| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <1409675865-11608-4-git-send-email-david.vrabel@citrix.com>
Date: Tue, 2 Sep 2014 17:37:45 +0100
From: David Vrabel <david.vrabel@...rix.com>
To: <linux-kernel@...r.kernel.org>
CC: David Vrabel <david.vrabel@...rix.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>, <x86@...nel.org>,
<xen-devel@...ts.xenproject.org>,
"Konrad Rzeszutek Wilk" <konrad.wilk@...cle.com>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: [PATCH 3/3] x86: remove the Xen-specific _PAGE_IOMAP PTE flag
The _PAGE_IO_MAP PTE flag was only used by Xen PV guests to mark PTEs
that were used to map I/O regions that are 1:1 in the p2m. This
allowed Xen to obtain the correct PFN when converting the MFNs read
from a PTE back to their PFN.
Xen guests no longer use _PAGE_IOMAP for this. Instead mfn_to_pfn()
returns the correct PFN by using a combination of the m2p and p2m to
determine if an MFN corresponds to a 1:1 mapping in the the p2m.
Remove _PAGE_IOMAP, replacing it with _PAGE_UNUSED2 to allow for
future uses of the PTE flag.
Signed-off-by: David Vrabel <david.vrabel@...rix.com>
Acked-by: "H. Peter Anvin" <hpa@...or.com>
---
arch/x86/include/asm/pgtable_types.h | 11 +++++------
arch/x86/mm/init_32.c | 2 +-
arch/x86/mm/init_64.c | 2 +-
arch/x86/pci/i386.c | 2 --
arch/x86/xen/enlighten.c | 2 --
5 files changed, 7 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index f216963..cee83b2 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -23,7 +23,6 @@
#define _PAGE_BIT_SPECIAL _PAGE_BIT_SOFTW1
#define _PAGE_BIT_CPA_TEST _PAGE_BIT_SOFTW1
#define _PAGE_BIT_SPLITTING _PAGE_BIT_SOFTW2 /* only valid on a PSE pmd */
-#define _PAGE_BIT_IOMAP _PAGE_BIT_SOFTW2 /* flag used to indicate IO mapping */
#define _PAGE_BIT_HIDDEN _PAGE_BIT_SOFTW3 /* hidden by kmemcheck */
#define _PAGE_BIT_SOFT_DIRTY _PAGE_BIT_SOFTW3 /* software dirty tracking */
#define _PAGE_BIT_NX 63 /* No execute: only valid after cpuid check */
@@ -52,7 +51,7 @@
#define _PAGE_PSE (_AT(pteval_t, 1) << _PAGE_BIT_PSE)
#define _PAGE_GLOBAL (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL)
#define _PAGE_SOFTW1 (_AT(pteval_t, 1) << _PAGE_BIT_SOFTW1)
-#define _PAGE_IOMAP (_AT(pteval_t, 1) << _PAGE_BIT_IOMAP)
+#define _PAGE_SOFTW2 (_AT(pteval_t, 1) << _PAGE_BIT_SOFTW2)
#define _PAGE_PAT (_AT(pteval_t, 1) << _PAGE_BIT_PAT)
#define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE)
#define _PAGE_SPECIAL (_AT(pteval_t, 1) << _PAGE_BIT_SPECIAL)
@@ -168,10 +167,10 @@
#define __PAGE_KERNEL_LARGE_NOCACHE (__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE)
#define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
-#define __PAGE_KERNEL_IO (__PAGE_KERNEL | _PAGE_IOMAP)
-#define __PAGE_KERNEL_IO_NOCACHE (__PAGE_KERNEL_NOCACHE | _PAGE_IOMAP)
-#define __PAGE_KERNEL_IO_UC_MINUS (__PAGE_KERNEL_UC_MINUS | _PAGE_IOMAP)
-#define __PAGE_KERNEL_IO_WC (__PAGE_KERNEL_WC | _PAGE_IOMAP)
+#define __PAGE_KERNEL_IO (__PAGE_KERNEL)
+#define __PAGE_KERNEL_IO_NOCACHE (__PAGE_KERNEL_NOCACHE)
+#define __PAGE_KERNEL_IO_UC_MINUS (__PAGE_KERNEL_UC_MINUS)
+#define __PAGE_KERNEL_IO_WC (__PAGE_KERNEL_WC)
#define PAGE_KERNEL __pgprot(__PAGE_KERNEL)
#define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO)
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 7d05565..c8140e1 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -537,7 +537,7 @@ static void __init pagetable_init(void)
permanent_kmaps_init(pgd_base);
}
-pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
+pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL);
EXPORT_SYMBOL_GPL(__supported_pte_mask);
/* user-defined highmem size */
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 5621c47..5d98476 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -151,7 +151,7 @@ early_param("gbpages", parse_direct_gbpages_on);
* around without checking the pgd every time.
*/
-pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
+pteval_t __supported_pte_mask __read_mostly = ~0;
EXPORT_SYMBOL_GPL(__supported_pte_mask);
int force_personality32;
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 2ae525e..37c1435 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -442,8 +442,6 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
*/
prot |= _PAGE_CACHE_UC_MINUS;
- prot |= _PAGE_IOMAP; /* creating a mapping for IO */
-
vma->vm_page_prot = __pgprot(prot);
if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index c0cb11f..be1cff5 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1559,8 +1559,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
#endif
__supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
- __supported_pte_mask |= _PAGE_IOMAP;
-
/*
* Prevent page tables from being allocated in highmem, even
* if CONFIG_HIGHPTE is enabled.
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists