| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Thomas Gleixner | 2258 | 23.67% | 42 | 14.69% |
| Borislav Petkov | 1689 | 17.70% | 12 | 4.20% |
| Peter Zijlstra | 629 | 6.59% | 22 | 7.69% |
| Andi Kleen | 624 | 6.54% | 14 | 4.90% |
| Venkatesh Pallipadi | 572 | 6.00% | 12 | 4.20% |
| Ingo Molnar | 537 | 5.63% | 30 | 10.49% |
| Arjan van de Ven | 384 | 4.03% | 7 | 2.45% |
| Dave Hansen | 292 | 3.06% | 13 | 4.55% |
| Shaohua Li | 274 | 2.87% | 2 | 0.70% |
| Toshi Kani | 210 | 2.20% | 4 | 1.40% |
| Kirill A. Shutemov | 185 | 1.94% | 2 | 0.70% |
| Suresh B. Siddha | 178 | 1.87% | 5 | 1.75% |
| Tom Lendacky | 177 | 1.86% | 4 | 1.40% |
| Juergen Gross | 155 | 1.62% | 5 | 1.75% |
| Dan J Williams | 86 | 0.90% | 3 | 1.05% |
| Wen Congyang | 67 | 0.70% | 1 | 0.35% |
| Pauli Nieminen | 64 | 0.67% | 1 | 0.35% |
| Sai Praneeth | 63 | 0.66% | 3 | 1.05% |
| Davidlohr Bueso A | 63 | 0.66% | 1 | 0.35% |
| Lan Tianyu | 60 | 0.63% | 1 | 0.35% |
| Brijesh Singh | 54 | 0.57% | 2 | 0.70% |
| Rafael J. Wysocki | 53 | 0.56% | 2 | 0.70% |
| Rick Edgecombe | 49 | 0.51% | 2 | 0.70% |
| Andrew Morton | 48 | 0.50% | 3 | 1.05% |
| Jane Chu | 48 | 0.50% | 2 | 0.70% |
| Thomas Hellstrom | 46 | 0.48% | 1 | 0.35% |
| Hugh Dickins | 45 | 0.47% | 2 | 0.70% |
| Tejun Heo | 44 | 0.46% | 3 | 1.05% |
| Linus Torvalds (pre-git) | 43 | 0.45% | 9 | 3.15% |
| Andrea Arcangeli | 38 | 0.40% | 3 | 1.05% |
| H. Peter Anvin | 38 | 0.40% | 1 | 0.35% |
| Ross Zwisler | 36 | 0.38% | 4 | 1.40% |
| Logan Gunthorpe | 34 | 0.36% | 1 | 0.35% |
| Saravanan D | 31 | 0.32% | 1 | 0.35% |
| Yinghai Lu | 30 | 0.31% | 2 | 0.70% |
| Matt Fleming | 30 | 0.31% | 6 | 2.10% |
| Tony Luck | 23 | 0.24% | 3 | 1.05% |
| Thomas Garnier | 20 | 0.21% | 1 | 0.35% |
| Andrew Lutomirski | 18 | 0.19% | 3 | 1.05% |
| Dave Jones | 18 | 0.19% | 2 | 0.70% |
| Chris Wilson | 18 | 0.19% | 1 | 0.35% |
| Michael Ellerman | 16 | 0.17% | 1 | 0.35% |
| Dexuan Cui | 15 | 0.16% | 2 | 0.70% |
| Alexey Dobriyan | 15 | 0.16% | 1 | 0.35% |
| Matthieu CASTET | 11 | 0.12% | 2 | 0.70% |
| Jeremy Fitzhardinge | 10 | 0.10% | 5 | 1.75% |
| Zachary Amsden | 9 | 0.09% | 2 | 0.70% |
| Harvey Harrison | 9 | 0.09% | 1 | 0.35% |
| Jan Beulich | 8 | 0.08% | 1 | 0.35% |
| Christoph Lameter | 8 | 0.08% | 1 | 0.35% |
| Christian Bornträger | 8 | 0.08% | 1 | 0.35% |
| René Herman | 8 | 0.08% | 2 | 0.70% |
| Ard Biesheuvel | 8 | 0.08% | 1 | 0.35% |
| Benjamin Thiel | 8 | 0.08% | 1 | 0.35% |
| Sebastian Andrzej Siewior | 7 | 0.07% | 1 | 0.35% |
| Nicholas Piggin | 7 | 0.07% | 2 | 0.70% |
| Eric Anholt | 7 | 0.07% | 1 | 0.35% |
| David Woodhouse | 6 | 0.06% | 1 | 0.35% |
| K. Y. Srinivasan | 5 | 0.05% | 2 | 0.70% |
| Pekka Paalanen | 5 | 0.05% | 1 | 0.35% |
| Alexander Duyck | 4 | 0.04% | 1 | 0.35% |
| Adrian Bunk | 3 | 0.03% | 1 | 0.35% |
| Qian Cai | 3 | 0.03% | 1 | 0.35% |
| Pavel Tatashin | 3 | 0.03% | 1 | 0.35% |
| Steven Rostedt | 3 | 0.03% | 1 | 0.35% |
| Linus Torvalds | 3 | 0.03% | 2 | 0.70% |
| Stanislaw Gruszka | 3 | 0.03% | 1 | 0.35% |
| Boris Ostrovsky | 3 | 0.03% | 1 | 0.35% |
| Avi Kivity | 3 | 0.03% | 1 | 0.35% |
| Christoph Hellwig | 2 | 0.02% | 1 | 0.35% |
| Aneesh Kumar K.V | 2 | 0.02% | 1 | 0.35% |
| Mike Rapoport | 1 | 0.01% | 1 | 0.35% |
| Huang Ying | 1 | 0.01% | 1 | 0.35% |
| Krish Sadhukhan | 1 | 0.01% | 1 | 0.35% |
| kbuild test robot | 1 | 0.01% | 1 | 0.35% |
| Vitaly Kuznetsov | 1 | 0.01% | 1 | 0.35% |
| Joerg Roedel | 1 | 0.01% | 1 | 0.35% |
| JoonSoo Kim | 1 | 0.01% | 1 | 0.35% |
| Total | 9540 | 286 |
// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2002 Andi Kleen, SuSE Labs. * Thanks to Ben LaHaise for precious feedback. */ #include <linux/highmem.h> #include <linux/memblock.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/interrupt.h> #include <linux/seq_file.h> #include <linux/debugfs.h> #include <linux/pfn.h> #include <linux/percpu.h> #include <linux/gfp.h> #include <linux/pci.h> #include <linux/vmalloc.h> #include <linux/libnvdimm.h> #include <linux/vmstat.h> #include <linux/kernel.h> #include <linux/cc_platform.h> #include <linux/set_memory.h> #include <linux/memregion.h> #include <asm/e820/api.h> #include <asm/processor.h> #include <asm/tlbflush.h> #include <asm/sections.h> #include <asm/setup.h> #include <linux/uaccess.h> #include <asm/pgalloc.h> #include <asm/proto.h> #include <asm/memtype.h> #include <asm/hyperv-tlfs.h> #include <asm/mshyperv.h> #include "../mm_internal.h" /* * The current flushing context - we pass it instead of 5 arguments: */ struct cpa_data { unsigned long *vaddr; pgd_t *pgd; pgprot_t mask_set; pgprot_t mask_clr; unsigned long numpages; unsigned long curpage; unsigned long pfn; unsigned int flags; unsigned int force_split : 1, force_static_prot : 1, force_flush_all : 1; struct page **pages; }; enum cpa_warn { CPA_CONFLICT, CPA_PROTECT, CPA_DETECT, }; static const int cpa_warn_level = CPA_PROTECT; /* * Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings) * using cpa_lock. So that we don't allow any other cpu, with stale large tlb * entries change the page attribute in parallel to some other cpu * splitting a large page entry along with changing the attribute. */ static DEFINE_SPINLOCK(cpa_lock); #define CPA_FLUSHTLB 1 #define CPA_ARRAY 2 #define CPA_PAGES_ARRAY 4 #define CPA_NO_CHECK_ALIAS 8 /* Do not search for aliases */ static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm) { return __pgprot(cachemode2protval(pcm)); } #ifdef CONFIG_PROC_FS static unsigned long direct_pages_count[PG_LEVEL_NUM]; void update_page_count(int level, unsigned long pages) { /* Protect against CPA */ spin_lock(&pgd_lock); direct_pages_count[level] += pages; spin_unlock(&pgd_lock); } static void split_page_count(int level) { if (direct_pages_count[level] == 0) return; direct_pages_count[level]--; if (system_state == SYSTEM_RUNNING) { if (level == PG_LEVEL_2M) count_vm_event(DIRECT_MAP_LEVEL2_SPLIT); else if (level == PG_LEVEL_1G) count_vm_event(DIRECT_MAP_LEVEL3_SPLIT); } direct_pages_count[level - 1] += PTRS_PER_PTE; } void arch_report_meminfo(struct seq_file *m) { seq_printf(m, "DirectMap4k: %8lu kB\n", direct_pages_count[PG_LEVEL_4K] << 2); #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) seq_printf(m, "DirectMap2M: %8lu kB\n", direct_pages_count[PG_LEVEL_2M] << 11); #else seq_printf(m, "DirectMap4M: %8lu kB\n", direct_pages_count[PG_LEVEL_2M] << 12); #endif if (direct_gbpages) seq_printf(m, "DirectMap1G: %8lu kB\n", direct_pages_count[PG_LEVEL_1G] << 20); } #else static inline void split_page_count(int level) { } #endif #ifdef CONFIG_X86_CPA_STATISTICS static unsigned long cpa_1g_checked; static unsigned long cpa_1g_sameprot; static unsigned long cpa_1g_preserved; static unsigned long cpa_2m_checked; static unsigned long cpa_2m_sameprot; static unsigned long cpa_2m_preserved; static unsigned long cpa_4k_install; static inline void cpa_inc_1g_checked(void) { cpa_1g_checked++; } static inline void cpa_inc_2m_checked(void) { cpa_2m_checked++; } static inline void cpa_inc_4k_install(void) { data_race(cpa_4k_install++); } static inline void cpa_inc_lp_sameprot(int level) { if (level == PG_LEVEL_1G) cpa_1g_sameprot++; else cpa_2m_sameprot++; } static inline void cpa_inc_lp_preserved(int level) { if (level == PG_LEVEL_1G) cpa_1g_preserved++; else cpa_2m_preserved++; } static int cpastats_show(struct seq_file *m, void *p) { seq_printf(m, "1G pages checked: %16lu\n", cpa_1g_checked); seq_printf(m, "1G pages sameprot: %16lu\n", cpa_1g_sameprot); seq_printf(m, "1G pages preserved: %16lu\n", cpa_1g_preserved); seq_printf(m, "2M