| Message ID | 20240306031929.42666-1-alexei.starovoitov@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | bpf: Introduce may_goto and cond_break | expand |
Hello: This series was applied to bpf/bpf-next.git (master) by Andrii Nakryiko <andrii@kernel.org>: On Tue, 5 Mar 2024 19:19:25 -0800 you wrote: > From: Alexei Starovoitov <ast@kernel.org> > > v5 -> v6: > - Rename BPF_JMA to BPF_JCOND > - Addressed Andrii's review comments > > v4 -> v5: > - rewrote patch 1 to avoid fake may_goto_reg and use 'u32 may_goto_cnt' instead. > This way may_goto handling is similar to bpf_loop() processing. > - fixed bug in patch 2 that RANGE_WITHIN should not use > rold->type == NOT_INIT as a safe signal. > - patch 3 fixed negative offset computation in cond_break macro > - using bpf_arena and cond_break recompiled lib/glob.c as bpf prog > and it works! It will be added as a selftest to arena series. > > [...] Here is the summary with links: - [v6,bpf-next,1/4] bpf: Introduce may_goto instruction https://git.kernel.org/bpf/bpf-next/c/9c4cab4e6756 - [v6,bpf-next,2/4] bpf: Recognize that two registers are safe when their ranges match https://git.kernel.org/bpf/bpf-next/c/cc570d85e66e - [v6,bpf-next,3/4] bpf: Add cond_break macro https://git.kernel.org/bpf/bpf-next/c/7825948e135b - [v6,bpf-next,4/4] selftests/bpf: Test may_goto https://git.kernel.org/bpf/bpf-next/c/8089b99d4649 You are awesome, thank you!
patchwork-bot+netdevbpf@ wrote: > Hello: > > This series was applied to bpf/bpf-next.git (master) > by Andrii Nakryiko <andrii@kernel.org>: > > On Tue, 5 Mar 2024 19:19:25 -0800 you wrote: > > From: Alexei Starovoitov <ast@kernel.org> > > > > v5 -> v6: > > - Rename BPF_JMA to BPF_JCOND > > - Addressed Andrii's review comments > > > > v4 -> v5: > > - rewrote patch 1 to avoid fake may_goto_reg and use 'u32 may_goto_cnt' instead. > > This way may_goto handling is similar to bpf_loop() processing. > > - fixed bug in patch 2 that RANGE_WITHIN should not use > > rold->type == NOT_INIT as a safe signal. > > - patch 3 fixed negative offset computation in cond_break macro > > - using bpf_arena and cond_break recompiled lib/glob.c as bpf prog > > and it works! It will be added as a selftest to arena series. > > > > [...] > > Here is the summary with links: > - [v6,bpf-next,1/4] bpf: Introduce may_goto instruction > https://git.kernel.org/bpf/bpf-next/c/9c4cab4e6756 > - [v6,bpf-next,2/4] bpf: Recognize that two registers are safe when their ranges match > https://git.kernel.org/bpf/bpf-next/c/cc570d85e66e > - [v6,bpf-next,3/4] bpf: Add cond_break macro > https://git.kernel.org/bpf/bpf-next/c/7825948e135b > - [v6,bpf-next,4/4] selftests/bpf: Test may_goto > https://git.kernel.org/bpf/bpf-next/c/8089b99d4649 > > You are awesome, thank you! > -- > Deet-doot-dot, I am a bot. > https://korg.docs.kernel.org/patchwork/pwbot.html > > Fwiw, I've been running this for a few days converting things to it. Tested-by: John Fastabend <john.fastabend@gmail.com> Acked-by: John Fastabend <john.fastabend@gmail.com>
From: Alexei Starovoitov <ast@kernel.org> v5 -> v6: - Rename BPF_JMA to BPF_JCOND - Addressed Andrii's review comments v4 -> v5: - rewrote patch 1 to avoid fake may_goto_reg and use 'u32 may_goto_cnt' instead. This way may_goto handling is similar to bpf_loop() processing. - fixed bug in patch 2 that RANGE_WITHIN should not use rold->type == NOT_INIT as a safe signal. - patch 3 fixed negative offset computation in cond_break macro - using bpf_arena and cond_break recompiled lib/glob.c as bpf prog and it works! It will be added as a selftest to arena series. v3 -> v4: - fix drained issue reported by John. may_goto insn could be implemented with sticky state (once reaches 0 it stays 0), but the verifier shouldn't assume that. It has to explore both branches. Arguably drained iterator state shouldn't be there at all. bpf_iter_css_next() is not sticky. Can be fixed, but auditing all iterators for stickiness. That's an orthogonal discussion. - explained JMA name reasons in patch 1 - fixed test_progs-no_alu32 issue and added another test v2 -> v3: Major change - drop bpf_can_loop() kfunc and introduce may_goto instruction instead kfunc is a function call while may_goto doesn't consume any registers and LLVM can produce much better code due to less register pressure. - instead of counting from zero to BPF_MAX_LOOPS start from it instead and break out of the loop when count reaches zero - use may_goto instruction in cond_break macro - recognize that 'exact' state comparison doesn't need to be truly exact. regsafe() should ignore precision and liveness marks, but range_within logic is safe to use while evaluating open coded iterators. Alexei Starovoitov (4): bpf: Introduce may_goto instruction bpf: Recognize that two registers are safe when their ranges match bpf: Add cond_break macro selftests/bpf: Test may_goto include/linux/bpf_verifier.h | 2 + include/uapi/linux/bpf.h | 5 + kernel/bpf/core.c | 1 + kernel/bpf/disasm.c | 4 + kernel/bpf/verifier.c | 212 +++++++++++++----- tools/include/uapi/linux/bpf.h | 5 + tools/testing/selftests/bpf/DENYLIST.s390x | 1 + .../testing/selftests/bpf/bpf_experimental.h | 12 + .../bpf/progs/verifier_iterating_callbacks.c | 103 ++++++++- 9 files changed, 292 insertions(+), 53 deletions(-)