| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
| */ |
| |
| #include <linux/mm.h> |
| #include <linux/module.h> |
| #include <linux/sched/signal.h> |
| |
| #include <asm/pgtable.h> |
| #include <asm/tlbflush.h> |
| #include <as-layout.h> |
| #include <mem_user.h> |
| #include <os.h> |
| #include <skas.h> |
| #include <kern_util.h> |
| |
| struct host_vm_change { |
| struct host_vm_op { |
| enum { NONE, MMAP, MUNMAP, MPROTECT } type; |
| union { |
| struct { |
| unsigned long addr; |
| unsigned long len; |
| unsigned int prot; |
| int fd; |
| __u64 offset; |
| } mmap; |
| struct { |
| unsigned long addr; |
| unsigned long len; |
| } munmap; |
| struct { |
| unsigned long addr; |
| unsigned long len; |
| unsigned int prot; |
| } mprotect; |
| } u; |
| } ops[1]; |
| int userspace; |
| int index; |
| struct mm_struct *mm; |
| void *data; |
| int force; |
| }; |
| |
| #define INIT_HVC(mm, force, userspace) \ |
| ((struct host_vm_change) \ |
| { .ops = { { .type = NONE } }, \ |
| .mm = mm, \ |
| .data = NULL, \ |
| .userspace = userspace, \ |
| .index = 0, \ |
| .force = force }) |
| |
| static void report_enomem(void) |
| { |
| printk(KERN_ERR "UML ran out of memory on the host side! " |
| "This can happen due to a memory limitation or " |
| "vm.max_map_count has been reached.\n"); |
| } |
| |
| static int do_ops(struct host_vm_change *hvc, int end, |
| int finished) |
| { |
| struct host_vm_op *op; |
| int i, ret = 0; |
| |
| for (i = 0; i < end && !ret; i++) { |
| op = &hvc->ops[i]; |
| switch (op->type) { |
| case MMAP: |
| if (hvc->userspace) |
| ret = map(&hvc->mm->context.id, op->u.mmap.addr, |
| op->u.mmap.len, op->u.mmap.prot, |
| op->u.mmap.fd, |
| op->u.mmap.offset, finished, |
| &hvc->data); |
| else |
| map_memory(op->u.mmap.addr, op->u.mmap.offset, |
| op->u.mmap.len, 1, 1, 1); |
| break; |
| case MUNMAP: |
| if (hvc->userspace) |
| ret = unmap(&hvc->mm->context.id, |
| op->u.munmap.addr, |
| op->u.munmap.len, finished, |
| &hvc->data); |
| else |
| ret = os_unmap_memory( |
| (void *) op->u.munmap.addr, |
| op->u.munmap.len); |
| |
| break; |
| case MPROTECT: |
| if (hvc->userspace) |
| ret = protect(&hvc->mm->context.id, |
| op->u.mprotect.addr, |
| op->u.mprotect.len, |
| op->u.mprotect.prot, |
| finished, &hvc->data); |
| else |
| ret = os_protect_memory( |
| (void *) op->u.mprotect.addr, |
| op->u.mprotect.len, |
| 1, 1, 1); |
| break; |
| default: |
| printk(KERN_ERR "Unknown op type %d in do_ops\n", |
| op->type); |
| BUG(); |
| break; |
| } |
| } |
| |
| if (ret == -ENOMEM) |
| report_enomem(); |
| |
| return ret; |
| } |
| |
| static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len, |
| unsigned int prot, struct host_vm_change *hvc) |
| { |
| __u64 offset; |
| struct host_vm_op *last; |
| int fd = -1, ret = 0; |
| |
| if (hvc->userspace) |
| fd = phys_mapping(phys, &offset); |
| else |
| offset = phys; |
| if (hvc->index != 0) { |
| last = &hvc->ops[hvc->index - 1]; |
| if ((last->type == MMAP) && |
| (last->u.mmap.addr + last->u.mmap.len == virt) && |
| (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) && |
| (last->u.mmap.offset + last->u.mmap.len == offset)) { |
| last->u.mmap.len += len; |
| return 0; |
| } |
| } |
| |
| if (hvc->index == ARRAY_SIZE(hvc->ops)) { |
| ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0); |
| hvc->index = 0; |
| } |
| |
| hvc->ops[hvc->index++] = ((struct host_vm_op) |
| { .type = MMAP, |
| .u = { .mmap = { .addr = virt, |
| .len = len, |
| .prot = prot, |
| .fd = fd, |
| .offset = offset } |
| } }); |
| return ret; |
| } |
| |
| static int add_munmap(unsigned long addr, unsigned long len, |