pages checked: %16lu\n", cpa_2m_checked); seq_printf(m, "2M pages sameprot: %16lu\n", cpa_2m_sameprot); seq_printf(m, "2M pages preserved: %16lu\n", cpa_2m_preserved); seq_printf(m, "4K pages set-checked: %16lu\n", cpa_4k_install); return 0; } static int cpastats_open(struct inode *inode, struct file *file) { return single_open(file, cpastats_show, NULL); } static const struct file_operations cpastats_fops = { .open = cpastats_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static int __init cpa_stats_init(void) { debugfs_create_file("cpa_stats", S_IRUSR, arch_debugfs_dir, NULL, &cpastats_fops); return 0; } late_initcall(cpa_stats_init); #else static inline void cpa_inc_1g_checked(void) { } static inline void cpa_inc_2m_checked(void) { } static inline void cpa_inc_4k_install(void) { } static inline void cpa_inc_lp_sameprot(int level) { } static inline void cpa_inc_lp_preserved(int level) { } #endif static inline int within(unsigned long addr, unsigned long start, unsigned long end) { return addr >= start && addr < end; } static inline int within_inclusive(unsigned long addr, unsigned long start, unsigned long end) { return addr >= start && addr <= 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; } static inline unsigned long highmap_end_pfn(void) { /* Do not reference physical address outside the kernel. */ return __pa_symbol(roundup(_brk_end, PMD_SIZE) - 1) >> PAGE_SHIFT; } static bool __cpa_pfn_in_highmap(unsigned long pfn) { /* * Kernel text has an alias mapping at a high address, known * here as "highmap". */ return within_inclusive(pfn, highmap_start_pfn(), highmap_end_pfn()); } #else static bool __cpa_pfn_in_highmap(unsigned long pfn) { /* There is no highmap on 32-bit */ return false; } #endif /* * See set_mce_nospec(). * * Machine check recovery code needs to change cache mode of poisoned pages to * UC to avoid speculative access logging another error. But passing the * address of the 1:1 mapping to set_memory_uc() is a fine way to encourage a * speculative access. So we cheat and flip the top bit of the address. This * works fine for the code that updates the page tables. But at the end of the * process we need to flush the TLB and cache and the non-canonical address * causes a #GP fault when used by the INVLPG and CLFLUSH instructions. * * But in the common case we already have a canonical address. This code * will fix the top bit if needed and is a no-op otherwise. */ static inline unsigned long fix_addr(unsigned long addr) { #ifdef CONFIG_X86_64 return (long)(addr << 1) >> 1; #else return addr; #endif } static unsigned long __cpa_addr(struct cpa_data *cpa, unsigned long idx) { if (cpa->flags & CPA_PAGES_ARRAY) { struct page *page = cpa->pages[idx]; if (unlikely(PageHighMem(page))) return 0; return (unsigned long)page_address(page); } if (cpa->flags & CPA_ARRAY) return cpa->vaddr[idx]; return *cpa->vaddr + idx * PAGE_SIZE; } /* * Flushing functions */ static void clflush_cache_range_opt(void *vaddr, unsigned int size) { const unsigned long clflush_size = boot_cpu_data.x86_clflush_size; void *p = (void *)((unsigned long)vaddr & ~(clflush_size - 1)); void *vend = vaddr + size; if (p >= vend) return; for (; p < vend; p += clflush_size) clflushopt(p); } /** * clflush_cache_range - flush a cache range with clflush * @vaddr: virtual start address * @size: number of bytes to flush * * CLFLUSHOPT is an unordered instruction which needs fencing with MFENCE or * SFENCE to avoid ordering issues. */ void clflush_cache_range(void *vaddr, unsigned int size) { mb(); clflush_cache_range_opt(vaddr, size); mb(); } EXPORT_SYMBOL_GPL(clflush_cache_range); #ifdef CONFIG_ARCH_HAS_PMEM_API void arch_invalidate_pmem(void *addr, size_t size) { clflush_cache_range(addr, size); } EXPORT_SYMBOL_GPL(arch_invalidate_pmem); #endif #ifdef CONFIG_ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION bool cpu_cache_has_invalidate_memregion(void) { return !cpu_feature_enabled(X86_FEATURE_HYPERVISOR); } EXPORT_SYMBOL_NS_GPL(cpu_cache_has_invalidate_memregion, DEVMEM); int cpu_cache_invalidate_memregion(int res_desc) { if (WARN_ON_ONCE(!cpu_cache_has_invalidate_memregion())) return -ENXIO; wbinvd_on_all_cpus(); return 0; } EXPORT_SYMBOL_NS_GPL(cpu_cache_invalidate_memregion, DEVMEM); #endif static void __cpa_flush_all(void *arg) { unsigned long cache = (unsigned long)arg; /* * Flush all to work around Errata in early athlons regarding * large page flushing. */ __flush_tlb_all(); if (cache && boot_cpu_data.x86 >= 4) wbinvd(); } static void cpa_flush_all(unsigned long cache) { BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); on_each_cpu(__cpa_flush_all, (void *) cache, 1); } static void __cpa_flush_tlb(void *data) { struct cpa_data *cpa = data; unsigned int i; for (i = 0; i < cpa->numpages; i++) flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa, i))); } static void cpa_flush(struct cpa_data *data, int cache) { struct cpa_data *cpa = data; unsigned int i; BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) { cpa_flush_all(cache); return; } if (cpa->force_flush_all || cpa->numpages > tlb_single_page_flush_ceiling) flush_tlb_all(); else on_each_cpu(__cpa_flush_tlb, cpa, 1); if (!cache) return; mb(); for (i = 0; i < cpa->numpages; i++) { unsigned long addr = __cpa_addr(cpa, i); unsigned int level; pte_t *pte = lookup_address(addr, &level); /* * Only flush present addresses: */ if (pte && (pte_val(*pte) & _PAGE_PRESENT)) clflush_cache_range_opt((void *)fix_addr(addr), PAGE_SIZE); } mb(); } static bool overlaps(unsigned long r1_start, unsigned long r1_end, unsigned long r2_start, unsigned long r2_end) { return (r1_start <= r2_end && r1_end >= r2_start) || (r2_start <= r1_end && r2_end >= r1_start); } #ifdef CONFIG_PCI_BIOS /* * The BIOS area between 640k and 1Mb needs to be executable for PCI BIOS * based config access (CONFIG_PCI_GOBIOS) support. */ #define BIOS_PFN PFN_DOWN(BIOS_BEGIN) #define BIOS_PFN_END PFN_DOWN(BIOS_END - 1) static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn) { if (pcibios_enabled && overlaps(spfn, epfn, BIOS_PFN, BIOS_PFN_END)) return _PAGE_NX; return 0; } #else static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn) { return 0; } #endif /* * The .rodata section needs to be read-only. Using the pfn catches all * aliases. This also includes __ro_after_init, so do not enforce until * kernel_set_to_readonly is true. */ static pgprotval_t protect_rodata(unsigned long spfn, unsigned long epfn) { unsigned long epfn_ro, spfn_ro = PFN_DOWN(__pa_symbol(__start_rodata)); /* * Note: __end_rodata is at page aligned and not inclusive, so * subtract 1 to get the last enforced PFN in the rodata area. */ epfn_ro = PFN_DOWN(__pa_symbol(__end_rodata)) - 1; if (kernel_set_to_readonly && overlaps(spfn, epfn, spfn_ro, epfn_ro)) return _PAGE_RW; return 0; } /* * Protect kernel text against becoming non executable by forbidding * _PAGE_NX. This protects only the high kernel mapping (_text -> _etext) * out of which the kernel actually executes. Do not protect the low * mapping. * * This does not cover __inittext since that is gone after boot. */ static pgprotval_t protect_kernel_text(unsigned long start, unsigned long end) { unsigned long t_end = (unsigned long)_etext - 1; unsigned long t_start = (unsigned long)_text; if (overlaps(start, end, t_start, t_end)) return _PAGE_NX; return 0; } #if defined(CONFIG_X86_64) /* * Once the kernel maps the text as RO (kernel_set_to_readonly is set), * kernel text mappings for the large page aligned text, rodata sections * will