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 75D9CCD4850 for ; Fri, 22 Sep 2023 19:06:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 10CC06B0305; Fri, 22 Sep 2023 15:06:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 096136B0307; Fri, 22 Sep 2023 15:06:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E79D36B0309; Fri, 22 Sep 2023 15:06:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id D9BFB6B0305 for ; Fri, 22 Sep 2023 15:06:29 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id AC760140158 for ; Fri, 22 Sep 2023 19:06:29 +0000 (UTC) X-FDA: 81265164498.04.0AAD040 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) by imf03.hostedemail.com (Postfix) with ESMTP id 196CE2001C for ; Fri, 22 Sep 2023 19:06:27 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=none; spf=none (imf03.hostedemail.com: domain of riel@shelob.surriel.com has no SPF policy when checking 96.67.55.147) smtp.mailfrom=riel@shelob.surriel.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695409588; a=rsa-sha256; cv=none; b=mtYz3AoYFeuJUeMrWcv+6QxtewtPNBUnwU/At8vXw4YGACDTD0VPm7HyWpv2MxA37qJU37 JxOnbyLIgcxunV6PdWy3y4qzLqCgidWnxjlg8m5hjpmmYZH7RtwlCxbsVjhsFURgdrp6Wx TBnEHs6a4+/nyPXvOS5GSKf0Sxvnv5g= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=none; spf=none (imf03.hostedemail.com: domain of riel@shelob.surriel.com has no SPF policy when checking 96.67.55.147) smtp.mailfrom=riel@shelob.surriel.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695409588; h=from:from:sender: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; bh=0txbjbIsHOWecgTF9GBcosacBBIoRx0J1P6iZProGvk=; b=oY4XkpubtWSEAKwmN/FOG3DT5hZW2IzkTX9PrqgDh/BIHnocsjGjKswQVd+yOy7hbjvqrW z5FGv8Yu0GdrErPWJmR/3kIMDvb5i9Q4m580wWnEpefDM+kJ/O3JQlhbLyZzd8pP4XVRet pJhJOVPR8cHhiuNHBocBnJ3ltFoSUR8= Received: from imladris.home.surriel.com ([10.0.13.28] helo=imladris.surriel.com) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qjlTP-0002Wy-1W; Fri, 22 Sep 2023 15:05:55 -0400 From: riel@surriel.com To: linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, muchun.song@linux.dev, mike.kravetz@oracle.com, leit@meta.com, willy@infradead.org, Rik van Riel Subject: [PATCH 1/3] hugetlbfs: extend hugetlb_vma_lock to private VMAs Date: Fri, 22 Sep 2023 15:02:29 -0400 Message-ID: <20230922190552.3963067-2-riel@surriel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230922190552.3963067-1-riel@surriel.com> References: <20230922190552.3963067-1-riel@surriel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 196CE2001C X-Stat-Signature: 8ues3b73usxe6cncz9nm3t1aeix9b73g X-HE-Tag: 1695409587-823983 X-HE-Meta: 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 P3BNqyRr n6paMxy1zMn2GZtJdtiGjS13Wkw0tCrr7oOtXYG7fQ8z7Ya8s9goarmgmvFcDbD8Dogx/ZquDHfFXat5GUj5Qkbsa91K/Aa64eNAkJhESdyd0liXdW4dY5DOg/bYLs74vcDQ0vLTWhyWVIa8Hs003VSODjkVirBZ+ozJ0ouLWPLzYSY58EkPB4qChsB2XWA5CVIJ5O9B+SJRkJNYO7zkM5zrfI2yt0MS9VoWTsgaubS+14NiRwZZ6AphuPeFLQgk+85U/0JmzXKKMlycB6SH0RGTpK3egI1vJ2CzfG/ubnJf9RbNaayYm6o43NrGt23daJRUhAbTLJYiEBiLF6GnxfgGcsQ== 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: From: Rik van Riel Extend the locking scheme used to protect shared hugetlb mappings from truncate vs page fault races, in order to protect private hugetlb mappings (with resv_map) against MADV_DONTNEED. Add a read-write semaphore to the resv_map data structure, and use that from the hugetlb_vma_(un)lock_* functions, in preparation for closing the race between MADV_DONTNEED and page faults. Signed-off-by: Rik van Riel --- include/linux/hugetlb.h | 6 ++++++ mm/hugetlb.c | 41 +++++++++++++++++++++++++++++++++++++---- 2 files changed, 43 insertions(+), 4 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 5b2626063f4f..694928fa06a3 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -60,6 +60,7 @@ struct resv_map { long adds_in_progress; struct list_head region_cache; long region_cache_count; + struct rw_semaphore rw_sema; #ifdef CONFIG_CGROUP_HUGETLB /* * On private mappings, the counter to uncharge reservations is stored @@ -1231,6 +1232,11 @@ static inline bool __vma_shareable_lock(struct vm_area_struct *vma) return (vma->vm_flags & VM_MAYSHARE) && vma->vm_private_data; } +static inline bool __vma_private_lock(struct vm_area_struct *vma) +{ + return (!