On Mon, Jun 22, 2026 at 7:37 AM Leon Hwang <[email protected]> wrote:
>
> Since interpreter is unable to handle the 'insn_is_cast_user()' insn,
> require JIT in __bpf_prog_select_runtime() when the prog has the insn.
>
> Fixes: 142fd4d2dcf5 ("bpf: Add x86-64 JIT support for bpf_addr_space_cast
> instruction.")
> Signed-off-by: Leon Hwang <[email protected]>
> ---
> include/linux/bpf.h | 1 +
> kernel/bpf/core.c | 1 +
> kernel/bpf/fixups.c | 2 ++
> 3 files changed, 4 insertions(+)
>
apologies if this was discussed before, but this seems unrelated to
the main patch set, why not send it as its own fix separately? same
for the next patch, no?
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 7719f6528445..5e1843d2859e 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1781,6 +1781,7 @@ struct bpf_prog_aux {
> bool changes_pkt_data;
> bool might_sleep;
> bool kprobe_write_ctx;
> + bool has_addr_space_cast_insn;
> struct {
> s32 keyring_serial;
> u8 keyring_type;
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 649cce41e13f..49398b5bd172 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -2620,6 +2620,7 @@ struct bpf_prog *__bpf_prog_select_runtime(struct
> bpf_verifier_env *env, struct
> goto finalize;
>
> if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
> + fp->aux->has_addr_space_cast_insn ||
> bpf_prog_has_kfunc_call(fp))
> jit_needed = true;
>
> diff --git a/kernel/bpf/fixups.c b/kernel/bpf/fixups.c
> index 3cf2cc6e3ab6..2d5958774b61 100644
> --- a/kernel/bpf/fixups.c
> +++ b/kernel/bpf/fixups.c
> @@ -1523,6 +1523,8 @@ int bpf_do_misc_fixups(struct bpf_verifier_env *env)
> insn->off = 0;
> insn->imm = 0;
> } /* cast from as(0) to as(1) should be handled by
> JIT */
> + if (insn_is_cast_user(insn))
> + prog->aux->has_addr_space_cast_insn = true;
> goto next_insn;
> }
>
> --
> 2.54.0
>
