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Diffstat (limited to 'arch/s390/lib/uaccess_pt.c')
-rw-r--r--arch/s390/lib/uaccess_pt.c401
1 files changed, 0 insertions, 401 deletions
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
deleted file mode 100644
index 404f2de296d..00000000000
--- a/arch/s390/lib/uaccess_pt.c
+++ /dev/null
@@ -1,401 +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 (pte_t *) 0x3a;
-
- pud = pud_offset(pgd, addr);
- if (pud_none(*pud) || unlikely(pud_bad(*pud)))
- return (pte_t *) 0x3b;
-
- pmd = pmd_offset(pud, addr);
- if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
- return (pte_t *) 0x10;
-
- return pte_offset_map(pmd, addr);
-}
-
-static __always_inline 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 ((unsigned long) pte < 0x1000)
- goto fault;
- if (!pte_present(*pte)) {
- pte = (pte_t *) 0x11;
- goto fault;
- } else if (write_user && !pte_write(*pte)) {
- pte = (pte_t *) 0x04;
- goto fault;
- }
-
- pfn = pte_pfn(*pte);
- 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);
- spin_unlock(&mm->page_table_lock);
- return n - done;
-fault:
- spin_unlock(&mm->page_table_lock);
- if (__handle_fault(uaddr, (unsigned long) pte, 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 __always_inline unsigned long __dat_user_addr(unsigned long uaddr)
-{
- struct mm_struct *mm = current->mm;
- unsigned long pfn;
- pte_t *pte;
- int rc;
-
-retry:
- pte = follow_table(mm, uaddr);
- if ((unsigned long) pte < 0x1000)
- goto fault;
- if (!pte_present(*pte)) {
- pte = (pte_t *) 0x11;
- goto fault;
- }
-
- pfn = pte_pfn(*pte);
- return (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
-fault:
- spin_unlock(&mm->page_table_lock);
- rc = __handle_fault(uaddr, (unsigned long) pte, 0);
- spin_lock(&mm->page_table_lock);
- if (!rc)
- goto retry;
- return 0;
-}
-
-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 ((unsigned long) pte < 0x1000)
- goto fault;
- if (!pte_present(*pte)) {
- pte = (pte_t *) 0x11;
- goto fault;
- }
-
- pfn = pte_pfn(*pte);
- 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));
- spin_unlock(&mm->page_table_lock);
- return done + 1;
-fault:
- spin_unlock(&mm->page_table_lock);
- if (__handle_fault(uaddr, (unsigned long) pte, 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, error_code;
- unsigned long uaddr_from = (unsigned long) from;
- unsigned long uaddr_to = (unsigned long) to;
- pte_t *pte_from, *pte_to;
- int write_user;
-
- if (segment_eq(get_fs(), KERNEL_DS)) {
- memcpy((void __force *) to, (void __force *) from, n);
- return 0;
- }
- done = 0;
-retry:
- spin_lock(&mm->page_table_lock);
- do {
- write_user = 0;
- uaddr = uaddr_from;
- pte_from = follow_table(mm, uaddr_from);
- error_code = (unsigned long) pte_from;
- if (error_code < 0x1000)
- goto fault;
- if (!pte_present(*pte_from)) {
- error_code = 0x11;
- goto fault;
- }
-
- write_user = 1;
- uaddr = uaddr_to;
- pte_to = follow_table(mm, uaddr_to);
- error_code = (unsigned long) pte_to;
- if (error_code < 0x1000)
- goto fault;
- if (!pte_present(*pte_to)) {
- error_code = 0x11;
- goto fault;
- } else if (!pte_write(*pte_to)) {
- error_code = 0x04;
- goto fault;
- }
-
- pfn_from = pte_pfn(*pte_from);
- pfn_to = pte_pfn(*pte_to);
- 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);
- spin_unlock(&mm->page_table_lock);
- return n - done;
-fault:
- spin_unlock(&mm->page_table_lock);
- if (__handle_fault(uaddr, error_code, 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" );
-
-static int __futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
-{
- int oldval = 0, newval, ret;
-
- 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;
- }
- if (ret == 0)
- *old = oldval;
- return ret;
-}
-
-int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
-{
- int ret;
-
- if (segment_eq(get_fs(), KERNEL_DS))
- return __futex_atomic_op_pt(op, uaddr, oparg, old);
- 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);
- ret = __futex_atomic_op_pt(op, uaddr, oparg, old);
- put_page(virt_to_page(uaddr));
- return ret;
-}
-
-static int __futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
-{
- int ret;
-
- asm volatile("0: cs %1,%4,0(%5)\n"
- "1: lr %0,%1\n"
- "2:\n"
- EX_TABLE(0b,2b) EX_TABLE(1b,2b)
- : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
- : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
- : "cc", "memory" );
- return ret;
-}
-
-int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
-{
- int ret;
-
- if (segment_eq(get_fs(), KERNEL_DS))
- return __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
- 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);
- ret = __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
- 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 2025-11-04 13:17:20 +0000