linux-stable/include/linux/mem_encrypt.h
Borislav Petkov 21d9bb4a05 x86/mm: Make the SME mask a u64
The SME encryption mask is for masking 64-bit pagetable entries. It
being an unsigned long works fine on X86_64 but on 32-bit builds in
truncates bits leading to Xen guests crashing very early.

And regardless, the whole SME mask handling shouldnt've leaked into
32-bit because SME is X86_64-only feature. So, first make the mask u64.
And then, add trivial 32-bit versions of the __sme_* macros so that
nothing happens there.

Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tom Lendacky <Thomas.Lendacky@amd.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas <Thomas.Lendacky@amd.com>
Fixes: 21729f81ce ("x86/mm: Provide general kernel support for memory encryption")
Link: http://lkml.kernel.org/r/20170907093837.76zojtkgebwtqc74@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-07 11:53:11 +02:00

53 lines
1.1 KiB
C

/*
* AMD Memory Encryption Support
*
* Copyright (C) 2016 Advanced Micro Devices, Inc.
*
* Author: Tom Lendacky <thomas.lendacky@amd.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __MEM_ENCRYPT_H__
#define __MEM_ENCRYPT_H__
#ifndef __ASSEMBLY__
#ifdef CONFIG_ARCH_HAS_MEM_ENCRYPT
#include <asm/mem_encrypt.h>
#else /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */
#define sme_me_mask 0ULL
#endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */
static inline bool sme_active(void)
{
return !!sme_me_mask;
}
static inline u64 sme_get_me_mask(void)
{
return sme_me_mask;
}
#ifdef CONFIG_AMD_MEM_ENCRYPT
/*
* The __sme_set() and __sme_clr() macros are useful for adding or removing
* the encryption mask from a value (e.g. when dealing with pagetable
* entries).
*/
#define __sme_set(x) ((x) | sme_me_mask)
#define __sme_clr(x) ((x) & ~sme_me_mask)
#else
#define __sme_set(x) (x)
#define __sme_clr(x) (x)
#endif
#endif /* __ASSEMBLY__ */
#endif /* __MEM_ENCRYPT_H__ */