gushchin2019-05-311-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cgroup local storage maps lack the memlock precharge check, which is performed before the memory allocation for most other bpf map types. Let's add it in order to unify all map types. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: Update __cgroup_bpf_run_filter_skb with cnbrakmo2019-05-311-5/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For egress packets, __cgroup_bpf_fun_filter_skb() will now call BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY() instead of PROG_CGROUP_RUN_ARRAY() in order to propagate congestion notifications (cn) requests to TCP callers. For egress packets, this function can return: NET_XMIT_SUCCESS (0) - continue with packet output NET_XMIT_DROP (1) - drop packet and notify TCP to call cwr NET_XMIT_CN (2) - continue with packet output and notify TCP to call cwr -EPERM - drop packet For ingress packets, this function will return -EPERM if any attached program was found and if it returned != 1 during execution. Otherwise 0 is returned. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: cgroup inet skb programs can return 0 to 3brakmo2019-05-312-3/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allows cgroup inet skb programs to return values in the range [0, 3]. The second bit is used to deterine if congestion occurred and higher level protocol should decrease rate. E.g. TCP would call tcp_enter_cwr() The bpf_prog must set expected_attach_type to BPF_CGROUP_INET_EGRESS at load time if it uses the new return values (i.e. 2 or 3). The expected_attach_type is currently not enforced for BPF_PROG_TYPE_CGROUP_SKB. e.g Meaning the current bpf_prog with expected_attach_type setting to BPF_CGROUP_INET_EGRESS can attach to BPF_CGROUP_INET_INGRESS. Blindly enforcing expected_attach_type will break backward compatibility. This patch adds a enforce_expected_attach_type bit to only enforce the expected_attach_type when it uses the new return value. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: cgroup: properly use bpf_prog_array apiStanislav Fomichev2019-05-291-11/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we don't have __rcu markers on the bpf_prog_array helpers, let's use proper rcu_dereference_protected to obtain array pointer under mutex. We also don't need __rcu annotations on cgroup_bpf.inactive since it's not read/updated concurrently. v4: * drop cgroup_rcu_xyz wrappers and use rcu APIs directly; presumably should be more clear to understand which mutex/refcount protects each particular place v3: * amend cgroup_rcu_dereference to include percpu_ref_is_dying; cgroup_bpf is now reference counted and we don't hold cgroup_mutex anymore in cgroup_bpf_release v2: * replace xchg with rcu_swap_protected Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Roman Gushchin <guro@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | | | bpf: remove __rcu annotations from bpf_prog_arrayStanislav Fomichev2019-05-291-24/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drop __rcu annotations and rcu read sections from bpf_prog_array helper functions. They are not needed since all existing callers call those helpers from the rcu update side while holding a mutex. This guarantees that use-after-free could not happen. In the next patches I'll fix the callers with missing rcu_dereference_protected to make sparse/lockdep happy, the proper way to use these helpers is: struct bpf_prog_array __rcu *progs = ...; struct bpf_prog_array *p; mutex_lock(&mtx); p = rcu_dereference_protected(progs, lockdep_is_held(&mtx)); bpf_prog_array_length(p); bpf_prog_array_copy_to_user(p, ...); bpf_prog_array_delete_safe(p, ...); bpf_prog_array_copy_info(p, ...); bpf_prog_array_copy(p, ...); bpf_prog_array_free(p); mutex_unlock(&mtx); No functional changes! rcu_dereference_protected with lockdep_is_held should catch any cases where we update prog array without a mutex (I've looked at existing call sites and I think we hold a mutex everywhere). Motivation is to fix sparse warnings: kernel/bpf/core.c:1803:9: warning: incorrect type in argument 1 (different address spaces) kernel/bpf/core.c:1803:9: expected struct callback_head *head kernel/bpf/core.c:1803:9: got struct callback_head [noderef] <asn:4> * kernel/bpf/core.c:1877:44: warning: incorrect type in initializer (different address spaces) kernel/bpf/core.c:1877:44: expected struct bpf_prog_array_item *item kernel/bpf/core.c:1877:44: got struct bpf_prog_array_item [noderef] <asn:4> * kernel/bpf/core.c:1901:26: warning: incorrect type in assignment (different address spaces) kernel/bpf/core.c:1901:26: expected struct bpf_prog_array_item *existing kernel/bpf/core.c:1901:26: got struct bpf_prog_array_item [noderef] <asn:4> * kernel/bpf/core.c:1935:26: warning: incorrect type in assignment (different address spaces) kernel/bpf/core.c:1935:26: expected struct bpf_prog_array_item *[assigned] existing kernel/bpf/core.c:1935:26: got struct bpf_prog_array_item [noderef] <asn:4> * v2: * remove comment about potential race; that can't happen because all callers are in rcu-update section Cc: Roman Gushchin <guro@fb.com> Acked-by: Roman Gushchin <guro@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | | | bpf: decouple the lifetime of cgroup_bpf from cgroup itselfRoman Gushchin2019-05-281-4/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the lifetime of bpf programs attached to a cgroup is bound to the