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=ham 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 04261C433E1 for ; Wed, 26 Aug 2020 13:47:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5F1922B3F for ; Wed, 26 Aug 2020 13:47:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598449649; bh=utze0tB1+aahNBP9StFTpBv5Dvo31DdVx8UO9tI2fCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fizfk99tcggKRwTpCtXHtLXhLnJ2fB0RVhVZWtoDudX00hdr/1swGYJ+VWuaZ49So ldW3iHQljN66j/SR5rH9A05W7ohXGABnJZsIjb8UJSc3QXr0nvGOBJlV5ub/vFSkBS G2mCEIszzOSE7mwngTrUpkuWHlL7p98dTNdvx+tA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730320AbgHZNr0 (ORCPT ); Wed, 26 Aug 2020 09:47:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:56636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730410AbgHZNq6 (ORCPT ); Wed, 26 Aug 2020 09:46:58 -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 5839D22B3F; Wed, 26 Aug 2020 13:46:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598449617; bh=utze0tB1+aahNBP9StFTpBv5Dvo31DdVx8UO9tI2fCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z3Z7+CzXY16mIhF3lxi8hsOcy2Ws3c6YRv+LxXjUxm4xGP34q8dogFYGOgqjtb5Cy zsCF4/Fnk3TvWmva4PSBfsj5d6l/prhBWdajgZKUOIqcc6hihhgtHmp/7/8BwaEGOi gGm1YW5YJvdKXhnQOHijh2eHwtiXys9uGJOV0B4U= From: Masami Hiramatsu To: Peter Zijlstra Cc: Eddy Wu , linux-kernel@vger.kernel.org, x86@kernel.org, "David S . Miller" , Steven Rostedt , Ingo Molnar , "Naveen N . Rao" , Anil S Keshavamurthy , linux-arch@vger.kernel.org Subject: [RFC PATCH 04/14] arm64: kprobes: Use generic kretprobe trampoline handler Date: Wed, 26 Aug 2020 22:46:53 +0900 Message-Id: <159844961309.510284.11211569117855524382.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <159844957216.510284.17683703701627367133.stgit@devnote2> References: <159844957216.510284.17683703701627367133.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 Signed-off-by: Masami Hiramatsu --- arch/arm64/kernel/probes/kprobes.c | 79 ++---------------------------------- 1 file changed, 4 insertions(+), 75 deletions(-) diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 5290f17a4d80..1e4768001039 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -464,87 +464,16 @@ 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, + (unsigned long)&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;