From 129d868ede1ea835ac97f0a9f2cf3f4ed00d8ea7 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 5 Jan 2023 11:26:47 -0800 Subject: bpf: Replace 0-length arrays with flexible arrays Zero-length arrays are deprecated [1]. Replace struct bpf_array's union of 0-length arrays with flexible arrays. Detected with GCC 13, by using -fstrict-flex-arrays=3: arch/x86/net/bpf_jit_comp.c: In function 'bpf_tail_call_direct_fixup': arch/x86/net/bpf_jit_comp.c:606:37: warning: array subscript is outside array bounds of 'void *[0]' [-Warray-bounds=] 606 | target = array->ptrs[poke->tail_call.key]; | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/filter.h:9, from arch/x86/net/bpf_jit_comp.c:9: include/linux/bpf.h:1527:23: note: while referencing 'ptrs' 1527 | void *ptrs[0] __aligned(8); | ^~~~ [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays Signed-off-by: Kees Cook Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20230105192646.never.154-kees@kernel.org --- include/linux/bpf.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1697bd87fc06..ae7771c7d750 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1523,9 +1523,9 @@ struct bpf_array { u32 index_mask; struct bpf_array_aux *aux; union { - char value[0] __aligned(8); - void *ptrs[0] __aligned(8); - void __percpu *pptrs[0] __aligned(8); + DECLARE_FLEX_ARRAY(char, value) __aligned(8); + DECLARE_FLEX_ARRAY(void *, ptrs) __aligned(8); + DECLARE_FLEX_ARRAY(void __percpu *, pptrs) __aligned(8); }; }; -- cgit v1.2.3 From 07cc2c931e8e1083a31f4c51d2244fe264af63bf Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Mon, 16 Jan 2023 11:10:07 +0100 Subject: livepatch: Improve the search performance of module_kallsyms_on_each_symbol() Currently we traverse all symbols of all modules to find the specified function for the specified module. But in reality, we just need to find the given module and then traverse all the symbols in it. Let's add a new parameter 'const char *modname' to function module_kallsyms_on_each_symbol(), then we can compare the module names directly in this function and call hook 'fn' after matching. If 'modname' is NULL, the symbols of all modules are still traversed for compatibility with other usage cases. Phase1: mod1-->mod2..(subsequent modules do not need to be compared) | Phase2: -->f1-->f2-->f3 Assuming that there are m modules, each module has n symbols on average, then the time complexity is reduced from O(m * n) to O(m) + O(n). Reviewed-by: Petr Mladek Acked-by: Song Liu Signed-off-by: Zhen Lei Signed-off-by: Jiri Olsa Acked-by: Miroslav Benes Reviewed-by: Luis Chamberlain Link: https://lore.kernel.org/r/20230116101009.23694-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- include/linux/module.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index 8c5909c0076c..514bc81568c5 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -879,11 +879,13 @@ static inline bool module_sig_ok(struct module *module) #endif /* CONFIG_MODULE_SIG */ #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) -int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, +int module_kallsyms_on_each_symbol(const char *modname, + int (*fn)(void *, const char *, struct module *, unsigned long), void *data); #else -static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, +static inline int module_kallsyms_on_each_symbol(const char *modname, + int (*fn)(void *, const char *, struct module *, unsigned long), void *data) { -- cgit v1.2.3 From f8064ab90d6644bc8338d2d7ff6a0d6e7a1b2ef3 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Sat, 21 Jan 2023 05:52:33 +0530 Subject: bpf: Invalidate slices on destruction of dynptrs on stack The previous commit implemented destroy_if_dynptr_stack_slot. It destroys the dynptr which given spi belongs to, but still doesn't invalidate the slices that belong to such a dynptr. While for the case of referenced dynptr, we don't allow their overwrite and return an error early, we still allow it and destroy the dynptr for unreferenced dynptr. To be able to enable precise and scoped invalidation of dynptr slices in this case, we must be able to associate the source dynptr of slices that have been obtained using bpf_dynptr_data. When doing destruction, only slices belonging to the dynptr being destructed should be invalidated, and nothing else. Currently, dynptr slices belonging to different dynptrs are indistinguishible. Hence, allocate a unique id to each dynptr (CONST_PTR_TO_DYNPTR and those on stack). This will be stored as part of reg->id. Whenever using bpf_dynptr_data, transfer this unique dynptr id to the returned PTR_TO_MEM_OR_NULL slice pointer, and store it in a new per-PTR_TO_MEM dynptr_id register state member. Finally, after establishing such a relationship between dynptrs and their slices, implement precise invalidation logic that only invalidates slices belong to the destroyed dynptr in destroy_if_dynptr_stack_slot. Acked-by: Joanne Koong Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20230121002241.2113993-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf_verifier.