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Diffstat (limited to 'arch/s390/lib/uaccess_pt.c')
-rw-r--r--arch/s390/lib/uaccess_pt.c210
1 files changed, 146 insertions, 64 deletions
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index 9017a63dda3d..466fb3383960 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -14,48 +14,132 @@
#include <asm/futex.h>
#include "uaccess.h"
+#ifndef CONFIG_64BIT
+#define AHI "ahi"
+#define SLR "slr"
+#else
+#define AHI "aghi"
+#define SLR "slgr"
+#endif
+
+static size_t strnlen_kernel(size_t count, const char __user *src)
+{
+ register unsigned long reg0 asm("0") = 0UL;
+ unsigned long tmp1, tmp2;
+
+ asm volatile(
+ " la %2,0(%1)\n"
+ " la %3,0(%0,%1)\n"
+ " "SLR" %0,%0\n"
+ "0: srst %3,%2\n"
+ " jo 0b\n"
+ " la %0,1(%3)\n" /* strnlen_kernel results includes \0 */
+ " "SLR" %0,%1\n"
+ "1:\n"
+ EX_TABLE(0b,1b)
+ : "+a" (count), "+a" (src), "=a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return count;
+}
+
+static size_t copy_in_kernel(size_t count, void __user *to,
+ const void __user *from)
+{
+ unsigned long tmp1;
+
+ asm volatile(
+ " "AHI" %0,-1\n"
+ " jo 5f\n"
+ " bras %3,3f\n"
+ "0:"AHI" %0,257\n"
+ "1: mvc 0(1,%1),0(%2)\n"
+ " la %1,1(%1)\n"
+ " la %2,1(%2)\n"
+ " "AHI" %0,-1\n"
+ " jnz 1b\n"
+ " j 5f\n"
+ "2: mvc 0(256,%1),0(%2)\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ "3:"AHI" %0,-256\n"
+ " jnm 2b\n"
+ "4: ex %0,1b-0b(%3)\n"
+ "5:"SLR" %0,%0\n"
+ "6:\n"
+ EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
+ : "+a" (count), "+a" (to), "+a" (from), "=a" (tmp1)
+ : : "cc", "memory");
+ return count;
+}
/*
* Returns kernel address for user virtual address. If the returned address is
* >= -4095 (IS_ERR_VALUE(x) returns true), a fault has occured and the address
* contains the (negative) exception code.
*/
-static __always_inline unsigned long follow_table(struct mm_struct *mm,
- unsigned long addr, int write)
+#ifdef CONFIG_64BIT
+static unsigned long follow_table(struct mm_struct *mm,
+ unsigned long address, int write)
{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *ptep;
+ unsigned long *table = (unsigned long *)__pa(mm->pgd);
+
+ switch (mm->context.asce_bits & _ASCE_TYPE_MASK) {
+ case _ASCE_TYPE_REGION1:
+ table = table + ((address >> 53) & 0x7ff);
+ if (unlikely(*table & _REGION_ENTRY_INV))
+ return -0x39UL;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ case _ASCE_TYPE_REGION2:
+ table = table + ((address >> 42) & 0x7ff);
+ if (unlikely(*table & _REGION_ENTRY_INV))
+ return -0x3aUL;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ case _ASCE_TYPE_REGION3:
+ table = table + ((address >> 31) & 0x7ff);
+ if (unlikely(*table & _REGION_ENTRY_INV))
+ return -0x3bUL;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ case _ASCE_TYPE_SEGMENT:
+ table = table + ((address >> 20) & 0x7ff);
+ if (unlikely(*table & _SEGMENT_ENTRY_INV))
+ return -0x10UL;
+ if (unlikely(*table & _SEGMENT_ENTRY_LARGE)) {
+ if (write && (*table & _SEGMENT_ENTRY_RO))
+ return -0x04UL;
+ return (*table & _SEGMENT_ENTRY_ORIGIN_LARGE) +
+ (address & ~_SEGMENT_ENTRY_ORIGIN_LARGE);
+ }
+ table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
+ }
+ table = table + ((address >> 12) & 0xff);
+ if (unlikely(*table & _PAGE_INVALID))
+ return -0x11UL;
+ if (write && (*table & _PAGE_RO))
+ return -0x04UL;
+ return (*table & PAGE_MASK) + (address & ~PAGE_MASK);
+}
- pgd = pgd_offset(mm, addr);
- if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
- return -0x3aUL;
+#else /* CONFIG_64BIT */
- pud = pud_offset(pgd, addr);
- if (pud_none(*pud) || unlikely(pud_bad(*pud)))
- return -0x3bUL;
