Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Andrii Nakryiko
On Wed, Jul 10, 2019 at 9:14 PM Yonghong Song wrote: > > > > On 7/10/19 6:45 PM, Andrii Nakryiko wrote: > > On Wed, Jul 10, 2019 at 5:36 PM Yonghong Song wrote: > >> > >> > >> > >> On 7/10/19 5:29 PM, Andrii Nakryiko wrote: > >>> On Wed, Jul 10, 2019 at 5:16 PM Yonghong Song wrote: > >

Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Andrii Nakryiko
On Wed, Jul 10, 2019 at 6:53 PM Yonghong Song wrote: > > > > On 7/10/19 6:45 PM, Andrii Nakryiko wrote: > > On Wed, Jul 10, 2019 at 5:36 PM Yonghong Song wrote: > >> > >> > >> > >> On 7/10/19 5:29 PM, Andrii Nakryiko wrote: > >>> On Wed, Jul 10, 2019 at 5:16 PM Yonghong Song wrote: > >

Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Yonghong Song
On 7/10/19 6:45 PM, Andrii Nakryiko wrote: > On Wed, Jul 10, 2019 at 5:36 PM Yonghong Song wrote: >> >> >> >> On 7/10/19 5:29 PM, Andrii Nakryiko wrote: >>> On Wed, Jul 10, 2019 at 5:16 PM Yonghong Song wrote: On 7/10/19 1:08 AM, Andrii Nakryiko wrote: > BTF verifier has

Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Yonghong Song
On 7/10/19 6:45 PM, Andrii Nakryiko wrote: > On Wed, Jul 10, 2019 at 5:36 PM Yonghong Song wrote: >> >> >> >> On 7/10/19 5:29 PM, Andrii Nakryiko wrote: >>> On Wed, Jul 10, 2019 at 5:16 PM Yonghong Song wrote: On 7/10/19 1:08 AM, Andrii Nakryiko wrote: > BTF verifier has

Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Andrii Nakryiko
On Wed, Jul 10, 2019 at 5:36 PM Yonghong Song wrote: > > > > On 7/10/19 5:29 PM, Andrii Nakryiko wrote: > > On Wed, Jul 10, 2019 at 5:16 PM Yonghong Song wrote: > >> > >> > >> > >> On 7/10/19 1:08 AM, Andrii Nakryiko wrote: > >>> BTF verifier has Different logic depending on whether we are follow

Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Yonghong Song
On 7/10/19 5:29 PM, Andrii Nakryiko wrote: > On Wed, Jul 10, 2019 at 5:16 PM Yonghong Song wrote: >> >> >> >> On 7/10/19 1:08 AM, Andrii Nakryiko wrote: >>> BTF verifier has Different logic depending on whether we are following >>> a PTR or STRUCT/ARRAY (or something else). This is an optimizati

Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Andrii Nakryiko
On Wed, Jul 10, 2019 at 5:16 PM Yonghong Song wrote: > > > > On 7/10/19 1:08 AM, Andrii Nakryiko wrote: > > BTF verifier has Different logic depending on whether we are following > > a PTR or STRUCT/ARRAY (or something else). This is an optimization to > > stop early in DFS traversal while resolvi

Re: [PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Yonghong Song
On 7/10/19 1:08 AM, Andrii Nakryiko wrote: > BTF verifier has Different logic depending on whether we are following > a PTR or STRUCT/ARRAY (or something else). This is an optimization to > stop early in DFS traversal while resolving BTF types. But it also > results in a size resolution bug, when

[PATCH bpf] bpf: fix BTF verifier size resolution logic

2019-07-10 Thread Andrii Nakryiko
BTF verifier has Different logic depending on whether we are following a PTR or STRUCT/ARRAY (or something else). This is an optimization to stop early in DFS traversal while resolving BTF types. But it also results in a size resolution bug, when there is a chain, e.g., of PTR -> TYPEDEF -> ARRAY,