From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 089/128] x86/hyperv: use vmalloc_exec for the hypercall page Date: Mon, 01 Jun 2020 21:50:15 -0700 Message-ID: <20200602045015.FWX-6Gmer%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]:41832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725793AbgFBEuR (ORCPT ); Tue, 2 Jun 2020 00:50:17 -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: x86/hyperv: use vmalloc_exec for the hypercall page Patch series "decruft the vmalloc API", v2. Peter noticed that with some dumb luck you can toast the kernel address space with exported vmalloc symbols. I used this as an opportunity to decruft the vmalloc.c API and make it much more systematic. This also removes any chance to create vmalloc mappings outside the designated areas or using executable permissions from modules. Besides that it removes more than 300 lines of code. This patch (of 29): Use the designated helper for allocating executable kernel memory, and remove the now unused PAGE_KERNEL_RX define. Link: http://lkml.kernel.org/r/20200414131348.444715-1-hch@lst.de Link: http://lkml.kernel.org/r/20200414131348.444715-2-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Michael Kelley Acked-by: Wei Liu 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: Minchan Kim Cc: Nitin Gupta Cc: Robin Murphy Cc: Sakari Ailus Cc: Stephen Hemminger Cc: Sumit Semwal Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Catalin Marinas Cc: Will Deacon Cc: Heiko Carstens Cc: Vasily Gorbik Signed-off-by: Andrew Morton --- arch/x86/hyperv/hv_init.c | 2 +- arch/x86/include/asm/pgtable_types.h | 2 -- 2 files changed, 1 insertion(+), 3 deletions(-) --- a/arch/x86/hyperv/hv_init.c~x86-hyperv-use-vmalloc_exec-for-the-hypercall-page +++ a/arch/x86/hyperv/hv_init.c @@ -379,7 +379,7 @@ void __init hyperv_init(void) guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id); - hv_hypercall_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX); + hv_hypercall_pg = vmalloc_exec(PAGE_SIZE); if (hv_hypercall_pg == NULL) { wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0); goto remove_cpuhp_state; --- a/arch/x86/include/asm/pgtable_types.h~x86-hyperv-use-vmalloc_exec-for-the-hypercall-page +++ a/arch/x86/include/asm/pgtable_types.h @@ -194,7 +194,6 @@ enum page_cache_mode { #define _PAGE_TABLE_NOENC (__PP|__RW|_USR|___A| 0|___D| 0| 0) #define _PAGE_TABLE (__PP|__RW|_USR|___A| 0|___D| 0| 0| _ENC) #define __PAGE_KERNEL_RO (__PP| 0| 0|___A|__NX|___D| 0|___G) -#define __PAGE_KERNEL_RX (__PP| 0| 0|___A| 0|___D| 0|___G) #define __PAGE_KERNEL_NOCACHE (__PP|__RW| 0|___A|__NX|___D| 0|___G| __NC) #define __PAGE_KERNEL_VVAR (__PP| 0|_USR|___A|__NX|___D| 0|___G) #define __PAGE_KERNEL_LARGE (__PP|__RW| 0|___A|__NX|___D|_PSE|___G) @@ -220,7 +219,6 @@ enum page_cache_mode { #define PAGE_KERNEL_RO __pgprot_mask(__PAGE_KERNEL_RO | _ENC) #define PAGE_KERNEL_EXEC __pgprot_mask(__PAGE_KERNEL_EXEC | _ENC) #define PAGE_KERNEL_EXEC_NOENC __pgprot_mask(__PAGE_KERNEL_EXEC | 0) -#define PAGE_KERNEL_RX __pgprot_mask(__PAGE_KERNEL_RX | _ENC) #define PAGE_KERNEL_NOCACHE __pgprot_mask(__PAGE_KERNEL_NOCACHE | _ENC) #define PAGE_KERNEL_LARGE __pgprot_mask(__PAGE_KERNEL_LARGE | _ENC) #define PAGE_KERNEL_LARGE_EXEC __pgprot_mask(__PAGE_KERNEL_LARGE_EXEC | _ENC) _