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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8EC96CAC5BB for ; Wed, 1 Oct 2025 19:27:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C7D2D8E000B; Wed, 1 Oct 2025 15:26:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C552E8E0003; Wed, 1 Oct 2025 15:26:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 995B28E000B; Wed, 1 Oct 2025 15:26:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 831068E0003 for ; Wed, 1 Oct 2025 15:26:56 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 3B0051A0259 for ; Wed, 1 Oct 2025 19:26:56 +0000 (UTC) X-FDA: 83950528032.18.E7660BD Received: from mail-lf1-f47.google.com (mail-lf1-f47.google.com [209.85.167.47]) by imf28.hostedemail.com (Postfix) with ESMTP id 55351C0007 for ; Wed, 1 Oct 2025 19:26:54 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Cb1OdtoT; spf=pass (imf28.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.47 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1759346814; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=FuOmVyVQXsumRDN0WySluCU+eClCoeXEAXwSkpYGp4g=; b=2mytwmt8FGBs1cr3CfAW2nohLrbIr8zzh+2VoAW8qgd3xr59y2j8lQPtLPh6T0seJxUO2l PHaHr/IUHJFFXZh3yk6DrEWCPMC7m0lM0ms/sF8s8VPFxtebIRBgqjPCSDFOy12t6UjvfQ dziVRfMUzq82I68owptoyWBsxo3w8OU= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Cb1OdtoT; spf=pass (imf28.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.47 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1759346814; a=rsa-sha256; cv=none; b=0G9yx1JuXYpsBq0mhLpBjPAHDSWdScr4LGXqkLLHK/p1AsTXVj/3opjBunTrrLZhmn01Iw X5I+c6iuFr+NzPR4S/2KxozqKDqgR6L6mSijIabX/YCz+ATqINGjKbNhJUzGgUrbLBrlzL vvS3bYMSE6QFwZFALFBs0zIhAeedlPs= Received: by mail-lf1-f47.google.com with SMTP id 2adb3069b0e04-57e36125e8aso196935e87.2 for ; Wed, 01 Oct 2025 12:26:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1759346813; x=1759951613; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=FuOmVyVQXsumRDN0WySluCU+eClCoeXEAXwSkpYGp4g=; b=Cb1OdtoTsvoh6FfvRRY1ye1+gEPM28ahl/dPz7vS3LrX2R6Pop13QChm35MyMPUunw UDq0BT4rGGyAXbt6Z+JngM4AVtRmK22YmeO9Ip9ysKDe2nxXVJKo5qngmwZ/pkTWPoFr KR+t9PlOuiVQZ4oFScwMoXI3Hvsiscn/t+qEujjhreRQirjnLXe4Gf88PIYJpGAmYuaY qgNflYY5CXANoLcg+hV6J6VN99/xOAQJTeBHrxJMaVroxe4d/cwtdQU+UKNS+nuFGbL7 ZKaIdQg/W/jsW55+HksNg5IXgKxT3MUsdqbV/eAgaM2GORGgDw6oEASMrcDEU9raJ6Np /6HA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759346813; x=1759951613; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=FuOmVyVQXsumRDN0WySluCU+eClCoeXEAXwSkpYGp4g=; b=omvMXocbQ6uCvJf+7JZkbYT5AjefKV9bOFEu+5Md/8ElB53prhhl1txJv377fRYg9o JzdHo1MitQKSxlF/AfE9q1oh180vQEoTGQbZZQ9oI73frUCvz7NplLZM1Uv/LARrLMTg 6bulElT1+5BVY0uxWVb0S0U6I9PFkI9dUSAhGNfC2IwPVpH2NOXGNC6UuUe/NXZ+LSdz E1cSLldkao7Q+OT6FljvwfM1ZipOmZSDbY2R+wBWwgJ3sqtbyMcLKhKDHElu6jB1gbkI 1SGBNezzQg0h1aOvdBBtOXk5g6gNOV50Ar0F2k/06cju4lYMnIu2VESz+u9Nhx1XCP0c DI2g== X-Gm-Message-State: AOJu0Yy59iFduDJ4VuywtFJ85G+Blz6bSknNowmL5DWbc5pRq8zqkD7+ viOIWFkelJLnH0LDqu246aAQK4KDrs3qjblgglx/vM4upzxWaSpfdilJsM0NbqsNlqU= X-Gm-Gg: ASbGncuP2VxDTazZjeBoV/DIptEF/1vfJNcHiOmk+162PDjCXdsNjLGVFgZOhUePqyt uk3tPK6i2gKRJS7/N0wYfinq8gFx9fJS6wha/MOFIcY9leg5HlPjRQAfxsO2l5DdRmaquqYrU0e mSI7TlN6+Qtzwl9962eweOXJ4DKnj7KCz4eFZx6z/H4aqD+P4ZdT2pZ5IJzhS8lHaRJAtWmExBG nkM+r7t8E90TsGUpmjX1w7DyjSakAzVyJwhWGSDk9LgJymtqENlccLHwVyfQ1+RTdB6qNDszh6Q KpdgSMxuIL0Z6gD17mOlSGSmVFR54y/HLAhcJAGRPArFd3BS3sE3O5nDht4hj/d/fIqgT6C0ViO WduKqbH+LcF3uEuw8ZeybZtUXkza9k06myjQBczrtJDNle8QbtR4= X-Google-Smtp-Source: AGHT+IHZQHFJ0S5f1OcQHCfxhezQQXZPltJgxW4zc1dj/mXykewUGOJa1V03DnNOst08ID094gfxBA== X-Received: by 2002:a05:6512:3e0a:b0:578:ed03:7b70 with SMTP id 2adb3069b0e04-58af9f6afccmr1528057e87.28.1759346812509; Wed, 01 Oct 2025 12:26:52 -0700 (PDT) Received: from localhost.localdomain ([2001:9b1:d5a0:a500::24b]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-58b0112414fsm136627e87.28.2025.10.01.12.26.