diff options
Diffstat (limited to 'arch/s390/lib/uaccess_std.c')
| -rw-r--r-- | arch/s390/lib/uaccess_std.c | 48 |
1 files changed, 18 insertions, 30 deletions
diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c index 6fbd06338270..4a75d475b06a 100644 --- a/arch/s390/lib/uaccess_std.c +++ b/arch/s390/lib/uaccess_std.c @@ -188,6 +188,8 @@ size_t strnlen_user_std(size_t size, const char __user *src) register unsigned long reg0 asm("0") = 0UL; unsigned long tmp1, tmp2; + if (unlikely(!size)) + return 0; asm volatile( " la %2,0(%1)\n" " la %3,0(%0,%1)\n" @@ -204,38 +206,24 @@ size_t strnlen_user_std(size_t size, const char __user *src) return size; } -size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst) +size_t strncpy_from_user_std(size_t count, const char __user *src, char *dst) { - register unsigned long reg0 asm("0") = 0UL; - unsigned long tmp1, tmp2; + size_t done, len, offset, len_str; - asm volatile( - " la %3,0(%1)\n" - " la %4,0(%0,%1)\n" - " sacf 256\n" - "0: srst %4,%3\n" - " jo 0b\n" - " sacf 0\n" - " la %0,0(%4)\n" - " jh 1f\n" /* found \0 in string ? */ - " "AHI" %4,1\n" /* include \0 in copy */ - "1:"SLR" %0,%1\n" /* %0 = return length (without \0) */ - " "SLR" %4,%1\n" /* %4 = copy length (including \0) */ - "2: mvcp 0(%4,%2),0(%1),%5\n" - " jz 9f\n" - "3:"AHI" %4,-256\n" - " la %1,256(%1)\n" - " la %2,256(%2)\n" - "4: mvcp 0(%4,%2),0(%1),%5\n" - " jnz 3b\n" - " j 9f\n" - "7: sacf 0\n" - "8:"LHI" %0,%6\n" - "9:\n" - EX_TABLE(0b,7b) EX_TABLE(2b,8b) EX_TABLE(4b,8b) - : "+a" (size), "+a" (src), "+d" (dst), "=a" (tmp1), "=a" (tmp2) - : "d" (reg0), "K" (-EFAULT) : "cc", "memory"); - return size; + if (unlikely(!count)) + return 0; + done = 0; + do { + offset = (size_t)src & ~PAGE_MASK; + len = min(count - done, PAGE_SIZE - offset); + if (copy_from_user_std(len, src, dst)) + return -EFAULT; + len_str = strnlen(dst, len); + done += len_str; + src += len_str; + dst += len_str; + } while ((len_str == len) && (done < count)); + return done; } #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \ |