/* 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/asm-extable.h>
#include <asm/processor.h>
#include <asm/ctl_reg.h>
#include <asm/extable.h>
#include <asm/facility.h>
#include <asm-generic/access_ok.h>
void debug_user_asce(int exit);
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
unsigned long __must_check
_copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key);
static __always_inline unsigned long __must_check
copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key)
{
if (check_copy_size(to, n, false))
n = _copy_from_user_key(to, from, n, key);
return n;
}
unsigned long __must_check
_copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key);
static __always_inline unsigned long __must_check
copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key)
{
if (check_copy_size(from, n, true))
n = _copy_to_user_key(to, from, n, key);
return n;
}
union oac {
unsigned int val;
struct {
struct {
unsigned short key : 4;
unsigned short : 4;
unsigned short as : 2;
unsigned short : 4;
unsigned short k : 1;
unsigned short a : 1;
} oac1;
struct {
unsigned short key : 4;
unsigned short : 4;
unsigned short as : 2;
unsigned short : 4;
unsigned short k : 1;
unsigned short a : 1;
} oac2;
};
};
int __noreturn __put_user_bad(void);
#define __put_user_asm(to, from, size) \
({ \
union oac __oac_spec = { \
.oac1.as = PSW_BITS_AS_SECONDARY, \
.oac1.a = 1, \
}; \
int __rc; \
\
asm volatile( \
" lr 0,%[spec]\n" \
"0: mvcos %[_to],%[_from],%[_size]\n" \
"1: xr %[rc],%[rc]\n" \
"2:\n" \
EX_TABLE_UA_STORE(0b, 2b, %[rc]) \
EX_TABLE_UA_STORE(1b, 2b, %[rc]) \
: [rc] "=&d" (__rc), [_to] "+Q" (*(to)) \
: [_size] "d" (size), [_from] "Q" (*(from)), \
[spec] "d" (__oac_spec.val) \
: "cc", "0"); \
__rc; \
})
static __always_inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
{
int rc;
switch (size) {
case 1:
rc = __put_user_asm((unsigned char __user *)ptr,
(unsigned char *)x,
size);
break;
case 2:
rc = __put_user_asm((unsigned short __user *)ptr,
(unsigned short *)x,
size);
break;
case 4:
rc = __put_user_asm((unsigned int __user *)ptr,
(unsigned int *)x,
size);
break;
case 8:
rc = __put_user_asm((unsigned long __user *)ptr,
(unsigned long *)x,
size);
break;
default:
__put_user_bad();
break;
}
return rc;
}
int __noreturn __get_user_bad(void);
#define __get_user_asm(to, from, size) \
({ \
union oac __oac_spec = { \
.oac2.as = PSW_BITS_AS_SECONDARY, \
.oac2.a = 1, \
}; \
int __rc; \
\
asm volatile( \
" lr 0,%[spec]\n" \
"0: mvcos 0(%[_to]),%[_from],%[_size]\n" \
"1: xr %[rc],%[rc]\n" \
"2:\n" \
EX_TABLE_UA_LOAD_MEM(0b, 2b, %[rc], %[_to], %[_ksize]) \
EX_TABLE_UA_LOAD_MEM(1b, 2b, %[rc], %[_to], %[_ksize]) \
: [rc] "=&d" (__rc), "=Q" (*(to)) \
: [_size] "d" (size), [_from] "Q" (*(from)), \
[spec] "d" (__oac_spec.val), [_to] "a" (to), \
[_ksize] "K" (size) \
: "cc", "0"); \
__rc; \
})
static __always_inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
{
int rc;
switch (size) {
case 1:
rc = __get_user_asm((unsigned char *)x,
(unsigned char __user *)ptr,
size);
break;
case 2:
rc = __get_user_asm((unsigned short *)x,
(unsigned short __user *)ptr,
size);
break;
case 4:
rc = __get_user_asm((unsigned int *)x,
(unsigned int __user *)ptr,
size);
break;
case 8:
rc = __get_user_asm((unsigned long *)x,
(unsigned long __user *)ptr,
size);
break;
default:
__get_user_bad();
break;
}
return rc;
}
/*
* 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); \
})
#define __get_user(x, ptr) \
({ \
int __gu_err = -EFAULT; \
\
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
unsigned char __x; \
\
__gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 2: { \
unsigned short __x; \
\
__gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 4: { \
unsigned int __x; \
\
__gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 8: { \
unsigned long __x; \
\
__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); \
})
/*
* Copy a null terminated string from userspace.
