From patchwork Thu Sep 12 15:10:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13802280 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 1C7D71B983D; Thu, 12 Sep 2024 15:10:15 +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=1726153815; cv=none; b=djJGQvnE0sFy46BHO6zu0fCV3Y09/rX0eS1Gwu0alWEJZ5fpiYwb9wdtPT2qfwNgm1oKIvNjyBou+kmpuCtUxRt8G3sbARfz5LnVwfCn5q2kvtcwC3XrfTA03X0zFM+7vTgezyn/W5AiOQetm5Pl+TMCFesRPHWbX4PkPq6Xsj0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726153815; c=relaxed/simple; bh=JYaRKeJmGRnsdkv3DZQuO4sB8FqXsYsH2vHflN4Nz3A=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=rHSqQuW3YzNw+lRsbeI27RpVPS73/D2cCVkDPl1MtKhMk6aNheXOouNdN5t5xaelgxPKGD1SDB2b6bhACDbCtQ6mCCh4RB9YBDsMZgxvN8COhz7n9SvU9yQnNE40WMpoodecflzgatUWBgBBKESnJ1wmC0NfHwpSmmvZ8tGRkNc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=l1d/yQWC; 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="l1d/yQWC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B2BFC4CEC3; Thu, 12 Sep 2024 15:10:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726153815; bh=JYaRKeJmGRnsdkv3DZQuO4sB8FqXsYsH2vHflN4Nz3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l1d/yQWCP1JcgRT4SCOEfHenA1VpO0whsgQnb024PPqBsn1BxwJiNene6g77udo8E 9TRBUuDo/1Nk5h9Qkw+fY8E9gb44ONfD6tMZ1O9CsArVKeWf2YqEd/ovzRdVxqUBRf daMIXerJvf8NhYUmZcDKROC68sqeKRbxXJhisTB/Hq8E+2kV3h+SzbRMtEtokwV08X 58n8zTG5hz+vveu83s9yRk6at6G0mMWxva5OoWDKIdiQkBBO0XJQzvqTj7H4m1x4gX pmv4ucF261YSBAXKg13P2t8BDR9mcxrzT5lWQN7/VL8VxLEdKzgC70+uNk7ppBQANf cIDlGbhxbo4uQ== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner , Guo Ren , linux-arch@vger.kernel.org Subject: [PATCH v14 11/19] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled Date: Fri, 13 Sep 2024 00:10:08 +0900 Message-Id: <172615380883.133222.6617351174325139337.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <172615368656.133222.2336770908714920670.stgit@devnote2> References: <172615368656.133222.2336770908714920670.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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=y --- 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 cdba9981b048..deb629f4a510 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2605,7 +2605,7 @@ struct bpf_session_run_ctx { void *data; }; -#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; @@ -2628,6 +2628,13 @@ struct user_syms { char *buf; }; +#ifndef CONFIG_HAVE_PT_REGS_TO_FTRACE_REGS_CAST +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_regs) +#else +#define bpf_kprobe_multi_pt_regs_ptr() (NULL) +#endif + static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) { unsigned long __user usymbol; @@ -2822,7 +2829,7 @@ static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 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 = { @@ -2834,6 +2841,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, .entry_ip = entry_ip, }; struct bpf_run_ctx *old_run_ctx; + struct pt_regs *regs; int err; if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { @@ -2844,6 +2852,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, migrate_disable(); rcu_read_lock(); + regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); err = bpf_prog_run(link->link.prog, regs); bpf_reset_run_ctx(old_run_ctx); @@ -2860,15 +2869,11 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, unsigned long ret_ip, struct ftrace_regs *fregs, void *data) { - struct pt_regs *regs = ftrace_get_regs(fregs); struct bpf_kprobe_multi_link *link; int err; - if (!regs) - return 0; - link = container_of(fp, struct bpf_kprobe_multi_link, fp); - err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, false, data); + err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs, false, data); return is_kprobe_session(link->link.prog) ? err : 0; } @@ -2878,13 +2883,9 @@ kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, void *data) { struct bpf_kprobe_multi_link *link; - struct pt_regs *regs = ftrace_get_regs(fregs); - - if (!regs) - return; link = container_of(fp, struct bpf_kprobe_multi_link, fp); - kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, true, data); + kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs, true, data); } static int symbols_cmp_r(const void *a, const void *b, const void *priv) @@ -3145,7 +3146,7 @@ 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_prog *prog) { return -EOPNOTSUPP;