be always read-only. For the kernel identity mappings covering the * holes caused by this alignment can be anything that user asks. * * This will preserve the large page mappings for kernel text/data at no * extra cost. */ static pgprotval_t protect_kernel_text_ro(unsigned long start, unsigned long end) { unsigned long t_end = (unsigned long)__end_rodata_hpage_align - 1; unsigned long t_start = (unsigned long)_text; unsigned int level; if (!kernel_set_to_readonly || !overlaps(start, end, t_start, t_end)) return 0; /* * Don't enforce the !RW mapping for the kernel text mapping, if * the current mapping is already using small page mapping. No * need to work hard to preserve large page mappings in this case. * * This also fixes the Linux Xen paravirt guest boot failure caused * by unexpected read-only mappings for kernel identity * mappings. In this paravirt guest case, the kernel text mapping * and the kernel identity mapping share the same page-table pages, * so the protections for kernel text and identity mappings have to * be the same. */ if (lookup_address(start, &level) && (level != PG_LEVEL_4K)) return _PAGE_RW; return 0; } #else static pgprotval_t protect_kernel_text_ro(unsigned long start, unsigned long end) { return 0; } #endif static inline bool conflicts(pgprot_t prot, pgprotval_t val) { return (pgprot_val(prot) & ~val) != pgprot_val(prot); } static inline void check_conflict(int warnlvl, pgprot_t prot, pgprotval_t val, unsigned long start, unsigned long end, unsigned long pfn, const char *txt) { static const char *lvltxt[] = { [CPA_CONFLICT] = "conflict", [CPA_PROTECT] = "protect", [CPA_DETECT] = "detect", }; if (warnlvl > cpa_warn_level || !conflicts(prot, val)) return; pr_warn("CPA %8s %10s: 0x%016lx - 0x%016lx PFN %lx req %016llx prevent %016llx\n", lvltxt[warnlvl], txt, start, end, pfn, (unsigned long long)pgprot_val(prot), (unsigned long long)val); } /* * Certain areas of memory on x86 require very specific protection flags, * for example the BIOS area or kernel text. Callers don't always get this * right (again, ioremap() on BIOS memory is not uncommon) so this function * checks and fixes these known static required protection bits. */ static inline pgprot_t static_protections(pgprot_t prot, unsigned long start, unsigned long pfn, unsigned long npg, unsigned long lpsize, int warnlvl) { pgprotval_t forbidden, res; unsigned long end; /* * There is no point in checking RW/NX conflicts when the requested * mapping is setting the page !PRESENT. */ if (!(pgprot_val(prot) & _PAGE_PRESENT)) return prot; /* Operate on the virtual address */ end = start + npg * PAGE_SIZE - 1; res = protect_kernel_text(start, end); check_conflict(warnlvl, prot, res, start, end, pfn, "Text NX"); forbidden = res; /* * Special case to preserve a large page. If the change spawns the * full large page mapping then there is no point to split it * up. Happens with ftrace and is going to be removed once ftrace * switched to text_poke(). */ if (lpsize != (npg * PAGE_SIZE) || (start & (lpsize - 1))) { res = protect_kernel_text_ro(start, end); check_conflict(warnlvl, prot, res, start, end, pfn, "Text RO"); forbidden |= res; } /* Check the PFN directly */ res = protect_pci_bios(pfn, pfn + npg - 1); check_conflict(warnlvl, prot, res, start, end, pfn, "PCIBIOS NX"); forbidden |= res; res = protect_rodata(pfn, pfn + npg - 1); check_conflict(warnlvl, prot, res, start, end, pfn, "Rodata RO"); forbidden |= res; return __pgprot(pgprot_val(prot) & ~forbidden); } /* * Validate strict W^X semantics. */ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long start, unsigned long pfn, unsigned long npg) { unsigned long end; /* * 32-bit has some unfixable W+X issues, like EFI code * and writeable data being in the same page. Disable * detection and enforcement there. */ if (IS_ENABLED(CONFIG_X86_32)) return new; /* Only verify when NX is supported: */ if (!(__supported_pte_mask & _PAGE_NX)) return new; if (!((pgprot_val(old) ^ pgprot_val(new)) & (_PAGE_RW | _PAGE_NX))) return new; if ((pgprot_val(new) & (_PAGE_RW | _PAGE_NX)) != _PAGE_RW) return new; end = start + npg * PAGE_SIZE - 1; WARN_ONCE(1, "CPA detected W^X violation: %016llx -> %016llx range: 0x%016lx - 0x%016lx PFN %lx\n", (unsigned long long)pgprot_val(old), (unsigned long long)pgprot_val(new), start, end, pfn); /* * For now, allow all permission change attempts by returning the * attempted permissions. This can 'return old' to actively * refuse the permission change at a later time. */ return new; } /* * Lookup the page table entry for a virtual address in a specific pgd. * Return a pointer to the entry and the level of the mapping. */ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, unsigned int *level) { p4d_t *p4d; pud_t *pud; pmd_t *pmd; *level = PG_LEVEL_NONE; if (pgd_none(*pgd)) return NULL; p4d = p4d_offset(pgd, address); if (p4d_none(*p4d)) return NULL; *level = PG_LEVEL_512G; if (p4d_large(*p4d) || !p4d_present(*p4d)) return (pte_t *)p4d; pud = pud_offset(p4d, address); if (pud_none(*pud)) return NULL; *level = PG_LEVEL_1G; if (pud_large(*pud) || !pud_present(*pud)) return (pte_t *)pud; pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) return NULL; *level = PG_LEVEL_2M; if (pmd_large(*pmd) || !pmd_present(*pmd)) return (pte_t *)pmd; *level = PG_LEVEL_4K; return pte_offset_kernel(pmd, address); } /* * Lookup the page table entry for a virtual address. Return a pointer * to the entry and the level of the mapping. * * Note: We return pud and pmd either when the entry is marked large * or when the present bit is not set. Otherwise we would return a * pointer to a nonexisting mapping. */ pte_t *lookup_address(unsigned long address, unsigned int *level) { return lookup_address_in_pgd(pgd_offset_k(address), address, level); } EXPORT_SYMBOL_GPL(lookup_address); static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address, unsigned int *level) { if (cpa->pgd) return lookup_address_in_pgd(cpa->pgd + pgd_index(address), address, level); return lookup_address(address, level); } /* * Lookup the PMD entry for a virtual address. Return a pointer to the entry * or NULL if not present. */ pmd_t *lookup_pmd_address(unsigned long address) { pgd_t *pgd; p4d_t *p4d; pud_t *pud; pgd = pgd_offset_k(address); if (pgd_none(*pgd)) return NULL; p4d = p4d_offset(pgd, address); if (p4d_none(*p4d) || p4d_large(*p4d) || !p4d_present(*p4d)) return NULL; pud = pud_offset(p4d, address); if (pud_none(*pud) || pud_large(*pud) || !pud_present(*pud)) return NULL; return pmd_offset(pud, address); } /* * This is necessary because __pa() does not work on some * kinds of memory, like vmalloc() or the alloc_remap() * areas on 32-bit NUMA systems. The percpu areas can * end up in this kind of memory, for instance. * * This could be optimized, but it is only intended to be * used at initialization time, and keeping it * unoptimized should increase the testing coverage for * the more obscure platforms. */ phys_addr_t slow_virt_to_phys(void *__virt_addr) { unsigned long virt_addr = (unsigned long)__virt_addr; phys_addr_t phys_addr; unsigned long offset; enum pg_level level; pte_t *pte; pte = lookup_address(virt_addr, &level); BUG_ON(!pte); /* * pXX_pfn() returns unsigned long, which must be cast to phys_addr_t * before being left-shifted PAGE_SHIFT bits -- this trick is to * make 32-PAE kernel work correctly. */ switch (level) { case PG_LEVEL_1G: phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; 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_MASK; break; default: phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; offset = virt_addr & ~PAGE_MASK; } return (phys_addr_t)(phys_addr | offset); } EXPORT_SYMBOL_GPL(slow_virt_to_phys); /* * Set the new pmd in all the pgds we know about: */ static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) { /* change init_mm */ set_pte_atomic(kpte, pte); #ifdef CONFIG_X86_32 if (!SHARED_KERNEL_PMD) { struct page *page; list_for_each_entry(page, &pgd_list, lru) { pgd_t *pgd; p4d_t *p4d; pud_t *pud; pmd_t *pmd; pgd = (pgd_t *)page_address(page) + pgd_index(address); p4d = p4d_offset(pgd, address); pud = pud_offset(p4d, address); pmd = pmd_offset(pud, address); set_pte_atomic((pte_t *)pmd, pte); } } #endif } static pgprot_t pgprot_clear_protnone_bits(pgprot_t prot) { /* * _PAGE_GLOBAL means "global page" for present PTEs. * But, it is also used to indicate _PAGE_PROTNONE * for non-present PTEs. * * This ensures that a _PAGE_GLOBAL PTE going from * present to non-present is not confused as * _PAGE_PROTNONE. */ if (!