Messages in this thread | | | Subject | Re: [PATCH v7 bpf-next 00/14] bpf: cgroup local storage | From | Daniel Borkmann <> | Date | Fri, 3 Aug 2018 10:14:23 +0200 |
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On 08/02/2018 11:27 PM, Roman Gushchin wrote: > This patchset implements cgroup local storage for bpf programs. > The main idea is to provide a fast accessible memory for storing > various per-cgroup data, e.g. number of transmitted packets. > > Cgroup local storage looks as a special type of map for userspace, > and is accessible using generic bpf maps API for reading and > updating of the data. The (cgroup inode id, attachment type) pair > is used as a map key. > > A user can't create new entries or destroy existing entries; > it happens automatically when a user attaches/detaches a bpf program > to a cgroup. > > From a bpf program's point of view, cgroup storage is accessible > without lookup using the special get_local_storage() helper function. > It takes a map fd as an argument. It always returns a valid pointer > to the corresponding memory area. > > To implement such a lookup-free access a pointer to the cgroup > storage is saved for an attachment of a bpf program to a cgroup, > if required by the program. Before running the program, it's saved > in a special global per-cpu variable, which is accessible from the > get_local_storage() helper. > > This patchset implement only cgroup local storage, however the API > is intentionally made extensible to support other local storage types > further: e.g. thread local storage, socket local storage, etc. > > v7->v6: > - fixed a use-after-free bug, caused by not clearing > prog->aux->cgroup_storage pointer after releasing the map > > v6->v5: > - fixed an error with returning -EINVAL instead of a pointer > > v5->v4: > - fixed an issue in verifier (test that flags == 0 properly) > - added a corresponding test > - added a note about synchronization, sync docs to tools/uapi/... > - switched the cgroup test to use XADD > - added a check for attr->max_entries to be 0, and atter->max_flags > to be sane > - use bpf_uncharge_memlock() in bpf_uncharge_memlock() > - rebased to bpf-next > > v4->v3: > - fixed a leak in cgroup attachment code (discovered by Daniel) > - cgroup storage map will be released if the corresponding > bpf program failed to load by any reason > - introduced bpf_uncharge_memlock() helper > > v3->v2: > - fixed more build and sparse issues > - rebased to bpf-next > > v2->v1: > - fixed build issues > - removed explicit rlimit calls in patch 14 > - rebased to bpf-next > > Signed-off-by: Roman Gushchin <guro@fb.com> > Cc: Alexei Starovoitov <ast@kernel.org> > Cc: Martin KaFai Lau <kafai@fb.com> > > Roman Gushchin (14): > bpf: add ability to charge bpf maps memory dynamically > bpf: introduce cgroup storage maps > bpf: pass a pointer to a cgroup storage using pcpu variable > bpf: allocate cgroup storage entries on attaching bpf programs > bpf: extend bpf_prog_array to store pointers to the cgroup storage > bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE > bpf: don't allow create maps of cgroup local storages > bpf: introduce the bpf_get_local_storage() helper function > bpf: sync bpf.h to tools/ > bpftool: add support for CGROUP_STORAGE maps > bpf/test_run: support cgroup local storage > selftests/bpf: add verifier cgroup storage tests > selftests/bpf: add a cgroup storage test > samples/bpf: extend test_cgrp2_attach2 test to use cgroup storage
Tossed the old series from bpf-next and replaced with this one which fixes the syzkaller issue, thanks Roman!
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