diff options
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/init.c | 14 | ||||
| -rw-r--r-- | arch/x86/mm/mem_encrypt_boot.S | 10 |
2 files changed, 20 insertions, 4 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index d8cfce221275..57ba5502aecf 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -77,10 +77,20 @@ static uint8_t __pte2cachemode_tbl[8] = { [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC, }; -/* Check that the write-protect PAT entry is set for write-protect */ +/* + * Check that the write-protect PAT entry is set for write-protect. + * To do this without making assumptions how PAT has been set up (Xen has + * another layout than the kernel), translate the _PAGE_CACHE_MODE_WP cache + * mode via the __cachemode2pte_tbl[] into protection bits (those protection + * bits will select a cache mode of WP or better), and then translate the + * protection bits back into the cache mode using __pte2cm_idx() and the + * __pte2cachemode_tbl[] array. This will return the really used cache mode. + */ bool x86_has_pat_wp(void) { - return __pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] == _PAGE_CACHE_MODE_WP; + uint16_t prot = __cachemode2pte_tbl[_PAGE_CACHE_MODE_WP]; + + return __pte2cachemode_tbl[__pte2cm_idx(prot)] == _PAGE_CACHE_MODE_WP; } enum page_cache_mode pgprot2cachemode(pgprot_t pgprot) diff --git a/arch/x86/mm/mem_encrypt_boot.S b/arch/x86/mm/mem_encrypt_boot.S index 3d1dba05fce4..9de3d900bc92 100644 --- a/arch/x86/mm/mem_encrypt_boot.S +++ b/arch/x86/mm/mem_encrypt_boot.S @@ -65,7 +65,10 @@ SYM_FUNC_START(sme_encrypt_execute) movq %rbp, %rsp /* Restore original stack pointer */ pop %rbp - RET + /* Offset to __x86_return_thunk would be wrong here */ + ANNOTATE_UNRET_SAFE + ret + int3 SYM_FUNC_END(sme_encrypt_execute) SYM_FUNC_START(__enc_copy) @@ -151,6 +154,9 @@ SYM_FUNC_START(__enc_copy) pop %r12 pop %r15 - RET + /* Offset to __x86_return_thunk would be wrong here */ + ANNOTATE_UNRET_SAFE + ret + int3 .L__enc_copy_end: SYM_FUNC_END(__enc_copy) |