(vma->vm_flags & VM_MAYSHARE)) && vma->vm_private_data; +} + /* * Safe version of huge_pte_offset() to check the locks. See comments * above huge_pte_offset(). diff --git a/mm/hugetlb.c b/mm/hugetlb.c index ba6d39b71cb1..ee7497f37098 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -97,6 +97,7 @@ static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma); static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma); static void hugetlb_unshare_pmds(struct vm_area_struct *vma, unsigned long start, unsigned long end); +static struct resv_map *vma_resv_map(struct vm_area_struct *vma); static inline bool subpool_is_free(struct hugepage_subpool *spool) { @@ -267,6 +268,10 @@ void hugetlb_vma_lock_read(struct vm_area_struct *vma) struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; down_read(&vma_lock->rw_sema); + } else if (__vma_private_lock(vma)) { + struct resv_map *resv_map = vma_resv_map(vma); + + down_read(&resv_map->rw_sema); } } @@ -276,6 +281,10 @@ void hugetlb_vma_unlock_read(struct vm_area_struct *vma) struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; up_read(&vma_lock->rw_sema); + } else if (__vma_private_lock(vma)) { + struct resv_map *resv_map = vma_resv_map(vma); + + up_read(&resv_map->rw_sema); } } @@ -285,6 +294,10 @@ void hugetlb_vma_lock_write(struct vm_area_struct *vma) struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; down_write(&vma_lock->rw_sema); + } else if (__vma_private_lock(vma)) { + struct resv_map *resv_map = vma_resv_map(vma); + + down_write(&resv_map->rw_sema); } } @@ -294,17 +307,27 @@ void hugetlb_vma_unlock_write(struct vm_area_struct *vma) struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; up_write(&vma_lock->rw_sema); + } else if (__vma_private_lock(vma)) { + struct resv_map *resv_map = vma_resv_map(vma); + + up_write(&resv_map->rw_sema); } } int hugetlb_vma_trylock_write(struct vm_area_struct *vma) { - struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; - if (!__vma_shareable_lock(vma)) - return 1; + if (__vma_shareable_lock(vma)) { + struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; - return down_write_trylock(&vma_lock->rw_sema); + return down_write_trylock(&vma_lock->rw_sema); + } else if (__vma_private_lock(vma)) { + struct resv_map *resv_map = vma_resv_map(vma); + + return down_write_trylock(&resv_map->rw_sema); + } + + return 1; } void hugetlb_vma_assert_locked(struct vm_area_struct *vma) @@ -313,6 +336,10 @@ void hugetlb_vma_assert_locked(struct vm_area_struct *vma) struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; lockdep_assert_held(&vma_lock->rw_sema); + } else if (__vma_private_lock(vma)) { + struct resv_map *resv_map = vma_resv_map(vma); + + lockdep_assert_held(&resv_map->rw_sema); } } @@ -345,6 +372,11 @@ static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma) struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; __hugetlb_vma_unlock_write_put(vma_lock); + } else if (__vma_private_lock(vma)) { + struct resv_map *resv_map = vma_resv_map(vma); + + /* no free for anon vmas, but still need to unlock */ + up_write(&resv_map->rw_sema); } } @@ -1068,6 +1100,7 @@ struct resv_map *resv_map_alloc(void) kref_init(&resv_map->refs); spin_lock_init(&resv_map->lock); INIT_LIST_HEAD(&resv_map->regions); + init_rwsem(&resv_map->rw_sema); resv_map->adds_in_progress = 0; /* -- 2.41.0