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[2620:137:e000::1:20]) by mx.google.com with ESMTP id f5-20020a170902ce8500b001a6e98a5f21si7910693plg.586.2023.06.15.05.52.44; Thu, 15 Jun 2023 05:52:57 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=ETYkAhwt; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344649AbjFOL7G (ORCPT + 99 others); Thu, 15 Jun 2023 07:59:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239068AbjFOL6t (ORCPT ); Thu, 15 Jun 2023 07:58:49 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA12E5FC0; Thu, 15 Jun 2023 04:53:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3D9A4637B1; Thu, 15 Jun 2023 11:52:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F06B1C433C8; Thu, 15 Jun 2023 11:52:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686829960; bh=vzXaLtl6SzbvAGUpSSunsAgBa5POCxudf8Ga0otXJQU=; h=From:To:Cc:Subject:Date:From; b=ETYkAhwtp5kNnRtpjzuT4+P3vKvOR2SXhqd4Q8qIpLEGQl6dYfiqvReb117moKwM0 LdRSt8WIYArfD9xxw9VDPZkTSWuHYapMzGO0mAQIHYlfaZalEYEUIxzcXQNxfgplip HFSkXpe4WVm8vK1ciYLuagzQS77bEkvoRMS9V0DxIqX/IpuS3JOBRhOuDHK1QlOQJh ZuVKK4rULuoGZdXfT5urJ5l1fOfaOuLe7P14w9PSeSu6nEAocRDhXIdQXNFJTwFShi /wM/YDUZ9tDa5U3Zf3y+3cTlwxPE9hKOABGrBM2pcfjZYmcgPaBrZrQlZmxvcaKYkJ pRsGyu2GFtomA== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Mark Rutland Cc: lkml , linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH] fprobe: Release rethook after the ftrace_ops is unregistered Date: Thu, 15 Jun 2023 13:52:36 +0200 Message-Id: <20230615115236.3476617-1-jolsa@kernel.org> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1768773205701132534?= X-GMAIL-MSGID: =?utf-8?q?1768773205701132534?= While running bpf selftests it's possible to get following fault: general protection fault, probably for non-canonical address \ 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI ... Call Trace: fprobe_handler+0xc1/0x270 ? __pfx_bpf_testmod_init+0x10/0x10 ? __pfx_bpf_testmod_init+0x10/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_testmod_init+0x22/0x80 ? do_one_initcall+0x63/0x2e0 ? rcu_is_watching+0xd/0x40 ? kmalloc_trace+0xaf/0xc0 ? do_init_module+0x60/0x250 ? __do_sys_finit_module+0xac/0x120 ? do_syscall_64+0x37/0x90 ? entry_SYSCALL_64_after_hwframe+0x72/0xdc In unregister_fprobe function we can't release fp->rethook while it's possible there are some of its users still running on another cpu. Moving rethook_free call after fp->ops is unregistered with unregister_ftrace_function call. Fixes: 5b0ab78998e3 ("fprobe: Add exit_handler support") Reviewed-by: Steven Rostedt (Google) Signed-off-by: Jiri Olsa Acked-by: Masami Hiramatsu (Google) --- kernel/trace/fprobe.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 18d36842faf5..0121e8c0d54e 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -364,19 +364,13 @@ int unregister_fprobe(struct fprobe *fp) fp->ops.saved_func != fprobe_kprobe_handler)) return -EINVAL; - /* - * rethook_free() starts disabling the rethook, but the rethook handlers - * may be running on other processors at this point. To make sure that all - * current running handlers are finished, call unregister_ftrace_function() - * after this. - */ - if (fp->rethook) - rethook_free(fp->rethook); - ret = unregister_ftrace_function(&fp->ops); if (ret < 0) return ret; + if (fp->rethook) + rethook_free(fp->rethook); + ftrace_free_filter(&fp->ops); return ret;