mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

x86/tdx: Preserve shared bit on mprotect() 

commit a0a8d15a79 upstream.

The TDX guest platform takes one bit from the physical address to
indicate if the page is shared (accessible by VMM). This bit is not part
of the physical_mask and is not preserved during mprotect(). As a
result, the 'shared' bit is lost during mprotect() on shared mappings.

_COMMON_PAGE_CHG_MASK specifies which PTE bits need to be preserved
during modification. AMD includes 'sme_me_mask' in the define to
preserve the 'encrypt' bit.

To cover both Intel and AMD cases, include 'cc_mask' in
_COMMON_PAGE_CHG_MASK instead of 'sme_me_mask'.

Reported-and-tested-by: Chris Oo <cho@microsoft.com>

Fixes: 41394e33f3 ("x86/tdx: Extend the confidential computing API to support TDX guests")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240424082035.4092071-1-kirill.shutemov%40linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kirill A. Shutemov 2024-04-24 11:20:35 +03:00 committed by Greg Kroah-Hartman
parent 2b56188d9b
commit 25c5f2e05e
2 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/x86/include/asm/coco.h
View File

@ -12,9 +12,10 @@ enum cc_vendor {
};
extern enum cc_vendor cc_vendor;
extern u64 cc_mask;
#ifdef CONFIG_ARCH_HAS_CC_PLATFORM
extern u64 cc_mask;
static inline void cc_set_mask(u64 mask)
{
RIP_REL_REF(cc_mask) = mask;
@ -24,6 +25,8 @@ u64 cc_mkenc(u64 val);
u64 cc_mkdec(u64 val);
void cc_random_init(void);
#else
static const u64 cc_mask = 0;
static inline u64 cc_mkenc(u64 val)
{
return val;

3
arch/x86/include/asm/pgtable_types.h
View File

@ -148,7 +148,7 @@
#define _COMMON_PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \
_PAGE_SPECIAL | _PAGE_ACCESSED | \
_PAGE_DIRTY_BITS | _PAGE_SOFT_DIRTY | \
_PAGE_DEVMAP | _PAGE_ENC | _PAGE_UFFD_WP)
_PAGE_DEVMAP | _PAGE_CC | _PAGE_UFFD_WP)
#define _PAGE_CHG_MASK (_COMMON_PAGE_CHG_MASK | _PAGE_PAT)
#define _HPAGE_CHG_MASK (_COMMON_PAGE_CHG_MASK | _PAGE_PSE | _PAGE_PAT_LARGE)
@ -173,6 +173,7 @@ enum page_cache_mode {
};
#endif
#define _PAGE_CC (_AT(pteval_t, cc_mask))
#define _PAGE_ENC (_AT(pteval_t, sme_me_mask))
#define _PAGE_CACHE_MASK (_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)