From: Jiri Olsa <olsajiri@gmail.com>
To: sashiko-reviews@lists.linux.dev
Cc: bpf@vger.kernel.org
Subject: Re: [PATCHv7 bpf-next 10/29] bpf: Add multi tracing attach types
Date: Thu, 4 Jun 2026 10:00:31 +0200 [thread overview]
Message-ID: <aiEwnwBeP69ZUpCA@krava> (raw)
In-Reply-To: <20260603113751.DC4C51F00893@smtp.kernel.org>
On Wed, Jun 03, 2026 at 11:37:51AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] Missing `BPF_TRACE_FENTRY_MULTI` and `BPF_TRACE_FEXIT_MULTI` cases in `btf_validate_prog_ctx_type` causes valid `.multi` programs using `u64 *ctx` to be rejected.
> --
>
> commit 0330f287f02c3a32c9ab8bf7f4f5a6ad6cf7366f
> Author: Jiri Olsa <jolsa@kernel.org>
>
> bpf: Add multi tracing attach types
>
> This commit introduces new program attach types BPF_TRACE_FENTRY_MULTI and
> BPF_TRACE_FEXIT_MULTI to support multi-tracing attachment. Base verifier
> support is added to recognize these types and accept them as sleepable
> programs, while deferring actual target validation to link creation.
>
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index 8ed484cb1a8a4..521ec2a9051ed 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> [ ... ]
> > @@ -16314,6 +16314,8 @@ static bool return_retval_range(struct bpf_verifier_env *env, struct bpf_retval_
> > case BPF_TRACE_FENTRY:
> > case BPF_TRACE_FEXIT:
> > case BPF_TRACE_FSESSION:
> > + case BPF_TRACE_FENTRY_MULTI:
> > + case BPF_TRACE_FEXIT_MULTI:
>
> [Severity: High]
> Are we missing an update to btf_validate_prog_ctx_type() in kernel/bpf/btf.c
> to handle these new multi types?
>
> Currently, BPF_TRACE_FENTRY and BPF_TRACE_FEXIT are explicitly whitelisted
> there to allow u64 * as a context type:
>
> kernel/bpf/btf.c:btf_validate_prog_ctx_type() {
> ...
> case BPF_TRACE_FENTRY:
> case BPF_TRACE_FEXIT:
> case BPF_MODIFY_RETURN:
> case BPF_TRACE_FSESSION:
> /* allow u64* as ctx */
> if (btf_is_int(t) && t->size == 8)
> return 0;
> break;
> ...
> }
>
> Without adding the new multi types to this switch statement, the verifier
> will fall back to the default canonical type (void *) and will reject valid
> multi programs that use BPF_PROG and u64 *ctx.
yes, we disabled direct ctx access for tracing multi programs
jirka
next prev parent reply other threads:[~2026-06-04 8:00 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-03 11:05 [PATCHv7 bpf-next 00/29] bpf: tracing_multi link Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 01/29] ftrace: Add ftrace_hash_count function Jiri Olsa
2026-06-03 11:26 ` sashiko-bot
2026-06-04 7:59 ` Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 02/29] ftrace: Add ftrace_hash_remove function Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 03/29] ftrace: Add add_ftrace_hash_entry function Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 04/29] bpf: Use mutex lock pool for bpf trampolines Jiri Olsa
2026-06-03 11:28 ` sashiko-bot
2026-06-04 7:59 ` Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 05/29] bpf: Add struct bpf_trampoline_ops object Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 06/29] bpf: Move trampoline image setup into bpf_trampoline_ops callbacks Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 07/29] bpf: Add bpf_trampoline_add/remove_prog functions Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 08/29] bpf: Add struct bpf_tramp_node object Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 09/29] bpf: Factor fsession link to use struct bpf_tramp_node Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 10/29] bpf: Add multi tracing attach types Jiri Olsa
2026-06-03 11:37 ` sashiko-bot
2026-06-04 8:00 ` Jiri Olsa [this message]
2026-06-03 11:52 ` bot+bpf-ci
2026-06-03 11:05 ` [PATCHv7 bpf-next 11/29] bpf: Move sleepable verification code to btf_id_allow_sleepable Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 12/29] bpf: Add bpf_trampoline_multi_attach/detach functions Jiri Olsa
2026-06-03 11:52 ` bot+bpf-ci
2026-06-03 11:05 ` [PATCHv7 bpf-next 13/29] bpf: Add support for tracing multi link Jiri Olsa
2026-06-03 11:41 ` sashiko-bot
2026-06-04 8:00 ` Jiri Olsa
2026-06-03 11:52 ` bot+bpf-ci
2026-06-04 8:00 ` Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 14/29] bpf: Add support for tracing_multi link cookies Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 15/29] bpf: Add support for tracing_multi link session Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 16/29] bpf: Add support for tracing_multi link fdinfo Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 17/29] libbpf: Add bpf_object_cleanup_btf function Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 18/29] libbpf: Add bpf_link_create support for tracing_multi link Jiri Olsa
2026-06-03 11:34 ` sashiko-bot
2026-06-04 7:59 ` Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 19/29] libbpf: Add btf_type_is_traceable_func function Jiri Olsa
2026-06-03 11:36 ` sashiko-bot
2026-06-04 7:59 ` Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 20/29] libbpf: Add support to create tracing multi link Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 21/29] selftests/bpf: Add tracing multi skel/pattern/ids attach tests Jiri Olsa
2026-06-03 13:40 ` sashiko-bot
2026-06-04 8:00 ` Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 22/29] selftests/bpf: Add tracing multi skel/pattern/ids module " Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 23/29] selftests/bpf: Add tracing multi intersect tests Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 24/29] selftests/bpf: Add tracing multi cookies test Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 25/29] selftests/bpf: Add tracing multi session test Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 26/29] selftests/bpf: Add tracing multi attach fails test Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 27/29] selftests/bpf: Add tracing multi verifier " Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 28/29] selftests/bpf: Add tracing multi attach benchmark test Jiri Olsa
2026-06-03 11:05 ` [PATCHv7 bpf-next 29/29] selftests/bpf: Add tracing multi attach rollback tests Jiri Olsa
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