From patchwork Tue Jul 20 15:09:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 12388505 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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 8C6FFC636C9 for ; Tue, 20 Jul 2021 15:10:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 23038610CC for ; Tue, 20 Jul 2021 15:10:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23038610CC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D1DC16B0036; Tue, 20 Jul 2021 11:10:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CF4DC6B005D; Tue, 20 Jul 2021 11:10:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBD456B006C; Tue, 20 Jul 2021 11:10:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0154.hostedemail.com [216.40.44.154]) by kanga.kvack.org (Postfix) with ESMTP id 887E86B0036 for ; Tue, 20 Jul 2021 11:10:07 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 0671F1851C328 for ; Tue, 20 Jul 2021 15:10:06 +0000 (UTC) X-FDA: 78383301612.11.8667B50 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf14.hostedemail.com (Postfix) with ESMTP id 668E560022EF for ; Tue, 20 Jul 2021 15:10:05 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id DB22D610A0; Tue, 20 Jul 2021 15:10:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626793804; bh=waF0yGZ/74FCKFwfsSHiFG6HeMntkph0RFHmK2X6nWk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wr6FlViYO8SKfm17hVN2pUi5fGp+Fk/QoWvAgyq3TtIVH/9dDFxOXPCzB/PejgO0h 8Qq/kxx409pXMf2qcAkZDEJUP3P3OhSYpV98cvMXDLpN16PoIW0oqNMuitJhNn7Kbg 8KF+V+QhXxbxgwvQl2ACrYt65CYiMfiTto/fmTyiA6ONeCuH7P9eqSPeOtWrxanZwz +t9tPZ6V2N5AFfRROR65fSgKOoRmHIZyG8v+8foim41EfKnVRb0QmOwR+A+AtmsArg k1Si2b+axOnw7C72U5GDa35Pk31LCRaatyrxS5eemD40HnSs09wom1B6xJ30duAFln SNBm8x0hT5m+g== From: Arnd Bergmann To: linux-arch@vger.kernel.org Cc: Arnd Bergmann , Christoph Hellwig , Alexander Viro , Andrew Morton , Borislav Petkov , Brian Gerst , Eric Biederman , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , Linux ARM , linux-kernel@vger.kernel.org, Linux-MM , kexec@lists.infradead.org, Christoph Hellwig Subject: [PATCH v4 2/4] mm: simplify compat_sys_move_pages Date: Tue, 20 Jul 2021 17:09:48 +0200 Message-Id: <20210720150950.3669610-3-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210720150950.3669610-1-arnd@kernel.org> References: <20210720150950.3669610-1-arnd@kernel.org> MIME-Version: 1.0 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 668E560022EF X-Stat-Signature: 54r7wefwd93qasdh5zcgu5axcso9kcda Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Wr6FlViY; spf=pass (imf14.hostedemail.com: domain of arnd@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=arnd@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-HE-Tag: 1626793805-239713 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: Arnd Bergmann The compat move_pages() implementation uses compat_alloc_user_space() for converting the pointer array. Moving the compat handling into the function itself is a bit simpler and lets us avoid the compat_alloc_user_space() call. Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann --- mm/migrate.c | 45 ++++++++++++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 15 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 34a9ad3e0a4f..60634d2653b9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1820,6 +1820,23 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages, mmap_read_unlock(mm); } +static int get_compat_pages_array(const void __user *chunk_pages[], + const void __user * __user *pages, + unsigned long chunk_nr) +{ + compat_uptr_t __user *pages32 = (compat_uptr_t __user *)pages; + compat_uptr_t p; + int i; + + for (i = 0; i < chunk_nr; i++) { + if (get_user(p, pages32 + i)) + return -EFAULT; + chunk_pages[i] = compat_ptr(p); + } + + return 0; +} + /* * Determine the nodes of a user array of pages and store it in * a user array of status. @@ -1839,8 +1856,15 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages, if (chunk_nr > DO_PAGES_STAT_CHUNK_NR) chunk_nr = DO_PAGES_STAT_CHUNK_NR; - if (copy_from_user(chunk_pages, pages, chunk_nr * sizeof(*chunk_pages))) - break; + if (in_compat_syscall()) { + if (get_compat_pages_array(chunk_pages, pages, + chunk_nr)) + break; + } else { + if (copy_from_user(chunk_pages, pages, + chunk_nr * sizeof(*chunk_pages))) + break; + } do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status); @@ -1945,23 +1969,14 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages, #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages, - compat_uptr_t __user *, pages32, + compat_uptr_t __user *, pages, const int __user *, nodes, int __user *, status, int, flags) { - const void __user * __user *pages; - int i; - - pages = compat_alloc_user_space(nr_pages * sizeof(void *)); - for (i = 0; i < nr_pages; i++) { - compat_uptr_t p; - - if (get_user(p, pages32 + i) || - put_user(compat_ptr(p), pages + i)) - return -EFAULT; - } - return kernel_move_pages(pid, nr_pages, pages, nodes, status, flags); + return kernel_move_pages(pid, nr_pages, + (const void __user *__user *)pages, + nodes, status, flags); } #endif /* CONFIG_COMPAT */