Re: SME/32-bit regression

From: Borislav Petkov
Date: Wed Sep 06 2017 - 05:45:20 EST


Btw,

Tom, pls remind me again, why didn't we make sme_me_mask u64?

Because this is the most logical type for a memory encryption mask which
covers 64 bits... In any case, the below builds fine here.

---
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__ */


--
Regards/Gruss,
Boris.

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