lifetime of the cgroup itself. It means that if a user forgets (or intentionally avoids) to detach a bpf program before removing the cgroup, it will stay attached up to the release of the cgroup. Since the cgroup can stay in the dying state (the state between being rmdir()'ed and being released) for a very long time, it leads to a waste of memory. Also, it blocks a possibility to implement the memcg-based memory accounting for bpf objects, because a circular reference dependency will occur. Charged memory pages are pinning the corresponding memory cgroup, and if the memory cgroup is pinning the attached bpf program, nothing will be ever released. A dying cgroup can not contain any processes, so the only chance for an attached bpf program to be executed is a live socket associated with the cgroup. So in order to release all bpf data early, let's count associated sockets using a new percpu refcounter. On cgroup removal the counter is transitioned to the atomic mode, and as soon as it reaches 0, all bpf programs are detached. Because cgroup_bpf_release() can block, it can't be called from the percpu ref counter callback directly, so instead an asynchronous work is scheduled. The reference counter is not socket specific, and can be used for any other types of programs, which can be executed from a cgroup-bpf hook outside of the process context, had such a need arise in the future. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: jolsa@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: verifier: randomize high 32-bit when BPF_F_TEST_RND_HI32 is setJiong Wang2019-05-241-11/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch randomizes high 32-bit of a definition when BPF_F_TEST_RND_HI32 is set. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: introduce new bpf prog load flags "BPF_F_TEST_RND_HI32"Jiong Wang2019-05-241-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | x86_64 and AArch64 perhaps are two arches that running bpf testsuite frequently, however the zero extension insertion pass is not enabled for them because of their hardware support. It is critical to guarantee the pass correction as it is supposed to be enabled at default for a couple of other arches, for example PowerPC, SPARC, arm, NFP etc. Therefore, it would be very useful if there is a way to test this pass on for example x86_64. The test methodology employed by this set is "poisoning" useless bits. High 32-bit of a definition is randomized if it is identified as not used by any later insn. Such randomization is only enabled under testing mode which is gated by the new bpf prog load flags "BPF_F_TEST_RND_HI32". Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: verifier: insert zero extension according to analysis resultJiong Wang2019-05-242-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After previous patches, verifier will mark a insn if it really needs zero extension on dst_reg. It is then for back-ends to decide how to use such information to eliminate unnecessary zero extension code-gen during JIT compilation. One approach is verifier insert explicit zero extension for those insns that need zero extension in a generic way, JIT back-ends then do not generate zero extension for sub-register write at default. However, only those back-ends which do not have hardware zero extension want this optimization. Back-ends like x86_64 and AArch64 have hardware zero extension support that the insertion should be disabled. This patch introduces new target hook "bpf_jit_needs_zext" which returns false at default, meaning verifier zero extension insertion is disabled at default. A back-end could override this hook to return true if it doesn't have hardware support and want verifier insert zero extension explicitly. Offload targets do not use this native target hook, instead, they could get the optimization results using bpf_prog_offload_ops.finalize. NOTE: arches could have diversified features, it is possible for one arch to have hardware zero extension support for some sub-register write insns but not for all. For example, PowerPC, SPARC have zero extended loads, but not for alu32. So when verifier zero extension insertion enabled, these JIT back-ends need to peephole insns to remove those zero extension inserted for insn that actually has hardware zero extension support. The peephole could be as simple as looking the next insn, if it is a special zero extension insn then it is safe to eliminate it if the current insn has hardware zero extension support. 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>
| * | | | | bpf: verifier: mark patched-insn with sub-register zext flagJiong Wang2019-05-241-4/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patched insns do not go through generic verification, therefore doesn't has zero extension information collected during insn walking. We don't bother analyze them at the moment, for any sub-register def comes from them, just conservatively mark it as needing zero extension. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | bpf: verifier: mark verified-insn with sub-register zext flagJiong Wang2019-05-241-13/+160
