From nobody Mon Nov 25 15:41:14 2024 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 657DE158A2E; Sat, 26 Oct 2024 04:37:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729917442; cv=none; b=r9ZyBV+M81oeBL5iiF6fF50FPtcuf1qOpoi9XB6STkdWDPorfTgU4i4D24KUtBfldaGv7Ivwcm/OScpJOZ+wzIGJnMz83fsV0GXj0qcQS8IJY4BI/dIfqcc2yiG8zdoPO9Rdr79SJd5i4K8O3u6qjSXVpdirgDXCenuRXWdVhYs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729917442; c=relaxed/simple; bh=nBiONpEv/wdcj9ivHPwXYq4ae4MTgGFPim3vv0QzGS4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ImW6GeMrGeTTo5Sa0t2G/LHi7dvbD5/+pfCgXRNSO5g7i4z6YeXMNP9uA/DLVrFp6GfT27urD5ZXqvtg5H/T4n18ha7sk0pV+ZjMqbkdPoJEaUg0HZvcRagu0KMqN7phf/xx5RhoZa+7k6Clzrm38gDWXlsCUdDLzHliOVxcECY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IJzgd7sJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IJzgd7sJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23CF7C4CEC6; Sat, 26 Oct 2024 04:37:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729917441; bh=nBiONpEv/wdcj9ivHPwXYq4ae4MTgGFPim3vv0QzGS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IJzgd7sJyBfG8Q4qTHwNeN//X5aJ2ojtJY+6bGodxmbf2dlx2sZcstGW/694k4F1J 5VjhbxSzRFC5BllcoRDZmdTlnP4dMxKofcQzO+KyjxPa5VyFmPthtIkq/1EJNUQiN5 H50cI4IJ2zuHLbAnCXUi0QL22l5pdA2GdS2lPhm8PBa82XyWn4xZsjS2n7RYtBrzNY qN06YGva3pNPZW354+hWwJXwH2X+mhC79dOjDhY0p+hP2DBBjSaOnDpKo3kzeevg6a yS+xHikNJz2hA7iu7rGLpLQjZgVo5Q9iBcpaeRuHVFVfRRALXZp1SSBWzIOtyj0moZ hfoQWloJMhT0g== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Alexei Starovoitov , Jiri Olsa , Alan Maguire , Mark Rutland , linux-arch@vger.kernel.org Subject: [PATCH v18 09/17] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled Date: Sat, 26 Oct 2024 13:37:16 +0900 Message-ID: <172991743594.443985.5579816797069077873.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <172991731968.443985.4558065903004844780.stgit@devnote2> References: <172991731968.443985.4558065903004844780.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Masami Hiramatsu (Google) Enable kprobe_multi feature if CONFIG_FPROBE is enabled. The pt_regs is converted from ftrace_regs by ftrace_partial_regs(), thus some registers may always returns 0. But it should be enough for function entry (access arguments) and exit (access return value). Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest --- Changes in v9: - Avoid wasting memory for bpf_kprobe_multi_pt_regs when CONFIG_HAVE_PT_REGS_TO_FTRACE_REGS_CAST=3Dy --- kernel/trace/bpf_trace.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index e7ea5568471c..1532e9172bf9 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2517,7 +2517,7 @@ struct bpf_session_run_ctx { void *data; }; =20 -#if defined(CONFIG_FPROBE) && defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) +#ifdef CONFIG_FPROBE struct bpf_kprobe_multi_link { struct bpf_link link; struct fprobe fp; @@ -2540,6 +2540,13 @@ struct user_syms { char *buf; }; =20 +#ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS +static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); +#define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_r= egs) +#else +#define bpf_kprobe_multi_pt_regs_ptr() (NULL) +#endif + static int copy_user_syms(struct user_syms *us, unsigned long __user *usym= s, u32 cnt) { unsigned long __user usymbol; @@ -2734,7 +2741,7 @@ static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_c= tx *ctx) =20 static int kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, - unsigned long entry_ip, struct pt_regs *regs, + unsigned long entry_ip, struct ftrace_regs *fregs, bool is_return, void *data) { struct bpf_kprobe_multi_run_ctx run_ctx =3D { @@ -2746,6 +2753,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_li= nk *link, .entry_ip =3D entry_ip, }; struct bpf_run_ctx *old_run_ctx; + struct pt_regs *regs; int err; =20 if (unlikely(__this_cpu_inc_return(bpf_prog_active) !=3D 1)) { @@ -2756,6 +2764,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_li= nk *link, =20 migrate_disable(); rcu_read_lock(); + regs =3D ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); old_run_ctx =3D bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); err =3D bpf_prog_run(link->link.prog, regs); bpf_reset_run_ctx(old_run_ctx); @@ -2772,15 +2781,11 @@ kprobe_multi_link_handler(struct fprobe *fp, unsign= ed long fentry_ip, unsigned long ret_ip, struct ftrace_regs *fregs, void *data) { - struct pt_regs *regs =3D ftrace_get_regs(fregs); struct bpf_kprobe_multi_link *link; int err; =20 - if (!regs) - return 0; - link =3D container_of(fp, struct bpf_kprobe_multi_link, fp); - err =3D kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, f= alse, data); + err =3D kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs, = false, data); return is_kprobe_session(link->link.prog) ? err : 0; } =20 @@ -2790,13 +2795,9 @@ kprobe_multi_link_exit_handler(struct fprobe *fp, un= signed long fentry_ip, void *data) { struct bpf_kprobe_multi_link *link; - struct pt_regs *regs =3D ftrace_get_regs(fregs); - - if (!regs) - return; =20 link =3D container_of(fp, struct bpf_kprobe_multi_link, fp); - kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, true, dat= a); + kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs, true, da= ta); } =20 static int symbols_cmp_r(const void *a, const void *b, const void *priv) @@ -3057,7 +3058,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr= *attr, struct bpf_prog *pr kvfree(cookies); return err; } -#else /* !CONFIG_FPROBE || !CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#else /* !CONFIG_FPROBE */ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_pr= og *prog) { return -EOPNOTSUPP;