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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E5436C001DF for ; Wed, 2 Aug 2023 12:01:48 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=iLT8cxgO; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RG9Z31DtJz3cJC for ; Wed, 2 Aug 2023 22:01:47 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=iLT8cxgO; dkim-atps=neutral Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (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 lists.ozlabs.org (Postfix) with ESMTPS id 4RG9Y20vfDz2yVp for ; Wed, 2 Aug 2023 22:00:54 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1690977653; bh=srbZojdru0tsVgAsnUb95vBNV7rieqJ2AhYM1AFAUrM=; h=From:To:Subject:In-Reply-To:References:Date:From; b=iLT8cxgOXWCuEWhGbMgv3A/ss6AewaDUdMGvdgf4waMQk/3e+8qxlXxi9V8Q9iS7Q +LYNkopSdouJbo3pepb7yYtv1z0baIGVkkol8gtRMll50x7dHucGe4G6UdSwVummIt tvlpZLuZWWYELKQQloZmRwSPOzPpkdry4NY5ATbFBeewzUKCqd8EaAPXd2Kp5MkG+d 3L5J1pRsehy/X7H+I5/N3+MLO6+yX5cmG9I3xue5yG41E1Wx1G1PYtWimcxCVxQ4oU GyqMyB0Ixr4Ax/qPlxxJUqUSM+8sAjOHWipSNMOfVMnb5uJ1ypxCOfBMkTiY7alAmg KWL1tLAPBkVoA== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4RG9Y15Kv6z4xJW; Wed, 2 Aug 2023 22:00:53 +1000 (AEST) From: Michael Ellerman To: Christophe Leroy , Benjamin Gray , "linuxppc-dev@lists.ozlabs.org" Subject: Re: [PATCH 0/7] Rework perf and ptrace watchpoint tracking In-Reply-To: <4a0d1740-bf19-0a96-1668-23d6188657cb@csgroup.eu> References: <20230801011744.153973-1-bgray@linux.ibm.com> <4a0d1740-bf19-0a96-1668-23d6188657cb@csgroup.eu> Date: Wed, 02 Aug 2023 22:00:47 +1000 Message-ID: <874jlh1wnk.fsf@mail.lhotse> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Christophe Leroy writes: > Le 01/08/2023 =C3=A0 03:17, Benjamin Gray a =C3=A9crit=C2=A0: >> Syzkaller triggered a null pointer dereference in the >> arch_unregister_hw_breakpoint() hook. This is due to accessing >> the bp->ctx->task field changing to -1 while we iterate the breakpoints. >>=20 >> This series refactors the breakpoint tracking logic to remove the >> dependency on bp->ctx entirely. It also simplifies handling of ptrace and >> perf breakpoints, making insertion less restrictive. > > Is there any link between this series and the following issue:=20 > https://github.com/linuxppc/issues/issues/38 AFAIK no, Ben started looking at the breakpoint code due to a syzkaller report of an oops. But this series would resolve that issue AFAICS, so I guess they are linked in that sense. cheers