Re: [PATCH bpf 1/2] bpf: fix alignment of netns_dev/netns_ino fields in bpf_{map,prog}_info
From: Song Liu <hidden>
Date: 2018-05-29 17:17:39
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On Sun, May 27, 2018 at 4:28 AM, Eugene Syromiatnikov [off-list ref] wrote:
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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 <redacted> 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 <redacted> --- 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. Thanks, Song
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struct bpf_map_info {@@ -1030,8 +1030,8 @@ struct bpf_map_info { __u32 map_flags; 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))); /* User bpf_sock_addr struct to access socket fields and sockaddr struct passeddiff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index c5ec897..903010a 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/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))); struct bpf_map_info {@@ -1030,8 +1030,8 @@ struct bpf_map_info { __u32 map_flags; 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))); /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed --2.1.4