Re: [PATCH v2 bpf-next 1/2] bpf: add verified_insns to bpf_prog_info and fdinfo
From: Andrii Nakryiko <hidden>
Date: 2021-10-18 21:22:39
Also in:
bpf
On Mon, Oct 11, 2021 at 1:54 PM Dave Marchevsky [off-list ref] wrote:
This stat is currently printed in the verifier log and not stored anywhere. To ease consumption of this data, add a field to bpf_prog_aux so it can be exposed via BPF_OBJ_GET_INFO_BY_FD and fdinfo. Signed-off-by: Dave Marchevsky <redacted> --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 2 +- kernel/bpf/syscall.c | 8 ++++++-- kernel/bpf/verifier.c | 1 + tools/include/uapi/linux/bpf.h | 2 +- 5 files changed, 10 insertions(+), 4 deletions(-)
[...]
quoted hunk ↗ jump to hunk
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 6fc59d61937a..d053fc7e7995 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h@@ -5591,7 +5591,7 @@ struct bpf_prog_info { char name[BPF_OBJ_NAME_LEN]; __u32 ifindex; __u32 gpl_compatible:1; - __u32 :31; /* alignment pad */ + __u32 verified_insns:31;
These 31 unused bits seem like a good place to add extra generic flags, not new counters. E.g., like a sleepable flag. So I wonder if it's better to use a dedicated u32 field for counters like verified_insns and keep these reserved fields for boolean flags? Daniel, I know you proposed to reuse those 31 bits. How strong do you feel about this? For any other kind of counter we seem to be using a complete dedicated integer field, so it would be consistent to keep doing that? Having a sleepable bit still seems like a good idea, btw :) but it's a separate change from Dave's.
__u64 netns_dev;
__u64 netns_ino;
__u32 nr_jited_ksyms;
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2.30.2