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 127058cfec47..aa83de1fe755 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -70,7 +70,10 @@ struct bpf_reg_state { u32 btf_id; }; - u32 mem_size; /* for PTR_TO_MEM | PTR_TO_MEM_OR_NULL */ + struct { /* for PTR_TO_MEM | PTR_TO_MEM_OR_NULL */ + u32 mem_size; + u32 dynptr_id; /* for dynptr slices */ + }; /* For dynptr stack slots */ struct { -- cgit v1.2.3 From 9d03ebc71a027ca495c60f6e94d3cda81921791f Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 19 Jan 2023 14:15:21 -0800 Subject: bpf: Rename bpf_{prog,map}_is_dev_bound to is_offloaded BPF offloading infra will be reused to implement bound-but-not-offloaded bpf programs. Rename existing helpers for clarity. No functional changes. Cc: John Fastabend Cc: David Ahern Cc: Martin KaFai Lau Cc: Willem de Bruijn Cc: Jesper Dangaard Brouer Cc: Anatoly Burakov Cc: Alexander Lobakin Cc: Magnus Karlsson Cc: Maryam Tahhan Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Reviewed-by: Jakub Kicinski Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20230119221536.3349901-3-sdf@google.com Signed-off-by: Martin KaFai Lau --- include/linux/bpf.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ae7771c7d750..1bb525c0130e 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2481,12 +2481,12 @@ void unpriv_ebpf_notify(int new_state); #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL) int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr); -static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux) +static inline bool bpf_prog_is_offloaded(const struct bpf_prog_aux *aux) { return aux->offload_requested; } -static inline bool bpf_map_is_dev_bound(struct bpf_map *map) +static inline bool bpf_map_is_offloaded(struct bpf_map *map) { return unlikely(map->ops == &bpf_map_offload_ops); } @@ -2513,12 +2513,12 @@ static inline int bpf_prog_offload_init(struct bpf_prog *prog, return -EOPNOTSUPP; } -static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux) +static inline bool bpf_prog_is_offloaded(struct bpf_prog_aux *aux) { return false; } -static inline bool bpf_map_is_dev_bound(struct bpf_map *map) +static inline bool bpf_map_is_offloaded(struct bpf_map *map) { return false; } -- cgit v1.2.3 From 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 19 Jan 2023 14:15:24 -0800 Subject: bpf: Introduce device-bound XDP programs New flag BPF_F_XDP_DEV_BOUND_ONLY plus all the infra to have a way to associate a netdev with a BPF program at load time. netdevsim checks are dropped in favor of generic check in dev_xdp_attach. Cc: John Fastabend Cc: David Ahern Cc: Martin KaFai Lau Cc: Jakub Kicinski Cc: Willem de Bruijn Cc: Jesper Dangaard Brouer Cc: Anatoly Burakov Cc: Alexander Lobakin Cc: Magnus Karlsson Cc: Maryam Tahhan Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20230119221536.3349901-6-sdf@google.com Signed-off-by: Martin KaFai Lau --- include/linux/bpf.h | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1bb525c0130e..b97a05bb47be 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1261,7 +1261,8 @@ struct bpf_prog_aux { enum bpf_prog_type saved_dst_prog_type; enum bpf_attach_type saved_dst_attach_type; bool verifier_zext; /* Zero extensions has been inserted by verifier. */ - bool offload_requested; + bool dev_bound; /* Program is bound to the netdev. */ + bool offload_requested; /* Program is bound and offloaded to the netdev. */ bool attach_btf_trace; /* true if attaching to BTF-enabled raw tp */ bool func_proto_unreliable; bool sleepable; @@ -2451,7 +2452,7 @@ void __bpf_free_used_maps(struct bpf_prog_aux *aux, bool bpf_prog_get_ok(struct bpf_prog *, enum bpf_prog_type *, bool); int bpf_prog_offload_compile(struct bpf_prog *prog); -void bpf_prog_offload_destroy(struct bpf_prog *prog); +void bpf_prog_dev_bound_destroy(struct bpf_prog *prog); int bpf_prog_offload_info_fill(struct bpf_prog_info *info, struct bpf_prog *prog); @@ -2479,7 +2480,13 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev); void unpriv_ebpf_notify(int new_state); #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL) -int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr); +int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr); +void bpf_dev_bound_netdev_unregister(struct net_device *dev); + +static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux) +{ + return aux->dev_bound; +} static inline bool bpf_prog_is_offloaded(const struct bpf_prog_aux *aux) { @@ -2507,12 +2514,21 @@ void sock_map_unhash(struct sock *sk); void sock_map_destroy(struct sock *sk); void sock_map_close(struct sock *sk, long timeout); #else -static inline int bpf_prog_offload_init(struct bpf_prog *prog, +static inline int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) { return -EOPNOTSUPP; } +static inline void bpf_dev_bound_netdev_unregister(struct net_device *dev) +{ +} + +static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux) +{ + return false; +} + static inline bool bpf_prog_is_offloaded(struct bpf_prog_aux *aux) { return false; -- cgit v1.2.3 From 3d76a4d3d4e591af3e789698affaad88a5a8e8ab Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 19 Jan 2023 14:15:26 -0800 Subject: bpf: XDP metadata RX kfuncs Define a new kfunc set (xdp_metadata_kfunc_ids) which implements all possible XDP metatada kfuncs. Not all devices have to implement them. If kfunc is not supported by the target device, the default implementation is called instead. The verifier, at load time, replaces a call to the generic kfunc with a call to the per-device one. Per-device kfunc pointers are stored in separate struct xdp_metadata_ops. Cc: John Fastabend Cc: David Ahern Cc: Martin KaFai Lau Cc: Jakub Kicinski Cc: Willem de Bruijn Cc: Jesper Dangaard Brouer Cc: Anatoly Burakov Cc: Alexander Lobakin Cc: Magnus Karlsson Cc: Maryam Tahhan Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20230119221536.3349901-8-sdf@google.com Signed-off-by: Martin KaFai Lau --- include/linux/bpf.h | 17 ++++++++++++++++- include/linux/netdevice.h | 8 ++++++++ 2 files changed, 24 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index b97a05bb47be..bb26c2e18092 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2480,6 +2480,9 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev); void unpriv_ebpf_notify(int new_state); #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL) +int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, + struct bpf_prog_aux *prog_aux); +void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id); int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr); void bpf_dev_bound_netdev_unregister(struct net_device *dev); @@ -2514,8 +2517,20 @@ void sock_map_unhash(struct sock *sk); void sock_map_destroy(struct sock *sk); void sock_map_close(struct sock *sk, long timeout); #else +static inline int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, + struct bpf_prog_aux *prog_aux) +{ + return -EOPNOTSUPP; +} + +static inline void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, + u32 func_id) +{ + return NULL; +} + static inline int bpf_prog_dev_bound_init(struct bpf_prog *prog, - union bpf_attr *attr) + union bpf_attr *attr) { return -EOPNOTSUPP; } diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index aad12a179e54..90f2be194bc5 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -74,6 +74,7 @@ struct udp_tunnel_nic_info; struct udp_tunnel_nic; struct bpf_prog; struct xdp_buff; +struct xdp_md; void synchronize_net(void); void netdev_set_default_ethtool_ops(struct net_device *dev, @@ -1618,6 +1619,11 @@ struct net_device_ops { bool cycles); }; +struct xdp_metadata_ops { + int (*xmo_rx_timestamp)(const struct xdp_md *ctx, u64 *timestamp); + int (*xmo_rx_hash)(const struct xdp_md *ctx, u32 *hash); +}; + /** * enum netdev_priv_flags - &struct net_device priv_flags * @@ -1801,6 +1807,7 @@ enum netdev_ml_priv_type { * * @netdev_ops: Includes several pointers to callbacks, * if one wants to override the ndo_*() functions + * @xdp_metadata_ops: Includes pointers to XDP metadata callbacks. * @ethtool_ops: Management operations * @l3mdev_ops: Layer 3 master device operations * @ndisc_ops: Includes callbacks for different IPv6 neighbour @@ -2050,6 +2057,7 @@ struct net_device { unsigned int flags; unsigned long long priv_flags; const struct net_device_ops *netdev_ops; + const struct xdp_metadata_ops *xdp_metadata_ops; int ifindex; unsigned short gflags; unsigned short hard_header_len; -- cgit v1.2.3 From fd7c211d6875013f81acc09868effe199b5d2c0c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Thu, 19 Jan 2023 14:15:27 -0800 Subject: bpf: Support consuming XDP HW metadata from fext programs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Instead of rejecting the attaching of PROG_TYPE_EXT programs to XDP programs that consume HW metadata, implement support for propagating the offload information. The extension program doesn't need to set a flag or ifindex, these will just be propagated from the target by the verifier. We need to create a separate offload object for the extension program, though, since it can be reattached to a different program later (which means we can't just inherit the offload information from the target). An additional check is added on attach that the new target is compatible with the offload information in the extension prog. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20230119221536.3349901-9-sdf@google.com Signed-off-by: Martin KaFai Lau --- include/linux/bpf.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index bb26c2e18092..ad4bb36d4c10 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2484,6 +2484,7 @@ int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, struct bpf_prog_aux *prog_aux); void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id); int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr); +int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, struct bpf_prog *old_prog); void bpf_dev_bound_netdev_unregister(struct net_device *dev); static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux) @@ -2496,6 +2497,8 @@ static inline bool bpf_prog_is_offloaded(const struct bpf_prog_aux *aux) return aux->offload_requested; } +bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs); + static inline bool bpf_map_is_offloaded(struct bpf_map *map) { return unlikely(map->ops == &bpf_map_offload_ops); @@ -2535,6 +2538,12 @@ static inline int bpf_prog_dev_bound_init(struct bpf_prog *prog, return -EOPNOTSUPP; } +static inline int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, + struct bpf_prog *old_prog) +{ + return -EOPNOTSUPP; +} + static inline void bpf_dev_bound_netdev_unregister(struct net_device *dev) { } @@ -2549,6 +2558,11 @@ static inline bool bpf_prog_is_offloaded(struct bpf_prog_aux *aux) return false; } +static inline bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs) +{ + return false; +} + static inline bool bpf_map_is_offloaded(struct bpf_map *map) { return false; -- cgit v1.2.3 From 57539b1c0ac2dcccbe64a7675ff466be009c040f Mon Sep 17 00:00:00 2001 From: David Vernet Date: Fri, 20 Jan 2023 13:25:15 -0600 Subject: bpf: Enable annotating trusted nested pointers In kfuncs, a "trusted" pointer is a pointer that the kfunc can assume is safe, and which the verifier will allow to be passed to a KF_TRUSTED_ARGS kfunc. Currently, a KF_TRUSTED_ARGS kfunc disallows any pointer to be passed at a nonzero offset, but sometimes this is in fact safe if the "nested" pointer's lifetime is inherited from its parent. For example, the const cpumask_t *cpus_ptr field in a struct task_struct will remain valid until the task itself is destroyed, and thus would also be safe to pass to a KF_TRUSTED_ARGS kfunc. While it would be conceptually simple to enable this by using BTF tags, gcc unfortunately does not yet support this. In the interim, this patch enables support for this by using a type-naming convention. A new BTF_TYPE_SAFE_NESTED macro is defined in verifier.c which allows a developer to specify the nested fields of a type which are considered trusted if its parent is also trusted. The verifier is also updated to account for this. A patch with selftests will be added in a follow-on change, along with documentation for this feature. Signed-off-by: David Vernet Link: https://lore.kernel.org/r/20230120192523.3650503-2-void@manifault.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ad4bb36d4c10..982213d97668 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2187,6 +2187,10 @@ struct bpf_core_ctx { const struct btf *btf; }; +bool btf_nested_type_is_trusted(struct bpf_verifier_log *log, + const struct bpf_reg_state *reg, + int off); + int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, int relo_idx, void *insn); -- cgit v1.2.3 From b613d335a743cf0e0ef0ccba9ad129904e2a26fb Mon Sep 17 00:00:00 2001 From: David Vernet Date: Fri, 20 Jan 2023 13:25:16 -0600 Subject: bpf: Allow trusted args to walk struct when checking BTF IDs When validating BTF types for KF_TRUSTED_ARGS kfuncs, the verifier currently enforces that the top-level type must match when calling the kfunc. In other words, the verifier does not allow the BPF program to pass a bitwise equivalent struct, despite it being allowed according to the C standard. For example, if you have the following type: struct nf_conn___init { struct nf_conn ct; }; The C standard stipulates that it would be safe to pass a struct nf_conn___init to a kfunc expecting a struct nf_conn. The verifier currently disallows this, however, as semantically kfuncs may want to enforce that structs that have equivalent types according to the C standard, but have different BTF IDs, are not able to be passed to kfuncs expecting one or the other. For example, struct nf_conn___init may not be queried / looked up, as it is allocated but may not yet be fully initialized. On the other hand, being able to pass types that are equivalent according to the C standard will be useful for other types