diff options
Diffstat (limited to 'arch/x86/mm/pat/set_memory.c')
| -rw-r--r-- | arch/x86/mm/pat/set_memory.c | 105 |
1 files changed, 71 insertions, 34 deletions
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index ef34ba21aa92..356758b7d4b4 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -220,6 +220,23 @@ within_inclusive(unsigned long addr, unsigned long start, unsigned long end) #ifdef CONFIG_X86_64 +/* + * The kernel image is mapped into two places in the virtual address space + * (addresses without KASLR, of course): + * + * 1. The kernel direct map (0xffff880000000000) + * 2. The "high kernel map" (0xffffffff81000000) + * + * We actually execute out of #2. If we get the address of a kernel symbol, it + * points to #2, but almost all physical-to-virtual translations point to #1. + * + * This is so that we can have both a directmap of all physical memory *and* + * take full advantage of the the limited (s32) immediate addressing range (2G) + * of x86_64. + * + * See Documentation/x86/x86_64/mm.rst for more detail. + */ + static inline unsigned long highmap_start_pfn(void) { return __pa_symbol(_text) >> PAGE_SHIFT; @@ -605,10 +622,6 @@ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long star { unsigned long end; - /* Kernel text is rw at boot up */ - if (system_state == SYSTEM_BOOTING) - return new; - /* * 32-bit has some unfixable W+X issues, like EFI code * and writeable data being in the same page. Disable @@ -765,11 +778,11 @@ phys_addr_t slow_virt_to_phys(void *__virt_addr) switch (level) { case PG_LEVEL_1G: phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; - offset = virt_addr & ~PUD_PAGE_MASK; + offset = virt_addr & ~PUD_MASK; break; case PG_LEVEL_2M: phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; - offset = virt_addr & ~PMD_PAGE_MASK; + offset = virt_addr & ~PMD_MASK; break; default: phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; @@ -1059,7 +1072,7 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, case PG_LEVEL_1G: ref_prot = pud_pgprot(*(pud_t *)kpte); ref_pfn = pud_pfn(*(pud_t *)kpte); - pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT; + pfninc = PMD_SIZE >> PAGE_SHIFT; lpaddr = address & PUD_MASK; lpinc = PMD_SIZE; /* @@ -1646,8 +1659,11 @@ repeat: return err; } -static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias); +static int __change_page_attr_set_clr(struct cpa_data *cpa, int primary); +/* + * Check the directmap and "high kernel map" 'aliases'. + */ static int cpa_process_alias(struct cpa_data *cpa) { struct cpa_data alias_cpa; @@ -1671,6 +1687,12 @@ static int cpa_process_alias(struct cpa_data *cpa) alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); alias_cpa.curpage = 0; + /* Directmap always has NX set, do not modify. */ + if (__supported_pte_mask & _PAGE_NX) { + alias_cpa.mask_clr.pgprot &= ~_PAGE_NX; + alias_cpa.mask_set.pgprot &= ~_PAGE_NX; + } + cpa->force_flush_all = 1; ret = __change_page_attr_set_clr(&alias_cpa, 0); @@ -1693,6 +1715,15 @@ static int cpa_process_alias(struct cpa_data *cpa) alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); alias_cpa.curpage = 0; + /* + * [_text, _brk_end) also covers data, do not modify NX except + * in cases where the highmap is the primary target. + */ + if (__supported_pte_mask & _PAGE_NX) { + alias_cpa.mask_clr.pgprot &= ~_PAGE_NX; + alias_cpa.mask_set.pgprot &= ~_PAGE_NX; + } + cpa->force_flush_all = 1; /* * The high mapping range is imprecise, so ignore the @@ -1705,12 +1736,19 @@ static int cpa_process_alias(struct cpa_data *cpa) return 0; } -static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias) +static int __change_page_attr_set_clr(struct cpa_data *cpa, int primary) { unsigned long numpages = cpa->numpages; unsigned long rempages = numpages; int ret = 0; + /* + * No changes, easy! + */ + if (!(pgprot_val(cpa->mask_set) | pgprot_val(cpa->mask_clr)) && + !cpa->force_split) + return ret; + while (rempages) { /* * Store the remaining nr of pages for the large page @@ -1723,13 +1761,13 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias) if (!debug_pagealloc_enabled()) spin_lock(&cpa_lock); - ret = __change_page_attr(cpa, checkalias); + ret = __change_page_attr(cpa, primary); if (!debug_pagealloc_enabled()) spin_unlock(&cpa_lock); if (ret) goto out; - if (checkalias) { + if (primary && !