Subject: [PATCH bpf 1/2] bpf: fix alignment of netns_dev/netns_ino fields in bpf_{map,prog}_info

From: Eugene Syromiatnikov <[email-masked]>
Date: Sun, 27 May 2018 13:28:42 +0200

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 <[email-masked]>
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 <[email-masked]>
---
 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)));
 
 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
diff --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