From patchwork Mon May 20 23:38:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Edgecombe, Rick P" X-Patchwork-Id: 1102434 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 457FjJ2wTyz9sBp for ; Tue, 21 May 2019 09:39:16 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727289AbfETXjG (ORCPT ); Mon, 20 May 2019 19:39:06 -0400 Received: from mga03.intel.com ([134.134.136.65]:25217 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727216AbfETXjF (ORCPT ); Mon, 20 May 2019 19:39:05 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 May 2019 16:39:05 -0700 X-ExtLoop1: 1 Received: from rpedgeco-mobl.amr.corp.intel.com (HELO localhost.intel.com) ([10.254.114.95]) by fmsmga008.fm.intel.com with ESMTP; 20 May 2019 16:39:04 -0700 From: Rick Edgecombe To: linux-kernel@vger.kernel.org, peterz@infradead.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, luto@amacapital.net Cc: dave.hansen@intel.com, namit@vmware.com, davem@davemloft.net, Rick Edgecombe , Meelis Roos , Borislav Petkov , Andy Lutomirski , Ingo Molnar , Rick Edgecombe Subject: [PATCH v2 1/2] vmalloc: Fix calculation of direct map addr range Date: Mon, 20 May 2019 16:38:40 -0700 Message-Id: <20190520233841.17194-2-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190520233841.17194-1-rick.p.edgecombe@intel.com> References: <20190520233841.17194-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Rick Edgecombe The calculation of the direct map address range to flush was wrong. This could cause problems on x86 if a RO direct map alias ever got loaded into the TLB. This shouldn't normally happen, but it could cause the permissions to remain RO on the direct map alias, and then the page would return from the page allocator to some other component as RO and cause a crash. So fix fix the address range calculation so the flush will include the direct map range. Fixes: 868b104d7379 ("mm/vmalloc: Add flag for freeing of special permsissions") Cc: Meelis Roos Cc: Peter Zijlstra Cc: "David S. Miller" Cc: Dave Hansen Cc: Borislav Petkov Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Nadav Amit Signed-off-by: Rick Edgecombe --- mm/vmalloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index c42872ed82ac..836888ae01f6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2159,9 +2159,10 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) * the vm_unmap_aliases() flush includes the direct map. */ for (i = 0; i < area->nr_pages; i++) { - if (page_address(area->pages[i])) { + addr = (unsigned long)page_address(area->pages[i]); + if (addr) { start = min(addr, start); - end = max(addr, end); + end = max(addr + PAGE_SIZE, end); } } From patchwork Mon May 20 23:38:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Edgecombe, Rick P" X-Patchwork-Id: 1102432 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 457FjH3WHSz9s9y for ; Tue, 21 May 2019 09:39:15 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727338AbfETXjH (ORCPT ); Mon, 20 May 2019 19:39:07 -0400 Received: from mga03.intel.com ([134.134.136.65]:25217 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727216AbfETXjG (ORCPT ); Mon, 20 May 2019 19:39:06 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 May 2019 16:39:06 -0700 X-ExtLoop1: 1 Received: from rpedgeco-mobl.amr.corp.intel.com (HELO localhost.intel.com) ([10.254.114.95]) by fmsmga008.fm.intel.com with ESMTP; 20 May 2019 16:39:05 -0700 From: Rick Edgecombe To: linux-kernel@vger.kernel.org, peterz@infradead.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, luto@amacapital.net Cc: dave.hansen@intel.com, namit@vmware.com, davem@davemloft.net, Rick Edgecombe , Meelis Roos , Borislav Petkov , Andy Lutomirski , Ingo Molnar , Rick Edgecombe Subject: [PATCH v2 2/2] vmalloc: Remove work as from vfree path Date: Mon, 20 May 2019 16:38:41 -0700 Message-Id: <20190520233841.17194-3-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190520233841.17194-1-rick.p.edgecombe@intel.com> References: <20190520233841.17194-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Rick Edgecombe Calling vm_unmap_alias() in vm_remove_mappings() could potentially be a lot of work to do on a free operation. Simply flushing the TLB instead of the whole vm_unmap_alias() operation makes the frees faster and pushes the heavy work to happen on allocation where it would be more expected. In addition to the extra work, vm_unmap_alias() takes some locks including a long hold of vmap_purge_lock, which will make all other VM_FLUSH_RESET_PERMS vfrees wait while the purge operation happens. Lastly, page_address() can involve locking and lookups on some configurations, so skip calling this by exiting out early when !CONFIG_ARCH_HAS_SET_DIRECT_MAP. Cc: Meelis Roos Cc: Peter Zijlstra Cc: "David S. Miller" Cc: Dave Hansen Cc: Borislav Petkov Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Nadav Amit Signed-off-by: Rick Edgecombe --- mm/vmalloc.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 836888ae01f6..8d03427626dc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2122,9 +2122,10 @@ static inline void set_area_direct_map(const struct vm_struct *area, /* Handle removing and resetting vm mappings related to the vm_struct. */ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) { + const bool has_set_direct = IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP); + const bool flush_reset = area->flags & VM_FLUSH_RESET_PERMS; unsigned long addr = (unsigned long)area->addr; - unsigned long start = ULONG_MAX, end = 0; - int flush_reset = area->flags & VM_FLUSH_RESET_PERMS; + unsigned long start = addr, end = addr + area->size; int i; /* @@ -2133,7 +2134,7 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) * This is concerned with resetting the direct map any an vm alias with * execute permissions, without leaving a RW+X window. */ - if (flush_reset && !IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { + if (flush_reset && !has_set_direct) { set_memory_nx(addr, area->nr_pages); set_memory_rw(addr, area->nr_pages); } @@ -2146,17 +2147,18 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) /* * If not deallocating pages, just do the flush of the VM area and - * return. + * return. If the arch doesn't have set_direct_map_(), also skip the + * below work. */ - if (!deallocate_pages) { - vm_unmap_aliases(); + if (!deallocate_pages || !has_set_direct) { + flush_tlb_kernel_range(start, end); return; } /* * If execution gets here, flush the vm mapping and reset the direct * map. Find the start and end range of the direct mappings to make sure - * the vm_unmap_aliases() flush includes the direct map. + * the flush_tlb_kernel_range() includes the direct map. */ for (i = 0; i < area->nr_pages; i++) { addr = (unsigned long)page_address(area->pages[i]); @@ -2172,7 +2174,7 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) * reset the direct map permissions to the default. */ set_area_direct_map(area, set_direct_map_invalid_noflush); - _vm_unmap_aliases(start, end, 1); + flush_tlb_kernel_range(start, end); set_area_direct_map(area, set_direct_map_default_noflush); }