(pgprot_val(prot) & _PAGE_PRESENT)) pgprot_val(prot) &= ~_PAGE_GLOBAL; return prot; } static int __should_split_large_page(pte_t *kpte, unsigned long address, struct cpa_data *cpa) { unsigned long numpages, pmask, psize, lpaddr, pfn, old_pfn; pgprot_t old_prot, new_prot, req_prot, chk_prot; pte_t new_pte, *tmp; enum pg_level level; /* * Check for races, another CPU might have split this page * up already: */ tmp = _lookup_address_cpa(cpa, address, &level); if (tmp != kpte) return 1; switch (level) { case PG_LEVEL_2M: old_prot = pmd_pgprot(*(pmd_t *)kpte); old_pfn = pmd_pfn(*(pmd_t *)kpte); cpa_inc_2m_checked(); break; case PG_LEVEL_1G: old_prot = pud_pgprot(*(pud_t *)kpte); old_pfn = pud_pfn(*(pud_t *)kpte); cpa_inc_1g_checked(); break; default: return -EINVAL; } psize = page_level_size(level); pmask = page_level_mask(level); /* * Calculate the number of pages, which fit into this large * page starting at address: */ lpaddr = (address + psize) & pmask; numpages = (lpaddr - address) >> PAGE_SHIFT; if (numpages < cpa->numpages) cpa->numpages = numpages; /* * We are safe now. Check whether the new pgprot is the same: * Convert protection attributes to 4k-format, as cpa->mask* are set * up accordingly. */ /* Clear PSE (aka _PAGE_PAT) and move PAT bit to correct position */ req_prot = pgprot_large_2_4k(old_prot); pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr); pgprot_val(req_prot) |= pgprot_val(cpa->mask_set); /* * req_prot is in format of 4k pages. It must be converted to large * page format: the caching mode includes the PAT bit located at * different bit positions in the two formats. */ req_prot = pgprot_4k_2_large(req_prot); req_prot = pgprot_clear_protnone_bits(req_prot); if (pgprot_val(req_prot) & _PAGE_PRESENT) pgprot_val(req_prot) |= _PAGE_PSE; /* * old_pfn points to the large page base pfn. So we need to add the * offset of the virtual address: */ pfn = old_pfn + ((address & (psize - 1)) >> PAGE_SHIFT); cpa->pfn = pfn; /* * Calculate the large page base address and the number of 4K pages * in the large page */ lpaddr = address & pmask; numpages = psize >> PAGE_SHIFT; /* * Sanity check that the existing mapping is correct versus the static * protections. static_protections() guards against !PRESENT, so no * extra conditional required here. */ chk_prot = static_protections(old_prot, lpaddr, old_pfn, numpages, psize, CPA_CONFLICT); if (WARN_ON_ONCE(pgprot_val(chk_prot) != pgprot_val(old_prot))) { /* * Split the large page and tell the split code to * enforce static protections. */ cpa->force_static_prot = 1; return 1; } /* * Optimization: If the requested pgprot is the same as the current * pgprot, then the large page can be preserved and no updates are * required independent of alignment and length of the requested * range. The above already established that the current pgprot is * correct, which in consequence makes the requested pgprot correct * as well if it is the same. The static protection scan below will * not come to a different conclusion. */ if (pgprot_val(req_prot) == pgprot_val(old_prot)) { cpa_inc_lp_sameprot(level); return 0; } /* * If the requested range does not cover the full page, split it up */ if (address != lpaddr || cpa->numpages != numpages) return 1; /* * Check whether the requested pgprot is conflicting with a static * protection requirement in the large page. */ new_prot = static_protections(req_prot, lpaddr, old_pfn, numpages, psize, CPA_DETECT); new_prot = verify_rwx(old_prot, new_prot, lpaddr, old_pfn, numpages); /* * If there is a conflict, split the large page. * * There used to be a 4k wise evaluation trying really hard to * preserve the large pages, but experimentation has shown, that this * does not help at all. There might be corner cases which would * preserve one large page occasionally, but it's really not worth the * extra code and cycles for the common case. */ if (pgprot_val(req_prot) != pgprot_val(new_prot)) return 1; /* All checks passed. Update the large page mapping. */ new_pte = pfn_pte(old_pfn, new_prot); __set_pmd_pte(kpte, address, new_pte); cpa->flags |= CPA_FLUSHTLB; cpa_inc_lp_preserved(level); return 0; } static int should_split_large_page(pte_t *kpte, unsigned long address, struct cpa_data *cpa) { int do_split; if (cpa->force_split) return 1; spin_lock(&pgd_lock); do_split = __should_split_large_page(kpte, address, cpa); spin_unlock(&pgd_lock); return do_split; } static void split_set_pte(struct cpa_data *cpa, pte_t *pte, unsigned long pfn, pgprot_t ref_prot, unsigned long address, unsigned long size) { unsigned int npg = PFN_DOWN(size); pgprot_t prot; /* * If should_split_large_page() discovered an inconsistent mapping, * remove the invalid protection in the split mapping. */ if (!cpa->force_static_prot) goto set; /* Hand in lpsize = 0 to enforce the protection mechanism */ prot = static_protections(ref_prot, address, pfn, npg, 0, CPA_PROTECT); if (pgprot_val(prot) == pgprot_val(ref_prot)) goto set; /* * If this is splitting a PMD, fix it up. PUD splits cannot be * fixed trivially as that would require to rescan the newly * installed PMD mappings after returning from split_large_page() * so an eventual further split can allocate the necessary PTE * pages. Warn for now and revisit it in case this actually * happens. */ if (size == PAGE_SIZE) ref_prot = prot; else pr_warn_once("CPA: Cannot fixup static protections for PUD split\n"); set: set_pte(pte, pfn_pte(pfn, ref_prot)); } static int __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, struct page *base) { unsigned long lpaddr, lpinc, ref_pfn, pfn, pfninc = 1; pte_t *pbase = (pte_t *)page_address(base); unsigned int i, level; pgprot_t ref_prot; pte_t *tmp; spin_lock(&pgd_lock); /* * Check for races, another CPU might have split this page * up for us already: */ tmp = _lookup_address_cpa(cpa, address, &level); if (tmp != kpte) { spin_unlock(&pgd_lock); return 1; } paravirt_alloc_pte(&init_mm, page_to_pfn(base)); switch (level) { case PG_LEVEL_2M: ref_prot = pmd_pgprot(*(pmd_t *)kpte); /* * Clear PSE (aka _PAGE_PAT) and move * PAT bit to correct position. */ ref_prot = pgprot_large_2_4k(ref_prot); ref_pfn = pmd_pfn(*(pmd_t *)kpte); lpaddr = address & PMD_MASK; lpinc = PAGE_SIZE; break; case PG_LEVEL_1G: ref_prot = pud_pgprot(*(pud_t *)kpte); ref_pfn = pud_pfn(*(pud_t *)kpte); pfninc = PMD_SIZE >> PAGE_SHIFT; lpaddr = address & PUD_MASK; lpinc = PMD_SIZE; /* * Clear the PSE flags if the PRESENT flag is not set * otherwise pmd_present/pmd_huge will return true * even on a non present pmd. */ if (!(pgprot_val(ref_prot) & _PAGE_PRESENT)) pgprot_val(ref_prot) &= ~_PAGE_PSE; break; default: spin_unlock(&pgd_lock); return 1; } ref_prot = pgprot_clear_protnone_bits(ref_prot); /* * Get the target pfn from the original entry: */ pfn = ref_pfn; for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc, lpaddr += lpinc) split_set_pte(cpa, pbase + i, pfn, ref_prot, lpaddr, lpinc); if (virt_addr_valid(address)) { unsigned long pfn = PFN_DOWN(__pa(address)); if (pfn_range_is_mapped(pfn, pfn + 1)) split_page_count(level); } /* * Install the new, split up pagetable. * * We use the standard kernel pagetable protections for the new * pagetable protections, the actual ptes set above control the * primary protection behavior: */ __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE))); /* * Do a global flush tlb after splitting the large page * and before we do the actual change page attribute in the PTE. * * Without this, we violate the TLB application note, that says: * "The TLBs may contain both ordinary and large-page * translations for a 4-KByte range of linear addresses. This * may occur if software modifies the paging structures so that * the page size used for the address range changes. If the two * translations differ with respect to page frame or attributes * (e.g., permissions), processor behavior is undefined and may * be implementation-specific." * * We do this global tlb flush inside the cpa_lock, so that we * don't allow any other cpu, with stale tlb entries change the * page attribute in parallel, that also falls into the * just split large page entry. */ flush_tlb_all(); spin_unlock(&pgd_lock); return 0; } static int split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address) { struct page *base; if (!debug_pagealloc_enabled()) spin_unlock(&cpa_lock); base = alloc_pages(GFP_KERNEL, 0); if (!debug_pagealloc_enabled()) spin_lock(&cpa_lock); if (!base) return -ENOMEM; if (__split_large_page(cpa, kpte, address, base)) __free_page(base); return 0; } static bool try_to_free_pte_page(pte_t *pte) { int i; for (i = 0; i < PTRS_PER_PTE; i++) if (!pte_none(pte[i])) return false; free_page((unsigned long)pte); return true; } static bool try_to_free_pmd_page(pmd_t *pmd) { int i; for (i = 0; i < PTRS_PER_PMD; i++) if (!pmd_none(pmd[i])) return false; free_page((unsigned long)pmd); return true; } static bool unmap_pte_range(pmd_t *pmd, unsigned long start, unsigned long end) { pte_t *pte = pte_offset_kernel(pmd, start); while (start < end) { set_pte(pte, __pte(0)); start += PAGE_SIZE; pte++; } if (try_to_free_pte_page((pte_t *)pmd_page_vaddr(*pmd))) { pmd_clear(pmd); return true; } return false; } static void __unmap_pmd_range(pud_t *pud, pmd_t *pmd, unsigned long start, unsigned long end) { if (unmap_pte_range(pmd, start, end)) if (try_to_free_pmd_page(pud_pgtable(*pud))) pud_clear(pud); } static void unmap_pmd_range(pud_t *pud, unsigned long start, unsigned long end) { pmd_t *pmd = pmd_offset(pud, start); /* * Not on a 2MB page boundary? */ if (start & (PMD_SIZE - 1)) { unsigned long next_page = (start + PMD_SIZE) & PMD_MASK; unsigned long pre_end = min_t(unsigned long, end, next_page); __unmap_pmd_range(pud, pmd, start, pre_end); start = pre_end; pmd++; } /* * Try to unmap in 2M chunks. */ while (end - start >= PMD_SIZE) { if (pmd_large(*pmd)) pmd_clear(pmd); else __unmap_pmd_range(pud, pmd, start, start + PMD_SIZE); start += PMD_SIZE; pmd++; } /* * 4K leftovers? */ if (start < end) return __unmap_pmd_range(pud, pmd, start, end); /* * Try again to free the PMD page if haven't succeeded above. */ if (!pud_none(*pud)) if (try_to_free_pmd_page(pud_pgtable(*pud))) pud_clear(pud); } static void unmap_pud_range(p4d_t *p4d, unsigned long start, unsigned long end) { pud_t *pud = pud_offset(p4d, start); /* * Not on a GB page boundary? */ if (start & (PUD_SIZE - 1)) { unsigned long next_page = (start + PUD_SIZE) & PUD_MASK; unsigned long pre_end = min_t(unsigned long, end, next_page); unmap_pmd_range(pud, start, pre_end); start = pre_end; pud++; } /* * Try to unmap in 1G chunks? */ while (end - start >= PUD_SIZE) { if (pud_large(*pud)) pud_clear(pud); else unmap_pmd_range(pud, start, start + PUD_SIZE); start += PUD_SIZE; pud++; } /* * 2M leftovers? */ if (start < end) unmap_pmd_range(pud, start, end); /* * No need to try to free the PUD page because we'll free it in * populate_pgd's error path */ } static int alloc_pte_page(pmd_t *pmd) { pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL); if (!pte) return -1; set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE)); return 0; } static int alloc_pmd_page(pud_t *pud) { pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL); if (!pmd) return -1; set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); return 0; } static void populate_pte(struct cpa_data *cpa, unsigned long start, unsigned long end, unsigned num_pages, pmd_t *pmd, pgprot_t pgprot) { pte_t *pte; pte = pte_offset_kernel(pmd, start); pgprot = pgprot_clear_protnone_bits(pgprot); while (num_pages-- && start < end) { set_pte(pte, pfn_pte(cpa->pfn, pgprot)); start += PAGE_SIZE; cpa->pfn++; pte++; } } static long populate_pmd(struct cpa_data *cpa, unsigned long start, unsigned long end, unsigned num_pages, pud_t *pud, pgprot_t pgprot) { long cur_pages = 0; pmd_t *pmd; pgprot_t pmd_pgprot; /* * Not on a 2M boundary? */ if (start & (PMD_SIZE - 1)) { unsigned long pre_end = start + (num_pages << PAGE_SHIFT); unsigned long next_page = (start + PMD_SIZE) & PMD_MASK; pre_end = min_t(unsigned long, pre_end, next_page); cur_pages = (pre_end - start) >> PAGE_SHIFT; cur_pages = min_t(unsigned int, num_pages, cur_pages); /* * Need a PTE page? */ pmd = pmd_offset(pud, start); if (pmd_none(*pmd)) if (alloc_pte_page(pmd)) return -1; populate_pte(cpa, start, pre_end, cur_pages, pmd, pgprot); start = pre_end; } /* * We mapped them all? */ if (num_pages == cur_pages) return cur_pages; pmd_pgprot = pgprot_4k_2_large(pgprot); while (end - start >= PMD_SIZE) { /* * We cannot use a 1G page so allocate a PMD page if needed. */ if (pud_none(*pud)) if (alloc_pmd_page(pud)) return -1; pmd = pmd_offset(pud, start); set_pmd(pmd, pmd_mkhuge(pfn_pmd(cpa->pfn, canon_pgprot(pmd_pgprot)))); start += PMD_SIZE; cpa->pfn += PMD_SIZE >> PAGE_SHIFT; cur_pages += PMD_SIZE >> PAGE_SHIFT; } /* * Map trailing 4K pages. */ if (start < end) { pmd = pmd_offset(pud, start); if (pmd_none(*pmd)) if (alloc_pte_page(pmd)) return -1; populate_pte(cpa, start, end, num_pages - cur_pages, pmd, pgprot); } return num_pages; } static int populate_pud(struct cpa_data *cpa, unsigned long start, p4d_t *p4d, pgprot_t pgprot) { pud_t *pud; unsigned long end; long cur_pages = 0; pgprot_t pud_pgprot; end = start + (cpa->numpages << PAGE_SHIFT); /* * Not on a Gb page boundary? => map everything up to it with * smaller pages. */ if (start & (PUD_SIZE - 1)) { unsigned long pre_end; unsigned long next_page = (start + PUD_SIZE) & PUD_MASK; pre_end = min_t(unsigned long, end, next_page); cur_pages = (pre_end - start) >> PAGE_SHIFT; cur_pages = min_t(int, (int)cpa->numpages, cur_pages); pud = pud_offset(p4d, start); /* * Need a PMD page? */ if (pud_none(*pud)) if (alloc_pmd_page(pud)) return -1; cur_pages = populate_pmd(cpa, start, pre_end, cur_pages, pud, pgprot); if (cur_pages < 0) return cur_pages; start = pre_end; } /* We mapped them all? */ if (cpa->numpages == cur_pages) return cur_pages; pud = pud_offset(p4d, start); pud_pgprot = pgprot_4k_2_large(pgprot); /* * Map everything starting from the Gb