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Oct 2025 12:26:52 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: linux-mm@kvack.org, Andrew Morton Cc: Michal Hocko , Baoquan He , LKML , Uladzislau Rezki , Michal Hocko Subject: [PATCH v3 04/10] mm/vmalloc: Defer freeing partly initialized vm_struct Date: Wed, 1 Oct 2025 21:26:40 +0200 Message-ID: <20251001192647.195204-5-urezki@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251001192647.195204-1-urezki@gmail.com> References: <20251001192647.195204-1-urezki@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: u1b5ut9m6pjza5i7bxciybu1ncpfyr4w X-Rspam-User: X-Rspamd-Queue-Id: 55351C0007 X-Rspamd-Server: rspam04 X-HE-Tag: 1759346814-137800 X-HE-Meta: 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 yl6dCefZ 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 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: List-Subscribe: List-Unsubscribe: __vmalloc_area_node() may call free_vmap_area() or vfree() on error paths, both of which can sleep. This becomes problematic if the function is invoked from an atomic context, such as when GFP_ATOMIC or GFP_NOWAIT is passed via gfp_mask. To fix this, unify error paths and defer the cleanup of partly initialized vm_struct objects to a workqueue. This ensures that freeing happens in a process context and avoids invalid sleeps in atomic regions. Acked-by: Michal Hocko Reviewed-by: Baoquan He Signed-off-by: Uladzislau Rezki (Sony) --- include/linux/vmalloc.h | 6 +++++- mm/vmalloc.c | 34 +++++++++++++++++++++++++++++++--- 2 files changed, 36 insertions(+), 4 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index eb54b7b3202f..1e43181369f1 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -50,7 +50,11 @@ struct iov_iter; /* in uio.h */ #endif struct vm_struct { - struct vm_struct *next; + union { + struct vm_struct *next; /* Early registration of vm_areas. */ + struct llist_node llnode; /* Asynchronous freeing on error paths. */ + }; + void *addr; unsigned long size; unsigned long flags; diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d83c01caaabe..9e29dd767c41 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3687,6 +3687,35 @@ vm_area_alloc_pages(gfp_t gfp, int nid, return nr_allocated; } +static LLIST_HEAD(pending_vm_area_cleanup); +static void cleanup_vm_area_work(struct work_struct *work) +{ + struct vm_struct *area, *tmp; + struct llist_node *head; + + head = llist_del_all(&pending_vm_area_cleanup); + if (!head) + return; + + llist_for_each_entry_safe(area, tmp, head, llnode) { + if (!area->pages) + free_vm_area(area); + else + vfree(area->addr); + } +} + +/* + * Helper for __vmalloc_area_node() to defer cleanup + * of partially initialized vm_struct in error paths. + */ +static DECLARE_WORK(cleanup_vm_area, cleanup_vm_area_work); +static void defer_vm_area_cleanup(struct vm_struct *area) +{ + if (llist_add(&area->llnode, &pending_vm_area_cleanup)) + schedule_work(&cleanup_vm_area); +} + static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot, unsigned int page_shift, int node) @@ -3718,8 +3747,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, warn_alloc(gfp_mask, NULL, "vmalloc error: size %lu, failed to allocated page array size %lu", nr_small_pages * PAGE_SIZE, array_size); - free_vm_area(area); - return NULL; + goto fail; } set_vm_area_page_order(area, page_shift - PAGE_SHIFT); @@ -3796,7 +3824,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, return area->addr; fail: - vfree(area->addr); + defer_vm_area_cleanup(area); return NULL; } -- 2.47.3