Use a wrapper for copy_to/from_user to chose the best usercopy method.
The mvcos instruction is better for sizes greater than 256 bytes, if
mvcos is not available a page table walk is better for sizes greater
than 1024 bytes. Also removed the redundant copy_to/from_user_std_small
functions.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
EXTRA_AFLAGS := -traditional
-lib-y += delay.o string.o uaccess_std.o
+lib-y += delay.o string.o uaccess_std.o uaccess_pt.o
lib-$(CONFIG_32BIT) += div64.o
lib-$(CONFIG_64BIT) += uaccess_mvcos.o
lib-$(CONFIG_SMP) += spinlock.o
#define SLR "slgr"
#endif
+extern size_t copy_from_user_std(size_t, const void __user *, void *);
+extern size_t copy_to_user_std(size_t, void __user *, const void *);
+
size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
{
register unsigned long reg0 asm("0") = 0x81UL;
return size;
}
+size_t copy_from_user_mvcos_check(size_t size, const void __user *ptr, void *x)
+{
+ if (size <= 256)
+ return copy_from_user_std(size, ptr, x);
+ return copy_from_user_mvcos(size, ptr, x);
+}
+
size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
{
register unsigned long reg0 asm("0") = 0x810000UL;
return size;
}
+size_t copy_to_user_mvcos_check(size_t size, void __user *ptr, const void *x)
+{
+ if (size <= 256)
+ return copy_to_user_std(size, ptr, x);
+ return copy_to_user_mvcos(size, ptr, x);
+}
+
size_t copy_in_user_mvcos(size_t size, void __user *to, const void __user *from)
{
register unsigned long reg0 asm("0") = 0x810081UL;
return size;
}
-extern size_t copy_from_user_std_small(size_t, const void __user *, void *);
-extern size_t copy_to_user_std_small(size_t, void __user *, const void *);
extern size_t strnlen_user_std(size_t, const char __user *);
extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
extern int futex_atomic_op(int, int __user *, int, int *);
extern int futex_atomic_cmpxchg(int __user *, int, int);
struct uaccess_ops uaccess_mvcos = {
- .copy_from_user = copy_from_user_mvcos,
- .copy_from_user_small = copy_from_user_std_small,
- .copy_to_user = copy_to_user_mvcos,
- .copy_to_user_small = copy_to_user_std_small,
+ .copy_from_user = copy_from_user_mvcos_check,
+ .copy_from_user_small = copy_from_user_std,
+ .copy_to_user = copy_to_user_mvcos_check,
+ .copy_to_user_small = copy_to_user_std,
.copy_in_user = copy_in_user_mvcos,
.clear_user = clear_user_mvcos,
.strnlen_user = strnlen_user_std,
--- /dev/null
+/*
+ * arch/s390/lib/uaccess_pt.c
+ *
+ * User access functions based on page table walks.
