From: Alexei Starovoitov <ast@xxxxxxxxxx>
v2->v3:
- contains bpf bits only, but cc-ing past audience for continuity
- since prerequisite patches landed, this series focus on the main
functionality of bpf_arena.
- adopted Andrii's approach to support arena in libbpf.
- simplified LLVM support. Instead of two instructions it's now only one.
- switched to cond_break (instead of open coded iters) in selftests
- implemented several follow-ups that will be sent after this set
. remember first IP and bpf insn that faulted in arena.
report to user space via bpftool
. copy paste and tweak glob_match() aka mini-regex as a selftests/bpf
- see patch 1 for detailed description of bpf_arena
v1->v2:
- Improved commit log with reasons for using vmap_pages_range() in arena.
Thanks to Johannes
- Added support for __arena global variables in bpf programs
- Fixed race conditions spotted by Barret
- Fixed wrap32 issue spotted by Barret
- Fixed bpf_map_mmap_sz() the way Andrii suggested
The work on bpf_arena was inspired by Barret's work:
https://github.com/google/ghost-userspace/blob/main/lib/queue.bpf.h
that implements queues, lists and AVL trees completely as bpf programs
using giant bpf array map and integer indices instead of pointers.
bpf_arena is a sparse array that allows to use normal C pointers to
build such data structures. Last few patches implement page_frag
allocator, link list and hash table as bpf programs.
v1:
bpf programs have multiple options to communicate with user space:
- Various ring buffers (perf, ftrace, bpf): The data is streamed
unidirectionally from bpf to user space.
- Hash map: The bpf program populates elements, and user space consumes
them via bpf syscall.
- mmap()-ed array map: Libbpf creates an array map that is directly
accessed by the bpf program and mmap-ed to user space. It's the fastest
way. Its disadvantage is that memory for the whole array is reserved at
the start.
Alexei Starovoitov (13):
bpf: Introduce bpf_arena.
bpf: Disasm support for addr_space_cast instruction.
bpf: Add x86-64 JIT support for PROBE_MEM32 pseudo instructions.
bpf: Add x86-64 JIT support for bpf_addr_space_cast instruction.
bpf: Recognize addr_space_cast instruction in the verifier.
bpf: Recognize btf_decl_tag("arg:arena") as PTR_TO_ARENA.
libbpf: Add __arg_arena to bpf_helpers.h
libbpf: Add support for bpf_arena.
bpftool: Recognize arena map type
bpf: Add helper macro bpf_addr_space_cast()
selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
selftests/bpf: Add bpf_arena_list test.
selftests/bpf: Add bpf_arena_htab test.
Andrii Nakryiko (1):
libbpf: Recognize __arena global varaibles.
arch/x86/net/bpf_jit_comp.c | 231 +++++++-
include/linux/bpf.h | 10 +-
include/linux/bpf_types.h | 1 +
include/linux/bpf_verifier.h | 1 +
include/linux/filter.h | 4 +
include/uapi/linux/bpf.h | 14 +
kernel/bpf/Makefile | 3 +
kernel/bpf/arena.c | 558 ++++++++++++++++++
kernel/bpf/btf.c | 19 +-
kernel/bpf/core.c | 16 +
kernel/bpf/disasm.c | 10 +
kernel/bpf/log.c | 3 +
kernel/bpf/syscall.c | 42 ++
kernel/bpf/verifier.c | 123 +++-
.../bpf/bpftool/Documentation/bpftool-map.rst | 2 +-
tools/bpf/bpftool/gen.c | 13 +
tools/bpf/bpftool/map.c | 2 +-
tools/include/uapi/linux/bpf.h | 14 +
tools/lib/bpf/bpf_helpers.h | 1 +
tools/lib/bpf/libbpf.c | 163 ++++-
tools/lib/bpf/libbpf.h | 2 +-
tools/lib/bpf/libbpf_probes.c | 7 +
tools/testing/selftests/bpf/DENYLIST.aarch64 | 2 +
tools/testing/selftests/bpf/DENYLIST.s390x | 2 +
tools/testing/selftests/bpf/bpf_arena_alloc.h | 67 +++
.../testing/selftests/bpf/bpf_arena_common.h | 70 +++
tools/testing/selftests/bpf/bpf_arena_htab.h | 100 ++++
tools/testing/selftests/bpf/bpf_arena_list.h | 92 +++
.../testing/selftests/bpf/bpf_experimental.h | 43 ++
.../selftests/bpf/prog_tests/arena_htab.c | 88 +++
.../selftests/bpf/prog_tests/arena_list.c | 68 +++
.../selftests/bpf/prog_tests/verifier.c | 2 +
.../testing/selftests/bpf/progs/arena_htab.c | 48 ++
.../selftests/bpf/progs/arena_htab_asm.c | 5 +
.../testing/selftests/bpf/progs/arena_list.c | 87 +++
.../selftests/bpf/progs/verifier_arena.c | 146 +++++
tools/testing/selftests/bpf/test_loader.c | 9 +-
37 files changed, 2028 insertions(+), 40 deletions(-)
create mode 100644 kernel/bpf/arena.c
create mode 100644 tools/testing/selftests/bpf/bpf_arena_alloc.h
create mode 100644 tools/testing/selftests/bpf/bpf_arena_common.h
create mode 100644 tools/testing/selftests/bpf/bpf_arena_htab.h
create mode 100644 tools/testing/selftests/bpf/bpf_arena_list.h
create mode 100644 tools/testing/selftests/bpf/prog_tests/arena_htab.c
create mode 100644 tools/testing/selftests/bpf/prog_tests/arena_list.c
create mode 100644 tools/testing/selftests/bpf/progs/arena_htab.c
create mode 100644 tools/testing/selftests/bpf/progs/arena_htab_asm.c
create mode 100644 tools/testing/selftests/bpf/progs/arena_list.c
create mode 100644 tools/testing/selftests/bpf/progs/verifier_arena.c
--
2.43.0
