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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 64754C4338F for ; Fri, 23 Jul 2021 04:47:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BEA660E95 for ; Fri, 23 Jul 2021 04:47:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229740AbhGWEF6 (ORCPT ); Fri, 23 Jul 2021 00:05:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbhGWEF5 (ORCPT ); Fri, 23 Jul 2021 00:05:57 -0400 Received: from ustc.edu.cn (email6.ustc.edu.cn [IPv6:2001:da8:d800::8]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E9A76C061575 for ; Thu, 22 Jul 2021 21:46:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mail.ustc.edu.cn; s=dkim; h=Received:Date:From:To:Cc:Subject: Message-ID:In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=RmTFR5sHYq+p4KauoZP/+FHafSyPUXZ/4/ /YrkOuHv4=; b=AuaH15T+Drpa92yftNj9Ipz3eeGHqMV0QiPOFACxcspsLszpUF 2ULlnO22Qm3w+a758nws38HBc22FbjlIYt3xhoZzSdRUxhDaKn3jAqrEuwb5SAzu +r7Wqs8XLQKzS++dO9OSK4a9o1Qbx44q6lMHnb8dRuV+ozzygU6cUB7Qw= Received: from xhacker (unknown [101.86.20.15]) by newmailweb.ustc.edu.cn (Coremail) with SMTP id LkAmygA3Pv6bSfpgdPkxAA--.1487S2; Fri, 23 Jul 2021 12:46:19 +0800 (CST) Date: Fri, 23 Jul 2021 12:40:25 +0800 From: Jisheng Zhang To: tongtiangen Cc: Andreas Schwab , Atish Patra , Palmer Dabbelt , Paul Walmsley , Albert Ou , linux-riscv , "linux-kernel@vger.kernel.org List" Subject: Re: [PATCH -next v2] riscv: add VMAP_STACK overflow detection Message-ID: <20210723124025.669cb4ec@xhacker> In-Reply-To: <20210723122925.67a14562@xhacker> References: <87bl6yrcmd.fsf@igel.home> <20210722213724.1f12a0e7@xhacker> <87zguexslf.fsf@igel.home> <20210723075432.098634a2@xhacker> <52e3626a-2b40-bda6-de0e-68ea12a86dd9@huawei.com> <20210723122925.67a14562@xhacker> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: LkAmygA3Pv6bSfpgdPkxAA--.1487S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Cr4DXw4rWF47JFykArWfAFb_yoW8ZrW5pF WUAa1akF4DJF1Ik3Z7Kw18Wa409Fs7A345Z3s5XF13AF9Yqa1rXr42gF45Ka47Gr13C3WY vr48KF97Ww45Ja7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUyIb7Iv0xC_Zr1lb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I 8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8Jw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41l42xK82IYc2Ij64vIr41l4I8I3I0E 4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGV WUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_ Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rV WrJr0_WFyUJwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j 6r4UJbIYCTnIWIevJa73UjIFyTuYvjxU7y89DUUUU X-CM-SenderInfo: xmv2xttqjtqzxdloh3xvwfhvlgxou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 23 Jul 2021 12:29:25 +0800 Jisheng Zhang wrote: > On Fri, 23 Jul 2021 09:36:47 +0800 > tongtiangen wrote: >=20 > > On 2021/7/23 7:54, Jisheng Zhang wrote: =20 > > > On Thu, 22 Jul 2021 17:42:52 +0200 > > > Andreas Schwab wrote: > > > =20 > > >> On Jul 22 2021, Jisheng Zhang wrote: > > >> =20 > > >>> I think we need to pin the stack before calling get_wchan(), could = you please > > >>> try below patch? =20 > > >> > > >> Thanks, this fixes the crash for me. > > >> > > >> Andreas. > > >> =20 > > > > > > Thanks for testing. I will send out formal patch later > > > > > > Thanks > > > > > > . > > > =20 > >=20 > > Hi all: > > I tried to reproduced this crash in openSUSE code repo=EF=BC=88=20 > > https://github.com/opensuse/kernel =EF=BC=89, but not reproduced succes= sfully. > >=20 > > From the patch of problem repair, the crash is due to task->stack is=20 > > released before calling get_wchan, the task state of maybe TASK_DEAD. > >=20 > > VMAP_STACK is used to detect kernel stack overflow, there is no=20 > > connection between the two, it makes me a little confused. =20 >=20 > I believe the bug exists from the first day of riscv mainlined. >=20 > Since THREAD_INFO_IN_TASK=3Dy in riscv, so when task stack can be freed > before being destroyed. typo: task stack can be freed before task is destroyed >=20 > When VMAP_STACK=3Dn, task's stack is allocated from linear mapping. When > task stack is freed, the corresponding mapping still exists, and since > get_wchan() only read, no harm is observed so far. >=20 > When VMAP_STACK=3Dy, task's stack is allocated from vmalloc area. When > task stack is freed, the corresponding mapping may not exist, so I expect > MMU fault here, thus the kernel panic. >=20 > In summary, the bug isn't related with VMAP_STACK, but VMAP_STACK makes > the bug observable. >=20 > Thanks >=20 >=20 >=20 > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv 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=-10.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 072C1C4338F for ; Fri, 23 Jul 2021 04:46:53 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ABCE460E77 for ; 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charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org T24gRnJpLCAyMyBKdWwgMjAyMSAxMjoyOToyNSArMDgwMApKaXNoZW5nIFpoYW5nIDxqc3poYW5n M0BtYWlsLnVzdGMuZWR1LmNuPiB3cm90ZToKCj4gT24gRnJpLCAyMyBKdWwgMjAyMSAwOTozNjo0 NyArMDgwMAo+IHRvbmd0aWFuZ2VuIDx0b25ndGlhbmdlbkBodWF3ZWkuY29tPiB3cm90ZToKPiAK PiA+IE9uIDIwMjEvNy8yMyA3OjU0LCBKaXNoZW5nIFpoYW5nIHdyb3RlOiAgCj4gPiA+IE9uIFRo dSwgMjIgSnVsIDIwMjEgMTc6NDI6NTIgKzAyMDAKPiA+ID4gQW5kcmVhcyBTY2h3YWIgPHNjaHdh