boundary, possibly with 1G pages */ while (boot_cpu_has(X86_FEATURE_GBPAGES) && end - start >= PUD_SIZE) { set_pud(pud, pud_mkhuge(pfn_pud(cpa->pfn, canon_pgprot(pud_pgprot)))); start += PUD_SIZE; cpa->pfn += PUD_SIZE >> PAGE_SHIFT; cur_pages += PUD_SIZE >> PAGE_SHIFT; pud++; } /* Map trailing leftover */ if (start < end) { long tmp; pud = pud_offset(p4d, start); if (pud_none(*pud)) if (alloc_pmd_page(pud)) return -1; tmp = populate_pmd(cpa, start, end, cpa->numpages - cur_pages, pud, pgprot); if (tmp < 0) return cur_pages; cur_pages += tmp; } return cur_pages; } /* * Restrictions for kernel page table do not necessarily apply when mapping in * an alternate PGD. */ static int populate_pgd(struct cpa_data *cpa, unsigned long addr) { pgprot_t pgprot = __pgprot(_KERNPG_TABLE); pud_t *pud = NULL; /* shut up gcc */ p4d_t *p4d; pgd_t *pgd_entry; long ret; pgd_entry = cpa->pgd + pgd_index(addr); if (pgd_none(*pgd_entry)) { p4d = (p4d_t *)get_zeroed_page(GFP_KERNEL); if (!p4d) return -1; set_pgd(pgd_entry, __pgd(__pa(p4d) | _KERNPG_TABLE)); } /* * Allocate a PUD page and hand it down for mapping. */ p4d = p4d_offset(pgd_entry, addr); if (p4d_none(*p4d)) { pud = (pud_t *)get_zeroed_page(GFP_KERNEL); if (!pud) return -1; set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE)); } pgprot_val(pgprot) &= ~pgprot_val(cpa->mask_clr); pgprot_val(pgprot) |= pgprot_val(cpa->mask_set); ret = populate_pud(cpa, addr, p4d, pgprot); if (ret < 0) { /* * Leave the PUD page in place in case some other CPU or thread * already found it, but remove any useless entries we just * added to it. */ unmap_pud_range(p4d, addr, addr + (cpa->numpages << PAGE_SHIFT)); return ret; } cpa->numpages = ret; return 0; } static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr, int primary) { if (cpa->pgd) { /* * Right now, we only execute this code path when mapping * the EFI virtual memory map regions, no other users * provide a ->pgd value. This may change in the future. */ return populate_pgd(cpa, vaddr); } /* * Ignore all non primary paths. */ if (!primary) { cpa->numpages = 1; return 0; } /* * Ignore the NULL PTE for kernel identity mapping, as it is expected * to have holes. * Also set numpages to '1' indicating that we processed cpa req for * one virtual address page and its pfn. TBD: numpages can be set based * on the initial value and the level returned by lookup_address(). */ if (within(vaddr, PAGE_OFFSET, PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) { cpa->numpages = 1; cpa->pfn = __pa(vaddr) >> PAGE_SHIFT; return 0; } else if (__cpa_pfn_in_highmap(cpa->pfn)) { /* Faults in the highmap are OK, so do not warn: */ return -EFAULT; } else { WARN(1, KERN_WARNING "CPA: called for zero pte. " "vaddr = %lx cpa->vaddr = %lx\n", vaddr, *cpa->vaddr); return -EFAULT; } } static int __change_page_attr(struct cpa_data *cpa, int primary) { unsigned long address; int do_split, err; unsigned int level; pte_t *kpte, old_pte; address = __cpa_addr(cpa, cpa->curpage); repeat: kpte = _lookup_address_cpa(cpa, address, &level); if (!kpte) return __cpa_process_fault(cpa, address, primary); old_pte = *kpte; if (pte_none(old_pte)) return __cpa_process_fault(cpa, address, primary); if (level == PG_LEVEL_4K) { pte_t new_pte; pgprot_t old_prot = pte_pgprot(old_pte); pgprot_t new_prot = pte_pgprot(old_pte); unsigned long pfn = pte_pfn(old_pte); pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr); pgprot_val(new_prot) |= pgprot_val(cpa->mask_set); cpa_inc_4k_install(); /* Hand in lpsize = 0 to enforce the protection mechanism */ new_prot = static_protections(new_prot, address, pfn, 1, 0, CPA_PROTECT); new_prot = verify_rwx(old_prot, new_prot, address, pfn, 1); new_prot = pgprot_clear_protnone_bits(new_prot); /* * We need to keep the pfn from the existing PTE, * after all we're only going to change it's attributes * not the memory it points to */ new_pte = pfn_pte(pfn, new_prot); cpa->pfn = pfn; /* * Do we really change anything ? */ if (pte_val(old_pte) != pte_val(new_pte)) { set_pte_atomic(kpte, new_pte); cpa->flags |= CPA_FLUSHTLB; } cpa->numpages = 1; return 0; } /* * Check, whether we can keep the large page intact * and just change the pte: */ do_split = should_split_large_page(kpte, address, cpa); /* * When the range fits into the existing large page, * return. cp->numpages and cpa->tlbflush have been updated in * try_large_page: */ if (do_split <= 0) return do_split; /* * We have to split the large page: */ err = split_large_page(cpa, kpte, address); if (!err) goto repeat; return err; } 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; unsigned long laddr = (unsigned long)__va(cpa->pfn << PAGE_SHIFT); unsigned long vaddr; int ret; if (!pfn_range_is_mapped(cpa->pfn, cpa->pfn + 1)) return 0; /* * No need to redo, when the primary call touched the direct * mapping already: */ vaddr = __cpa_addr(cpa, cpa->curpage); if (!(within(vaddr, PAGE_OFFSET, PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)))) { alias_cpa = *cpa; alias_cpa.vaddr = &laddr; 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); if (ret) return ret; } #ifdef CONFIG_X86_64 /* * If the primary call didn't touch the high mapping already * and the physical address is inside the kernel map, we need * to touch the high mapped kernel as well: */ if (!within(vaddr, (unsigned long)_text, _brk_end) && __cpa_pfn_in_highmap(cpa->pfn)) { unsigned long temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) + __START_KERNEL_map - phys_base; alias_cpa = *cpa; alias_cpa.vaddr = &temp_cpa_vaddr; 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 * return value. */ __change_page_attr_set_clr(&alias_cpa, 0); } #endif return 0; } 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 * preservation check. */ cpa->numpages = rempages; /* for array changes, we can't use large page */ if (cpa->flags & (CPA_ARRAY | CPA_PAGES_ARRAY)) cpa->numpages = 1; if (!debug_pagealloc_enabled()) spin_lock(&cpa_lock); ret = __change_page_attr(cpa, primary); if (!debug_pagealloc_enabled()) spin_unlock(&cpa_lock); if (ret) goto out; if (primary && !(cpa->flags & CPA_NO_CHECK_ALIAS)) { ret = cpa_process_alias(cpa); if (ret) goto out; } /* * Adjust the number of pages with the result of the * CPA operation. Either a large page has been * preserved or a single page update happened. */ BUG_ON(cpa->numpages > rempages || !cpa->numpages); rempages -= cpa->numpages; cpa->curpage += cpa->numpages; } out: /* Restore the original numpages */ cpa->numpages = numpages; return ret; } static int change_page_attr_set_clr(unsigned long *addr, int numpages, pgprot_t mask_set, pgprot_t mask_clr, int force_split, int in_flag, struct page **pages) { struct cpa_data cpa; int ret, cache; memset(&cpa, 0, sizeof(cpa)); /* * Check, if we are requested to set a not supported * feature. Clearing non-supported features is OK. */ mask_set = canon_pgprot(mask_set); if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split) return 0; /* Ensure we are PAGE_SIZE aligned */ if (in_flag & CPA_ARRAY) { int i; for (i = 0; i < numpages; i++) { if (addr[i] & ~PAGE_MASK) { addr[i] &= PAGE_MASK; WARN_ON_ONCE(1); } } } else if (!(in_flag & CPA_PAGES_ARRAY)) { /* * in_flag of CPA_PAGES_ARRAY implies it is aligned. * No need to check in that case */ if (*addr & ~PAGE_MASK) { *addr &= PAGE_MASK; /* * People should not be passing in unaligned addresses: */ WARN_ON_ONCE(1); } } /* Must avoid aliasing mappings in the highmem code */ kmap_flush_unused(); vm_unmap_aliases(); cpa.vaddr = addr; cpa.pages = pages; cpa.numpages = numpages; cpa.mask_set = mask_set; cpa.mask_clr = mask_clr; cpa.flags = in_flag; cpa.curpage = 0; cpa.force_split = force_split; ret = __change_page_attr_set_clr(&cpa, 1); /* * Check whether we really changed something: */ if (!