From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2A584A1A for ; Wed, 24 Apr 2024 00:26:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713918414; cv=none; b=IBhfkIVjoJ6KVwMwJpeNQXtKa6uuHeaeuZglM29ksvXV0veFZTmGSHHnkdOHpOGX2sDordtJUGG/qsKCDRsOi6WlaMgenVVAam5OMcTxfIg+mg4LBPWpzDAK65EqFZrso1qXLTtDTZRmv2npkG4lrTm1wI6zJI+dVhquglE+bPE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713918414; c=relaxed/simple; bh=V7UO0I173fj0tAlkHHq0Chp6no+hBWSdgDXJzvHXeok=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=PcloxUhy9IvHeGXjESq96qXJwk8zuw8e7t7EkevwNGsQYGFGqvsrw3jOvPnltyuiFcu9I8hLxlRQOytUW+YlUiQ0Rr0RSeZxhFsVpOTbAeotRgXa+UVOcBjcciuvQpagcRI3teCfvfYotorGbTd0tPzZV+FcPaV3v1XVNpmU38Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=eQ6Qx3mA; arc=none smtp.client-ip=209.85.214.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="eQ6Qx3mA" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-1e3f6f03594so47474905ad.0 for ; Tue, 23 Apr 2024 17:26:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1713918412; x=1714523212; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=+TQX/MJ9R8YSn1f8Ybmod8tw8BtmZJa+LvQNkKu8OdA=; b=eQ6Qx3mAHXZzy/Hphmy/tZPRJBUXs+1G4ocbETV+vKet/r0QHuxQ4B47ayTiUjujPO zjmo+E1XeLeiR0XULnF7kwd66Orb0K/A4xNto8gMerWVCf8Hs+NwS0H4WYdWpGCHCqo6 Fa31YotZCvsgZoyn24IPeerXeMVdyuKuRKBBLXdCdoR6GUIOvpcdoztFMxaKpY9WcRvv eVj6R1TYQdnD6lfwT5/4pTZh7lDxIcFYMuqFGueNHRpRT7WIeV0TwHmVGjFJT7sJaz/z gBbod0nTWD9ENzAU83ptedXf4ewUeEQPUoLVHfzOA4oGxhEmroMPeUbiJ2xef6T/2PpS NueA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713918412; x=1714523212; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+TQX/MJ9R8YSn1f8Ybmod8tw8BtmZJa+LvQNkKu8OdA=; b=g/z7vZdaUIkhUQgYfwgHmv2Jeri+OBBlbLEqllE37IKNr2eQZ5KYlvXzxJi1Mc1GOn u46kxKDd6oLu1EmBAdNKy5HaczP2FWaP1drpxDTjBy+imbqJW7rEKBvA4gXlT9HjRtrz lI4DMJf2Hkdr6wzVG5rNZiLrLTT6eFdxgW53Ga2n9wvNM8yVGfTmW5oFhIJrvBbkEfcC Yoj9wiviJnHezd+gA6UJyoFZP++gSYdhokSevOe4EkVGqMvn1XX8nBLQTZwwRq9n62zO WaLXZgYvug9KDR19gm1SDr31OAh4qMag3xjhlZuyx1paSKEZsBfcrnlWnrGtHtjB78b2 vDmg== X-Forwarded-Encrypted: i=1; AJvYcCW+LhRb5zaxjG2M6wTVDx77kTpzadjbnzgQTDvLHR0u+36xDqNh4aQREuh9lopsiFnzUQupufn9SE2nMpbsCHAgRag1 X-Gm-Message-State: AOJu0Ywt7no5hZOQPTbnmTpisUtwKqIGaKZxM5ub7CDFj27I1XVlBSFz /lSzEY0iumK+TMwCyjqQ1kB+cNkcY4lO4ZREzEM6UZAgnl1zoyaxs0OC9e5MgmsW6loQk5PlsqK Z1hJmG6m3XdpY45zbcnLgtHOetvI= X-Google-Smtp-Source: AGHT+IGimV/6WqXFRE6KZfArx7WG0RrXoyaaXpQjDEjTnXiaRZSIb3lFVH6uBBX7hCQGOi7cA+mHPIUV44+Yz040xtk= X-Received: by 2002:a17:903:40cf:b0:1e0:b62a:c0a2 with SMTP id t15-20020a17090340cf00b001e0b62ac0a2mr1228147pld.51.1713918412149; Tue, 23 Apr 2024 17:26:52 -0700 (PDT) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240422121241.1307168-1-jolsa@kernel.org> <20240422121241.1307168-2-jolsa@kernel.org> In-Reply-To: <20240422121241.1307168-2-jolsa@kernel.org> From: Andrii Nakryiko Date: Tue, 23 Apr 2024 17:26:39 -0700 Message-ID: Subject: Re: [PATCH bpf-next 1/7] bpf: Add support for kprobe multi session attach To: Jiri Olsa Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Viktor Malik , "Masami Hiramatsu (Google)" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Apr 22, 2024 at 5:12=E2=80=AFAM Jiri Olsa wrote: > > Adding support to attach bpf program for entry and return probe > of the same function. This is common use case which at the moment > requires to create two kprobe multi links. > > Adding new BPF_TRACE_KPROBE_MULTI_SESSION attach type that instructs > kernel to attach single link program to both entry and exit probe. > > It's possible to control execution of the bpf program on return > probe simply by returning zero or non zero from the entry bpf > program execution to execute or not the bpf program on return > probe respectively. > > Signed-off-by: Jiri Olsa > --- > include/uapi/linux/bpf.h | 1 + > kernel/bpf/syscall.c | 7 ++++++- > kernel/trace/bpf_trace.c | 28 ++++++++++++++++++++-------- > tools/include/uapi/linux/bpf.h | 1 + > 4 files changed, 28 insertions(+), 9 deletions(-) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index cee0a7915c08..fb8ecb199273 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -1115,6 +1115,7 @@ enum bpf_attach_type { > BPF_CGROUP_UNIX_GETSOCKNAME, > BPF_NETKIT_PRIMARY, > BPF_NETKIT_PEER, > + BPF_TRACE_KPROBE_MULTI_SESSION, let's use a shorter BPF_TRACE_KPROBE_SESSION? we'll just know that it's multi-variant (there is no point in adding non-multi kprobes going forward anyways, it's a new default) > __MAX_BPF_ATTACH_TYPE > }; > [...] > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index afb232b1d7c2..3b15a40f425f 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -1631,6 +1631,17 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, c= onst struct bpf_prog *prog) > } > } > > +static bool is_kprobe_multi(const struct bpf_prog *prog) > +{ > + return prog->expected_attach_type =3D=3D BPF_TRACE_KPROBE_MULTI |= | > + prog->expected_attach_type =3D=3D BPF_TRACE_KPROBE_MULTI_S= ESSION; > +} > + > +static inline bool is_kprobe_multi_session(const struct bpf_prog *prog) ditto, this multi is just a distraction at this point, IMO > +{ > + return prog->expected_attach_type =3D=3D BPF_TRACE_KPROBE_MULTI_S= ESSION; > +} > + > static const struct bpf_func_proto * > kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *= prog) > { [...]