From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 099/128] mm: only allow page table mappings for built-in zsmalloc Date: Mon, 01 Jun 2020 21:50:58 -0700 Message-ID: <20200602045058.uysN1AQ1j%akpm@linux-foundation.org> References: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:43402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726122AbgFBEvA (ORCPT ); Tue, 2 Jun 2020 00:51:00 -0400 In-Reply-To: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: airlied@linux.ie, akpm@linux-foundation.org, benh@kernel.crashing.org, borntraeger@de.ibm.com, catalin.marinas@arm.com, christophe.leroy@c-s.fr, daniel.vetter@ffwll.ch, daniel@ffwll.ch, gor@linux.ibm.com, gregkh@linuxfoundation.org, haiyangz@microsoft.com, hannes@cmpxchg.org, hch@lst.de, heiko.carstens@de.ibm.com, kys@microsoft.com, labbott@redhat.com, linux-mm@kvack.org, mark.rutland@arm.com, mikelley@microsoft.com, minchan@kernel.org, mm-commits@vger.kernel.org, ngupta@vflare.org, paulus@ozlabs.org, peterz@infradead.org, robin.murphy@arm.com, sakari.ailus@linux.intel.com, sthemmin@microsoft.com, sumit.semwal@linaro.org, torvalds@linux-foundation.org, wei.liu@kernel.org, will@kernel.org, xiang@kernel.org From: Christoph Hellwig Subject: mm: only allow page table mappings for built-in zsmalloc This allows to unexport map_vm_area and unmap_kernel_range, which are rather deep internal and should not be available to modules, as they for example allow fine grained control of mapping permissions, and also allow splitting the setup of a vmalloc area and the actual mapping and thus expose vmalloc internals. zsmalloc is typically built-in and continues to work (just like the percpu-vm code using a similar patter), while modular zsmalloc also continues to work, but must use copies. Link: http://lkml.kernel.org/r/20200414131348.444715-12-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Peter Zijlstra (Intel) Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Daniel Vetter Cc: Daniel Vetter Cc: David Airlie Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Johannes Weiner Cc: "K. Y. Srinivasan" Cc: Laura Abbott Cc: Mark Rutland Cc: Michael Kelley Cc: Minchan Kim Cc: Nitin Gupta Cc: Robin Murphy Cc: Sakari Ailus Cc: Stephen Hemminger Cc: Sumit Semwal Cc: Wei Liu Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Heiko Carstens Cc: Paul Mackerras Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton --- mm/Kconfig | 2 +- mm/vmalloc.c | 2 -- 2 files changed, 1 insertion(+), 3 deletions(-) --- a/mm/Kconfig~mm-only-allow-page-table-mappings-for-built-in-zsmalloc +++ a/mm/Kconfig @@ -707,7 +707,7 @@ config ZSMALLOC config ZSMALLOC_PGTABLE_MAPPING bool "Use page table mapping to access object in zsmalloc" - depends on ZSMALLOC + depends on ZSMALLOC=y help By default, zsmalloc uses a copy-based object mapping method to access allocations that span two pages. However, if a particular --- a/mm/vmalloc.c~mm-only-allow-page-table-mappings-for-built-in-zsmalloc +++ a/mm/vmalloc.c @@ -2047,7 +2047,6 @@ void unmap_kernel_range(unsigned long ad vunmap_page_range(addr, end); flush_tlb_kernel_range(addr, end); } -EXPORT_SYMBOL_GPL(unmap_kernel_range); int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages) { @@ -2059,7 +2058,6 @@ int map_vm_area(struct vm_struct *area, return err > 0 ? 0 : err; } -EXPORT_SYMBOL_GPL(map_vm_area); static inline void setup_vmalloc_vm_locked(struct vm_struct *vm, struct vmap_area *va, unsigned long flags, const void *caller) _