| struct host_vm_change *hvc) |
| { |
| struct host_vm_op *last; |
| int ret = 0; |
| |
| if ((addr >= STUB_START) && (addr < STUB_END)) |
| return -EINVAL; |
| |
| if (hvc->index != 0) { |
| last = &hvc->ops[hvc->index - 1]; |
| if ((last->type == MUNMAP) && |
| (last->u.munmap.addr + last->u.mmap.len == addr)) { |
| last->u.munmap.len += len; |
| return 0; |
| } |
| } |
| |
| if (hvc->index == ARRAY_SIZE(hvc->ops)) { |
| ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0); |
| hvc->index = 0; |
| } |
| |
| hvc->ops[hvc->index++] = ((struct host_vm_op) |
| { .type = MUNMAP, |
| .u = { .munmap = { .addr = addr, |
| .len = len } } }); |
| return ret; |
| } |
| |
| static int add_mprotect(unsigned long addr, unsigned long len, |
| unsigned int prot, struct host_vm_change *hvc) |
| { |
| struct host_vm_op *last; |
| int ret = 0; |
| |
| if (hvc->index != 0) { |
| last = &hvc->ops[hvc->index - 1]; |
| if ((last->type == MPROTECT) && |
| (last->u.mprotect.addr + last->u.mprotect.len == addr) && |
| (last->u.mprotect.prot == prot)) { |
| last->u.mprotect.len += len; |
| return 0; |
| } |
| } |
| |
| if (hvc->index == ARRAY_SIZE(hvc->ops)) { |
| ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0); |
| hvc->index = 0; |
| } |
| |
| hvc->ops[hvc->index++] = ((struct host_vm_op) |
| { .type = MPROTECT, |
| .u = { .mprotect = { .addr = addr, |
| .len = len, |
| .prot = prot } } }); |
| return ret; |
| } |
| |
| #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1)) |
| |
| static inline int update_pte_range(pmd_t *pmd, unsigned long addr, |
| unsigned long end, |
| struct host_vm_change *hvc) |
| { |
| pte_t *pte; |
| int r, w, x, prot, ret = 0; |
| |
| pte = pte_offset_kernel(pmd, addr); |
| do { |
| if ((addr >= STUB_START) && (addr < STUB_END)) |
| continue; |
| |
| r = pte_read(*pte); |
| w = pte_write(*pte); |
| x = pte_exec(*pte); |
| if (!pte_young(*pte)) { |
| r = 0; |
| w = 0; |
| } else if (!pte_dirty(*pte)) |
| w = 0; |
| |
| prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) | |
| (x ? UM_PROT_EXEC : 0)); |
| if (hvc->force || pte_newpage(*pte)) { |
| if (pte_present(*pte)) { |
| if (pte_newpage(*pte)) |
| ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK, |
| PAGE_SIZE, prot, hvc); |
| } else |
| ret = add_munmap(addr, PAGE_SIZE, hvc); |
| } else if (pte_newprot(*pte)) |
| ret = add_mprotect(addr, PAGE_SIZE, prot, hvc); |
| *pte = pte_mkuptodate(*pte); |
| } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret)); |
| return ret; |
| } |
| |
| static inline int update_pmd_range(pud_t *pud, unsigned long addr, |
| unsigned long end, |
| struct host_vm_change *hvc) |
| { |
| pmd_t *pmd; |
| unsigned long next; |
| int ret = 0; |
| |
| pmd = pmd_offset(pud, addr); |
| do { |
| next = pmd_addr_end(addr, end); |
| if (!pmd_present(*pmd)) { |
| if (hvc->force || pmd_newpage(*pmd)) { |
| ret = add_munmap(addr, next - addr, hvc); |
| pmd_mkuptodate(*pmd); |
| } |
| } |
| else ret = update_pte_range(pmd, addr, next, hvc); |
| } while (pmd++, addr = next, ((addr < end) && !ret)); |
| return ret; |
| } |
| |
| static inline int update_pud_range(pgd_t *pgd, unsigned long addr, |
| unsigned long end, |
| struct host_vm_change *hvc) |
| { |
| pud_t *pud; |
| unsigned long next; |
| int ret = 0; |
| |
| pud = pud_offset(pgd, addr); |
| do { |
| next = pud_addr_end(addr, end); |
| if (!pud_present(*pud)) { |
| if (hvc->force || pud_newpage(*pud)) { |
| ret = add_munmap(addr, next - addr, hvc); |
| pud_mkuptodate(*pud); |
| } |
| } |
| else ret = update_pmd_range(pud, addr, next, hvc); |
| } while (pud++, addr = next, ((addr < end) && !ret)); |
| return ret; |
| } |
| |
| void fix_range_common(struct mm_struct *mm, unsigned long start_addr, |
| unsigned long end_addr, int force) |
| { |
| pgd_t *pgd; |
| struct host_vm_change hvc; |
| unsigned long addr = start_addr, next; |
| int ret = 0, userspace = 1; |
| |
| hvc = INIT_HVC(mm, force, userspace); |
| pgd = pgd_offset(mm, addr); |
| do { |
| next = pgd_addr_end(addr, end_addr); |
| if (!pgd_present(*pgd)) { |
| if (force || pgd_newpage(*pgd)) { |
| ret = add_munmap(addr, next - addr, &hvc); |
| pgd_mkuptodate(*pgd); |
| } |
| } |
| else ret = update_pud_range(pgd, addr, next, &hvc); |
| } while (pgd++, addr = next, ((addr < end_addr) && !ret)); |
| |
| if (!ret) |
| ret = do_ops(&hvc, hvc.index, 1); |
| |
| /* This is not an else because ret is modified above */ |
| if (ret) { |
| printk(KERN_ERR "fix_range_common: failed, killing current " |
| "process: %d\n", task_tgid_vnr(current)); |
| /* We are under mmap_sem, release it such that current can terminate */ |
| up_write(¤t->mm->mmap_sem); |
| force_sig(SIGKILL); |
| do_signal(¤t->thread.regs); |
| } |
| } |
| |
| static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end) |
| { |
| struct mm_struct *mm; |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| unsigned long addr, last; |
| int updated = 0, err = 0, force = 0, userspace = 0; |
| struct host_vm_change hvc; |
| |
| mm = &init_mm; |
| hvc = INIT_HVC(mm, force, userspace); |
| for (addr = start; addr < end;) { |
| pgd = pgd_offset(mm, addr); |
| if (!pgd_present(*pgd)) { |
| last = ADD_ROUND(addr, PGDIR_SIZE); |
| if (last > end) |
| last = end; |
| if (pgd_newpage(*pgd)) { |
| updated = 1; |
| err = add_munmap(addr, last - addr, &hvc); |
| if (err < 0) |
| panic("munmap failed, errno = %d\n", |
| -err); |
| } |
| addr = last; |
| continue; |
| } |
| |
| pud = pud_offset(pgd, addr); |
| if (!pud_present(*pud)) { |
| last = ADD_ROUND(addr, PUD_SIZE); |
| if (last > end) |
| last = end; |
| if (pud_newpage(*pud)) { |
| updated = 1; |
| err = add_munmap(addr, last - addr, &hvc); |
| if (err < 0) |
| panic("munmap failed, errno = %d\n", |
| -err); |
| } |
| addr = last; |
| continue; |
| } |
| |
| pmd = pmd_offset(pud, addr); |
| if (!pmd_present(*pmd)) { |
| last = ADD_ROUND(addr, PMD_SIZE); |
| if (last > end) |
| last = end; |
| if (pmd_newpage(*pmd)) { |
| updated = 1; |
| err = add_munmap(addr, last - addr, &hvc); |
| if (err < 0) |
| panic("munmap failed, errno = %d\n", |
| -err); |
| } |
| addr = last; |
| continue; |
| } |
| |
| pte = pte_offset_kernel(pmd, addr); |
| if (!pte_present(*pte) || pte_newpage(*pte)) { |
| updated = 1; |
| err = add_munmap(addr, PAGE_SIZE, &hvc); |
| if (err < 0) |
| panic("munmap failed, errno = %d\n", |
| -err); |
| if (pte_present(*pte)) |
| err = add_mmap(addr, pte_val(*pte) & PAGE_MASK, |
| PAGE_SIZE, 0, &hvc); |
| } |
| else if (pte_newprot(*pte)) { |
| updated = 1; |
| err = add_mprotect(addr, PAGE_SIZE, 0, &hvc); |
| } |
| addr += PAGE_SIZE; |
| } |
| if (!err) |
| err = do_ops(&hvc, hvc.index, 1); |
| |
| if (err < 0) |
| panic("flush_tlb_kernel failed, errno = %d\n", err); |
| return updated; |
| } |
| |
| void flush_tlb_page(struct vm_area_struct *vma, unsigned long address) |
| { |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| struct mm_struct *mm = vma->vm_mm; |
| void *flush = NULL; |
| int r, w, x, prot, err = 0; |
| struct mm_id *mm_id; |
| |
| address &= PAGE_MASK; |
| pgd = pgd_offset(mm, address); |
| if (!pgd_present(*pgd)) |
| goto kill; |
| |
| pud = pud_offset(pgd, address); |
| if (!pud_present(*pud)) |
| goto kill; |
| |
