On Sat, Apr 18, 2026 at 06:49:09AM +0000, [email protected] wrote: > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > > --- a/include/uapi/linux/bpf.h > > +++ b/include/uapi/linux/bpf.h > > @@ -1154,6 +1154,8 @@ enum bpf_attach_type { > > BPF_TRACE_KPROBE_SESSION, > > BPF_TRACE_UPROBE_SESSION, > > BPF_TRACE_FSESSION, > > + BPF_TRACE_FENTRY_MULTI, > > + BPF_TRACE_FEXIT_MULTI, > > __MAX_BPF_ATTACH_TYPE > > }; > > In RFC v2 (Feb 4, 2026), Leon Hwang asked whether BPF_TRACE_FSESSION_MULTI > should be added alongside BPF_TRACE_FENTRY_MULTI and BPF_TRACE_FEXIT_MULTI > for API consistency, since BPF_TRACE_FSESSION exists and is handled > similarly to FENTRY/FEXIT. You acknowledged this with 'good catch, will add > it' but BPF_TRACE_FSESSION_MULTI was never added in any subsequent version > (v1, v2, v3, v4, or v5). > > Is this attach type intentionally omitted, or should it be included to > complete the multi tracing API?
ansrewed in the other reply > > Reference: > https://lore.kernel.org/bpf/[email protected]/ > > [ ... ] > > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > > --- a/kernel/bpf/verifier.c > > +++ b/kernel/bpf/verifier.c > > [ ... ] > > > @@ -19368,7 +19379,17 @@ > > if (ret < 0) > > return ret; > > > > - if (tgt_prog) { > > + /* *.multi programs don't need an address during program > > + * verification, we just take the module ref if needed. > > + */ > > + if (is_tracing_multi_id(prog, btf_id)) { > > + if (btf_is_module(btf)) { > > + mod = btf_try_get_module(btf); > > + if (!mod) > > + return -ENOENT; > > + } > > + addr = 0; > > + } else if (tgt_prog) { > > This isn't a bug, but the new multi-line comment here uses the old kernel > comment style with text on the same line as the opening '/*'. The BPF > subsystem guide mandates the modern multi-line style with '/*' on its own > line for new code under kernel/bpf/, even if surrounding code still uses > the old style. > > Should the comment be reformatted as: > > /* > * *.multi programs don't need an address during program > * verification, we just take the module ref if needed. > */ sure jirka > > > @@ -19396,6 +19417,12 @@ > > ret = -EINVAL; > > switch (prog->type) { > > case BPF_PROG_TYPE_TRACING: > > + /* *.multi sleepable programs will pass initial > > sleepable check, > > + * the actual attached btf ids are checked > > later during the link > > + * attachment. > > + */ > > + if (is_tracing_multi_id(prog, btf_id)) > > + ret = 0; > > The same comment style issue appears here. Should this also use the modern > style with '/*' on its own line? > > Note that another comment you added in check_attach_btf_id uses the correct > modern style, making this inconsistency clearly fixable. > > > --- > 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/24598000047