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | eBPF ISA specification requires high 32-bit cleared when low 32-bit sub-register is written. This applies to destination register of ALU32 etc. JIT back-ends must guarantee this semantic when doing code-gen. x86_64 and AArch64 ISA has the same semantics, so the corresponding JIT back-end doesn't need to do extra work. However, 32-bit arches (arm, x86, nfp etc.) and some other 64-bit arches (PowerPC, SPARC etc) need to do explicit zero extension to meet this requirement, otherwise code like the following will fail. u64_value = (u64) u32_value ... other uses of u64_value This is because compiler could exploit the semantic described above and save those zero extensions for extending u32_value to u64_value, these JIT back-ends are expected to guarantee this through inserting extra zero extensions which however could be a significant increase on the code size. Some benchmarks show there could be ~40% sub-register writes out of total insns, meaning at least ~40% extra code-gen. One observation is these extra zero extensions are not always necessary. Take above code snippet for example, it is possible u32_value will never be casted into a u64, the value of high 32-bit of u32_value then could be ignored and extra zero extension could be eliminated. This patch implements this idea, insns defining sub-registers will be marked when the high 32-bit of the defined sub-register matters. For those unmarked insns, it is safe to eliminate high 32-bit clearnace for them. Algo: - Split read flags into READ32 and READ64. - Record index of insn that does sub-register write. Keep the index inside reg state and update it during verifier insn walking. - A full register read on a sub-register marks its definition insn as needing zero extension on dst register. A new sub-register write overrides the old one. - When propagating read64 during path pruning, also mark any insn defining a sub-register that is read in the pruned path as full-register. 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>
| * | | | | bpf: convert explored_states to hash tableAlexei Starovoitov2019-05-241-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All prune points inside a callee bpf function most likely will have different callsites. For example, if function foo() is called from two callsites the half of explored states in all prune points in foo() will be useless for subsequent walking of one of those callsites. Fortunately explored_states pruning heuristics keeps the number of states per prune point small, but walking these states is still a waste of cpu time when the callsite of the current state is different from the callsite of the explored state. To improve pruning logic convert explored_states into hash table and use simple insn_idx ^ callsite hash to select hash bucket. This optimization has no effect on programs without bpf2bpf calls and drastically improves programs with calls. In the later case it reduces total memory consumption in 1M scale tests by almost 3 times (peak_states drops from 5752 to 2016). Care should be taken when comparing the states for equivalency. Since the same hash bucket can now contain states with different indices the insn_idx has to be part of verifier_state and compared. Different hash table sizes and different hash functions were explored, but the results were not significantly better vs this patch. They can be improved in the future. Hit/miss heuristic is not counting index miscompare as a miss. Otherwise verifier stats become unstable when experimenting with different hash functions. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | | | bpf: split explored_statesAlexei Starovoitov2019-05-241-18/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | split explored_states into prune_point boolean mark and link list of explored states. This removes STATE_LIST_MARK hack and allows marks to be separate from states. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | | | bpf: cleanup explored_statesAlexei Starovoitov2019-05-241-9/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clean up explored_states to prep for introduction of hashtable No functional changes. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | | | bpf: bump jmp sequence limitAlexei Starovoitov2019-05-231-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The limit of 1024 subsequent jumps was causing otherwise valid programs to be rejected. Bump it to 8192 and make the error more verbose. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | | | | | Merge branch 'timers/vdso' into timers/coreThomas Gleixner2019-07-037-21/+33
|\ \ \ \ \ \ | | |_|_|/ / | |/| | | | | | | | | | so the hyper-v clocksource update can be applied.
| * | | | | Merge tag 'spdx-5.2-rc6' of ↵Linus Torvalds2019-06-213-12/+3
| |\ \ \ \ \ | | |_|_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx Pull still more SPDX updates from Greg KH: "Another round of SPDX updates for 5.2-rc6 Here is what I am guessing is going to be the last "big" SPDX update for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates that were "easy" to determine by pattern matching. The ones after this are going to be a bit more difficult and the people on the spdx list will be discussing them on a case-by-case basis now. Another 5000+ files are fixed up, so our overall totals are: Files checked: 64545 Files with SPDX: 45529 Compared to the 5.1 kernel which was: Files checked: 63848 Files with SPDX: 22576 This is a huge improvement. Also, we deleted another 20000 lines of boilerplate license crud, always nice to see in a diffstat" * tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits) treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485 ...
| | * | | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2019-06-191-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 451Thomas Gleixner2019-06-192-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this file is subject to the terms and conditions of version 2 of the gnu general public license see the file copying in the main directory of the linux distribution for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 5 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081200.872755311@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2019-06-175-9/+30
| |\ \ \ \ \ | | |/ / / / | |/| | | / | | | |_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: "Lots of bug fixes here: 1) Out of bounds access in __bpf_skc_lookup, from Lorenz Bauer. 2) Fix rate reporting in cfg80211_calculate_bitrate_he(), from John Crispin. 3) Use after free in psock backlog workqueue, from John Fastabend. 4) Fix source port matching in fdb peer flow rule of mlx5, from Raed Salem. 5) Use atomic_inc_not_zero() in fl6_sock_lookup(), from Eric Dumazet. 6) Network header needs to be set for packet redirect in nfp, from John Hurley. 7) Fix udp zerocopy refcnt, from Willem de Bruijn. 8) Don't assume linear buffers in vxlan and geneve error handlers, from Stefano Brivio. 9) Fix TOS matching in mlxsw, from Jiri Pirko. 10) More SCTP cookie memory leak fixes, from Neil Horman. 11) Fix VLAN filtering in rtl8366, from Linus Walluij. 12) Various TCP SACK payload size and fragmentation memory limit fixes from Eric Dumazet. 13) Use after free in pneigh_get_next(), also from Eric Dumazet. 14) LAPB control block leak fix from Jeremy Sowden" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (145 commits) lapb: fixed leak of control-blocks. tipc: purge deferredq list for each grp member in tipc_group_delete ax25: fix inconsistent lock state in ax25_destroy_timer neigh: fix use-after-free read in pneigh_get_next tcp: fix compile error if !CONFIG_SYSCTL hv_sock: Suppress bogus "may be used uninitialized" warnings be2net: Fix number of Rx queues used for flow hashing net: handle 802.1P vlan 0 packets properly tcp: enforce tcp_min_snd_mss in tcp_mtu_probing() tcp: add tcp_min_snd_mss sysctl tcp: tcp_fragment() should apply sane memory limits tcp: limit payload size of sacked skbs Revert "net: phylink: set the autoneg state in phylink_phy_change" bpf: fix nested bpf tracepoints with per-cpu data bpf: Fix out of bounds memory access in bpf_sk_storage vsock/virtio: set SOCK_DONE on peer shutdown net: dsa: rtl8366: Fix up VLAN filtering net: phylink: set the autoneg state in phylink_phy_change net: add high_order_alloc_disable sysctl/static key tcp: add tcp_tx_skb_cache sysctl ...
| | * | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2019-06-152-4/+14
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf 2019-06-15 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) fix stack layout of JITed x64 bpf code, from Alexei. 2) fix out of bounds memory access in bpf_sk_storage, from Arthur. 3) fix lpm trie walk, from Jonathan. 4) fix nested bpf_perf_event_output, from Matt. 5) and several other fixes. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | | * | | bpf, devmap: Add missing RCU read lock on flushToshiaki Makita2019-06-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | .ndo_xdp_xmit() assumes it is called under RCU. For example virtio_net uses RCU to detect it has setup the resources for tx. The assumption accidentally broke when introducing bulk queue in devmap. Fixes: 5d053f9da431 ("bpf: devmap prepare xdp frames for bulking") Reported-by: David Ahern <dsahern@gmail.com> Signed-off-by: Toshiaki Makita <toshiaki.makita1@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | | * | | bpf, devmap: Add missing bulk queue freeToshiaki Makita2019-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dev_map_free() forgot to free bulk queue when freeing its entries. Fixes: 5d053f9da431 ("bpf: devmap prepare xdp frames for bulking") Signed-off-by: Toshiaki Makita <toshiaki.makita1@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | | * | | bpf, devmap: Fix premature entry free on destroying mapToshiaki Makita2019-06-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dev_map_free() waits for flush_needed bitmap to be empty in order to ensure all flush operations have completed before freeing its entries. However the corresponding clear_bit() was called before using the entries, so the entries could be used after free. All access to the entries needs to be done before clearing the bit. It seems commit a5e2da6e9787 ("bpf: netdev is never null in __dev_map_flush") accidentally changed the clear_bit() and memory access order. Note that the problem happens only in __dev_map_flush(), not in dev_map_flush_old(). dev_map_flush_old() is called only after nulling out the corresponding netdev_map entry, so dev_map_free() never frees the entry thus no such race happens there. Fixes: a5e2da6e9787 ("bpf: netdev is never null in __dev_map_flush") Signed-off-by: Toshiaki Makita <toshiaki.makita1@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | | * | | bpf: lpm_trie: check left child of last leftmost node for NULLJonathan Lemon2019-06-111-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the leftmost parent node of the tree has does not have a child on the left side, then trie_get_next_key (and bpftool map dump) will not look at the child on the right. This leads to the traversal missing elements. Lookup is not affected. Update selftest to handle this case. Reproducer: bpftool map create /sys/fs/bpf/lpm type lpm_trie key 6 \ value 1 entries 256 name test_lpm flags 1 bpftool map update pinned /sys/fs/bpf/lpm key 8 0 0 0 0 0 value 1 bpftool map update pinned /sys/fs/bpf/lpm key 16 0 0 0 0 128 value 2 bpftool map dump pinned /sys/fs/bpf/lpm Returns only 1 element. (2 expected) Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE") Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * | | | sysctl: define proc_do_static_key()Eric Dumazet2019-06-141-1/+0
| | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert proc_dointvec_minmax_bpf_stats() into a more generic helper, since we are going to use jump labels more often. Note that sysctl_bpf_stats_enabled is removed, since it is no longer needed/used. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2019-06-072-4/+16
| | |\ \ \ | | | |_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf 2019-06-07 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix several bugs in riscv64 JIT code emission which forgot to clear high 32-bits for alu32 ops, from Björn and Luke with selftests covering all relevant BPF alu ops from Björn and Jiong. 2) Two fixes for UDP BPF reuseport that avoid calling the program in case of __udp6_lib_err and UDP GRO which broke reuseport_select_sock() assumption that skb->data is pointing to transport header, from Martin. 3) Two fixes for BPF sockmap: a use-after-free from sleep in psock's backlog workqueue, and a missing restore of sk_write_space when psock gets dropped, from Jakub and John. 4) Fix unconnected UDP sendmsg hook API which is insufficient as-is since it breaks standard applications like DNS if reverse NAT is not performed upon receive, from Daniel. 5) Fix an out-of-bounds read in __bpf_skc_lookup which in case of AF_INET6 fails to verify that the length of the tuple is long enough, from Lorenz. 6) Fix libbpf's libbpf__probe_raw_btf to return an fd instead of 0/1 (for {un,}successful probe) as that is expected to be propagated as an fd to load_sk_storage_btf() and thus closing the wrong descriptor otherwise, from Michal. 7) Fix bpftool's JSON output for the case when a lookup fails, from Krzesimir. 8) Minor misc fixes in docs, samples and selftests, from various others. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | | * | bpf: fix unconnected udp hooksDaniel Borkmann2019-06-062-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intention of cgroup bind/connect/sendmsg BPF hooks is to act transparently to applications as also stated in original motivation in 7828f20e3779 ("Merge branch 'bpf-cgroup-bind-connect'"). When recently integrating the latter two hooks into Cilium to enable host based load-balancing with Kubernetes, I ran into the issue that pods couldn't start up as DNS got broken. Kubernetes typically sets up DNS as a service and is thus subject to load-balancing. Upon further debugging, it turns out that the cgroupv2 sendmsg BPF hooks API is currently insufficient and thus not usable as-is for standard applications shipped with most distros. To break down the issue we ran into with a simple example: # cat /etc/resolv.conf nameserver 147.75.207.207 nameserver 147.75.207.208 For the purpose of a simple test, we set up above IPs as service IPs and transparently redirect traffic to a different DNS backend server for that node: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 The attached BPF program is basically selecting one of the backends if the service IP/port matches on the cgroup hook. DNS breaks here, because the hooks are not transparent enough to applications which have built-in msg_name address checks: # nslookup 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ;; connection timed out; no servers could be reached # dig 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; connection timed out; no servers could be reached For comparison, if none of the service IPs is used, and we tell nslookup to use 8.8.8.8 directly it works just fine, of course: # nslookup 1.1.1.1 8.8.8.8 1.1.1.1.in-addr.arpa name = one.one.one.one. In order to fix this and thus act more transparent to the application, this needs reverse translation on recvmsg() side. A minimal fix for this API is to add similar recvmsg() hooks behind the BPF cgroups static key such that the program can track state and replace the current sockaddr_in{,6} with the original service IP. From BPF side, this basically tracks the service tuple plus socket cookie in an LRU map where the reverse NAT can then be retrieved via map value as one example. Side-note: the BPF cgroups static key should be converted to a per-hook static key in future. Same example after this fix: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 Lookups work fine now: # nslookup 1.1.1.1 1.1.1.1.in-addr.arpa name = one.one.one.one. Authoritative answers can be found from: # dig 1.1.1.1 ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 51550 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;1.1.1.1. IN A ;; AUTHORITY SECTION: . 23426 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2019052001 1800 900 604800 86400 ;; Query time: 17 msec ;; SERVER: 147.75.207.207#53(147.75.207.207) ;; WHEN: Tue May 21 12:59:38 UTC 2019 ;; MSG SIZE rcvd: 111 And from an actual packet level it shows that we're using the back end server when talking via 147.75.207.20{7,8} front end: # tcpdump -i any udp [...] 