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Diffstat (limited to 'arch/s390/lib/uaccess_pt.c')
-rw-r--r--arch/s390/lib/uaccess_pt.c441
1 files changed, 0 insertions, 441 deletions
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
deleted file mode 100644
index 5efdfe9f5e7..00000000000
--- a/arch/s390/lib/uaccess_pt.c
+++ /dev/null
@@ -1,441 +0,0 @@
-/*
- * arch/s390/lib/uaccess_pt.c
- *
- * User access functions based on page table walks for enhanced
- * system layout without hardware support.
- *
- * Copyright IBM Corp. 2006
- * Author(s): Gerald Schaefer (gerald.schaefer@de.ibm.com)
- */
-
-#include <linux/errno.h>
-#include <linux/hardirq.h>
-#include <linux/mm.h>
-#include <asm/uaccess.h>
-#include <asm/futex.h>
-#include "uaccess.h"
-
-static inline pte_t *follow_table(struct mm_struct *mm, unsigned long addr)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
-
- pgd = pgd_offset(mm, addr);
- if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
- return NULL;
-
- pud = pud_offset(pgd, addr);
- if (pud_none(*pud) || unlikely(pud_bad(*pud)))
- return NULL;
-
- pmd = pmd_offset(pud, addr);
- if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
- return NULL;
-
- return pte_offset_map(pmd, addr);
-}
-
-static int __handle_fault(struct mm_struct *mm, unsigned long address,
- int write_access)
-{
- struct vm_area_struct *vma;
- int ret = -EFAULT;
- int fault;
-
- if (in_atomic())
- return ret;
- down_read(&mm->mmap_sem);
- vma = find_vma(mm, address);
- if (unlikely(!vma))
- goto out;
- if (unlikely(vma->vm_start > address)) {
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto out;
- if (expand_stack(vma, address))
- goto out;
- }
-
- if (!write_access) {
- /* page not present, check vm flags */
- if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
- goto out;
- } else {
- if (!(vma->vm_flags & VM_WRITE))
- goto out;
- }
-
-survive:
- fault = handle_mm_fault(mm, vma, address, write_access);
- if (unlikely(fault & VM_FAULT_ERROR)) {
- if (fault & VM_FAULT_OOM)
- goto out_of_memory;
- else if (fault & VM_FAULT_SIGBUS)
- goto out_sigbus;
- BUG();
- }
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
- ret = 0;
-out:
- up_read(&mm->mmap_sem);
- return ret;
-
-out_of_memory:
- up_read(&mm->mmap_sem);
- if (is_global_init(current)) {
- yield();
- down_read(&mm->mmap_sem);
- goto survive;
- }
- printk("VM: killing process %s\n", current->comm);
- return ret;
-
-out_sigbus:
- up_read(&mm->mmap_sem);
- current->thread.prot_addr = address;
- current->thread.trap_no = 0x11;
- force_sig(SIGBUS, current);
- return ret;
-}
-
-static size_t __user_copy_pt(unsigned long uaddr, void *kptr,
- size_t n, int write_user)
-{
- struct mm_struct *mm = current->mm;
- unsigned long offset, pfn, done, size;
- pte_t *pte;
- void *from, *to;
-
- done = 0;
-retry:
- spin_lock(&mm->page_table_lock);
- do {
- pte = follow_table(mm, uaddr);
- if (!pte || !pte_present(*pte) ||
- (write_user && !pte_write(*pte)))
- goto fault;
-
- pfn = pte_pfn(*pte);
- if (!pfn_valid(pfn))
- goto out;
-
- offset = uaddr & (PAGE_SIZE - 1);
- size = min(n - done, PAGE_SIZE - offset);
- if (write_user) {
- to = (void *)((pfn << PAGE_SHIFT) + offset);
- from = kptr + done;
- } else {
- from = (void *)((pfn << PAGE_SHIFT) + offset);
- to = kptr + done;
- }
- memcpy(to, from, size);
- done += size;
- uaddr += size;
- } while (done < n);
-out:
- spin_unlock(&mm->page_table_lock);
- return n - done;
-fault:
- spin_unlock(&mm->page_table_lock);
- if (__handle_fault(mm, uaddr, write_user))
- return n - done;
- goto retry;
-}
-
-/*
- * Do DAT for user address by page table walk, return kernel address.
- * This function needs to be called with current->mm->page_table_lock held.
