Messages in this thread | | | Date | Tue, 16 Sep 2014 15:16:06 -0400 (EDT) | Subject | Re: [PATCH v12 net-next 03/11] bpf: add lookup/update/delete/iterate methods to BPF maps | From | David Miller <> |
| |
From: Alexei Starovoitov <ast@plumgrid.com> Date: Mon, 15 Sep 2014 12:18:33 -0700
> @@ -83,6 +112,15 @@ union bpf_attr { > __u32 value_size; /* size of value in bytes */ > __u32 max_entries; /* max number of entries in a map */ > }; > + > + struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */ > + int map_fd; > + void __user *key; > + union { > + void __user *value; > + void __user *next_key; > + }; > + }; > }; > > #endif /* _UAPI__LINUX_BPF_H__ */
Depending upon the processor ABI, this change can increase the alignment requirements of union bpf_attr. So the structure is not compatible between patch #1 and patch #3 here.
Also, you haven't implemented any compat layer whatsoever for the necessary translations. This happens because you are using pointers which are different sized between 32-bit and 64-bit ABIs.
I would suggest you use instead something like "aligned_u64" since these are just arbitrary userland cookies and using "aligned_u64" vs. "u64" will make it so that you don't have to deal with the 64-bit type alignment differences between x86-32 and x86-64 while writing the compat wrappers (if any).
| |