12:59:52.698732 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.698735 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) [...] In order to be flexible and to have same semantics as in sendmsg BPF programs, we only allow return codes in [1,1] range. In the sendmsg case the program is called if msg->msg_name is present which can be the case in both, connected and unconnected UDP. The former only relies on the sockaddr_in{,6} passed via connect(2) if passed msg->msg_name was NULL. Therefore, on recvmsg side, we act in similar way to call into the BPF program whenever a non-NULL msg->msg_name was passed independent of sk->sk_state being TCP_ESTABLISHED or not. Note that for TCP case, the msg->msg_name is ignored in the regular recvmsg path and therefore not relevant. For the case of ip{,v6}_recv_error() paths, picked up via MSG_ERRQUEUE, the hook is not called. This is intentional as it aligns with the same semantics as in case of TCP cgroup BPF hooks right now. This might be better addressed in future through a different bpf_attach_type such that this case can be distinguished from the regular recvmsg paths, for example. Fixes: 1cedee13d25a ("bpf: Hooks for sys_sendmsg") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrey Ignatov <rdna@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Martynas Pumputis <m@lambda.lt> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | | | | timekeeping: Use proper clock specifier names in functionsJason A. Donenfeld2019-06-221-1/+1
|/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes boot uniformly boottime and tai uniformly clocktai, to address the remaining oversights. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Link: https://lkml.kernel.org/r/20190621203249.3909-2-Jason@zx2c4.com
* | | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 363Thomas Gleixner2019-06-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): released under terms in gpl version 2 see copying extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 5 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081035.689962394@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295Thomas Gleixner2019-06-058-72/+8
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 64 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206Thomas Gleixner2019-05-307-28/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 107 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171438.615055994@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2019-05-301-5/+1
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge tag 'spdx-5.2-rc2' of ↵Linus Torvalds2019-05-211-0/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull SPDX update from Greg KH: "Here is a series of patches that add SPDX tags to different kernel files, based on two different things: - SPDX entries are added to a bunch of files that we missed a year ago that do not have any license information at all. These were either missed because the tool saw the MODULE_LICENSE() tag, or some EXPORT_SYMBOL tags, and got confused and thought the file had a real license, or the files have been added since the last big sweep, or they were Makefile/Kconfig files, which we didn't touch last time. - Add GPL-2.0-only or GPL-2.0-or-later tags to files where our scan tools can determine the license text in the file itself. Where this happens, the license text is removed, in order to cut down on the 700+ different ways we have in the kernel today, in a quest to get rid of all of these. These patches have been out for review on the linux-spdx@vger mailing list, and while they were created by automatic tools, they were hand-verified by a bunch of different people, all whom names are on the patches are reviewers. The reason for these "large" patches is if we were to continue to progress at the current rate of change in the kernel, adding license tags to individual files in different subsystems, we would be finished in about 10 years at the earliest. There will be more series of these types of patches coming over the next few weeks as the tools and reviewers crunch through the more "odd" variants of how to say "GPLv2" that developers have come up with over the years, combined with other fun oddities (GPL + a BSD disclaimer?) that are being unearthed, with the goal for the whole kernel to be cleaned up. These diffstats are not small, 3840 files are touched, over 10k lines removed in just 24 patches" * tag 'spdx-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (24 commits) treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 23 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 22 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 21 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 20 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 19 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 17 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 15 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 14 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 12 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 11 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 10 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 9 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 7 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 5 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 4 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 3 ...
| * treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | bpf: relax inode permission check for retrieving bpf programChenbo Feng2019-05-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | For iptable module to load a bpf program from a pinned location, it only retrieve a loaded program and cannot change the program content so requiring a write permission for it might not be necessary. Also when adding or removing an unrelated iptable rule, it might need to flush and reload the xt_bpf related rules as well and triggers the inode permission check. It might be better to remove the write premission check for the inode so we won't need to grant write access to all the processes that flush and restore iptables rules. Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf, lru: avoid messing with eviction heuristics upon syscall lookupDaniel Borkmann2019-05-141-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the biggest issues we face right now with picking LRU map over regular hash table is that a map walk out of user space, for example, to just dump the existing entries or to remove certain ones, will completely mess up LRU eviction heuristics and wrong entries such as just created ones will get evicted instead. The reason for this is that we mark an entry as "in use" via bpf_lru_node_set_ref() from system call lookup side as well. Thus upon walk, all entries are being marked, so information of actual least recently used ones are "lost". In case of Cilium where it can be used (besides others) as a BPF based connection tracker, this current behavior causes disruption upon control plane changes that need to walk the map from user space to evict certain entries. Discussion result from bpfconf [0] was that we should simply just remove marking from system call side as no good use case could be found where it's actually needed there. Therefore this patch removes marking for regular LRU and per-CPU flavor. If there ever should be a need in future, the behavior could be selected via map creation flag, but due to mentioned reason we avoid this here. [0] http://vger.kernel.org/bpfconf.html Fixes: 29ba732acbee ("bpf: Add BPF_MAP_TYPE_LRU_HASH") Fixes: 8f8449384ec3 ("bpf: Add BPF_MAP_TYPE_LRU_PERCPU_HASH") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: add map_lookup_elem_sys_only for lookups from syscall sideDaniel Borkmann2019-05-141-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a callback map_lookup_elem_sys_only() that map implementations could use over map_lookup_elem() from system call side in case the map implementation needs to handle the latter differently than from the BPF data path. If map_lookup_elem_sys_only() is set, this will be preferred pick for map lookups out of user space. This hook is used in a follow-up fix for LRU map, but once development window opens, we can convert other map types from map_lookup_elem() (here, the one called upon BPF_MAP_LOOKUP_ELEM cmd is meant) over to use the callback to simplify and clean up the latter. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: devmap: fix use-after-free Read in __dev_map_entry_freeEric Dumazet2019-05-141-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | synchronize_rcu() is fine when the rcu callbacks only need to free memory (kfree_rcu() or direct kfree() call rcu call backs) __dev_map_entry_free() is a bit more complex, so we need to make sure that call queued __dev_map_entry_free() callbacks have completed. sysbot report: BUG: KASAN: use-after-free in dev_map_flush_old kernel/bpf/devmap.c:365 [inline] BUG: KASAN: use-after-free in __dev_map_entry_free+0x2a8/0x300 kernel/bpf/devmap.c:379 Read of size 8 at addr ffff8801b8da38c8 by task ksoftirqd/1/18 CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.17.0+ #39 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 dev_map_flush_old kernel/bpf/devmap.c:365 [inline] __dev_map_entry_free+0x2a8/0x300 kernel/bpf/devmap.c:379 __rcu_reclaim kernel/rcu/rcu.h:178 [inline] rcu_do_batch kernel/rcu/tree.c:2558 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2785 [inline] rcu_process_callbacks+0xe9d/0x1760 kernel/rcu/tree.c:2802 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284 run_ksoftirqd+0x86/0x100 kernel/softirq.c:645 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Allocated by task 6675: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:706 [inline] dev_map_alloc+0x208/0x7f0 kernel/bpf/devmap.c:102 find_and_alloc_map kernel/bpf/syscall.c:129 [inline] map_create+0x393/0x1010 kernel/bpf/syscall.c:453 __do_sys_bpf kernel/bpf/syscall.c:2351 [inline] __se_sys_bpf kernel/bpf/syscall.c:2328 [inline] __x64_sys_bpf+0x303/0x510 kernel/bpf/syscall.c:2328 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 dev_map_free+0x4fa/0x670 kernel/bpf/devmap.c:191 bpf_map_free_deferred+0xba/0xf0 kernel/bpf/syscall.c:262 process_one_work+0xc64/0x1b70 kernel/workqueue.c:2153 worker_thread+0x181/0x13a0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 The buggy address belongs to the object at ffff8801b8da37c0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff8801b8da37c0, ffff8801b8da39c0) The buggy address belongs to the page: page:ffffea0006e368c0 count:1 mapcount:0 mapping:ffff8801da800940 index:0xffff8801b8da3540 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0007217b88 ffffea0006e30cc8 ffff8801da800940 raw: ffff8801b8da3540 ffff8801b8da3040 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b8da3780: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801b8da3800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801b8da3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801b8da3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b8da3980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc Fixes: 546ac1ffb70d ("bpf: add devmap, a map for storing net device references") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot+457d3e2ffbcf31aee5c0@syzkaller.appspotmail.com Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: fix undefined behavior in narrow load handlingKrzesimir Nowak2019-05-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 31fd85816dbe ("bpf: permits narrower