(cpa->flags & CPA_NO_CHECK_ALIAS)) { ret = cpa_process_alias(cpa); if (ret) goto out; @@ -1757,7 +1795,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, struct page **pages) { struct cpa_data cpa; - int ret, cache, checkalias; + int ret, cache; memset(&cpa, 0, sizeof(cpa)); @@ -1803,20 +1841,11 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, cpa.numpages = numpages; cpa.mask_set = mask_set; cpa.mask_clr = mask_clr; - cpa.flags = 0; + cpa.flags = in_flag; cpa.curpage = 0; cpa.force_split = force_split; - if (in_flag & (CPA_ARRAY | CPA_PAGES_ARRAY)) - cpa.flags |= in_flag; - - /* No alias checking for _NX bit modifications */ - checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX; - /* Has caller explicitly disabled alias checking? */ - if (in_flag & CPA_NO_CHECK_ALIAS) - checkalias = 0; - - ret = __change_page_attr_set_clr(&cpa, checkalias); + ret = __change_page_attr_set_clr(&cpa, 1); /* * Check whether we really changed something: @@ -2047,6 +2076,16 @@ int set_memory_ro(unsigned long addr, int numpages) return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0); } +int set_memory_rox(unsigned long addr, int numpages) +{ + pgprot_t clr = __pgprot(_PAGE_RW); + + if (__supported_pte_mask & _PAGE_NX) + clr.pgprot |= _PAGE_NX; + + return change_page_attr_clear(&addr, numpages, clr, 0); +} + int set_memory_rw(unsigned long addr, int numpages) { return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0); @@ -2059,11 +2098,9 @@ int set_memory_np(unsigned long addr, int numpages) int set_memory_np_noalias(unsigned long addr, int numpages) { - int cpa_flags = CPA_NO_CHECK_ALIAS; - return change_page_attr_set_clr(&addr, numpages, __pgprot(0), __pgprot(_PAGE_PRESENT), 0, - cpa_flags, NULL); + CPA_NO_CHECK_ALIAS, NULL); } int set_memory_4k(unsigned long addr, int numpages) @@ -2280,7 +2317,7 @@ static int __set_pages_p(struct page *page, int numpages) .numpages = numpages, .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW), .mask_clr = __pgprot(0), - .flags = 0}; + .flags = CPA_NO_CHECK_ALIAS }; /* * No alias checking needed for setting present flag. otherwise, @@ -2288,7 +2325,7 @@ static int __set_pages_p(struct page *page, int numpages) * mappings (this adds to complexity if we want to do this from * atomic context especially). Let's keep it simple! */ - return __change_page_attr_set_clr(&cpa, 0); + return __change_page_attr_set_clr(&cpa, 1); } static int __set_pages_np(struct page *page, int numpages) @@ -2299,7 +2336,7 @@ static int __set_pages_np(struct page *page, int numpages) .numpages = numpages, .mask_set = __pgprot(0), .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), - .flags = 0}; + .flags = CPA_NO_CHECK_ALIAS }; /* * No alias checking needed for setting not present flag. otherwise, @@ -2307,7 +2344,7 @@ static int __set_pages_np(struct page *page, int numpages) * mappings (this adds to complexity if we want to do this from * atomic context especially). Let's keep it simple! */ - return __change_page_attr_set_clr(&cpa, 0); + return __change_page_attr_set_clr(&cpa, 1); } int set_direct_map_invalid_noflush(struct page *page) @@ -2378,7 +2415,7 @@ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, .numpages = numpages, .mask_set = __pgprot(0), .mask_clr = __pgprot(~page_flags & (_PAGE_NX|_PAGE_RW)), - .flags = 0, + .flags = CPA_NO_CHECK_ALIAS, }; WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); @@ -2391,7 +2428,7 @@ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags); - retval = __change_page_attr_set_clr(&cpa, 0); + retval = __change_page_attr_set_clr(&cpa, 1); __flush_tlb_all(); out: @@ -2421,12 +2458,12 @@ int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address, .numpages = numpages, .mask_set = __pgprot(0), .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), - .flags = 0, + .flags = CPA_NO_CHECK_ALIAS, }; WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); - retval = __change_page_attr_set_clr(&cpa, 0); + retval = __change_page_attr_set_clr(&cpa, 1); __flush_tlb_all(); return retval; |