From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.4 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 10879 invoked from network); 31 Jul 2023 14:16:01 -0000 Received: from second.openwall.net (193.110.157.125) by inbox.vuxu.org with ESMTPUTF8; 31 Jul 2023 14:16:01 -0000 Received: (qmail 11329 invoked by uid 550); 31 Jul 2023 14:15:56 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 11290 invoked from network); 31 Jul 2023 14:15:55 -0000 X-Proofpoint-ORIG-GUID: EYLOEyeKgAzvzoPHLztu10vq8xk3pfhh X-Proofpoint-GUID: EYLOEyeKgAzvzoPHLztu10vq8xk3pfhh X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.591,18.0.957 definitions=2023-07-11_09:2023-07-11,2023-07-11 signatures=0 X-Proofpoint-Spam-Details: rule=interactive_user_notspam policy=interactive_user score=0 phishscore=0 adultscore=0 spamscore=0 mlxscore=0 bulkscore=0 suspectscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2307110153 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=apple.com; h=from : content-type : content-transfer-encoding : mime-version : subject : date : references : to : in-reply-to : message-id; s=20180706; bh=Ifzk5X2pzQ7+Gwc99uP7wVsv57WpTw6h/a8fOkRFvXs=; b=wPbj0UGQiIQ+XZjgRdd7eTuEEOjXvC2BJC9jTgiuEczyXNmREBWB4QNmiL6cr0bdPf/I mhKmmpX2DtYCYkPjoCo0g59+4aHQs9LsCNmKdPJmWzjLp5fMHW50xdri3KYcvCnsqLy2 Yt91wWW5d42zF3QAZVna/UPXRfKaFPslwHpoXVDLNquwetuzNmE/UrJzLIwmADx0GUBO PxsWqwF3DzrCaoljml7qb1hg/bZZywjG0lWItfs+YE3pImPuIMjHwV0EP0PjYvgmDJg/ TZAe+9Rqs02sBNFt0H/I7ui+ky+haNB0Boqxc706Av+9WrRlAzii9Ogv52P6BIan6JbP 8w== X-Va-A: X-Va-T-CD: 14dc138f66d48087821ca031f1b11e6a X-Va-E-CD: 2ba2d57c85ff06d6428107dbfb6d0e3f X-Va-R-CD: d020f7537544c47fda03c99c75c693a9 X-Va-ID: b4eb1d14-8041-4331-b056-5b3fcfc61e03 X-Va-CD: 0 X-V-A: X-V-T-CD: 14dc138f66d48087821ca031f1b11e6a X-V-E-CD: 2ba2d57c85ff06d6428107dbfb6d0e3f X-V-R-CD: d020f7537544c47fda03c99c75c693a9 X-V-ID: 88be9834-704b-489d-afaa-d1a1ea29e716 X-V-CD: 0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.591,18.0.957 definitions=2023-07-31_06:2023-07-31,2023-07-31 signatures=0 From: Alastair Houghton Content-type: text/plain; charset=utf-8 Content-transfer-encoding: quoted-printable MIME-version: 1.0 (Mac OS X Mail 16.0 \(3769.100.3\)) Date: Mon, 31 Jul 2023 15:15:30 +0100 References: <6CAFA15F-FF1C-4343-8D7F-00A44A815CEA@apple.com> To: musl@lists.openwall.com In-reply-to: Message-id: <78023E0A-E006-4F36-98B2-9C8894C5B7EF@apple.com> X-Mailer: Apple Mail (2.3769.100.3) Subject: Re: [musl] [PATCH] Add options to configure script to control frame pointer omission and EH unwind information > On 29 Jul 2023, at 06:25, alice wrote: >=20 > i believe the proposed change, and the rationale for it, had already = been > thoroughly discussed and rejected in > https://www.openwall.com/lists/musl/2021/07/16/1 Thanks for the link. That was an interesting read. > there is no intent to allow 'runtime use' of this data (i.e. allow = backtraces), > outside of what already works with an external debugger. It=E2=80=99s worth noting (and I think the Alpine folks did mention this = in the thread you highlighted) that external debuggers don=E2=80=99t = work inside Docker containers, at least by default, and that that = cluster operators are unlikely to want to make the changes that would be = required to fix that because they create security holes. At the same time, generating backtraces in e.g. assertion failure = routines or from a C++ unhandled exception handler can be a useful thing = to do and is not nearly as risky as trying to do that from a SEGV = handler. With no EH frame information and no frame pointers, those = backtraces are going to stop the moment they hit musl=E2=80=99s code. = Maybe that=E2=80=99s OK =E2=80=94 there aren=E2=80=99t that many things = in the C library that involve calling out to user code anyway. > unrelatedly (to the prior rejection), i believe these days there has = been work > on the SFrame format (as opposed to EH), to allow easier backtracing = (they > aren't mutually exclusive). maybe that is better to build on these = days? As I understand it that=E2=80=99s a Linux kernel thing, and not really = applicable outside of that context. What I was mostly trying to do is get (LLVM) libunwind=E2=80=99s tests = to pass out of the box, without having to disable things for musl. = Maybe I just disable those tests for now. Kind regards, Alastair.