Messages in this thread Patch in this message | | | Date | Thu, 7 Sep 2017 11:38:37 +0200 | From | Borislav Petkov <> | Subject | [PATCH] x86/mm: Make the SME mask a u64 |
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On Wed, Sep 06, 2017 at 07:26:40PM -0500, Brijesh Singh wrote: > 32-bit seems to be working well - thanks
Thanks Boris and Brijesh for testing!
--- From: Borislav Petkov <bp@suse.de>
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> Fixes: 21729f81ce8a ("x86/mm: Provide general kernel support for memory encryption") --- arch/x86/include/asm/mem_encrypt.h | 4 ++-- arch/x86/mm/mem_encrypt.c | 2 +- include/linux/mem_encrypt.h | 13 +++++++++---- 3 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 8e618fcf1f7c..6a77c63540f7 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -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) { } diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index 0fbd09269757..3fcc8e01683b 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -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 */ diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h index 1255f09f5e42..265a9cd21cb4 100644 --- a/include/linux/mem_encrypt.h +++ b/include/linux/mem_encrypt.h @@ -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__ */ -- 2.13.0 -- Regards/Gruss, Boris.
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