YkBsaW51eC1tNjhrLm9yZz4gd3JvdGU6Cj4gPiA+ICAgIAo+ID4gPj4gT24gSnVsIDIyIDIwMjEs IEppc2hlbmcgWmhhbmcgd3JvdGU6Cj4gPiA+PiAgICAKPiA+ID4+PiBJIHRoaW5rIHdlIG5lZWQg dG8gcGluIHRoZSBzdGFjayBiZWZvcmUgY2FsbGluZyBnZXRfd2NoYW4oKSwgY291bGQgeW91IHBs ZWFzZQo+ID4gPj4+IHRyeSBiZWxvdyBwYXRjaD8gICAgCj4gPiA+Pgo+ID4gPj4gVGhhbmtzLCB0 aGlzIGZpeGVzIHRoZSBjcmFzaCBmb3IgbWUuCj4gPiA+Pgo+ID4gPj4gQW5kcmVhcy4KPiA+ID4+ ICAgIAo+ID4gPgo+ID4gPiBUaGFua3MgZm9yIHRlc3RpbmcuIEkgd2lsbCBzZW5kIG91dCBmb3Jt YWwgcGF0Y2ggbGF0ZXIKPiA+ID4KPiA+ID4gVGhhbmtzCj4gPiA+Cj4gPiA+IC4KPiA+ID4gICAg Cj4gPiAKPiA+IEhpIGFsbDoKPiA+IEkgdHJpZWQgdG8gcmVwcm9kdWNlZCB0aGlzIGNyYXNoIGlu IG9wZW5TVVNFIGNvZGUgcmVwb++8iCAKPiA+IGh0dHBzOi8vZ2l0aHViLmNvbS9vcGVuc3VzZS9r ZXJuZWwg77yJLCBidXQgbm90IHJlcHJvZHVjZWQgc3VjY2Vzc2Z1bGx5Lgo+ID4gCj4gPiAgRnJv bSB0aGUgcGF0Y2ggb2YgcHJvYmxlbSByZXBhaXIsIHRoZSBjcmFzaCBpcyBkdWUgdG8gdGFzay0+ c3RhY2sgaXMgCj4gPiByZWxlYXNlZCBiZWZvcmUgY2FsbGluZyBnZXRfd2NoYW4sIHRoZSB0YXNr IHN0YXRlIG9mIG1heWJlIFRBU0tfREVBRC4KPiA+IAo+ID4gVk1BUF9TVEFDSyBpcyB1c2VkIHRv IGRldGVjdCBrZXJuZWwgc3RhY2sgb3ZlcmZsb3csIHRoZXJlIGlzIG5vIAo+ID4gY29ubmVjdGlv biBiZXR3ZWVuIHRoZSB0d28sIGl0IG1ha2VzIG1lIGEgbGl0dGxlIGNvbmZ1c2VkLiAgCj4gCj4g SSBiZWxpZXZlIHRoZSBidWcgZXhpc3RzIGZyb20gdGhlIGZpcnN0IGRheSBvZiByaXNjdiBtYWlu bGluZWQuCj4gCj4gU2luY2UgVEhSRUFEX0lORk9fSU5fVEFTSz15IGluIHJpc2N2LCBzbyB3aGVu IHRhc2sgc3RhY2sgY2FuIGJlIGZyZWVkCj4gYmVmb3JlIGJlaW5nIGRlc3Ryb3llZC4KCnR5cG86 IHRhc2sgc3RhY2sgY2FuIGJlIGZyZWVkIGJlZm9yZSB0YXNrIGlzIGRlc3Ryb3llZAoKPiAKPiBX aGVuIFZNQVBfU1RBQ0s9biwgdGFzaydzIHN0YWNrIGlzIGFsbG9jYXRlZCBmcm9tIGxpbmVhciBt YXBwaW5nLiBXaGVuCj4gdGFzayBzdGFjayBpcyBmcmVlZCwgdGhlIGNvcnJlc3BvbmRpbmcgbWFw cGluZyBzdGlsbCBleGlzdHMsIGFuZCBzaW5jZQo+IGdldF93Y2hhbigpIG9ubHkgcmVhZCwgbm8g aGFybSBpcyBvYnNlcnZlZCBzbyBmYXIuCj4gCj4gV2hlbiBWTUFQX1NUQUNLPXksIHRhc2sncyBz dGFjayBpcyBhbGxvY2F0ZWQgZnJvbSB2bWFsbG9jIGFyZWEuIFdoZW4KPiB0YXNrIHN0YWNrIGlz IGZyZWVkLCB0aGUgY29ycmVzcG9uZGluZyBtYXBwaW5nIG1heSBub3QgZXhpc3QsIHNvIEkgZXhw ZWN0Cj4gTU1VIGZhdWx0IGhlcmUsIHRodXMgdGhlIGtlcm5lbCBwYW5pYy4KPiAKPiBJbiBzdW1t YXJ5LCB0aGUgYnVnIGlzbid0IHJlbGF0ZWQgd2l0aCBWTUFQX1NUQUNLLCBidXQgVk1BUF9TVEFD SyBtYWtlcwo+IHRoZSBidWcgb2JzZXJ2YWJsZS4KPiAKPiBUaGFua3MKPiAKPiAKPiAKPiBfX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwo+IGxpbnV4LXJpc2N2 IG1haWxpbmcgbGlzdAo+IGxpbnV4LXJpc2N2QGxpc3RzLmluZnJhZGVhZC5vcmcKPiBodHRwOi8v bGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LXJpc2N2CgoKCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmxpbnV4LXJpc2N2IG1h aWxpbmcgbGlzdApsaW51eC1yaXNjdkBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5p bmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtcmlzY3YK