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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3BA4C433EF for ; Thu, 9 Jun 2022 22:16:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 301C58D004F; Thu, 9 Jun 2022 18:16:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2B1AE8D0034; Thu, 9 Jun 2022 18:16:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 152FC8D004F; Thu, 9 Jun 2022 18:16:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 056CB8D0034 for ; Thu, 9 Jun 2022 18:16:53 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id BF6A61076 for ; Thu, 9 Jun 2022 22:16:52 +0000 (UTC) X-FDA: 79560108264.12.FB2076A Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) by imf21.hostedemail.com (Postfix) with ESMTP id 4A9F51C007F for ; Thu, 9 Jun 2022 22:16:52 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id v127-20020a256185000000b0065cbe0f6999so21241639ybb.22 for ; Thu, 09 Jun 2022 15:16:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=a7HKcIF+i0T4+qY1S/nBDjlBN8LZbn3HajfMjAd6pgE=; b=myr+KdqGBf+8fU62rrrc6vdWLC4zQ+EyY6QFdgZ42GfmTyENhLo1IAw3h2RNkQhUwn 0XIlmFI5we6dPTmcL5OoVRYkNlg1LkiEp4m7TTvZUlR6ue+fe982BLupBD9KlWv7xdeq tEyC52lTuBzUzYKgufcIPK7Ci1BaDygPGjKQT8u6/zm5afnc2zO7GbJDlDaelSa5C9I6 m1gTG8o78bI6STaoseXyxF12CneUqy+nHYwCQMj9r7YNbTeNrJ/xKj0EQk+nA9+z1UEj WUT+SwL4WoBwN+LsZ0RrnI0mPP8hfuMvwOWrNlfSbRwkDqmNF92nH57ZSUm5tqv4Qcz4 Lc7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=a7HKcIF+i0T4+qY1S/nBDjlBN8LZbn3HajfMjAd6pgE=; b=NzFGUT/8qh6uZne2H+B/bN314XZZ5YI6wADYIoNVo91hCEMtzEhddzWYMJNpXhZPz1 xYLAGxRB+JAMjd/Af+pMHLHDeM0OcHxanGdv/B1AX/9pJr9mY/llNBMurPbw5EFTp+mj HHRDyVupWRxBVwv2TiAZu0woxcrYYTrqBwmhmciHOGgrHz3PXCdpbzdSINzFlC7B6utP CKmiceceuBtsTBLglzrc3AjJHyFo9uuI9XZzjrMQKEgjMVnqfFAJzvVBZKBMqmuAHBpI nmAJtTxYYdffgUO2z++F6JbnGe38pvbRp1tGQEoeirCsjkgOhZjdJVQcPmJdoYFO2vJy LXBQ== X-Gm-Message-State: AOAM5316AEZg/hqKAU75YR1UXQYwYf5AJD4WUpIDfLVxiJ/YpPPFIBmw uRlLzdD87HDfAAFE79bmhoscF62NjiqNCw== X-Google-Smtp-Source: ABdhPJxssTaeezzS7wEt6X3VKCQoaymqGu0EUoWOB6KOG9bWlT0i99Upi+R4v9esUZodWYU8smo6tDC44wMwrQ== X-Received: from shakeelb.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:28b]) (user=shakeelb job=sendgmr) by 2002:a25:2003:0:b0:663:e799:4ab5 with SMTP id g3-20020a252003000000b00663e7994ab5mr13476183ybg.403.1654813011398; Thu, 09 Jun 2022 15:16:51 -0700 (PDT) Date: Thu, 9 Jun 2022 22:16:47 +0000 In-Reply-To: Message-Id: <20220609221647.lqxljj4wlb6mcuvr@google.com> Mime-Version: 1.0 References: <20220609191221.rv3lqbhipnvvzt67@google.com> Subject: Re: [next] arm64: boot failed - next-20220606 From: Shakeel Butt To: Roman Gushchin Cc: Naresh Kamboju , Linux-Next Mailing List , open list , regressions@lists.linux.dev, lkft-triage@lists.linaro.org, Linux ARM , linux-mm , Stephen Rothwell , Andrew Morton , Ard Biesheuvel , Arnd Bergmann , Catalin Marinas , Raghuram Thammiraju , Mark Brown , Will Deacon , Vasily Averin , Qian Cai Content-Type: text/plain; charset="us-ascii" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1654813012; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=a7HKcIF+i0T4+qY1S/nBDjlBN8LZbn3HajfMjAd6pgE=; b=dGjbRcQwMG+SiOMNXLJo9a+GjXZWYNss+cKCumu0zNQC2ILa9YK2+SuKa67B4jpKhNtDdA iRTHQOQSyhDFLtnEj0jGZLWNlrGfMFGUwtFRVb+Z7pr6demBnx82bzh4WGEf17HG/shvRo 5ocfK9d0EQwFXsw1rXgY64w6Dibun8w= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1654813012; a=rsa-sha256; cv=none; b=4OeB9wcFbR3MWm9e3PHb0321TI+ucqCB7KRcXwvw+fEoVj9Es6jEopVkihlaNOxLa4AInk J3YfVZLOA028DTVJ31P+URJbbPWatl989s4z+PRxGouhpgWxm8uKBE3xSN5bcK4HnG4vrz O74oJYHD3mxSyPKEqANzISDEGI5fk08= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=myr+KdqG; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf21.hostedemail.com: domain of 3U3GiYggKCNoOD6GAAH7CKKCHA.8KIHEJQT-IIGR68G.KNC@flex--shakeelb.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=3U3GiYggKCNoOD6GAAH7CKKCHA.8KIHEJQT-IIGR68G.KNC@flex--shakeelb.bounces.google.com X-Rspamd-Server: rspam11 X-Rspam-User: Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=myr+KdqG; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf21.hostedemail.com: domain of 3U3GiYggKCNoOD6GAAH7CKKCHA.8KIHEJQT-IIGR68G.KNC@flex--shakeelb.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=3U3GiYggKCNoOD6GAAH7CKKCHA.8KIHEJQT-IIGR68G.KNC@flex--shakeelb.bounces.google.com X-Stat-Signature: ah6kodxgfy4exb9hhgbk4u4ww4ir4qxe X-Rspamd-Queue-Id: 4A9F51C007F X-HE-Tag: 1654813012-869068 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jun 09, 2022 at 03:05:08PM -0700, Roman Gushchin wrote: > On Thu, Jun 09, 2022 at 07:12:21PM +0000, Shakeel Butt wrote: > > On Thu, Jun 09, 2022 at 10:56:09AM -0700, Roman Gushchin wrote: > > > On Thu, Jun 09, 2022 at 10:47:35AM -0700, Shakeel Butt wrote: > > > > On Thu, Jun 9, 2022 at 10:27 AM Roman Gushchin wrote: > > > > > > > > > [...] > > > > > +struct mem_cgroup *mem_cgroup_from_obj(void *p) > > > > > +{ > > > > > + struct folio *folio; > > > > > + > > > > > + if (mem_cgroup_disabled()) > > > > > + return NULL; > > > > > + > > > > > + if (unlikely(is_vmalloc_addr(p))) > > > > > + folio = page_folio(vmalloc_to_page(p)); > > > > > > > > Do we need to check for NULL from vmalloc_to_page(p)? > > > > > > Idk, can it realistically return NULL after is_vmalloc_addr() returned true? > > > I would be surprised, but maybe I'm missing something. > > > > is_vmalloc_addr() is simply checking the range and some buggy caller can > > provide an unmapped address within the range. Maybe VM_BUG_ON() should > > be good enough (though no strong opinion either way). > > No strong opinion here as well, but I think we don't have to be too defensive > here. Actually we'll know anyway, unlikely a null pointer dereference will be > unnoticed. And it's not different to calling mem_cgroup_from_obj() with some > random invalid address now. > Sounds good. You can add my ack when you send the official version of the patch.