Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 21d9bb4a authored by Borislav Petkov's avatar Borislav Petkov Committed by Ingo Molnar
Browse files

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: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarTom Lendacky <Thomas.Lendacky@amd.com>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas <Thomas.Lendacky@amd.com>
Fixes: 21729f81 ("x86/mm: Provide general kernel support for memory encryption")
Link: http://lkml.kernel.org/r/20170907093837.76zojtkgebwtqc74@pd.tnic


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 1c9fe440

arch/x86/include/asm/mem_encrypt.h

+2 −2
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 


#ifdef CONFIG_AMD_MEM_ENCRYPT



extern unsigned long sme_me_mask;

extern u64 sme_me_mask;



void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,

			 unsigned long decrypted_kernel_vaddr,
@@ -49,7 +49,7 @@ void swiotlb_set_mem_attributes(void *vaddr, unsigned long size); 


#else	/* !CONFIG_AMD_MEM_ENCRYPT */



#define sme_me_mask	0UL

#define sme_me_mask	0ULL



static inline void __init sme_early_encrypt(resource_size_t paddr,

					    unsigned long size) { }

arch/x86/mm/mem_encrypt.c

+1 −1
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ static char sme_cmdline_off[] __initdata = "off"; 
 * reside in the .data section so as not to be zeroed out when the .bss

 * section is later cleared.

 */

unsigned long sme_me_mask __section(.data) = 0;

u64 sme_me_mask __section(.data) = 0;

EXPORT_SYMBOL_GPL(sme_me_mask);



/* Buffer used for early in-place encryption by BSP, no locking needed */

include/linux/mem_encrypt.h

+9 −4
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 


#else	/* !CONFIG_ARCH_HAS_MEM_ENCRYPT */



#define sme_me_mask	0UL

#define sme_me_mask	0ULL



#endif	/* CONFIG_ARCH_HAS_MEM_ENCRYPT */
@@ -30,18 +30,23 @@ static inline bool sme_active(void) 
	return !!sme_me_mask;

}



static inline unsigned long sme_get_me_mask(void)

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)		((unsigned long)(x) | sme_me_mask)

#define __sme_clr(x)		((unsigned long)(x) & ~sme_me_mask)

#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__ */