From patchwork Wed Nov 8 14:29:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13450188 X-Patchwork-Delegate: bpf@iogearbox.net 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 A5B5D1C292; Wed, 8 Nov 2023 14:30:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="c1hd7F4K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E22AC433C8; Wed, 8 Nov 2023 14:30:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699453803; bh=x87p6LsSh0DkSyVn29mHeJbsXBvI/Rrv9TUScfOAGeQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c1hd7F4KCEdlrut/a1IsxdBKr/SsPSOeh5V35DQXtxz7QG/hDuLE1ZBoSTWc4G5Um IThXDqUK0ug4hZVrr0rfQq4PW9xiF3GLS5R17fJFqNLQz83XpqcPFdi1WwlFTQrN0N /FFOV2KBxgumoDev7mVAzqnCZkdT85LPM5MPDDXPO0Bo9JjNQ2ti1UmY4suTI6IRo6 MzK/Rm4VZ0oa+jJUw9hsuDE4skyFEM0Y2kCjvRDkJBHCMTXZ+/oTtFvx1z/GHqcZNp LW0SxxNhCnMy/1JosL2lmaDu2fwltvV1tNuD9NMZOadOU4N8jNViLEmKbkQ3JtW/TM Fksn9Osn9RF6Q== 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: [RFC PATCH v2 29/31] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled Date: Wed, 8 Nov 2023 23:29:58 +0900 Message-Id: <169945379763.55307.4367798179163394870.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <169945345785.55307.5003201137843449313.stgit@devnote2> References: <169945345785.55307.5003201137843449313.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC 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 from previous series: NOTHING, Update against the new series. --- kernel/trace/bpf_trace.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index a4b5e34b0419..96d6e9993f75 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2501,7 +2501,7 @@ static int __init bpf_event_init(void) fs_initcall(bpf_event_init); #endif /* CONFIG_MODULES */ -#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; @@ -2524,6 +2524,8 @@ struct user_syms { char *buf; }; +static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); + static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) { unsigned long __user usymbol; @@ -2700,13 +2702,14 @@ 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) { struct bpf_kprobe_multi_run_ctx run_ctx = { .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)) { @@ -2716,6 +2719,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, migrate_disable(); rcu_read_lock(); + regs = ftrace_partial_regs(fregs, this_cpu_ptr(&bpf_kprobe_multi_pt_regs)); old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); err = bpf_prog_run(link->link.prog, regs); bpf_reset_run_ctx(old_run_ctx); @@ -2733,13 +2737,9 @@ kprobe_multi_link_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 0; link = container_of(fp, struct bpf_kprobe_multi_link, fp); - kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); + kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs); return 0; } @@ -2749,13 +2749,9 @@ 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); + kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs); } static int symbols_cmp_r(const void *a, const void *b, const void *priv) @@ -3012,7 +3008,7 @@ 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;