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=-11.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 C7E01C433E6 for ; Fri, 10 Jul 2020 20:00:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 82CBB2075D for ; Fri, 10 Jul 2020 20:00:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="R65UmsUf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82CBB2075D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id F24DB8D0002; Fri, 10 Jul 2020 16:00:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EAEA08D0001; Fri, 10 Jul 2020 16:00:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D76488D0002; Fri, 10 Jul 2020 16:00:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0183.hostedemail.com [216.40.44.183]) by kanga.kvack.org (Postfix) with ESMTP id BC3928D0001 for ; Fri, 10 Jul 2020 16:00:38 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 3F4CB45B3 for ; Fri, 10 Jul 2020 20:00:38 +0000 (UTC) X-FDA: 77023233756.26.chin78_1e11a9b26ed1 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id 36DC01804A30B for ; Fri, 10 Jul 2020 20:00:37 +0000 (UTC) X-HE-Tag: chin78_1e11a9b26ed1 X-Filterd-Recvd-Size: 5579 Received: from mail-lf1-f68.google.com (mail-lf1-f68.google.com [209.85.167.68]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Fri, 10 Jul 2020 20:00:36 +0000 (UTC) Received: by mail-lf1-f68.google.com with SMTP id s16so3837932lfp.12 for ; Fri, 10 Jul 2020 13:00:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=VGGNYIiYtfiau26k3ZU9GdTLqalXbW1YfEG5XzhHZro=; b=R65UmsUf6sEGi28q+oBAELsbkXGXV7TsSBUSRYm+1Fi5AuTRLgWzkg0hajhjTZwYpJ kbwYWolWZkH2JZ0b4Ne4dTX7ywYrpsdYY4ag4HfmAAxpPbgd6n/b3mUKo2+XciPMIxN4 GsKqqa12+SMKjtSgDqDYHyi3A3RMe1tDJRpK5Ki0GKjipHc9YbrjbyzgaoLEHJQ0RkJi 5WfrPH88+Z4U5FkO2t/3LYigg4IZN8rTje1Yp4pq3qSWKvFYofS3CuA+3ffOtTbXWxut xyJRHTiWGXlRVJuUu4f1ahqyNyDhg0xRzDX2n5afNGcvdcPWBhK3frGvzAIIcadFwbjz OsEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=VGGNYIiYtfiau26k3ZU9GdTLqalXbW1YfEG5XzhHZro=; b=BdkNx/qwi/dJEWps02Ea7/yQ0j5VCIY1Ol1usmDIa2nLUw2rjlMlOy+BisDKJ2Aap+ o5W0B2Fj5E/g2rZiFBrXxO2NOJsZBU5p0vTogXpibwP7U0G1ScksIbisftA+Lh8aaXRX 4bB8ZAzN5lRlRil9Ei5f1RhufglSDK9NZrNOPF1WMRxNMhpEFmQe+4SQoxapnQ5dtRR7 mUP5UQT21wBRvL0qje51k0bb2IXyBugPfXFq7Yqrn5FbCU+BCHPa1v7ISQ+lyD7Gb5zP 7Xgb0qmyZfUb0RdbV7LPJN3vRwlVjCfOTfUyTGu2AE0HgE0oxek+dN/EDP5cbvXSOitQ UWhA== X-Gm-Message-State: AOAM532FLmzzj79SQvjXuXIRaEmZYoWNt6/yHD0SEHZqz0BV7Z5bwvv3 gzQAOF/JVBAB6Uugbao6ohg= X-Google-Smtp-Source: ABdhPJzDVAgLOZni4F+IW3+70sdYnze8gvj4viMEUGip9JI1iibh1hU/HLt771jJFm5tRv+H8zzIoA== X-Received: by 2002:a05:6512:20f:: with SMTP id a15mr44267476lfo.118.1594411234831; Fri, 10 Jul 2020 13:00:34 -0700 (PDT) Received: from pc636 (h5ef52e31.seluork.dyn.perspektivbredband.net. [94.245.46.49]) by smtp.gmail.com with ESMTPSA id g142sm2511187lfd.41.2020.07.10.13.00.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jul 2020 13:00:32 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Fri, 10 Jul 2020 22:00:30 +0200 To: Matthew Wilcox Cc: "Uladzislau Rezki (Sony)" , Andrew Morton , linux-mm@kvack.org, LKML , Hillf Danton , Michal Hocko , Oleksiy Avramchenko , Steven Rostedt Subject: Re: [PATCH 1/1] mm/vmalloc.c: Add an error message if two areas overlap Message-ID: <20200710200030.GB19487@pc636> References: <20200710194042.2510-1-urezki@gmail.com> <20200710194406.GP12769@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200710194406.GP12769@casper.infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: 36DC01804A30B X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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 Fri, Jul 10, 2020 at 08:44:06PM +0100, Matthew Wilcox wrote: > On Fri, Jul 10, 2020 at 09:40:42PM +0200, Uladzislau Rezki (Sony) wrote: > > Before triggering a BUG() it would be useful to understand > > how two areas overlap between each other. Print information > > about start/end addresses of both VAs and their addresses. > > > > For example if both are identical it could mean double free. > > > > Signed-off-by: Uladzislau Rezki (Sony) > > --- > > mm/vmalloc.c | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index 5a2b55c8dd9a..1679b01febcd 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -549,8 +549,13 @@ find_va_links(struct vmap_area *va, > > else if (va->va_end > tmp_va->va_start && > > va->va_start >= tmp_va->va_end) > > link = &(*link)->rb_right; > > - else > > + else { > > + pr_err("Overlaps: 0x%px(0x%lx-0x%lx), 0x%px(0x%lx-0x%lx)\n", > > + va, va->va_start, va->va_end, tmp_va, > > + tmp_va->va_start, tmp_va->va_end); > > It might be helpful to have a "vmalloc:" prefix to that string to indicate > where to start searching. And I don't think we're supposed to use %px > without a really good justification these days. > That makes sense, i will add such prefix for sure. As for %px i can just use a casting to (unsigned long) and 0x%lx prefix. > > Can we do without the BUG()? Maybe just break out and decline to insert > the conflicting range? > When i developed that logic, i was thinking about that but for some reason i went with BUG_ON(), do not remember why. But i agree we shold avoid of it. Let me think about it one more time. > > BUG(); > > + } > > } while (*link); > > > > *parent = &tmp_va->rb_node; > > @@ -1993,6 +1998,9 @@ static void vmap_init_free_space(void) > > insert_vmap_area_augment(free, NULL, > > &free_vmap_area_root, > > &free_vmap_area_list); > > + insert_vmap_area_augment(free, NULL, > > + &free_vmap_area_root, > > + &free_vmap_area_list); > > This is surely testing code that you forgot to delete? > Yes, i forgot to remove it. Thanks for your comments! -- Vlad Rezki