*/
long __must_check strncpy_from_user(char *dst, const char __user *src, long count);
long __must_check strnlen_user(const char __user *src, long count);
/*
* 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);
}
void *s390_kernel_write(void *dst, const void *src, size_t size);
int __noreturn __put_kernel_bad(void);
#define __put_kernel_asm(val, to, insn) \
({ \
int __rc; \
\
asm volatile( \
"0: " insn " %[_val],%[_to]\n" \
"1: xr %[rc],%[rc]\n" \
"2:\n" \
EX_TABLE_UA_STORE(0b, 2b, %[rc]) \
EX_TABLE_UA_STORE(1b, 2b, %[rc]) \
: [rc] "=d" (__rc), [_to] "+Q" (*(to)) \
: [_val] "d" (val) \
: "cc"); \
__rc; \
})
#define __put_kernel_nofault(dst, src, type, err_label) \
do { \
unsigned long __x = (unsigned long)(*((type *)(src))); \
int __pk_err; \
\
switch (sizeof(type)) { \
case 1: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "stc"); \
break; \
case 2: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "sth"); \
break; \
case 4: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "st"); \
break; \
case 8: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "stg"); \
break; \
default: \
__pk_err = __put_kernel_bad(); \
break; \
} \
if (unlikely(__pk_err)) \
goto err_label; \
} while (0)
int __noreturn __get_kernel_bad(void);
#define __get_kernel_asm(val, from, insn) \
({ \
int __rc; \
\
asm volatile( \
"0: " insn " %[_val],%[_from]\n" \
"1: xr %[rc],%[rc]\n" \
"2:\n" \
EX_TABLE_UA_LOAD_REG(0b, 2b, %[rc], %[_val]) \
EX_TABLE_UA_LOAD_REG(1b, 2b, %[rc], %[_val]) \
: [rc] "=d" (__rc), [_val] "=d" (val) \
: [_from] "Q" (*(from)) \
: "cc"); \
__rc; \
})
#define __get_kernel_nofault(dst, src, type, err_label) \
do { \
int __gk_err; \
\
switch (sizeof(type)) { \
case 1: { \
unsigned char __x; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "ic"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
case 2: { \
unsigned short __x; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "lh"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
case 4: { \
unsigned int __x; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "l"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
case 8: { \
unsigned long __x; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "lg"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
default: \
__gk_err = __get_kernel_bad(); \
break; \
} \
if (unlikely(__gk_err)) \
goto err_label; \
} while (0)
void __cmpxchg_user_key_called_with_bad_pointer(void);
#define CMPXCHG_USER_KEY_MAX_LOOPS 128
static __always_inline int __cmpxchg_user_key(unsigned long address, void *uval,
__uint128_t old, __uint128_t new,
unsigned long key, int size)
{
int rc = 0;
switch (size) {
case 1: {
unsigned int prev, shift, mask, _old, _new;
unsigned long count;
shift = (3 ^ (address & 3)) << 3;
address ^= address & 3;
_old = ((unsigned int)old & 0xff) << shift;
_new = ((unsigned int)new & 0xff) << shift;
mask = ~(0xff << shift);
asm volatile(
" spka 0(%[key])\n"
" sacf 256\n"
" llill %[count],%[max_loops]\n"
"0: l %[prev],%[address]\n"
"1: nr %[prev],%[mask]\n"
" xilf %[mask],0xffffffff\n"
" or %[new],%[prev]\n"
" or %[prev],%[tmp]\n"
"2: lr %[tmp],%[prev]\n"
"3: cs %[prev],%[new],%[address]\n"
"4: jnl 5f\n"
" xr %[tmp],%[prev]\n"
" xr %[new],%[tmp]\n"
" nr %[tmp],%[mask]\n"
" jnz 5f\n"
" brct %[count],2b\n"
"5: sacf 768\n"
" spka %[default_key]\n"
EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
: [rc] "+&d" (rc),
[prev] "=&d" (prev),
[address] "+Q" (*(int *)address),
[tmp] "+&d" (_old),
[new] "+&d" (_new),
[mask] "+&d" (mask),
[count] "=a" (count)
: [key] "%[count]" (key << 4),
[default_key] "J" (PAGE_DEFAULT_KEY),
[max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
: "memory", "cc");
*(unsigned char *)uval = prev >> shift;
if (!count)
rc = -EAGAIN;
return rc;
}
case 2: {
unsigned int prev, shift, mask, _old, _new;
unsigned long count;
shift = (2 ^ (address & 2)) << 3;
