Messages in this thread | | | Subject | Re: [PATCH bpf 1/2] bpf: fix alignment of netns_dev/netns_ino fields in bpf_{map,prog}_info | From | Daniel Borkmann <> | Date | Sat, 2 Jun 2018 05:28:46 +0200 |
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On 05/29/2018 07:17 PM, Song Liu wrote: > On Sun, May 27, 2018 at 4:28 AM, Eugene Syromiatnikov <esyr@redhat.com> wrote: >> Recent introduction of netns_dev/netns_ino to bpf_map_info/bpf_prog info >> has broken compat, as offsets of these fields are different in 32-bit >> and 64-bit ABIs. One fix (other than implementing compat support in >> syscall in order to handle this discrepancy) is to use __aligned_u64 >> instead of __u64 for these fields. >> >> Reported-by: Dmitry V. Levin <ldv@altlinux.org> >> Fixes: 52775b33bb507 ("bpf: offload: report device information about >> offloaded maps") >> Fixes: 675fc275a3a2d ("bpf: offload: report device information for >> offloaded programs") >> >> Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com> >> --- >> include/uapi/linux/bpf.h | 8 ++++---- >> tools/include/uapi/linux/bpf.h | 8 ++++---- >> 2 files changed, 8 insertions(+), 8 deletions(-) >> >> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h >> index c5ec897..903010a 100644 >> --- a/include/uapi/linux/bpf.h >> +++ b/include/uapi/linux/bpf.h >> @@ -1017,8 +1017,8 @@ struct bpf_prog_info { >> __aligned_u64 map_ids; >> char name[BPF_OBJ_NAME_LEN]; >> __u32 ifindex; >> - __u64 netns_dev; >> - __u64 netns_ino; >> + __aligned_u64 netns_dev; >> + __aligned_u64 netns_ino; >> } __attribute__((aligned(8))); > > Shall we add a __u32 padding variable before netns_dev? We can use it > for in the future.
Agree with Song, and definitely prefer that approach since we already use the hole as a bitfield in net-next; like this https://patchwork.ozlabs.org/patch/924415/.
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