(cpa.flags & CPA_FLUSHTLB)) goto out; /* * No need to flush, when we did not set any of the caching * attributes: */ cache = !!pgprot2cachemode(mask_set); /* * On error; flush everything to be sure. */ if (ret) { cpa_flush_all(cache); goto out; } cpa_flush(&cpa, cache); out: return ret; } static inline int change_page_attr_set(unsigned long *addr, int numpages, pgprot_t mask, int array) { return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0, (array ? CPA_ARRAY : 0), NULL); } static inline int change_page_attr_clear(unsigned long *addr, int numpages, pgprot_t mask, int array) { return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0, (array ? CPA_ARRAY : 0), NULL); } static inline int cpa_set_pages_array(struct page **pages, int numpages, pgprot_t mask) { return change_page_attr_set_clr(NULL, numpages, mask, __pgprot(0), 0, CPA_PAGES_ARRAY, pages); } static inline int cpa_clear_pages_array(struct page **pages, int numpages, pgprot_t mask) { return change_page_attr_set_clr(NULL, numpages, __pgprot(0), mask, 0, CPA_PAGES_ARRAY, pages); } /* * __set_memory_prot is an internal helper for callers that have been passed * a pgprot_t value from upper layers and a reservation has already been taken. * If you want to set the pgprot to a specific page protocol, use the * set_memory_xx() functions. */ int __set_memory_prot(unsigned long addr, int numpages, pgprot_t prot) { return change_page_attr_set_clr(&addr, numpages, prot, __pgprot(~pgprot_val(prot)), 0, 0, NULL); } int _set_memory_uc(unsigned long addr, int numpages) { /* * for now UC MINUS. see comments in ioremap() * If you really need strong UC use ioremap_uc(), but note * that you cannot override IO areas with set_memory_*() as * these helpers cannot work with IO memory. */ return change_page_attr_set(&addr, numpages, cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS), 0); } int set_memory_uc(unsigned long addr, int numpages) { int ret; /* * for now UC MINUS. see comments in ioremap() */ ret = memtype_reserve(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, _PAGE_CACHE_MODE_UC_MINUS, NULL); if (ret) goto out_err; ret = _set_memory_uc(addr, numpages); if (ret) goto out_free; return 0; out_free: memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); out_err: return ret; } EXPORT_SYMBOL(set_memory_uc); int _set_memory_wc(unsigned long addr, int numpages) { int ret; ret = change_page_attr_set(&addr, numpages, cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS), 0); if (!ret) { ret = change_page_attr_set_clr(&addr, numpages, cachemode2pgprot(_PAGE_CACHE_MODE_WC), __pgprot(_PAGE_CACHE_MASK), 0, 0, NULL); } return ret; } int set_memory_wc(unsigned long addr, int numpages) { int ret; ret = memtype_reserve(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, _PAGE_CACHE_MODE_WC, NULL); if (ret) return ret; ret = _set_memory_wc(addr, numpages); if (ret) memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); return ret; } EXPORT_SYMBOL(set_memory_wc); int _set_memory_wt(unsigned long addr, int numpages) { return change_page_attr_set(&addr, numpages, cachemode2pgprot(_PAGE_CACHE_MODE_WT), 0); } int _set_memory_wb(unsigned long addr, int numpages) { /* WB cache mode is hard wired to all cache attribute bits being 0 */ return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_CACHE_MASK), 0); } int set_memory_wb(unsigned long addr, int numpages) { int ret; ret = _set_memory_wb(addr, numpages); if (ret) return ret; memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); return 0; } EXPORT_SYMBOL(set_memory_wb); /* Prevent speculative access to a page by marking it not-present */ #ifdef CONFIG_X86_64 int set_mce_nospec(unsigned long pfn) { unsigned long decoy_addr; int rc; /* SGX pages are not in the 1:1 map */ if (arch_is_platform_page(pfn << PAGE_SHIFT)) return 0; /* * We would like to just call: * set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1); * but doing that would radically increase the odds of a * speculative access to the poison page because we'd have * the virtual address of the kernel 1:1 mapping sitting * around in registers. * Instead we get tricky. We create a non-canonical address * that looks just like the one we want, but has bit 63 flipped. * This relies on set_memory_XX() properly sanitizing any __pa() * results with __PHYSICAL_MASK or PTE_PFN_MASK. */ decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63)); rc = set_memory_np(decoy_addr, 1); if (rc) pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn); return rc; } static int set_memory_p(unsigned long *addr, int numpages) { return change_page_attr_set(addr, numpages, __pgprot(_PAGE_PRESENT), 0); } /* Restore full speculative operation to the pfn. */ int clear_mce_nospec(unsigned long pfn) { unsigned long addr = (unsigned long) pfn_to_kaddr(pfn); return set_memory_p(&addr, 1); } EXPORT_SYMBOL_GPL(clear_mce_nospec); #endif /* CONFIG_X86_64 */ int set_memory_x(unsigned long addr, int numpages) { if (!(__supported_pte_mask & _PAGE_NX)) return 0; return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0); } int set_memory_nx(unsigned long addr, int numpages) { if (!(__supported_pte_mask & _PAGE_NX)) return 0; return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0); } 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); } int set_memory_np(unsigned long addr, int numpages) { return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_PRESENT), 0); } int set_memory_np_noalias(unsigned long addr, int numpages) { return change_page_attr_set_clr(&addr, numpages, __pgprot(0), __pgprot(_PAGE_PRESENT), 0, CPA_NO_CHECK_ALIAS, NULL); } int set_memory_4k(unsigned long addr, int numpages) { return change_page_attr_set_clr(&addr, numpages, __pgprot(0), __pgprot(0), 1, 0, NULL); } int set_memory_nonglobal(unsigned long addr, int numpages) { return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_GLOBAL), 0); } int set_memory_global(unsigned long addr, int numpages) { return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_GLOBAL), 0); } /* * __set_memory_enc_pgtable() is used for the hypervisors that get * informed about "encryption" status via page tables. */ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc) { pgprot_t empty = __pgprot(0); struct cpa_data cpa; int ret; /* Should not be working on unaligned addresses */ if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr)) addr &= PAGE_MASK; memset(&cpa, 0, sizeof(cpa)); cpa.vaddr = &addr; cpa.numpages = numpages; cpa.mask_set = enc ? pgprot_encrypted(empty) : pgprot_decrypted(empty); cpa.mask_clr = enc ? pgprot_decrypted(empty) : pgprot_encrypted(empty); cpa.pgd = init_mm.pgd; /* Must avoid aliasing mappings in the highmem code */ kmap_flush_unused(); vm_unmap_aliases(); /* Flush the caches as needed before changing the encryption attribute. */ if (x86_platform.guest.enc_tlb_flush_required(enc)) cpa_flush(&cpa, x86_platform.guest.enc_cache_flush_required()); /* Notify hypervisor that we are about to set/clr encryption attribute. */ x86_platform.guest.enc_status_change_prepare(addr, numpages, enc); ret = __change_page_attr_set_clr(&cpa, 1); /* * After changing the encryption attribute, we need to flush TLBs again * in case any speculative TLB caching occurred (but no need to flush * caches again). We could just use