From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8C93C433E2 for ; Fri, 28 Aug 2020 12:28:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B4E220848 for ; Fri, 28 Aug 2020 12:28:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598617720; bh=PddMsZfi66noEb05sSeRW/PrF1jKd2532FhhOsMWHs4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rouWRJ3z33rJ72gM6huCniYXQKUVwHYpO+v9tWoxyv9dbNpqEnxnoqXAK3/2oGdQY sBwsdgSEHrzS62u6PwyPpTZqcG/pJ1/Zo0eq/rdbZyAsLriLYnSRYVW0Fir9wnBShs zR7OL79GhPLoiJh/XaQV/p7QsSlt8nfQbhFOoQ6U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729371AbgH1M2d (ORCPT ); Fri, 28 Aug 2020 08:28:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:39512 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729350AbgH1M12 (ORCPT ); Fri, 28 Aug 2020 08:27:28 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 60B222086A; Fri, 28 Aug 2020 12:27:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598617647; bh=PddMsZfi66noEb05sSeRW/PrF1jKd2532FhhOsMWHs4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hPnEM/wN6Yn5VeBa7qM70ns0rSQT7Ggd0JSVuXz0cS7cjHR1fZjCGm1XHmPJZfJJ0 n4BC7aVh+DHP9uCx7rijWsGX/mxGLcKAT4sU2ouGNncntyJb6WcJYRMSTcrCOy/DdU HQZiARksa1BocYvLh/4Yq76KEDTx5gtdhLzZZqag= From: Masami Hiramatsu To: linux-kernel@vger.kernel.org, Peter Zijlstra Cc: Eddy_Wu@trendmicro.com, x86@kernel.org, davem@davemloft.net, rostedt@goodmis.org, naveen.n.rao@linux.ibm.com, anil.s.keshavamurthy@intel.com, linux-arch@vger.kernel.org, cameron@moodycamel.com, oleg@redhat.com, will@kernel.org, paulmck@kernel.org, mhiramat@kernel.org Subject: [PATCH v4 04/23] arm64: kprobes: Use generic kretprobe trampoline handler Date: Fri, 28 Aug 2020 21:27:22 +0900 Message-Id: <159861764221.992023.10214437014901668680.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <159861759775.992023.12553306821235086809.stgit@devnote2> References: <159861759775.992023.12553306821235086809.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use the generic kretprobe trampoline handler, and use the kernel_stack_pointer(regs) for framepointer verification. Signed-off-by: Masami Hiramatsu --- arch/arm64/kernel/probes/kprobes.c | 78 +----------------------------------- 1 file changed, 3 insertions(+), 75 deletions(-) diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 5290f17a4d80..deba738142ed 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -464,87 +464,15 @@ int __init arch_populate_kprobe_blacklist(void) void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) { - struct kretprobe_instance *ri = NULL; - struct hlist_head *head, empty_rp; - struct hlist_node *tmp; - unsigned long flags, orig_ret_address = 0; - unsigned long trampoline_address = - (unsigned long)&kretprobe_trampoline; - kprobe_opcode_t *correct_ret_addr = NULL; - - INIT_HLIST_HEAD(&empty_rp); - kretprobe_hash_lock(current, &head, &flags); - - /* - * It is possible to have multiple instances associated with a given - * task either because multiple functions in the call path have - * return probes installed on them, and/or more than one - * return probe was registered for a target function. - * - * We can handle this because: - * - instances are always pushed into the head of the list - * - when multiple return probes are registered for the same - * function, the (chronologically) first instance's ret_addr - * will be the real return address, and all the rest will - * point to kretprobe_trampoline. - */ - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* another task is sharing our hash bucket */ - continue; - - orig_ret_address = (unsigned long)ri->ret_addr; - - if (orig_ret_address != trampoline_address) - /* - * This is the real return address. Any other - * instances associated with this task are for - * other calls deeper on the call stack - */ - break; - } - - kretprobe_assert(ri, orig_ret_address, trampoline_address); - - correct_ret_addr = ri->ret_addr; - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* another task is sharing our hash bucket */ - continue; - - orig_ret_address = (unsigned long)ri->ret_addr; - if (ri->rp && ri->rp->handler) { - __this_cpu_write(current_kprobe, &ri->rp->kp); - get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; - ri->ret_addr = correct_ret_addr; - ri->rp->handler(ri, regs); - __this_cpu_write(current_kprobe, NULL); - } - - recycle_rp_inst(ri, &empty_rp); - - if (orig_ret_address != trampoline_address) - /* - * This is the real return address. Any other - * instances associated with this task are for - * other calls deeper on the call stack - */ - break; - } - - kretprobe_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } - return (void *)orig_ret_address; + return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, + (void *)kernel_stack_pointer(regs)); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *)regs->regs[30]; + ri->fp = (void *)kernel_stack_pointer(regs); /* replace return addr (x30) with trampoline */ regs->regs[30] = (long)&kretprobe_trampoline;