aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/bpf/bpf_inode_storage.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2021-05-24bpf: Fix spelling mistakesZhen Lei1-1/+1
Fix some spelling mistakes in comments: aother ==> another Netiher ==> Neither desribe ==> describe intializing ==> initializing funciton ==> function wont ==> won't and move the word 'the' at the end to the next line accross ==> across pathes ==> paths triggerred ==> triggered excute ==> execute ether ==> either conervative ==> conservative convetion ==> convention markes ==> marks interpeter ==> interpreter Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210525025659.8898-2-thunder.leizhen@huawei.com
2021-03-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-1/+1
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-08bpf: Change inode_storage's lookup_elem return value from NULL to -EBADFTal Lossos1-1/+1
bpf_fd_inode_storage_lookup_elem() returned NULL when getting a bad FD, which caused -ENOENT in bpf_map_copy_value. -EBADF error is better than -ENOENT for a bad FD behaviour. The patch was partially contributed by CyberArk Software, Inc. Fixes: 8ea636848aca ("bpf: Implement bpf_local_storage for inodes") Signed-off-by: Tal Lossos <tallossos@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210307120948.61414-1-tallossos@gmail.com
2021-02-26bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]Song Liu1-1/+1
BPF helpers bpf_task_storage_[get|delete] could hold two locks: bpf_local_storage_map_bucket->lock and bpf_local_storage->lock. Calling these helpers from fentry/fexit programs on functions in bpf_*_storage.c may cause deadlock on either locks. Prevent such deadlock with a per cpu counter, bpf_task_storage_busy. We need this counter to be global, because the two locks here belong to two different objects: bpf_local_storage_map and bpf_local_storage. If we pick one of them as the owner of the counter, it is still possible to trigger deadlock on the other lock. For example, if bpf_local_storage_map owns the counters, it cannot prevent deadlock on bpf_local_storage->lock when two maps are used. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210225234319.336131-3-songliubraving@fb.com
2021-01-22bpf, inode_storage: Put file handler if no storage was foundPan Bian1-1/+5
Put file f if inode_storage_ptr() returns NULL. Fixes: 8ea636848aca ("bpf: Implement bpf_local_storage for inodes") Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210121020856.25507-1-bianpan2016@163.com
2021-01-12bpf: Fix typo in bpf_inode_storage.cKP Singh1-2/+2
Fix "gurranteed" -> "guaranteed" in bpf_inode_storage.c Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210112075525.256820-4-kpsingh@kernel.org
2021-01-12bpf: Local storage helpers should check nullness of owner ptr passedKP Singh1-1/+4
The verifier allows ARG_PTR_TO_BTF_ID helper arguments to be NULL, so helper implementations need to check this before dereferencing them. This was already fixed for the socket storage helpers but not for task and inode. The issue can be reproduced by attaching an LSM program to inode_rename hook (called when moving files) which tries to get the inode of the new file without checking for its nullness and then trying to move an existing file to a new path: mv existing_file new_file_does_not_exist The report including the sample program and the steps for reproducing the bug: https://lore.kernel.org/bpf/CANaYP3HWkH91SN=wTNO9FL_2ztHfqcXKX38SSE-JJ2voh+vssw@mail.gmail.com Fixes: 4cf1bc1f1045 ("bpf: Implement task local storage") Fixes: 8ea636848aca ("bpf: Implement bpf_local_storage for inodes") Reported-by: Gilad Reti <gilad.reti@gmail.com> Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210112075525.256820-3-kpsingh@kernel.org
2020-09-21bpf: Allow specifying a BTF ID per argument in function protosLorenz Bauer1-5/+3
Function prototypes using ARG_PTR_TO_BTF_ID currently use two ways to signal which BTF IDs are acceptable. First, bpf_func_proto.btf_id is an array of IDs, one for each argument. This array is only accessed up to the highest numbered argument that uses ARG_PTR_TO_BTF_ID and may therefore be less than five arguments long. It usually points at a BTF_ID_LIST. Second, check_btf_id is a function pointer that is called by the verifier if present. It gets the actual BTF ID of the register, and the argument number we're currently checking. It turns out that the only user check_arg_btf_id ignores the argument, and is simply used to check whether the BTF ID has a struct sock_common at it's start. Replace both of these mechanisms with an explicit BTF ID for each argument in a function proto. Thanks to btf_struct_ids_match this is very flexible: check_arg_btf_id can be replaced by requiring struct sock_common. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200921121227.255763-5-lmb@cloudflare.com
2020-08-28bpf: Add map_meta_equal map opsMartin KaFai Lau1-0/+1
Some properties of the inner map is used in the verification time. When an inner map is inserted to an outer map at runtime, bpf_map_meta_equal() is currently used to ensure those properties of the inserting inner map stays the same as the verification time. In particular, the current bpf_map_meta_equal() checks max_entries which turns out to be too restrictive for most of the maps which do not use max_entries during the verification time. It limits the use case that wants to replace a smaller inner map with a larger inner map. There are some maps do use max_entries during verification though. For example, the map_gen_lookup in array_map_ops uses the max_entries to generate the inline lookup code. To accommodate differences between maps, the map_meta_equal is added to bpf_map_ops. Each map-type can decide what to check when its map is used as an inner map during runtime. Also, some map types cannot be used as an inner map and they are currently black listed in bpf_map_meta_alloc() in map_in_map.c. It is not unusual that the new map types may not aware that such blacklist exists. This patch enforces an explicit opt-in and only allows a map to be used as an inner map if it has implemented the map_meta_equal ops. It is based on the discussion in [1]. All maps that support inner map has its map_meta_equal points to bpf_map_meta_equal in this patch. A later patch will relax the max_entries check for most maps. bpf_types.h counts 28 map types. This patch adds 23 ".map_meta_equal" by using coccinelle. -5 for BPF_MAP_TYPE_PROG_ARRAY BPF_MAP_TYPE_(PERCPU)_CGROUP_STORAGE BPF_MAP_TYPE_STRUCT_OPS BPF_MAP_TYPE_ARRAY_OF_MAPS BPF_MAP_TYPE_HASH_OF_MAPS The "if (inner_map->inner_map_meta)" check in bpf_map_meta_alloc() is moved such that the same error is returned. [1]: https://lore.kernel.org/bpf/20200522022342.899756-1-kafai@fb.com/ Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200828011806.1970400-1-kafai@fb.com
2020-08-25bpf: Implement bpf_local_storage for inodesKP Singh1-0/+273
Similar to bpf_local_storage for sockets, add local storage for inodes. The life-cycle of storage is managed with the life-cycle of the inode. i.e. the storage is destroyed along with the owning inode. The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the security blob which are now stackable and can co-exist with other LSMs. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200825182919.1118197-6-kpsingh@chromium.org