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| author | Amery Hung <ameryhung@gmail.com> | 2026-09-11 15:04:00 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-11 20:16:03 -0700 |
| commit | 0cc91f0e72415cbd17697e2f8fd0cd8de5c7aae9 (patch) | |
| tree | c143cc72c4df13ce6392411c168606aa8416df57 /include/linux | |
| parent | 5fa6e69e2e6618bfa1061c8012aacf81798e2b1e (diff) | |
| download | linux-next-0cc91f0e72415cbd17697e2f8fd0cd8de5c7aae9.tar.gz linux-next-0cc91f0e72415cbd17697e2f8fd0cd8de5c7aae9.zip | |
bpf: Align helper and kfunc ARG_PTR_TO_PROG_AUX handling
The verifier supplies a bpf_prog_aux argument to both
bpf_timer_set_callback() and kfuncs rather than reading it from the BPF
program. The helper prototype leaves its third argument unused, while
the kfunc path identifies the argument from BTF at every call.
Add ARG_PTR_TO_PROG_AUX, record it in the helper prototype, and classify
the kfunc argument when its prototype is generated. Because other
ignored and implicit arguments are already represented by ARG_IGNORE,
the generated prototype has no internal ARG_UNUSED gaps. Validate in
one place that it contains at most one prog-aux argument and that the
argument is register-passed, as required by the BPF_LD_IMM64 fixup.
Record the argument register in the per-instruction metadata for both
call kinds. Drive the helper fixup from that metadata instead of the
helper ID and its hard-coded R3, matching the existing kfunc fixup.
bpf_call_arg_meta::arg_prog is then no longer needed.
No functional change beyond reporting invalid kfunc signatures when
the call is added rather than when it is verified.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Link: https://lore.kernel.org/r/20260911220415.1396439-9-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/linux/bpf_verifier.h | 1 |
2 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 54af5562ec95..aa4d3bb5e8cc 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -923,6 +923,7 @@ enum bpf_arg_type { ARG_PTR_TO_TASK_WORK, /* pointer to bpf_task_work */ ARG_PTR_TO_IRQ_FLAG, /* pointer to saved IRQ flags on the stack */ ARG_PTR_TO_RES_SPIN_LOCK, /* pointer to bpf_res_spin_lock */ + ARG_PTR_TO_PROG_AUX, /* pointer to the caller's bpf_prog_aux */ ARG_IGNORE, /* argument the verifier does not check at all */ __BPF_ARG_TYPE_MAX, diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 6b973b94ee75..1e7593e8d5c5 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -1599,7 +1599,6 @@ struct bpf_call_arg_meta { struct btf *arg_btf; u32 arg_btf_id; bool arg_owning_ref; - bool arg_prog; struct { struct btf_field *field; |