s390/uaccess: use sane length for __strncpy_from_user()

[karo-tx-linux.git] / arch / s390 / lib / uaccess.c

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index f481fcde067ba145f6cc2ace122d9d0a543ebe00..b3bd3f23b8e851c7f67e46cb527e20603512e7f5 100644 (file)
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -26,7 +26,7 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr
        tmp1 = -4096UL;
        asm volatile(
                "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
-               "9: jz    7f\n"
+               "6: jz    4f\n"
                "1: algr  %0,%3\n"
                "   slgr  %1,%3\n"
                "   slgr  %2,%3\n"
@@ -35,23 +35,13 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr
                "   nr    %4,%3\n"      /* %4 = (ptr + 4095) & -4096 */
                "   slgr  %4,%1\n"
                "   clgr  %0,%4\n"      /* copy crosses next page boundary? */
-               "   jnh   4f\n"
+               "   jnh   5f\n"
                "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
-               "10:slgr  %0,%4\n"
-               "   algr  %2,%4\n"
-               "4: lghi  %4,-1\n"
-               "   algr  %4,%0\n"      /* copy remaining size, subtract 1 */
-               "   bras  %3,6f\n"      /* memset loop */
-               "   xc    0(1,%2),0(%2)\n"
-               "5: xc    0(256,%2),0(%2)\n"
-               "   la    %2,256(%2)\n"
-               "6: aghi  %4,-256\n"
-               "   jnm   5b\n"
-               "   ex    %4,0(%3)\n"
-               "   j     8f\n"
-               "7: slgr  %0,%0\n"
-               "8:\n"
-               EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
+               "7: slgr  %0,%4\n"
+               "   j     5f\n"
+               "4: slgr  %0,%0\n"
+               "5:\n"
+               EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
                : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
                : "d" (reg0) : "cc", "memory");
        return size;
@@ -67,49 +57,38 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
        asm volatile(
                "   sacf  0\n"
                "0: mvcp  0(%0,%2),0(%1),%3\n"
-               "10:jz    8f\n"
+               "7: jz    5f\n"
                "1: algr  %0,%3\n"
                "   la    %1,256(%1)\n"
                "   la    %2,256(%2)\n"
                "2: mvcp  0(%0,%2),0(%1),%3\n"
-               "11:jnz   1b\n"
-               "   j     8f\n"
+               "8: jnz   1b\n"
+               "   j     5f\n"
                "3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
                "   lghi  %3,-4096\n"
                "   nr    %4,%3\n"      /* %4 = (ptr + 255) & -4096 */
                "   slgr  %4,%1\n"
                "   clgr  %0,%4\n"      /* copy crosses next page boundary? */
-               "   jnh   5f\n"
+               "   jnh   6f\n"
                "4: mvcp  0(%4,%2),0(%1),%3\n"
-               "12:slgr  %0,%4\n"
-               "   algr  %2,%4\n"
-               "5: lghi  %4,-1\n"
-               "   algr  %4,%0\n"      /* copy remaining size, subtract 1 */
-               "   bras  %3,7f\n"      /* memset loop */
-               "   xc    0(1,%2),0(%2)\n"
-               "6: xc    0(256,%2),0(%2)\n"
-               "   la    %2,256(%2)\n"
-               "7: aghi  %4,-256\n"
-               "   jnm   6b\n"
-               "   ex    %4,0(%3)\n"
-               "   j     9f\n"
-               "8: slgr  %0,%0\n"
-               "9: sacf  768\n"
-               EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
-               EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
+               "9: slgr  %0,%4\n"
+               "   j     6f\n"
+               "5: slgr  %0,%0\n"
+               "6: sacf  768\n"
+               EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+               EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
                : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
                : : "cc", "memory");
        return size;
 }
 
-unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
+unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-       check_object_size(to, n, false);
        if (static_branch_likely(&have_mvcos))
                return copy_from_user_mvcos(to, from, n);
        return copy_from_user_mvcp(to, from, n);
 }
-EXPORT_SYMBOL(__copy_from_user);
+EXPORT_SYMBOL(raw_copy_from_user);
 
 static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
                                               unsigned long size)
@@ -176,14 +155,13 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
        return size;
 }
 
-unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
+unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-       check_object_size(from, n, true);
        if (static_branch_likely(&have_mvcos))
                return copy_to_user_mvcos(to, from, n);
        return copy_to_user_mvcs(to, from, n);
 }
-EXPORT_SYMBOL(__copy_to_user);
+EXPORT_SYMBOL(raw_copy_to_user);
 
 static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
                                               unsigned long size)
@@ -240,13 +218,13 @@ static inline unsigned long copy_in_user_mvc(void __user *to, const void __user
        return size;
 }
 
-unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
+unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
        if (static_branch_likely(&have_mvcos))
                return copy_in_user_mvcos(to, from, n);
        return copy_in_user_mvc(to, from, n);
 }
-EXPORT_SYMBOL(__copy_in_user);
+EXPORT_SYMBOL(raw_copy_in_user);
 
 static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
 {
@@ -359,8 +337,8 @@ long __strncpy_from_user(char *dst, const char __user *src, long size)
                return 0;
        done = 0;
        do {
-               offset = (size_t)src & ~PAGE_MASK;
-               len = min(size - done, PAGE_SIZE - offset);
+               offset = (size_t)src & (L1_CACHE_BYTES - 1);
+               len = min(size - done, L1_CACHE_BYTES - offset);
                if (copy_from_user(dst, src, len))
                        return -EFAULT;
                len_str = strnlen(dst, len);