summaryrefslogtreecommitdiffstats
path: root/arch/x86/include/asm
diff options
context:
space:
mode:
authorDave Hansen <dave.hansen@linux.intel.com>2018-04-06 22:55:06 +0200
committerIngo Molnar <mingo@kernel.org>2018-04-09 18:27:32 +0200
commit8a57f4849f4fa22ed18a941164a214083fc020a2 (patch)
tree1580ded01e6ad41670b6b01525f19e308cf820ee /arch/x86/include/asm
parentx86/mm: Undo double _PAGE_PSE clearing (diff)
downloadlinux-8a57f4849f4fa22ed18a941164a214083fc020a2.tar.xz
linux-8a57f4849f4fa22ed18a941164a214083fc020a2.zip
x86/mm: Introduce "default" kernel PTE mask
The __PAGE_KERNEL_* page permissions are "raw". They contain bits that may or may not be supported on the current processor. They need to be filtered by a mask (currently __supported_pte_mask) to turn them into a value that we can actually set in a PTE. These __PAGE_KERNEL_* values all contain _PAGE_GLOBAL. But, with PTI, we want to be able to support _PAGE_GLOBAL (have the bit set in __supported_pte_mask) but not have it appear in any of these masks by default. This patch creates a new mask, __default_kernel_pte_mask, and applies it when creating all of the PAGE_KERNEL_* masks. This makes PAGE_KERNEL_* safe to use anywhere (they only contain supported bits). It also ensures that PAGE_KERNEL_* contains _PAGE_GLOBAL on PTI=n kernels but clears _PAGE_GLOBAL when PTI=y. We also make __default_kernel_pte_mask a non-GPL exported symbol because there are plenty of driver-available interfaces that take PAGE_KERNEL_* permissions. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180406205506.030DB6B6@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r--arch/x86/include/asm/pgtable_types.h29
1 files changed, 16 insertions, 13 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..1e5a40673953 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -196,19 +196,21 @@ enum page_cache_mode {
#define __PAGE_KERNEL_NOENC (__PAGE_KERNEL)
#define __PAGE_KERNEL_NOENC_WP (__PAGE_KERNEL_WP)
-#define PAGE_KERNEL __pgprot(__PAGE_KERNEL | _PAGE_ENC)
-#define PAGE_KERNEL_NOENC __pgprot(__PAGE_KERNEL)
-#define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO | _PAGE_ENC)
-#define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC | _PAGE_ENC)
-#define PAGE_KERNEL_EXEC_NOENC __pgprot(__PAGE_KERNEL_EXEC)
-#define PAGE_KERNEL_RX __pgprot(__PAGE_KERNEL_RX | _PAGE_ENC)
-#define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE | _PAGE_ENC)
-#define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE | _PAGE_ENC)
-#define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC | _PAGE_ENC)
-#define PAGE_KERNEL_VVAR __pgprot(__PAGE_KERNEL_VVAR | _PAGE_ENC)
-
-#define PAGE_KERNEL_IO __pgprot(__PAGE_KERNEL_IO)
-#define PAGE_KERNEL_IO_NOCACHE __pgprot(__PAGE_KERNEL_IO_NOCACHE)
+#define default_pgprot(x) __pgprot((x) & __default_kernel_pte_mask)
+
+#define PAGE_KERNEL default_pgprot(__PAGE_KERNEL | _PAGE_ENC)
+#define PAGE_KERNEL_NOENC default_pgprot(__PAGE_KERNEL)
+#define PAGE_KERNEL_RO default_pgprot(__PAGE_KERNEL_RO | _PAGE_ENC)
+#define PAGE_KERNEL_EXEC default_pgprot(__PAGE_KERNEL_EXEC | _PAGE_ENC)
+#define PAGE_KERNEL_EXEC_NOENC default_pgprot(__PAGE_KERNEL_EXEC)
+#define PAGE_KERNEL_RX default_pgprot(__PAGE_KERNEL_RX | _PAGE_ENC)
+#define PAGE_KERNEL_NOCACHE default_pgprot(__PAGE_KERNEL_NOCACHE | _PAGE_ENC)
+#define PAGE_KERNEL_LARGE default_pgprot(__PAGE_KERNEL_LARGE | _PAGE_ENC)
+#define PAGE_KERNEL_LARGE_EXEC default_pgprot(__PAGE_KERNEL_LARGE_EXEC | _PAGE_ENC)
+#define PAGE_KERNEL_VVAR default_pgprot(__PAGE_KERNEL_VVAR | _PAGE_ENC)
+
+#define PAGE_KERNEL_IO default_pgprot(__PAGE_KERNEL_IO)
+#define PAGE_KERNEL_IO_NOCACHE default_pgprot(__PAGE_KERNEL_IO_NOCACHE)
#endif /* __ASSEMBLY__ */
@@ -483,6 +485,7 @@ static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)
typedef struct page *pgtable_t;
extern pteval_t __supported_pte_mask;
+extern pteval_t __default_kernel_pte_mask;
extern void set_nx(void);
extern int nx_enabled;