Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/21/17 2:00 PM, Daniel Borkmann wrote: On 08/21/2017 10:44 PM, Edward Cree wrote: On 21/08/17 21:27, Daniel Borkmann wrote: On 08/21/2017 08:36 PM, Edward Cree wrote: On 19/08/17 00:37, Alexei Starovoitov wrote: [...] I'm tempted to just rip out env->varlen_map_value_access and always

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/21/17 2:00 PM, Daniel Borkmann wrote: On 08/21/2017 10:44 PM, Edward Cree wrote: On 21/08/17 21:27, Daniel Borkmann wrote: On 08/21/2017 08:36 PM, Edward Cree wrote: On 19/08/17 00:37, Alexei Starovoitov wrote: [...] I'm tempted to just rip out env->varlen_map_value_access and always

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/21/17 1:24 PM, Edward Cree wrote: On 18/08/17 15:16, Edward Cree wrote: On 18/08/17 04:21, Alexei Starovoitov wrote: It seems you're trying to sort-of do per-fake-basic block liveness analysis, but our state_list_marks are not correct if we go with canonical basic block definition, since

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/21/17 1:24 PM, Edward Cree wrote: On 18/08/17 15:16, Edward Cree wrote: On 18/08/17 04:21, Alexei Starovoitov wrote: It seems you're trying to sort-of do per-fake-basic block liveness analysis, but our state_list_marks are not correct if we go with canonical basic block definition, since

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 08/21/2017 10:44 PM, Edward Cree wrote: On 21/08/17 21:27, Daniel Borkmann wrote: On 08/21/2017 08:36 PM, Edward Cree wrote: On 19/08/17 00:37, Alexei Starovoitov wrote: [...] I'm tempted to just rip out env->varlen_map_value_access and always check the whole thing, because honestly I

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 08/21/2017 10:44 PM, Edward Cree wrote: On 21/08/17 21:27, Daniel Borkmann wrote: On 08/21/2017 08:36 PM, Edward Cree wrote: On 19/08/17 00:37, Alexei Starovoitov wrote: [...] I'm tempted to just rip out env->varlen_map_value_access and always check the whole thing, because honestly I

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 21/08/17 21:27, Daniel Borkmann wrote: > On 08/21/2017 08:36 PM, Edward Cree wrote: >> On 19/08/17 00:37, Alexei Starovoitov wrote: > [...] >> I'm tempted to just rip out env->varlen_map_value_access and always check >> the whole thing, because honestly I don't know what it was meant to do >>

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 21/08/17 21:27, Daniel Borkmann wrote: > On 08/21/2017 08:36 PM, Edward Cree wrote: >> On 19/08/17 00:37, Alexei Starovoitov wrote: > [...] >> I'm tempted to just rip out env->varlen_map_value_access and always check >> the whole thing, because honestly I don't know what it was meant to do >>

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 08/21/2017 08:36 PM, Edward Cree wrote: On 19/08/17 00:37, Alexei Starovoitov wrote: [...] I'm tempted to just rip out env->varlen_map_value_access and always check the whole thing, because honestly I don't know what it was meant to do originally or how it can ever do any useful

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 08/21/2017 08:36 PM, Edward Cree wrote: On 19/08/17 00:37, Alexei Starovoitov wrote: [...] I'm tempted to just rip out env->varlen_map_value_access and always check the whole thing, because honestly I don't know what it was meant to do originally or how it can ever do any useful

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 18/08/17 15:16, Edward Cree wrote: > On 18/08/17 04:21, Alexei Starovoitov wrote: >> It seems you're trying to sort-of do per-fake-basic block liveness >> analysis, but our state_list_marks are not correct if we go with >> canonical basic block definition, since we mark the jump insn and >> not

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 18/08/17 15:16, Edward Cree wrote: > On 18/08/17 04:21, Alexei Starovoitov wrote: >> It seems you're trying to sort-of do per-fake-basic block liveness >> analysis, but our state_list_marks are not correct if we go with >> canonical basic block definition, since we mark the jump insn and >> not

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 19/08/17 00:37, Alexei Starovoitov wrote: > that '14: safe' above is not correct. > > Disabling liveness as: > @@ -3282,7 +3288,7 @@ static bool regsafe(struct bpf_reg_state *rold, > struct bpf_reg_state *rcur, > bool varlen_map_access, struct idpair

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 19/08/17 00:37, Alexei Starovoitov wrote: > that '14: safe' above is not correct. > > Disabling liveness as: > @@ -3282,7 +3288,7 @@ static bool regsafe(struct bpf_reg_state *rold, > struct bpf_reg_state *rcur, > bool varlen_map_access, struct idpair

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/18/17 7:16 AM, Edward Cree wrote: On 18/08/17 04:21, Alexei Starovoitov wrote: On 8/15/17 12:34 PM, Edward Cree wrote: State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/18/17 7:16 AM, Edward Cree wrote: On 18/08/17 04:21, Alexei Starovoitov wrote: On 8/15/17 12:34 PM, Edward Cree wrote: State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 18/08/17 04:21, Alexei Starovoitov wrote: > On 8/15/17 12:34 PM, Edward Cree wrote: >> State of a register doesn't matter if it wasn't read in reaching an exit; >> a write screens off all reads downstream of it from all explored_states >> upstream of it. >> This allows us to prune many more

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 18/08/17 04:21, Alexei Starovoitov wrote: > On 8/15/17 12:34 PM, Edward Cree wrote: >> State of a register doesn't matter if it wasn't read in reaching an exit; >> a write screens off all reads downstream of it from all explored_states >> upstream of it. >> This allows us to prune many more

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/15/17 12:34 PM, Edward Cree wrote: State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This allows us to prune many more branches; here are some processed insn counts for some

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 8/15/17 12:34 PM, Edward Cree wrote: State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This allows us to prune many more branches; here are some processed insn counts for some

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

From: Daniel Borkmann Date: Wed, 16 Aug 2017 00:12:58 +0200 > On 08/15/2017 09:34 PM, Edward Cree wrote: >> State of a register doesn't matter if it wasn't read in reaching an >> exit; >> a write screens off all reads downstream of it from all >> explored_states >>

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

From: Daniel Borkmann Date: Wed, 16 Aug 2017 00:12:58 +0200 > On 08/15/2017 09:34 PM, Edward Cree wrote: >> State of a register doesn't matter if it wasn't read in reaching an >> exit; >> a write screens off all reads downstream of it from all >> explored_states >> upstream of it. >> This

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 08/15/2017 09:34 PM, Edward Cree wrote: State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This allows us to prune many more branches; here are some processed insn counts for

Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

On 08/15/2017 09:34 PM, Edward Cree wrote: State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This allows us to prune many more branches; here are some processed insn counts for

[PATCH v3 net-next] bpf/verifier: track liveness for pruning

State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This allows us to prune many more branches; here are some processed insn counts for some Cilium programs: Program

[PATCH v3 net-next] bpf/verifier: track liveness for pruning

State of a register doesn't matter if it wasn't read in reaching an exit; a write screens off all reads downstream of it from all explored_states upstream of it. This allows us to prune many more branches; here are some processed insn counts for some Cilium programs: Program