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Commit d319bb79 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
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x86-64: Map the HPET NX 



Currently the HPET mapping is a user-accessible syscall
instruction at a fixed address some of the time.

A sufficiently determined hacker might be able to guess when.

Signed-off-by: default avatarAndy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/ab41b525a4ca346b1ca1145d16fb8d181861a8aa.1307292171.git.luto@mit.edu


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 0d7b8547

arch/x86/include/asm/pgtable_types.h

+2 −2
Original line number Diff line number Diff line
@@ -107,8 +107,8 @@ 
#define __PAGE_KERNEL_NOCACHE		(__PAGE_KERNEL | _PAGE_PCD | _PAGE_PWT)

#define __PAGE_KERNEL_UC_MINUS		(__PAGE_KERNEL | _PAGE_PCD)

#define __PAGE_KERNEL_VSYSCALL		(__PAGE_KERNEL_RX | _PAGE_USER)

#define __PAGE_KERNEL_VSYSCALL_NOCACHE	(__PAGE_KERNEL_VSYSCALL | _PAGE_PCD | _PAGE_PWT)

#define __PAGE_KERNEL_VVAR		(__PAGE_KERNEL_RO | _PAGE_USER)

#define __PAGE_KERNEL_VVAR_NOCACHE	(__PAGE_KERNEL_VVAR | _PAGE_PCD | _PAGE_PWT)

#define __PAGE_KERNEL_LARGE		(__PAGE_KERNEL | _PAGE_PSE)

#define __PAGE_KERNEL_LARGE_NOCACHE	(__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE)

#define __PAGE_KERNEL_LARGE_EXEC	(__PAGE_KERNEL_EXEC | _PAGE_PSE)
@@ -130,8 +130,8 @@ 
#define PAGE_KERNEL_LARGE_NOCACHE	__pgprot(__PAGE_KERNEL_LARGE_NOCACHE)

#define PAGE_KERNEL_LARGE_EXEC		__pgprot(__PAGE_KERNEL_LARGE_EXEC)

#define PAGE_KERNEL_VSYSCALL		__pgprot(__PAGE_KERNEL_VSYSCALL)

#define PAGE_KERNEL_VSYSCALL_NOCACHE	__pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE)

#define PAGE_KERNEL_VVAR		__pgprot(__PAGE_KERNEL_VVAR)

#define PAGE_KERNEL_VVAR_NOCACHE	__pgprot(__PAGE_KERNEL_VVAR_NOCACHE)



#define PAGE_KERNEL_IO			__pgprot(__PAGE_KERNEL_IO)

#define PAGE_KERNEL_IO_NOCACHE		__pgprot(__PAGE_KERNEL_IO_NOCACHE)

arch/x86/kernel/hpet.c

+1 −1
Original line number Diff line number Diff line
@@ -71,7 +71,7 @@ static inline void hpet_set_mapping(void) 
{

	hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);

#ifdef CONFIG_X86_64

	__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);

	__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VVAR_NOCACHE);

#endif

}