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-rw-r--r--arch/um/kernel/tlb.c619
1 files changed, 619 insertions, 0 deletions
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
new file mode 100644
index 000000000..5be1b0da9
--- /dev/null
+++ b/arch/um/kernel/tlb.c
@@ -0,0 +1,619 @@
+// 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/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 (virt + len > STUB_START && virt < STUB_END)
+ return -EINVAL;
+
+ 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 + len > 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 (addr + len > STUB_START && addr < STUB_END)
+ return -EINVAL;
+
+ 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(p4d_t *p4d, unsigned long addr,
+ unsigned long end,
+ struct host_vm_change *hvc)
+{
+ pud_t *pud;
+ unsigned long next;
+ int ret = 0;
+
+ pud = pud_offset(p4d, 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;
+}
+
+static inline int update_p4d_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end,
+ struct host_vm_change *hvc)
+{
+ p4d_t *p4d;
+ unsigned long next;
+ int ret = 0;
+
+ p4d = p4d_offset(pgd, addr);
+ do {
+ next = p4d_addr_end(addr, end);
+ if (!p4d_present(*p4d)) {
+ if (hvc->force || p4d_newpage(*p4d)) {
+ ret = add_munmap(addr, next - addr, hvc);
+ p4d_mkuptodate(*p4d);
+ }
+ } else
+ ret = update_pud_range(p4d, addr, next, hvc);
+ } while (p4d++, 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_p4d_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) {
+ struct mm_id *mm_idp = &current->mm->context.id;
+
+ printk(KERN_ERR "fix_range_common: failed, killing current "
+ "process: %d\n", task_tgid_vnr(current));
+ mm_idp->kill = 1;
+ }
+}
+
+static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
+{
+ struct mm_struct *mm;
+ pgd_t *pgd;
+ p4d_t *p4d;
+ 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;
+ }
+
+ p4d = p4d_offset(pgd, addr);
+ if (!p4d_present(*p4d)) {
+ last = ADD_ROUND(addr, P4D_SIZE);
+ if (last > end)
+ last = end;
+ if (p4d_newpage(*p4d)) {
+ 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(p4d, 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;
+ p4d_t *p4d;
+ 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;
+
+ if (address >= STUB_START && address < STUB_END)
+ goto kill;
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ goto kill;
+
+ p4d = p4d_offset(pgd, address);
+ if (!p4d_present(*p4d))
+ goto kill;
+
+ pud = pud_offset(p4d, 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);
+}
+
+void flush_tlb_all(void)
+{
+ /*
+ * Don't bother flushing if this address space is about to be
+ * destroyed.
+ */
+ if (atomic_read(&current->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;
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-30 03:52:47 +0000