linux-stable/arch/s390/include/asm/uaccess.h
Vasily Gorbik 01eb42afb4 s390/kasan: fix strncpy_from_user kasan checks
arch/s390/lib/uaccess.c is built without kasan instrumentation. Kasan
checks are performed explicitly in copy_from_user/copy_to_user
functions. But since those functions could be inlined, calls from
files like uaccess.c with instrumentation disabled won't generate
kasan reports. This is currently the case with strncpy_from_user
function which was revealed by newly added kasan test. Avoid inlining of
copy_from_user/copy_to_user when the kernel is built with kasan support
to make sure kasan checks are fully functional.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-24 13:28:46 +02:00

281 lines
6.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Hartmut Penner (hp@de.ibm.com),
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* Derived from "include/asm-i386/uaccess.h"
*/
#ifndef __S390_UACCESS_H
#define __S390_UACCESS_H
/*
* User space memory access functions
*/
#include <asm/processor.h>
#include <asm/ctl_reg.h>
#include <asm/extable.h>
#include <asm/facility.h>
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
* get_fs() == KERNEL_DS, checking is bypassed.
*
* For historical reasons, these macros are grossly misnamed.
*/
#define KERNEL_DS (0)
#define KERNEL_DS_SACF (1)
#define USER_DS (2)
#define USER_DS_SACF (3)
#define get_fs() (current->thread.mm_segment)
#define segment_eq(a,b) (((a) & 2) == ((b) & 2))
void set_fs(mm_segment_t fs);
static inline int __range_ok(unsigned long addr, unsigned long size)
{
return 1;
}
#define __access_ok(addr, size) \
({ \
__chk_user_ptr(addr); \
__range_ok((unsigned long)(addr), (size)); \
})
#define access_ok(addr, size) __access_ok(addr, size)
unsigned long __must_check
raw_copy_from_user(void *to, const void __user *from, unsigned long n);
unsigned long __must_check
raw_copy_to_user(void __user *to, const void *from, unsigned long n);
#ifndef CONFIG_KASAN
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
#endif
#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
#define __put_get_user_asm(to, from, size, spec) \
({ \
register unsigned long __reg0 asm("0") = spec; \
int __rc; \
\
asm volatile( \
"0: mvcos %1,%3,%2\n" \
"1: xr %0,%0\n" \
"2:\n" \
".pushsection .fixup, \"ax\"\n" \
"3: lhi %0,%5\n" \
" jg 2b\n" \
".popsection\n" \
EX_TABLE(0b,3b) EX_TABLE(1b,3b) \
: "=d" (__rc), "+Q" (*(to)) \
: "d" (size), "Q" (*(from)), \
"d" (__reg0), "K" (-EFAULT) \
: "cc"); \
__rc; \
})
static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
{
unsigned long spec = 0x010000UL;
int rc;
switch (size) {
case 1:
rc = __put_get_user_asm((unsigned char __user *)ptr,
(unsigned char *)x,
size, spec);
break;
case 2:
rc = __put_get_user_asm((unsigned short __user *)ptr,
(unsigned short *)x,
size, spec);
break;
case 4:
rc = __put_get_user_asm((unsigned int __user *)ptr,
(unsigned int *)x,
size, spec);
break;
case 8:
rc = __put_get_user_asm((unsigned long __user *)ptr,
(unsigned long *)x,
size, spec);
break;
}
return rc;
}
static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
{
unsigned long spec = 0x01UL;
int rc;
switch (size) {
case 1:
rc = __put_get_user_asm((unsigned char *)x,
(unsigned char __user *)ptr,
size, spec);
break;
case 2:
rc = __put_get_user_asm((unsigned short *)x,
(unsigned short __user *)ptr,
size, spec);
break;
case 4:
rc = __put_get_user_asm((unsigned int *)x,
(unsigned int __user *)ptr,
size, spec);
break;
case 8:
rc = __put_get_user_asm((unsigned long *)x,
(unsigned long __user *)ptr,
size, spec);
break;
}
return rc;
}
#else /* CONFIG_HAVE_MARCH_Z10_FEATURES */
static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
{
size = raw_copy_to_user(ptr, x, size);
return size ? -EFAULT : 0;
}
static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
{
size = raw_copy_from_user(x, ptr, size);
return size ? -EFAULT : 0;
}
#endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*/
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __x = (x); \
int __pu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof (*(ptr))) { \
case 1: \
case 2: \
case 4: \
case 8: \
__pu_err = __put_user_fn(&__x, ptr, \
sizeof(*(ptr))); \
break; \
default: \
__put_user_bad(); \
break; \
} \
__builtin_expect(__pu_err, 0); \
})
#define put_user(x, ptr) \
({ \
might_fault(); \
__put_user(x, ptr); \
})
int __put_user_bad(void) __attribute__((noreturn));
#define __get_user(x, ptr) \
({ \
int __gu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
unsigned char __x = 0; \
__gu_err = __get_user_fn(&__x, ptr, \
sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 2: { \
unsigned short __x = 0; \
__gu_err = __get_user_fn(&__x, ptr, \
sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 4: { \
unsigned int __x = 0; \
__gu_err = __get_user_fn(&__x, ptr, \
sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 8: { \
unsigned long long __x = 0; \
__gu_err = __get_user_fn(&__x, ptr, \
sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
default: \
__get_user_bad(); \
break; \
} \
__builtin_expect(__gu_err, 0); \
})
#define get_user(x, ptr) \
({ \
might_fault(); \
__get_user(x, ptr); \
})
int __get_user_bad(void) __attribute__((noreturn));
unsigned long __must_check
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n);
/*
* Copy a null terminated string from userspace.
*/
long __strncpy_from_user(char *dst, const char __user *src, long count);
static inline long __must_check
strncpy_from_user(char *dst, const char __user *src, long count)
{
might_fault();
return __strncpy_from_user(dst, src, count);
}
unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count);
static inline unsigned long strnlen_user(const char __user *src, unsigned long n)
{
might_fault();
return __strnlen_user(src, n);
}
/*
* Zero Userspace
*/
unsigned long __must_check __clear_user(void __user *to, unsigned long size);
static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
{
might_fault();
return __clear_user(to, n);
}
int copy_to_user_real(void __user *dest, void *src, unsigned long count);
void s390_kernel_write(void *dst, const void *src, size_t size);
#endif /* __S390_UACCESS_H */