| pmd = pmd_offset(pud, address); |
| if (!pmd_present(*pmd)) |
| goto kill; |
| |
| pte = pte_offset_kernel(pmd, address); |
| |
| r = pte_read(*pte); |
| w = pte_write(*pte); |
| x = pte_exec(*pte); |
| if (!pte_young(*pte)) { |
| r = 0; |
| w = 0; |
| } else if (!pte_dirty(*pte)) { |
| w = 0; |
| } |
| |
| mm_id = &mm->context.id; |
| prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) | |
| (x ? UM_PROT_EXEC : 0)); |
| if (pte_newpage(*pte)) { |
| if (pte_present(*pte)) { |
| unsigned long long offset; |
| int fd; |
| |
| fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset); |
| err = map(mm_id, address, PAGE_SIZE, prot, fd, offset, |
| 1, &flush); |
| } |
| else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush); |
| } |
| else if (pte_newprot(*pte)) |
| err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush); |
| |
| if (err) { |
| if (err == -ENOMEM) |
| report_enomem(); |
| |
| goto kill; |
| } |
| |
| *pte = pte_mkuptodate(*pte); |
| |
| return; |
| |
| kill: |
| printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address); |
| force_sig(SIGKILL); |
| } |
| |
| pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address) |
| { |
| return pgd_offset(mm, address); |
| } |
| |
| pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address) |
| { |
| return pud_offset(pgd, address); |
| } |
| |
| pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address) |
| { |
| return pmd_offset(pud, address); |
| } |
| |
| pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address) |
| { |
| return pte_offset_kernel(pmd, address); |
| } |
| |
| pte_t *addr_pte(struct task_struct *task, unsigned long addr) |
| { |
| pgd_t *pgd = pgd_offset(task->mm, addr); |
| pud_t *pud = pud_offset(pgd, addr); |
| pmd_t *pmd = pmd_offset(pud, addr); |
| |
| return pte_offset_map(pmd, addr); |
| } |
| |
| void flush_tlb_all(void) |
| { |
| /* |
| * Don't bother flushing if this address space is about to be |
| * destroyed. |
| */ |
| if (atomic_read(¤t->mm->mm_users) == 0) |
| return; |
| |
| flush_tlb_mm(current->mm); |
| } |
| |
| void flush_tlb_kernel_range(unsigned long start, unsigned long end) |
| { |
| flush_tlb_kernel_range_common(start, end); |
| } |
| |
| void flush_tlb_kernel_vm(void) |
| { |
| flush_tlb_kernel_range_common(start_vm, end_vm); |
| } |
| |
| void __flush_tlb_one(unsigned long addr) |
| { |
| flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE); |
| } |
| |
| static void fix_range(struct mm_struct *mm, unsigned long start_addr, |
| unsigned long end_addr, int force) |
| { |
| /* |
| * Don't bother flushing if this address space is about to be |
| * destroyed. |
| */ |
| if (atomic_read(&mm->mm_users) == 0) |
| return; |
| |
| fix_range_common(mm, start_addr, end_addr, force); |
| } |
| |
| void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, |
| unsigned long end) |
| { |
| if (vma->vm_mm == NULL) |
| flush_tlb_kernel_range_common(start, end); |
| else fix_range(vma->vm_mm, start, end, 0); |
| } |
| EXPORT_SYMBOL(flush_tlb_range); |
| |
| void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, |
| unsigned long end) |
| { |
| fix_range(mm, start, end, 0); |
| } |
| |
| void flush_tlb_mm(struct mm_struct *mm) |
| { |
| struct vm_area_struct *vma = mm->mmap; |
| |
| while (vma != NULL) { |
| fix_range(mm, vma->vm_start, vma->vm_end, 0); |
| vma = vma->vm_next; |
| } |
| } |
| |
| void force_flush_all(void) |
| { |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma = mm->mmap; |
| |
| while (vma != NULL) { |
| fix_range(mm, vma->vm_start, vma->vm_end, 1); |
| vma = vma->vm_next; |
| } |
| } |