bpf: Collect kfuncs after resolving program resources

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The kfunc descriptors include argument prototypes generated while calls are
collected. Some argument classifications need program auxiliary state derived
from referenced maps, such as the arena associated with the program.

This avoids a footgun in get_kfunc_arg_type() checks where we do
validation on whether program has prog->aux->arena and it hasn't been
resolved yet.

check_and_resolve_insns() records used maps and populates that state. It must
remain after bpf_check_btf_info(), which applies kernel-side CO-RE relocations,
so that instruction validation and the program tag observe the relocated
instruction stream.

Move only add_kfuncs() after instruction and resource resolution. Subprogram
discovery and validation remain before the full BTF phase because that phase
needs the complete subprogram layout. Add a short comment describing the
resource resolution phase at the call site.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Link: https://patch.msgid.link/20260808003938.3486067-4-memxor@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>

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Kumar Kartikeya Dwivedi 2026-08-08 02:39:23 +02:00 • committed by Eduard Zingerman

parent 41f36ffa3a

commit d98b2d445f

1 changed files with 6 additions and 5 deletions

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kernel/bpf/verifier.c

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