From 0490d6d7ba0a479fdd805da54ae25220ce5b514d Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 14 Apr 2023 14:30:44 +0200 Subject: [PATCH] s390/mm: enable ARCH_HAS_SET_DIRECT_MAP Implement the set_direct_map_*() API, which allows to invalidate and set default permissions to pages within the direct mapping. Note that kernel_page_present(), which is also supposed to be part of this API, is intentionally not implemented. The reason for this is that kernel_page_present() is only used (and currently only makes sense) for suspend/resume, which isn't supported on s390. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik --- arch/s390/Kconfig | 1 + arch/s390/include/asm/set_memory.h | 7 ++++++ arch/s390/mm/pageattr.c | 35 ++++++++++++++++++++++++++++++ 3 files changed, 43 insertions(+) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index a7568449ca59..37986abfe007 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -77,6 +77,7 @@ config S390 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_SCALED_CPUTIME + select ARCH_HAS_SET_DIRECT_MAP select ARCH_HAS_SET_MEMORY select ARCH_HAS_STRICT_KERNEL_RWX select ARCH_HAS_STRICT_MODULE_RWX diff --git a/arch/s390/include/asm/set_memory.h b/arch/s390/include/asm/set_memory.h index ec3f44c602eb..7a3eefd7a242 100644 --- a/arch/s390/include/asm/set_memory.h +++ b/arch/s390/include/asm/set_memory.h @@ -12,6 +12,8 @@ enum { _SET_MEMORY_NX_BIT, _SET_MEMORY_X_BIT, _SET_MEMORY_4K_BIT, + _SET_MEMORY_INV_BIT, + _SET_MEMORY_DEF_BIT, }; #define SET_MEMORY_RO BIT(_SET_MEMORY_RO_BIT) @@ -19,6 +21,8 @@ enum { #define SET_MEMORY_NX BIT(_SET_MEMORY_NX_BIT) #define SET_MEMORY_X BIT(_SET_MEMORY_X_BIT) #define SET_MEMORY_4K BIT(_SET_MEMORY_4K_BIT) +#define SET_MEMORY_INV BIT(_SET_MEMORY_INV_BIT) +#define SET_MEMORY_DEF BIT(_SET_MEMORY_DEF_BIT) int __set_memory(unsigned long addr, int numpages, unsigned long flags); @@ -58,4 +62,7 @@ static inline int set_memory_4k(unsigned long addr, int numpages) return __set_memory(addr, numpages, SET_MEMORY_4K); } +int set_direct_map_invalid_noflush(struct page *page); +int set_direct_map_default_noflush(struct page *page); + #endif diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c index 77f31791044d..0b196dea2d92 100644 --- a/arch/s390/mm/pageattr.c +++ b/arch/s390/mm/pageattr.c @@ -4,6 +4,7 @@ * Author(s): Jan Glauber */ #include +#include #include #include #include @@ -101,6 +102,14 @@ static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC)); else if (flags & SET_MEMORY_X) new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC)); + if (flags & SET_MEMORY_INV) { + new = set_pte_bit(new, __pgprot(_PAGE_INVALID)); + } else if (flags & SET_MEMORY_DEF) { + new = __pte(pte_val(new) & PAGE_MASK); + new = set_pte_bit(new, PAGE_KERNEL); + if (!MACHINE_HAS_NX) + new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC)); + } pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE); ptep++; addr += PAGE_SIZE; @@ -151,6 +160,14 @@ static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); else if (flags & SET_MEMORY_X) new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); + if (flags & SET_MEMORY_INV) { + new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID)); + } else if (flags & SET_MEMORY_DEF) { + new = __pmd(pmd_val(new) & PMD_MASK); + new = set_pmd_bit(new, SEGMENT_KERNEL); + if (!MACHINE_HAS_NX) + new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); + } pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); } @@ -232,6 +249,14 @@ static void modify_pud_page(pud_t *pudp, unsigned long addr, new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); else if (flags & SET_MEMORY_X) new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); + if (flags & SET_MEMORY_INV) { + new = set_pud_bit(new, __pgprot(_REGION_ENTRY_INVALID)); + } else if (flags & SET_MEMORY_DEF) { + new = __pud(pud_val(new) & PUD_MASK); + new = set_pud_bit(new, REGION3_KERNEL); + if (!MACHINE_HAS_NX) + new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); + } pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); } @@ -325,6 +350,16 @@ int __set_memory(unsigned long addr, int numpages, unsigned long flags) return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags); } +int set_direct_map_invalid_noflush(struct page *page) +{ + return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_INV); +} + +int set_direct_map_default_noflush(struct page *page) +{ + return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF); +} + #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE) static void ipte_range(pte_t *pte, unsigned long address, int nr)