- */
-static unsigned long __dat_user_addr(unsigned long uaddr)
-{
- struct mm_struct *mm = current->mm;
- unsigned long pfn, ret;
- pte_t *pte;
- int rc;
-
- ret = 0;
-retry:
- pte = follow_table(mm, uaddr);
- if (!pte || !pte_present(*pte))
- goto fault;
-
- pfn = pte_pfn(*pte);
- if (!pfn_valid(pfn))
- goto out;
-
- ret = (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
-out:
- return ret;
-fault:
- spin_unlock(&mm->page_table_lock);
- rc = __handle_fault(mm, uaddr, 0);
- spin_lock(&mm->page_table_lock);
- if (rc)
- goto out;
- goto retry;
-}
-
-size_t copy_from_user_pt(size_t n, const void __user *from, void *to)
-{
- size_t rc;
-
- if (segment_eq(get_fs(), KERNEL_DS)) {
- memcpy(to, (void __kernel __force *) from, n);
- return 0;
- }
- rc = __user_copy_pt((unsigned long) from, to, n, 0);
- if (unlikely(rc))
- memset(to + n - rc, 0, rc);
- return rc;
-}
-
-size_t copy_to_user_pt(size_t n, void __user *to, const void *from)
-{
- if (segment_eq(get_fs(), KERNEL_DS)) {
- memcpy((void __kernel __force *) to, from, n);
- return 0;
- }
- return __user_copy_pt((unsigned long) to, (void *) from, n, 1);
-}
-
-static size_t clear_user_pt(size_t n, void __user *to)
-{
- long done, size, ret;
-
- if (segment_eq(get_fs(), KERNEL_DS)) {
- memset((void __kernel __force *) to, 0, n);
- return 0;
- }
- done = 0;
- do {
- if (n - done > PAGE_SIZE)
- size = PAGE_SIZE;
- else
- size = n - done;
- ret = __user_copy_pt((unsigned long) to + done,
- &empty_zero_page, size, 1);
- done += size;
- if (ret)
- return ret + n - done;
- } while (done < n);
- return 0;
-}
-
-static size_t strnlen_user_pt(size_t count, const char __user *src)
-{
- char *addr;
- unsigned long uaddr = (unsigned long) src;
- struct mm_struct *mm = current->mm;
- unsigned long offset, pfn, done, len;
- pte_t *pte;
- size_t len_str;
-
- if (segment_eq(get_fs(), KERNEL_DS))
- return strnlen((const char __kernel __force *) src, count) + 1;
- done = 0;
-retry:
- spin_lock(&mm->page_table_lock);
- do {
- pte = follow_table(mm, uaddr);
- if (!pte || !pte_present(*pte))
- goto fault;
-
- pfn = pte_pfn(*pte);
- if (!pfn_valid(pfn)) {
- done = -1;
- goto out;
- }
-
- offset = uaddr & (PAGE_SIZE-1);
- addr = (char *)(pfn << PAGE_SHIFT) + offset;
- len = min(count - done, PAGE_SIZE - offset);
- len_str = strnlen(addr, len);
- done += len_str;
- uaddr += len_str;
- } while ((len_str == len) && (done < count));
-out:
- spin_unlock(&mm->page_table_lock);
- return done + 1;
-fault:
- spin_unlock(&mm->page_table_lock);
- if (__handle_fault(mm, uaddr, 0)) {
- return 0;
- }
- goto retry;
-}
-
-static size_t strncpy_from_user_pt(size_t count, const char __user *src,
- char *dst)
-{
- size_t n = strnlen_user_pt(count, src);
-
- if (!n)
- return -EFAULT;
- if (n > count)
- n = count;
- if (segment_eq(get_fs(), KERNEL_DS)) {
- memcpy(dst, (const char __kernel __force *) src, n);
- if (dst[n-1] == '\0')
- return n-1;
- else
- return n;
- }
- if (__user_copy_pt((unsigned long) src, dst, n, 0))
- return -EFAULT;
- if (dst[n-1] == '\0')
- return n-1;
- else
- return n;
-}
-
-static size_t copy_in_user_pt(size_t n, void __user *to,
- const void __user *from)
-{
- struct mm_struct *mm = current->mm;
- unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to,
- uaddr, done, size;
- unsigned long uaddr_from = (unsigned long) from;
- unsigned long uaddr_to = (unsigned long) to;
- pte_t *pte_from, *pte_to;
- int write_user;
-
- done = 0;
-retry:
- spin_lock(&mm->page_table_lock);
- do {
- pte_from = follow_table(mm, uaddr_from);
- if (!pte_from || !pte_present(*pte_from)) {