address ^= address & 2;
_old = ((unsigned int)old & 0xffff) << shift;
_new = ((unsigned int)new & 0xffff) << shift;
mask = ~(0xffff << shift);
asm volatile(
" spka 0(%[key])\n"
" sacf 256\n"
" llill %[count],%[max_loops]\n"
"0: l %[prev],%[address]\n"
"1: nr %[prev],%[mask]\n"
" xilf %[mask],0xffffffff\n"
" or %[new],%[prev]\n"
" or %[prev],%[tmp]\n"
"2: lr %[tmp],%[prev]\n"
"3: cs %[prev],%[new],%[address]\n"
"4: jnl 5f\n"
" xr %[tmp],%[prev]\n"
" xr %[new],%[tmp]\n"
" nr %[tmp],%[mask]\n"
" jnz 5f\n"
" brct %[count],2b\n"
"5: sacf 768\n"
" spka %[default_key]\n"
EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
: [rc] "+&d" (rc),
[prev] "=&d" (prev),
[address] "+Q" (*(int *)address),
[tmp] "+&d" (_old),
[new] "+&d" (_new),
[mask] "+&d" (mask),
[count] "=a" (count)
: [key] "%[count]" (key << 4),
[default_key] "J" (PAGE_DEFAULT_KEY),
[max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
: "memory", "cc");
*(unsigned short *)uval = prev >> shift;
if (!count)
rc = -EAGAIN;
return rc;
}
case 4: {
unsigned int prev = old;
asm volatile(
" spka 0(%[key])\n"
" sacf 256\n"
"0: cs %[prev],%[new],%[address]\n"
"1: sacf 768\n"
" spka %[default_key]\n"
EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
: [rc] "+&d" (rc),
[prev] "+&d" (prev),
[address] "+Q" (*(int *)address)
: [new] "d" ((unsigned int)new),
[key] "a" (key << 4),
[default_key] "J" (PAGE_DEFAULT_KEY)
: "memory", "cc");
*(unsigned int *)uval = prev;
return rc;
}
case 8: {
unsigned long prev = old;
asm volatile(
" spka 0(%[key])\n"
" sacf 256\n"
"0: csg %[prev],%[new],%[address]\n"
"1: sacf 768\n"
" spka %[default_key]\n"
EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
: [rc] "+&d" (rc),
[prev] "+&d" (prev),
[address] "+QS" (*(long *)address)
: [new] "d" ((unsigned long)new),
[key] "a" (key << 4),
[default_key] "J" (PAGE_DEFAULT_KEY)
: "memory", "cc");
*(unsigned long *)uval = prev;
return rc;
}
case 16: {
__uint128_t prev = old;
asm volatile(
" spka 0(%[key])\n"
" sacf 256\n"
"0: cdsg %[prev],%[new],%[address]\n"
"1: sacf 768\n"
" spka %[default_key]\n"
EX_TABLE_UA_LOAD_REGPAIR(0b, 1b, %[rc], %[prev])
EX_TABLE_UA_LOAD_REGPAIR(1b, 1b, %[rc], %[prev])
: [rc] "+&d" (rc),
[prev] "+&d" (prev),
[address] "+QS" (*(__int128_t *)address)
: [new] "d" (new),
[key] "a" (key << 4),
[default_key] "J" (PAGE_DEFAULT_KEY)
: "memory", "cc");
*(__uint128_t *)uval = prev;
return rc;
}
}
__cmpxchg_user_key_called_with_bad_pointer();
return rc;
}
/**
* cmpxchg_user_key() - cmpxchg with user space target, honoring storage keys
* @ptr: User space address of value to compare to @old and exchange with
* @new. Must be aligned to sizeof(*@ptr).
* @uval: Address where the old value of *@ptr is written to.
* @old: Old value. Compared to the content pointed to by @ptr in order to
* determine if the exchange occurs. The old value read from *@ptr is
* written to *@uval.
* @new: New value to place at *@ptr.
* @key: Access key to use for checking storage key protection.
*
* Perform a cmpxchg on a user space target, honoring storage key protection.
* @key alone determines how key checking is performed, neither
* storage-protection-override nor fetch-protection-override apply.
* The caller must compare *@uval and @old to determine if values have been
* exchanged. In case of an exception *@uval is set to zero.
*
* Return: 0: cmpxchg executed
* -EFAULT: an exception happened when trying to access *@ptr
* -EAGAIN: maxed out number of retries (byte and short only)
*/
#define cmpxchg_user_key(ptr, uval, old, new, key) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(uval) __uval = (uval); \
\
BUILD_BUG_ON(sizeof(*(__ptr)) != sizeof(*(__uval))); \
might_fault(); \
__chk_user_ptr(__ptr); \
__cmpxchg_user_key((unsigned long)(__ptr), (void *)(__uval), \
(old), (new), (key), sizeof(*(__ptr))); \
})
#endif /* __S390_UACCESS_H */