+ *
+ * Copyright IBM Corp. 2006
+ * Author(s): Gerald Schaefer (gerald.schaefer@de.ibm.com)
+ */
+
+#include <linux/errno.h>
+#include <asm/uaccess.h>
+#include <linux/mm.h>
+#include <asm/futex.h>
+
+static inline int __handle_fault(struct mm_struct *mm, unsigned long address,
+ int write_access)
+{
+ struct vm_area_struct *vma;
+ int ret = -EFAULT;
+
+ 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:
+ switch (handle_mm_fault(mm, vma, address, write_access)) {
+ case VM_FAULT_MINOR:
+ current->min_flt++;
+ break;
+ case VM_FAULT_MAJOR:
+ current->maj_flt++;
+ break;
+ case VM_FAULT_SIGBUS:
+ goto out_sigbus;
+ case VM_FAULT_OOM:
+ goto out_of_memory;
+ default:
+ BUG();
+ }
+ ret = 0;
+out:
+ up_read(&mm->mmap_sem);
+ return ret;
+
+out_of_memory:
+ up_read(&mm->mmap_sem);
+ if (current->pid == 1) {
+ yield();
+ 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 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;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ void *from, *to;
+
+ done = 0;
+retry:
+ spin_lock(&mm->page_table_lock);
+ do {
+ pgd = pgd_offset(mm, uaddr);
+ if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+ goto fault;
+
+ pmd = pmd_offset(pgd, uaddr);
+ if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+ goto fault;
+
+ pte = pte_offset_map(pmd, 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;
+}
+
+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);
+}
#define SLR "slgr"
#endif
+extern size_t copy_from_user_pt(size_t n, const void __user *from, void *to);
+extern size_t copy_to_user_pt(size_t n, void __user *to, const void *from);
+
size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
{
unsigned long tmp1, tmp2;
return size;
}
-size_t copy_from_user_std_small(size_t size, const void __user *ptr, void *x)
+size_t copy_from_user_std_check(size_t size, const void __user *ptr, void *x)
{
- unsigned long tmp1, tmp2;
-
- tmp1 = 0UL;
- asm volatile(
- "0: mvcp 0(%0,%2),0(%1),%3\n"
- " "SLR" %0,%0\n"
- " j 5f\n"
- "1: la %4,255(%1)\n" /* %4 = ptr + 255 */
- " "LHI" %3,-4096\n"
- " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
- " "SLR" %4,%1\n"
- " "CLR" %0,%4\n" /* copy crosses next page boundary? */
- " jnh 5f\n"
- "2: mvcp 0(%4,%2),0(%1),%3\n"
- " "SLR" %0,%4\n"
- " "ALR" %2,%4\n"
- "3:"LHI" %4,-1\n"
- " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
- " bras %3,4f\n"
- " xc 0(1,%2),0(%2)\n"
- "4: ex %4,0(%3)\n"
- "5:\n"
- EX_TABLE(0b,1b) EX_TABLE(2b,3b)
- : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
- : : "cc", "memory");
- return size;
+ if (size <= 1024)
+ return copy_from_user_std(size, ptr, x);
+ return copy_from_user_pt(size, ptr, x);
}
size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
return size;
}
-size_t copy_to_user_std_small(size_t size, void __user *ptr, const void *x)
+size_t copy_to_user_std_check(size_t size, void __user *ptr, const void *x)
{
- unsigned long tmp1, tmp2;
-
- tmp1 = 0UL;
- asm volatile(
- "0: mvcs 0(%0,%1),0(%2),%3\n"
- " "SLR" %0,%0\n"
- " j 3f\n"
- "1: la %4,255(%1)\n" /* ptr + 255 */
- " "LHI" %3,-4096\n"
- " nr %4,%3\n" /* (ptr + 255) & -4096UL */
- " "SLR" %4,%1\n"
- " "CLR" %0,%4\n" /* copy crosses next page boundary? */
- " jnh 3f\n"
- "2: mvcs 0(%4,%1),0(%2),%3\n"
- " "SLR" %0,%4\n"
- "3:\n"
- EX_TABLE(0b,1b) EX_TABLE(2b,3b)
- : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
- : : "cc", "memory");
- return size;
+ if (size <= 1024)
+ return copy_to_user_std(size, ptr, x);
+ return copy_to_user_pt(size, ptr, x);
}
size_t copy_in_user_std(size_t size, void __user *to, const void __user *from)
}
struct uaccess_ops uaccess_std = {
- .copy_from_user = copy_from_user_std,
- .copy_from_user_small = copy_from_user_std_small,
- .copy_to_user = copy_to_user_std,
- .copy_to_user_small = copy_to_user_std_small,
+ .copy_from_user = copy_from_user_std_check,
+ .copy_from_user_small = copy_from_user_std,
+ .copy_to_user = copy_to_user_std_check,
+ .copy_to_user_small = copy_to_user_std,
.copy_in_user = copy_in_user_std,
.clear_user = clear_user_std,
.strnlen_user = strnlen_user_std,
projects / cascardo / linux.git / commitdiff