load from bpf program context fields") made the verifier add AND instructions to clear the unwanted bits with a mask when doing a narrow load. The mask is computed with (1 << size * 8) - 1 where "size" is the size of the narrow load. When doing a 4 byte load of a an 8 byte field the verifier shifts the literal 1 by 32 places to the left. This results in an overflow of a signed integer, which is an undefined behavior. Typically, the computed mask was zero, so the result of the narrow load ended up being zero too. Cast the literal to long long to avoid overflows. Note that narrow load of the 4 byte fields does not have the undefined behavior, because the load size can only be either 1 or 2 bytes, so shifting 1 by 8 or 16 places will not overflow it. And reading 4 bytes would not be a narrow load of a 4 bytes field. Fixes: 31fd85816dbe ("bpf: permits narrower load from bpf program context fields") Reviewed-by: Alban Crequy <alban@kinvolk.io> Reviewed-by: Iago López Galeiras <iago@kinvolk.io> Signed-off-by: Krzesimir Nowak <krzesimir@kinvolk.io> Cc: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: fix out of bounds backwards jmps due to dead code removalDaniel Borkmann2019-05-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | systemtap folks reported the following splat recently: [ 7790.862212] WARNING: CPU: 3 PID: 26759 at arch/x86/kernel/kprobes/core.c:1022 kprobe_fault_handler+0xec/0xf0 [...] [ 7790.864113] CPU: 3 PID: 26759 Comm: sshd Not tainted 5.1.0-0.rc7.git1.1.fc31.x86_64 #1 [ 7790.864198] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS[...] [ 7790.864314] RIP: 0010:kprobe_fault_handler+0xec/0xf0 [ 7790.864375] Code: 48 8b 50 [...] [ 7790.864714] RSP: 0018:ffffc06800bdbb48 EFLAGS: 00010082 [ 7790.864812] RAX: ffff9e2b75a16320 RBX: 0000000000000000 RCX: 0000000000000000 [ 7790.865306] RDX: ffffffffffffffff RSI: 000000000000000e RDI: ffffc06800bdbbf8 [ 7790.865514] RBP: ffffc06800bdbbf8 R08: 0000000000000000 R09: 0000000000000000 [ 7790.865960] R10: 0000000000000000 R11: 0000000000000000 R12: ffffc06800bdbbf8 [ 7790.866037] R13: ffff9e2ab56a0418 R14: ffff9e2b6d0bb400 R15: ffff9e2b6d268000 [ 7790.866114] FS: 00007fde49937d80(0000) GS:ffff9e2b75a00000(0000) knlGS:0000000000000000 [ 7790.866193] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7790.866318] CR2: 0000000000000000 CR3: 000000012f312000 CR4: 00000000000006e0 [ 7790.866419] Call Trace: [ 7790.866677] do_user_addr_fault+0x64/0x480 [ 7790.867513] do_page_fault+0x33/0x210 [ 7790.868002] async_page_fault+0x1e/0x30 [ 7790.868071] RIP: 0010: (null) [ 7790.868144] Code: Bad RIP value. [ 7790.868229] RSP: 0018:ffffc06800bdbca8 EFLAGS: 00010282 [ 7790.868362] RAX: ffff9e2b598b60f8 RBX: ffffc06800bdbe48 RCX: 0000000000000004 [ 7790.868629] RDX: 0000000000000004 RSI: ffffc06800bdbc6c RDI: ffff9e2b598b60f0 [ 7790.868834] RBP: ffffc06800bdbcf8 R08: 0000000000000000 R09: 0000000000000004 [ 7790.870432] R10: 00000000ff6f7a03 R11: 0000000000000000 R12: 0000000000000001 [ 7790.871859] R13: ffffc06800bdbcb8 R14: 0000000000000000 R15: ffff9e2acd0a5310 [ 7790.873455] ? vfs_read+0x5/0x170 [ 7790.874639] ? vfs_read+0x1/0x170 [ 7790.875834] ? trace_call_bpf+0xf6/0x260 [ 7790.877044] ? vfs_read+0x1/0x170 [ 7790.878208] ? vfs_read+0x5/0x170 [ 7790.879345] ? kprobe_perf_func+0x233/0x260 [ 7790.880503] ? vfs_read+0x1/0x170 [ 7790.881632] ? vfs_read+0x5/0x170 [ 7790.882751] ? kprobe_ftrace_handler+0x92/0xf0 [ 7790.883926] ? __vfs_read+0x30/0x30 [ 7790.885050] ? ftrace_ops_assist_func+0x94/0x100 [ 7790.886183] ? vfs_read+0x1/0x170 [ 7790.887283] ? vfs_read+0x5/0x170 [ 7790.888348] ? ksys_read+0x5a/0xe0 [ 7790.889389] ? do_syscall_64+0x5c/0xa0 [ 7790.890401] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe After some debugging, turns out that the logic in 2cbd95a5c4fb ("bpf: change parameters of call/branch offset adjustment") has a bug that is exposed after 52875a04f4b2 ("bpf: verifier: remove dead code") in that we miss some of the jump offset adjustments after code patching when we remove dead code, more concretely, upon backward jump spanning over the area that is being removed. BPF insns of a case that was hit pre 52875a04f4b2: [...] 676: (85) call bpf_perf_event_output#-47616 677: (05) goto pc-636 678: (62) *(u32 *)(r10 -64) = 0 679: (bf) r7 = r10 680: (07) r7 += -64 681: (05) goto pc-44 682: (05) goto pc-1 683: (05) goto pc-1 BPF insns afterwards: [...] 618: (85) call bpf_perf_event_output#-47616 619: (05) goto pc-638 620: (62) *(u32 *)(r10 -64) = 0 621: (bf) r7 = r10 622: (07) r7 += -64 623: (05) goto pc-44 To illustrate the bug, situation looks as follows: ____ 0 | | <-- foo: [...] 1 |____| 2 |____| <-- pos / end_new ^ 3 | | | 4 | | | len 5 |____| | (remove region) 6 | | <-- end_old v 7 | | 8 | | <-- curr (jmp foo) 9 |____| The condition curr >= end_new && curr + off + 1 < end_new in the branch delta adjustments is never hit because curr + off + 1 < end_new is compared as unsigned and therefore curr + off + 1 > end_new in unsigned realm as curr + off + 1 becomes negative since the insns are memmove()'d before the offset adjustments. Correct BPF insns after this fix: [...] 618: (85) call bpf_perf_event_output#-47216 619: (05) goto pc-578 620: (62) *(u32 *)(r10 -64) = 0 621: (bf) r7 = r10 622: (07) r7 += -64 623: (05) goto pc-44 Note that unprivileged case is not affected from this. Fixes: 52875a04f4b2 ("bpf: verifier: remove dead code") Fixes: 2cbd95a5c4fb ("bpf: change parameters of call/branch offset adjustment") Reported-by: Frank Ch. Eigler <fche@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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