From: Jiong Wang <jiong.wang@netronome.com>
To: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Jiong Wang <jiong.wang@netronome.com>,
alexei.starovoitov@gmail.com, daniel@iogearbox.net,
bpf@vger.kernel.org, netdev@vger.kernel.org,
oss-drivers@netronome.com
Subject: Re: [PATCH v3 bpf-next 05/19] bpf: split read liveness into REG_LIVE_READ64 and REG_LIVE_READ32
Date: Sat, 13 Apr 2019 07:39:45 +0100 [thread overview]
Message-ID: <87h8b2flxq.fsf@netronome.com> (raw)
In-Reply-To: <20190412180734.2f863fbe@cakuba.netronome.com>
Jakub Kicinski writes:
> On Fri, 12 Apr 2019 22:59:38 +0100, Jiong Wang wrote:
>> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
>> index c722015..3c5ca00 100644
>> --- a/kernel/bpf/verifier.c
>> +++ b/kernel/bpf/verifier.c
>> @@ -1135,7 +1135,7 @@ static int check_subprogs(struct bpf_verifier_env *env)
>> */
>> static int mark_reg_read(struct bpf_verifier_env *env,
>> const struct bpf_reg_state *state,
>> - struct bpf_reg_state *parent)
>> + struct bpf_reg_state *parent, u8 flags)
>> {
>> bool writes = parent == state->parent; /* Observe write marks */
>> int cnt = 0;
>> @@ -1150,17 +1150,17 @@ static int mark_reg_read(struct bpf_verifier_env *env,
>> parent->var_off.value, parent->off);
>> return -EFAULT;
>> }
>> - if (parent->live & REG_LIVE_READ)
>> + if ((parent->live & REG_LIVE_READ) == flags)
>> /* The parentage chain never changes and
>> - * this parent was already marked as LIVE_READ.
>> + * this parent was already marked with all read bits.
>
> No big deal, but I though said you'd modify this patch here...
Ouch, sorry, I created one internal branch before start the test
changes. Looks like the branch is v10 which listed before v2~v9 that
somehow later I switched v9 for the test changing thought it is the latest
branch.
Regards,
Jiong
>
>> * There is no need to keep walking the chain again and
>> - * keep re-marking all parents as LIVE_READ.
>> + * keep re-marking all parents with reads bits in flags.
>> * This case happens when the same register is read
>> * multiple times without writes into it in-between.
>> */
>> break;
>> /* ... then we depend on parent's value */
>> - parent->live |= REG_LIVE_READ;
>> + parent->live |= flags;
>> state = parent;
>> parent = state->parent;
>> writes = true;
>
>> @@ -6227,12 +6317,19 @@ static int propagate_liveness_reg(struct bpf_verifier_env *env,
>> struct bpf_reg_state *reg,
>> struct bpf_reg_state *parent_reg)
>> {
>> + u8 parent_bits = parent_reg->live & REG_LIVE_READ;
>> + u8 bits = reg->live & REG_LIVE_READ;
>> + u8 bits_diff = parent_bits ^ bits;
>> + u8 bits_prop = bits_diff & bits;
>> int err;
>>
>> - if (parent_reg->live & REG_LIVE_READ || !(reg->live & REG_LIVE_READ))
>> + /* "reg" and "parent_reg" has the same read bits, or the bit doesn't
>> + * belong to "reg".
>> + */
>> + if (!bits_diff || !bits_prop)
>> return 0;
>
> .. and here?
next prev parent reply other threads:[~2019-04-13 6:39 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-12 21:59 [PATCH v3 bpf-next 00/19] bpf: eliminate zero extensions for sub-register writes Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 01/19] bpf: refactor propagate_liveness to eliminate duplicated for loop Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 02/19] bpf: refactor propagate_liveness to eliminate code redundance Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 03/19] bpf: factor out reg and stack slot propagation into "propagate_liveness_reg" Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 04/19] bpf: refactor "check_reg_arg" to eliminate code redundancy Jiong Wang
2019-04-13 0:12 ` Alexei Starovoitov
2019-04-13 7:00 ` Jiong Wang
2019-04-15 5:41 ` Alexei Starovoitov
2019-04-12 21:59 ` [PATCH v3 bpf-next 05/19] bpf: split read liveness into REG_LIVE_READ64 and REG_LIVE_READ32 Jiong Wang
2019-04-13 1:07 ` Jakub Kicinski
2019-04-13 6:39 ` Jiong Wang [this message]
2019-04-12 21:59 ` [PATCH v3 bpf-next 06/19] bpf: mark lo32 writes that should be zero extended into hi32 Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 07/19] bpf: reduce false alarm by refining helper call arg types Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 08/19] bpf: insert explicit zero extension insn when hardware doesn't do it implicitly Jiong Wang
2019-04-15 9:59 ` Naveen N. Rao
2019-04-15 10:11 ` Naveen N. Rao
2019-04-15 11:24 ` Jiong Wang
2019-04-15 18:21 ` Naveen N. Rao
2019-04-15 19:28 ` Jiong Wang
2019-04-16 6:41 ` Naveen N. Rao
2019-04-16 7:47 ` [oss-drivers] " Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 09/19] bpf: introduce new bpf prog load flags "BPF_F_TEST_RND_HI32" Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 10/19] bpf: randomize high 32-bit when BPF_F_TEST_RND_HI32 is set Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 11/19] libbpf: add "prog_flags" to bpf_program/bpf_prog_load_attr/bpf_load_program_attr Jiong Wang
2019-04-13 1:08 ` Jakub Kicinski
2019-04-12 21:59 ` [PATCH v3 bpf-next 12/19] selftests: enable hi32 randomization for all tests Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 13/19] arm: bpf: eliminate zero extension code-gen Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 14/19] powerpc: " Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 15/19] s390: " Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 16/19] sparc: " Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 17/19] x32: " Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 18/19] riscv: " Jiong Wang
2019-04-12 21:59 ` [PATCH v3 bpf-next 19/19] nfp: " Jiong Wang
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