Re: [PATCH bpf 1/2] bpf: Revalidate iterator programs on link update
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From: bot+bpf-ci@kernel.org
Date: 2026-10-08 17:13:28
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bpf, linux-kselftest, lkml
bpf: Revalidate iterator programs on link update
TL;DR: Nit only: Documentation/bpf/bpf_iterators.rst may need updating for the new validate_target callback in struct bpf_iter_reg and for when it is invoked (BPF_LINK_UPDATE only). No code problems reported.
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diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 0ecb9418dfbd..5aa786eba3ea 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h
[ ... ]
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@@ -3024,6 +3026,7 @@ enum bpf_iter_feature { struct bpf_iter_reg { const char *target; bpf_iter_attach_target_t attach_target; + bpf_iter_validate_target_t validate_target; bpf_iter_detach_target_t detach_target; bpf_iter_show_fdinfo_t show_fdinfo; bpf_iter_fill_link_info_t fill_link_info;
This isn't a bug, but should Documentation/bpf/bpf_iterators.rst be updated
for the new member?
That file carries a copy of struct bpf_iter_reg that listed attach_target
and detach_target exactly as they appeared in this header before the patch:
bpf_iter_attach_target_t attach_target;
bpf_iter_detach_target_t detach_target;
It now lacks validate_target.
The field table in the same file also describes the callbacks as:
attach_target and detach_target
Allows for target specific link_create action since some targets may
need special processing. Called during the user space link_create
stage.
Nothing there says that validate_target is invoked only from
bpf_iter_link_replace() (BPF_LINK_UPDATE), and that a target's
attach_target has to call its validator itself at link_create time, since
bpf_iter_link_attach() does not call it generically.
A new iterator author working from the documentation would not learn that
program-dependent checks belong in validate_target as well as in
attach_target.
Should the struct listing and the field table describe validate_target and
when it is invoked?
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/37809581821