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 CC2FDC433E6 for ; Sat, 29 Aug 2020 13:18:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A81C220825 for ; Sat, 29 Aug 2020 13:18:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598707101; bh=7qLDneVasGQ0/b4+77PfZX2MYbCLfBSdGwzzwl0JWGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XKw+rA2SKt/BE1mQSq2fIV1ExTcoyH3jOPcfXXQEo1zBi8FUAb4p+0w2pGMcnWNNE K7koq8Ub33sNXj8vC1URF25vGYPUi7aJXLw0mkZbldmatqf24V9MibuHSunEV4X8uD oKBiD15ULo8xppkK2xpav3W/FHNcd1VNMz792Kf0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727997AbgH2NRc (ORCPT ); Sat, 29 Aug 2020 09:17:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:53204 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727904AbgH2NB7 (ORCPT ); Sat, 29 Aug 2020 09:01:59 -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 D9F2920CC7; Sat, 29 Aug 2020 13:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598706119; bh=7qLDneVasGQ0/b4+77PfZX2MYbCLfBSdGwzzwl0JWGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S+sCuf3Ver1se2b80IiDdBF05PgzPE2idRg8g0BXz9ORKPXHs77nfi/TePD8pBCrG BTiuyD/9WajpKS1D2tNZz57MHvdvWGEzup/CebFHlkUDdYkGmSRQKOxDZ+iYTE+SSd PlvMUNz37OBfKtvEzEIMTr8lGMV28YkTRjFMcckg= 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 v5 10/21] powerpc: kprobes: Use generic kretprobe trampoline handler Date: Sat, 29 Aug 2020 22:01:48 +0900 Message-Id: <159870610825.1229682.2090635992093223399.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <159870598914.1229682.15230803449082078353.stgit@devnote2> References: <159870598914.1229682.15230803449082078353.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 --- Changes in v2: Fix to use correct trampoline_address. --- arch/powerpc/kernel/kprobes.c | 53 ++--------------------------------------- 1 file changed, 3 insertions(+), 50 deletions(-) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 6ab9b4d037c3..01ab2163659e 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -218,6 +218,7 @@ bool arch_kprobe_on_func_entry(unsigned long offset) void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *)regs->link; + ri->fp = NULL; /* Replace the return addr with trampoline addr */ regs->link = (unsigned long)kretprobe_trampoline; @@ -396,50 +397,9 @@ asm(".global kretprobe_trampoline\n" */ static int trampoline_probe_handler(struct kprobe *p, 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; - - 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 an multiple functions in the call path - * have a return probe installed on them, and/or more than one return - * return probe was registered for a target function. - * - * We can handle this because: - * - instances are always inserted at the head of the list - * - when multiple return probes are registered for the same - * function, the first instance's ret_addr will point to 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; - - if (ri->rp && ri->rp->handler) - ri->rp->handler(ri, regs); - - orig_ret_address = (unsigned long)ri->ret_addr; - 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_assert(ri, orig_ret_address, trampoline_address); + unsigned long orig_ret_address; + orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); /* * We get here through one of two paths: * 1. by taking a trap -> kprobe_handler() -> here @@ -458,13 +418,6 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) regs->nip = orig_ret_address - 4; regs->link = orig_ret_address; - kretprobe_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } - return 0; } NOKPROBE_SYMBOL(trampoline_probe_handler);