From patchwork Wed Jul 3 10:11:07 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: 13721704 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 03458143758; Wed, 3 Jul 2024 10:11:12 +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=1720001473; cv=none; b=KTVqYdoCKAAeQteHO0qzCneqYKdc9KkVg/o+PM0S59iWEZKQyGpDP5smLYCCZgVEVIsdnCT1aotCTcCuxBm+17St5pn6UEwHOpO8WfLIsY0jntW2LGYPWTgOjCjCvYyhFKZAjUmp6R4LxXAXoiONQ48OiBh18oTwUziTMaKA2TU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720001473; c=relaxed/simple; bh=OtlEX+N2t22ZO0stHC9uK5V+uqtQ/aaFzUaCS8qHyPs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=QcPo7Ox3UUB8f44u94aMEROifIOqfG1ICZbE8e2boWjMVK/gax0hbvnQwDmcUHB2Rk/hQ+yCE8sTqTxNU7gDuAKjA/YG4o5/5MrXGGi1373PokQanw2YLtX1+gcHTEzV1MBtmk8LhA8dBvVub8yvbpn+D9p0/j1KAEWg8gGrsyA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rxIYkZcG; 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="rxIYkZcG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1432AC32781; Wed, 3 Jul 2024 10:11:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720001472; bh=OtlEX+N2t22ZO0stHC9uK5V+uqtQ/aaFzUaCS8qHyPs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rxIYkZcGUcc9gfnGdG5yW4Jmigr8H/S6zs9NwCzHe8JfCciF5l0zxi4aJnysN8pjV a1maAmcFMJfTPznNccowSoqXMj2c1K4RTfSiGZtEUIVwZkujCDJ0pfQifJ0GxtrHYC Aq/BezJWWthV/f5iWNH3gG7g9m6nnGXoYIcFdXt0UAyeU3MICY4PtcCfTwDi4Jrx+D SQTW/jJ2G8htqoJmcLUVReCAXX0m9jXm5cnVt5++w39xs3KpGqrqpdXZZ7koj97umo L9ZrBi5lf7rkayW/qDnR7EqGm81egFKwfOpy4zmZV+Wrqtw2JwlPIg6yMBywlH/9L+ AclTEGVZ5McDg== 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 Subject: [PATCH v12 11/19] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled Date: Wed, 3 Jul 2024 19:11:07 +0900 Message-Id: <172000146719.63468.13245486388278577139.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <172000134410.63468.13742222887213469474.stgit@devnote2> References: <172000134410.63468.13742222887213469474.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 f72b421abe9b..77fd63027286 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2602,7 +2602,7 @@ 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; @@ -2625,6 +2625,13 @@ 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; @@ -2819,7 +2826,7 @@ 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 = { @@ -2831,6 +2838,7 @@ 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)) { @@ -2841,6 +2849,7 @@ 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); @@ -2857,15 +2866,11 @@ 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; } @@ -2875,13 +2880,9 @@ 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) @@ -3142,7 +3143,7 @@ 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;