- uaddr = uaddr_from;
- write_user = 0;
- goto fault;
- }
-
- pte_to = follow_table(mm, uaddr_to);
- if (!pte_to || !pte_present(*pte_to) || !pte_write(*pte_to)) {
- uaddr = uaddr_to;
- write_user = 1;
- goto fault;
- }
-
- pfn_from = pte_pfn(*pte_from);
- if (!pfn_valid(pfn_from))
- goto out;
- pfn_to = pte_pfn(*pte_to);
- if (!pfn_valid(pfn_to))
- goto out;
-
- offset_from = uaddr_from & (PAGE_SIZE-1);
- offset_to = uaddr_from & (PAGE_SIZE-1);
- offset_max = max(offset_from, offset_to);
- size = min(n - done, PAGE_SIZE - offset_max);
-
- memcpy((void *)(pfn_to << PAGE_SHIFT) + offset_to,
- (void *)(pfn_from << PAGE_SHIFT) + offset_from, size);
- done += size;
- uaddr_from += size;
- uaddr_to += size;
- } while (done < n);
-out:
- spin_unlock(&mm->page_table_lock);
- return n - done;
-fault:
- spin_unlock(&mm->page_table_lock);
- if (__handle_fault(mm, uaddr, write_user))
- return n - done;
- goto retry;
-}
-
-#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
- asm volatile("0: l %1,0(%6)\n" \
- "1: " insn \
- "2: cs %1,%2,0(%6)\n" \
- "3: jl 1b\n" \
- " lhi %0,0\n" \
- "4:\n" \
- EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \
- : "=d" (ret), "=&d" (oldval), "=&d" (newval), \
- "=m" (*uaddr) \
- : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
- "m" (*uaddr) : "cc" );
-
-int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
-{
- int oldval = 0, newval, ret;
-
- spin_lock(&current->mm->page_table_lock);
- uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
- if (!uaddr) {
- spin_unlock(&current->mm->page_table_lock);
- return -EFAULT;
- }
- get_page(virt_to_page(uaddr));
- spin_unlock(&current->mm->page_table_lock);
- switch (op) {
- case FUTEX_OP_SET:
- __futex_atomic_op("lr %2,%5\n",
- ret, oldval, newval, uaddr, oparg);
- break;
- case FUTEX_OP_ADD:
- __futex_atomic_op("lr %2,%1\nar %2,%5\n",
- ret, oldval, newval, uaddr, oparg);
- break;
- case FUTEX_OP_OR:
- __futex_atomic_op("lr %2,%1\nor %2,%5\n",
- ret, oldval, newval, uaddr, oparg);
- break;
- case FUTEX_OP_ANDN:
- __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
- ret, oldval, newval, uaddr, oparg);
- break;
- case FUTEX_OP_XOR:
- __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
- ret, oldval, newval, uaddr, oparg);
- break;
- default:
- ret = -ENOSYS;
- }
- put_page(virt_to_page(uaddr));
- *old = oldval;
- return ret;
-}
-
-int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
-{
- int ret;
-
- if (!current->mm)
- return -EFAULT;
- spin_lock(&current->mm->page_table_lock);
- uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
- if (!uaddr) {
- spin_unlock(&current->mm->page_table_lock);
- return -EFAULT;
- }
- get_page(virt_to_page(uaddr));
- spin_unlock(&current->mm->page_table_lock);
- asm volatile(" cs %1,%4,0(%5)\n"
- "0: lr %0,%1\n"
- "1:\n"
- EX_TABLE(0b,1b)
- : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
- : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
- : "cc", "memory" );
- put_page(virt_to_page(uaddr));
- return ret;
-}
-
-struct uaccess_ops uaccess_pt = {
- .copy_from_user = copy_from_user_pt,
- .copy_from_user_small = copy_from_user_pt,
- .copy_to_user = copy_to_user_pt,
- .copy_to_user_small = copy_to_user_pt,
- .copy_in_user = copy_in_user_pt,
- .clear_user = clear_user_pt,
- .strnlen_user = strnlen_user_pt,
- .strncpy_from_user = strncpy_from_user_pt,
- .futex_atomic_op = futex_atomic_op_pt,
- .futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt,
-};
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 03:41:52 +0000