From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 36EFE6B0253 for ; Mon, 16 Apr 2018 11:25:53 -0400 (EDT) Received: by mail-wr0-f198.google.com with SMTP id m7so13317746wrb.16 for ; Mon, 16 Apr 2018 08:25:53 -0700 (PDT) Received: from theia.8bytes.org (8bytes.org. [2a01:238:4383:600:38bc:a715:4b6d:a889]) by mx.google.com with ESMTPS id w55si3016905edd.51.2018.04.16.08.25.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Apr 2018 08:25:51 -0700 (PDT) From: Joerg Roedel Subject: [PATCH 29/35] x86/ldt: Reserve address-space range on 32 bit for the LDT Date: Mon, 16 Apr 2018 17:25:17 +0200 Message-Id: <1523892323-14741-30-git-send-email-joro@8bytes.org> In-Reply-To: <1523892323-14741-1-git-send-email-joro@8bytes.org> References: <1523892323-14741-1-git-send-email-joro@8bytes.org> Sender: owner-linux-mm@kvack.org List-ID: To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , Pavel Machek , "David H . Gutteridge" , jroedel@suse.de, joro@8bytes.org From: Joerg Roedel Reserve 2MB/4MB of address-space for mapping the LDT to user-space on 32 bit PTI kernels. Signed-off-by: Joerg Roedel --- arch/x86/include/asm/pgtable_32_types.h | 7 +++++-- arch/x86/mm/dump_pagetables.c | 9 +++++++++ 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h index e3225e8..1fa76c9 100644 --- a/arch/x86/include/asm/pgtable_32_types.h +++ b/arch/x86/include/asm/pgtable_32_types.h @@ -50,13 +50,16 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */ ((FIXADDR_TOT_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1)) \ & PMD_MASK) -#define PKMAP_BASE \ +#define LDT_BASE_ADDR \ ((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK) +#define PKMAP_BASE \ + ((LDT_BASE_ADDR - PAGE_SIZE) & PMD_MASK) + #ifdef CONFIG_HIGHMEM # define VMALLOC_END (PKMAP_BASE - 2 * PAGE_SIZE) #else -# define VMALLOC_END (CPU_ENTRY_AREA_BASE - 2 * PAGE_SIZE) +# define VMALLOC_END (LDT_BASE_ADDR - 2 * PAGE_SIZE) #endif #define MODULES_VADDR VMALLOC_START diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index 84498da..956c886 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -122,6 +122,9 @@ enum address_markers_idx { #ifdef CONFIG_HIGHMEM PKMAP_BASE_NR, #endif +#ifdef CONFIG_MODIFY_LDT_SYSCALL + LDT_NR, +#endif CPU_ENTRY_AREA_NR, FIXADDR_START_NR, END_OF_SPACE_NR, @@ -135,6 +138,9 @@ static struct addr_marker address_markers[] = { #ifdef CONFIG_HIGHMEM [PKMAP_BASE_NR] = { 0UL, "Persistent kmap() Area" }, #endif +#ifdef CONFIG_MODIFY_LDT_SYSCALL + [LDT_NR] = { 0UL, "LDT remap" }, +#endif [CPU_ENTRY_AREA_NR] = { 0UL, "CPU entry area" }, [FIXADDR_START_NR] = { 0UL, "Fixmap area" }, [END_OF_SPACE_NR] = { -1, NULL } @@ -608,6 +614,9 @@ static int __init pt_dump_init(void) # endif address_markers[FIXADDR_START_NR].start_address = FIXADDR_START; address_markers[CPU_ENTRY_AREA_NR].start_address = CPU_ENTRY_AREA_BASE; +# ifdef CONFIG_MODIFY_LDT_SYSCALL + address_markers[LDT_NR].start_address = LDT_BASE_ADDR; +# endif #endif return 0; } -- 2.7.4