bpf: fix uapi bpf_prog_info fields alignment

Merge commit 1c8c5a9d38f60 ("Merge
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next") undid the
fix from commit 36f9814a494 ("bpf: fix uapi hole for 32 bit compat
applications") by taking the gpl_compatible 1-bit field definition from
commit b85fab0e67b162 ("bpf: Add gpl_compatible flag to struct
bpf_prog_info") as is. That breaks architectures with 16-bit alignment
like m68k. Add 31-bit pad after gpl_compatible to restore alignment of
following fields.

Thanks to Dmitry V. Levin his analysis of this bug history.

Signed-off-by: Baruch Siach <[email protected]>
Acked-by: Song Liu <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Linus Torvalds <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index a8b823c30b434d8022ebeab666d7072a09473be5..29a5bc3d5c6661181251d1427d1a0742c4e397c0 100644 (file)
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3143,6 +3143,7 @@ struct bpf_prog_info {
        char name[BPF_OBJ_NAME_LEN];
        __u32 ifindex;
        __u32 gpl_compatible:1;
+       __u32 :31; /* alignment pad */
        __u64 netns_dev;
        __u64 netns_ino;
        __u32 nr_jited_ksyms;

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index a8b823c30b434d8022ebeab666d7072a09473be5..29a5bc3d5c6661181251d1427d1a0742c4e397c0 100644 (file)
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3143,6 +3143,7 @@ struct bpf_prog_info {
        char name[BPF_OBJ_NAME_LEN];
        __u32 ifindex;
        __u32 gpl_compatible:1;
+       __u32 :31; /* alignment pad */
        __u64 netns_dev;
        __u64 netns_ino;
        __u32 nr_jited_ksyms;