cpa_flush_all(), but in case TLB * flushing gets optimized in the cpa_flush() path use the same logic * as above. */ cpa_flush(&cpa, 0); /* Notify hypervisor that we have successfully set/clr encryption attribute. */ if (!ret) { if (!x86_platform.guest.enc_status_change_finish(addr, numpages, enc)) ret = -EIO; } return ret; } static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) { if (hv_is_isolation_supported()) return hv_set_mem_host_visibility(addr, numpages, !enc); if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) return __set_memory_enc_pgtable(addr, numpages, enc); return 0; } int set_memory_encrypted(unsigned long addr, int numpages) { return __set_memory_enc_dec(addr, numpages, true); } EXPORT_SYMBOL_GPL(set_memory_encrypted); int set_memory_decrypted(unsigned long addr, int numpages) { return __set_memory_enc_dec(addr, numpages, false); } EXPORT_SYMBOL_GPL(set_memory_decrypted); int set_pages_uc(struct page *page, int numpages) { unsigned long addr = (unsigned long)page_address(page); return set_memory_uc(addr, numpages); } EXPORT_SYMBOL(set_pages_uc); static int _set_pages_array(struct page **pages, int numpages, enum page_cache_mode new_type) { unsigned long start; unsigned long end; enum page_cache_mode set_type; int i; int free_idx; int ret; for (i = 0; i < numpages; i++) { if (PageHighMem(pages[i])) continue; start = page_to_pfn(pages[i]) << PAGE_SHIFT; end = start + PAGE_SIZE; if (memtype_reserve(start, end, new_type, NULL)) goto err_out; } /* If WC, set to UC- first and then WC */ set_type = (new_type == _PAGE_CACHE_MODE_WC) ? _PAGE_CACHE_MODE_UC_MINUS : new_type; ret = cpa_set_pages_array(pages, numpages, cachemode2pgprot(set_type)); if (!ret && new_type == _PAGE_CACHE_MODE_WC) ret = change_page_attr_set_clr(NULL, numpages, cachemode2pgprot( _PAGE_CACHE_MODE_WC), __pgprot(_PAGE_CACHE_MASK), 0, CPA_PAGES_ARRAY, pages); if (ret) goto err_out; return 0; /* Success */ err_out: free_idx = i; for (i = 0; i < free_idx; i++) { if (PageHighMem(pages[i])) continue; start = page_to_pfn(pages[i]) << PAGE_SHIFT; end = start + PAGE_SIZE; memtype_free(start, end); } return -EINVAL; } int set_pages_array_uc(struct page **pages, int numpages) { return _set_pages_array(pages, numpages, _PAGE_CACHE_MODE_UC_MINUS); } EXPORT_SYMBOL(set_pages_array_uc); int set_pages_array_wc(struct page **pages, int numpages) { return _set_pages_array(pages, numpages, _PAGE_CACHE_MODE_WC); } EXPORT_SYMBOL(set_pages_array_wc); int set_pages_wb(struct page *page, int numpages) { unsigned long addr = (unsigned long)page_address(page); return set_memory_wb(addr, numpages); } EXPORT_SYMBOL(set_pages_wb); int set_pages_array_wb(struct page **pages, int numpages) { int retval; unsigned long start; unsigned long end; int i; /* WB cache mode is hard wired to all cache attribute bits being 0 */ retval = cpa_clear_pages_array(pages, numpages, __pgprot(_PAGE_CACHE_MASK)); if (retval) return retval; for (i = 0; i < numpages; i++) { if (PageHighMem(pages[i])) continue; start = page_to_pfn(pages[i]) << PAGE_SHIFT; end = start + PAGE_SIZE; memtype_free(start, end); } return 0; } EXPORT_SYMBOL(set_pages_array_wb); int set_pages_ro(struct page *page, int numpages) { unsigned long addr = (unsigned long)page_address(page); return set_memory_ro(addr, numpages); } int set_pages_rw(struct page *page, int numpages) { unsigned long addr = (unsigned long)page_address(page); return set_memory_rw(addr, numpages); } static int __set_pages_p(struct page *page, int numpages) { unsigned long tempaddr = (unsigned long) page_address(page); struct cpa_data cpa = { .vaddr = &tempaddr, .pgd = NULL, .numpages = numpages, .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW), .mask_clr = __pgprot(0), .flags = CPA_NO_CHECK_ALIAS }; /* * No alias checking needed for setting present flag. otherwise, * we may need to break large pages for 64-bit kernel text * 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, 1); } static int __set_pages_np(struct page *page, int numpages) { unsigned long tempaddr = (unsigned long) page_address(page); struct cpa_data cpa = { .vaddr = &tempaddr, .pgd = NULL, .numpages = numpages, .mask_set = __pgprot(0), .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), .flags = CPA_NO_CHECK_ALIAS }; /* * No alias checking needed for setting not present flag. otherwise, * we may need to break large pages for 64-bit kernel text * 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, 1); } int set_direct_map_invalid_noflush(struct page *page) { return __set_pages_np(page, 1); } int set_direct_map_default_noflush(struct page *page) { return __set_pages_p(page, 1); } #ifdef CONFIG_DEBUG_PAGEALLOC void __kernel_map_pages(struct page *page, int numpages, int enable) { if (PageHighMem(page)) return; if (!enable) { debug_check_no_locks_freed(page_address(page), numpages * PAGE_SIZE); } /* * The return value is ignored as the calls cannot fail. * Large pages for identity mappings are not used at boot time * and hence no memory allocations during large page split. */ if (enable) __set_pages_p(page, numpages); else __set_pages_np(page, numpages); /* * We should perform an IPI and flush all tlbs, * but that can deadlock->flush only current cpu. * Preemption needs to be disabled around __flush_tlb_all() due to * CR3 reload in __native_flush_tlb(). */ preempt_disable(); __flush_tlb_all(); preempt_enable(); arch_flush_lazy_mmu_mode(); } #endif /* CONFIG_DEBUG_PAGEALLOC */ bool kernel_page_present(struct page *page) { unsigned int level; pte_t *pte; if (PageHighMem(page)) return false; pte = lookup_address((unsigned long)page_address(page), &level); return (pte_val(*pte) & _PAGE_PRESENT); } int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, unsigned numpages, unsigned long page_flags) { int retval = -EINVAL; struct cpa_data cpa = { .vaddr = &address, .pfn = pfn, .pgd = pgd, .numpages = numpages, .mask_set = __pgprot(0), .mask_clr = __pgprot(~page_flags & (_PAGE_NX|_PAGE_RW)), .flags = CPA_NO_CHECK_ALIAS, }; WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); if (!(__supported_pte_mask & _PAGE_NX)) goto out; if (!(page_flags & _PAGE_ENC)) cpa.mask_clr = pgprot_encrypted(cpa.mask_clr); cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags); retval = __change_page_attr_set_clr(&cpa, 1); __flush_tlb_all(); out: return retval; } /* * __flush_tlb_all() flushes mappings only on current CPU and hence this * function shouldn't be used in an SMP environment. Presently, it's used only * during boot (way before smp_init()) by EFI subsystem and hence is ok. */ int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address, unsigned long numpages) { int retval; /* * The typical sequence for unmapping is to find a pte through * lookup_address_in_pgd() (ideally, it should never return NULL because * the address is already mapped) and change it's protections. As pfn is * the *target* of a mapping, it's not useful while unmapping. */ struct cpa_data cpa = { .vaddr = &address, .pfn = 0, .pgd = pgd, .numpages = numpages, .mask_set = __pgprot(0), .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), .flags = CPA_NO_CHECK_ALIAS, }; WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); retval = __change_page_attr_set_clr(&cpa, 1); __flush_tlb_all(); return retval; } /* * The testcases use internal knowledge of the implementation that shouldn't * be exposed to the rest of the kernel. Include these directly here. */ #ifdef CONFIG_CPA_DEBUG #include "cpa-test.c" #endif
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