of kfunc / kptrs enabled by BPF. For example, in a follow-on patch, a series of kfuncs will be added which allow programs to do bitwise queries on cpumasks that are either allocated by the program (in which case they'll be a 'struct bpf_cpumask' type that wraps a cpumask_t as its first element), or a cpumask that was allocated by the main kernel (in which case it will just be a straight cpumask_t, as in task->cpus_ptr). Having the two types of cpumasks allows us to distinguish between the two for when a cpumask is read-only vs. mutatable. A struct bpf_cpumask can be mutated by e.g. bpf_cpumask_clear(), whereas a regular cpumask_t cannot be. On the other hand, a struct bpf_cpumask can of course be queried in the exact same manner as a cpumask_t, with e.g. bpf_cpumask_test_cpu(). If we were to enforce that top level types match, then a user that's passing a struct bpf_cpumask to a read-only cpumask_t argument would have to cast with something like bpf_cast_to_kern_ctx() (which itself would need to be updated to expect the alias, and currently it only accommodates a single alias per prog type). Additionally, not specifying KF_TRUSTED_ARGS is not an option, as some kfuncs take one argument as a struct bpf_cpumask *, and another as a struct cpumask * (i.e. cpumask_t). In order to enable this, this patch relaxes the constraint that a KF_TRUSTED_ARGS kfunc must have strict type matching, and instead only enforces strict type matching if a type is observed to be a "no-cast alias" (i.e., that the type names are equivalent, but one is suffixed with ___init). Additionally, in order to try and be conservative and match existing behavior / expectations, this patch also enforces strict type checking for acquire kfuncs. We were already enforcing it for release kfuncs, so this should also improve the consistency of the semantics for kfuncs. Signed-off-by: David Vernet Link: https://lore.kernel.org/r/20230120192523.3650503-3-void@manifault.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 982213d97668..1bec48d9e5d9 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2191,6 +2191,10 @@ bool btf_nested_type_is_trusted(struct bpf_verifier_log *log, const struct bpf_reg_state *reg, int off); +bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log, + const struct btf *reg_btf, u32 reg_id, + const struct btf *arg_btf, u32 arg_id); + int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, int relo_idx, void *insn); -- cgit v1.2.3 From 51a52a29ebaa8395de090fa415c6e1b2899a50f1 Mon Sep 17 00:00:00 2001 From: David Vernet Date: Wed, 25 Jan 2023 10:47:34 -0600 Subject: bpf: Pass const struct bpf_prog * to .check_member The .check_member field of struct bpf_struct_ops is currently passed the member's btf_type via const struct btf_type *t, and a const struct btf_member *member. This allows the struct_ops implementation to check whether e.g. an ops is supported, but it would be useful to also enforce that the struct_ops prog being loaded for that member has other qualities, like being sleepable (or not). This patch therefore updates the .check_member() callback to also take a const struct bpf_prog *prog argument. Signed-off-by: David Vernet Link: https://lore.kernel.org/r/20230125164735.785732-4-void@manifault.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1bec48d9e5d9..0d868ef1b973 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1422,7 +1422,8 @@ struct bpf_struct_ops { const struct bpf_verifier_ops *verifier_ops; int (*init)(struct btf *btf); int (*check_member)(const struct btf_type *t, - const struct btf_member *member); + const struct btf_member *member, + const struct bpf_prog *prog); int (*init_member)(const struct btf_type *t, const struct btf_member *member, void *kdata, const void *udata); -- cgit v1.2.3 From 7dd880592a88799f3ef48fda507849a75f11cbf0 Mon Sep 17 00:00:00 2001 From: David Vernet Date: Wed, 25 Jan 2023 10:47:35 -0600 Subject: bpf/selftests: Verify struct_ops prog sleepable behavior In a set of prior changes, we added the ability for struct_ops programs to be sleepable. This patch enhances the dummy_st_ops selftest suite to validate this behavior by adding a new sleepable struct_ops entry to dummy_st_ops. Signed-off-by: David Vernet Link: https://lore.kernel.org/r/20230125164735.785732-5-void@manifault.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 0d868ef1b973..14a0264fac57 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1474,6 +1474,7 @@ struct bpf_dummy_ops { int (*test_1)(struct bpf_dummy_ops_state *cb); int (*test_2)(struct bpf_dummy_ops_state *cb, int a1, unsigned short a2, char a3, unsigned long a4); + int (*test_sleepable)(struct bpf_dummy_ops_state *cb); }; int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr, -- cgit v1.2.3