+static unsigned long follow_table(struct mm_struct *mm,
+ unsigned long address, int write)
+{
+ unsigned long *table = (unsigned long *)__pa(mm->pgd);
- pmd = pmd_offset(pud, addr);
- if (pmd_none(*pmd))
+ table = table + ((address >> 20) & 0x7ff);
+ if (unlikely(*table & _SEGMENT_ENTRY_INV))
return -0x10UL;
- if (pmd_large(*pmd)) {
- if (write && (pmd_val(*pmd) & _SEGMENT_ENTRY_RO))
- return -0x04UL;
- return (pmd_val(*pmd) & HPAGE_MASK) + (addr & ~HPAGE_MASK);
- }
- if (unlikely(pmd_bad(*pmd)))
- return -0x10UL;
-
- ptep = pte_offset_map(pmd, addr);
- if (!pte_present(*ptep))
+ table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
+ table = table + ((address >> 12) & 0xff);
+ if (unlikely(*table & _PAGE_INVALID))
return -0x11UL;
- if (write && !pte_write(*ptep))
+ if (write && (*table & _PAGE_RO))
return -0x04UL;
-
- return (pte_val(*ptep) & PAGE_MASK) + (addr & ~PAGE_MASK);
+ return (*table & PAGE_MASK) + (address & ~PAGE_MASK);
}
+#endif /* CONFIG_64BIT */
+
static __always_inline size_t __user_copy_pt(unsigned long uaddr, void *kptr,
size_t n, int write_user)
{
@@ -123,10 +207,8 @@ 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;
- }
+ if (segment_eq(get_fs(), KERNEL_DS))
+ return copy_in_kernel(n, (void __user *) to, from);
rc = __user_copy_pt((unsigned long) from, to, n, 0);
if (unlikely(rc))
memset(to + n - rc, 0, rc);
@@ -135,30 +217,28 @@ size_t copy_from_user_pt(size_t n, const void __user *from, void *to)
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;
- }
+ if (segment_eq(get_fs(), KERNEL_DS))
+ return copy_in_kernel(n, to, (void __user *) from);
return __user_copy_pt((unsigned long) to, (void *) from, n, 1);
}
static size_t clear_user_pt(size_t n, void __user *to)
{
+ void *zpage = (void *) empty_zero_page;
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);
+ if (segment_eq(get_fs(), KERNEL_DS))
+ ret = copy_in_kernel(n, to, (void __user *) zpage);
+ else
+ ret = __user_copy_pt((unsigned long) to, zpage, size, 1);
done += size;
+ to += size;
if (ret)
return ret + n - done;
} while (done < n);
@@ -172,8 +252,10 @@ static size_t strnlen_user_pt(size_t count, const char __user *src)
unsigned long offset, done, len, kaddr;
size_t len_str;
+ if (unlikely(!count))
+ return 0;
if (segment_eq(get_fs(), KERNEL_DS))
- return strnlen((const char __kernel __force *) src, count) + 1;
+ return strnlen_kernel(count, src);
done = 0;
retry:
spin_lock(&mm->page_table_lock);
@@ -200,25 +282,27 @@ fault:
static size_t strncpy_from_user_pt(size_t count, const char __user *src,
char *dst)
{
- size_t n = strnlen_user_pt(count, src);
+ size_t done, len, offset, len_str;
- 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;
+ if (unlikely(!count))
+ return 0;
+ done = 0;
+ do {
+ offset = (size_t)src & ~PAGE_MASK;
+ len = min(count - done, PAGE_SIZE - offset);
+ if (segment_eq(get_fs(), KERNEL_DS)) {
+ if (copy_in_kernel(len, (void __user *) dst, src))
+ return -EFAULT;
+ } else {
+ if (__user_copy_pt((unsigned long) src, dst, len, 0))
+ return -EFAULT;
+ }
+ len_str = strnlen(dst, len);
+ done += len_str;
+ src += len_str;
+ dst += len_str;
+ } while ((len_str == len) && (done < count));
+ return done;
}
static size_t copy_in_user_pt(size_t n, void __user *to,
@@ -231,10 +315,8 @@ static size_t copy_in_user_pt(size_t n, void __user *to,
unsigned long kaddr_to, kaddr_from;
int write_user;
- if (segment_eq(get_fs(), KERNEL_DS)) {
- memcpy((void __force *) to, (void __force *) from, n);
- return 0;
- }
+ if (segment_eq(get_fs(), KERNEL_DS))
+ return copy_in_kernel(n, to, from);
done = 0;
retry:
spin_lock(&mm->page_table_lock);
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