| Current File : //usr/lib/modules/6.14.0-1012-aws/build/arch/s390/include/asm/uaccess.h |
/* 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/extable.h>
#include <asm/facility.h>
#include <asm-generic/access_ok.h>
#include <linux/instrumented.h>
void debug_user_asce(int exit);
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;
};
};
static __always_inline __must_check unsigned long
raw_copy_from_user_key(void *to, const void __user *from, unsigned long size, unsigned long key)
{
unsigned long rem;
union oac spec = {
.oac2.key = key,
.oac2.as = PSW_BITS_AS_SECONDARY,
.oac2.k = 1,
.oac2.a = 1,
};
asm_inline volatile(
" lr %%r0,%[spec]\n"
"0: mvcos 0(%[to]),0(%[from]),%[size]\n"
"1: jz 5f\n"
" algr %[size],%[val]\n"
" slgr %[from],%[val]\n"
" slgr %[to],%[val]\n"
" j 0b\n"
"2: la %[rem],4095(%[from])\n" /* rem = from + 4095 */
" nr %[rem],%[val]\n" /* rem = (from + 4095) & -4096 */
" slgr %[rem],%[from]\n"
" clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"3: mvcos 0(%[to]),0(%[from]),%[rem]\n"
"4: slgr %[size],%[rem]\n"
" j 6f\n"
"5: lghi %[size],0\n"
"6:\n"
EX_TABLE(0b, 2b)
EX_TABLE(1b, 2b)
EX_TABLE(3b, 6b)
EX_TABLE(4b, 6b)
: [size] "+&a" (size), [from] "+&a" (from), [to] "+&a" (to), [rem] "=&a" (rem)
: [val] "a" (-4096UL), [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
static __always_inline __must_check unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
return raw_copy_from_user_key(to, from, n, 0);
}
static __always_inline __must_check unsigned long
raw_copy_to_user_key(void __user *to, const void *from, unsigned long size, unsigned long key)
{
unsigned long rem;
union oac spec = {
.oac1.key = key,
.oac1.as = PSW_BITS_AS_SECONDARY,
.oac1.k = 1,
.oac1.a = 1,
};
asm_inline volatile(
" lr %%r0,%[spec]\n"
"0: mvcos 0(%[to]),0(%[from]),%[size]\n"
"1: jz 5f\n"
" algr %[size],%[val]\n"
" slgr %[to],%[val]\n"
" slgr %[from],%[val]\n"
" j 0b\n"
"2: la %[rem],4095(%[to])\n" /* rem = to + 4095 */
" nr %[rem],%[val]\n" /* rem = (to + 4095) & -4096 */
" slgr %[rem],%[to]\n"
" clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"3: mvcos 0(%[to]),0(%[from]),%[rem]\n"
"4: slgr %[size],%[rem]\n"
" j 6f\n"
"5: lghi %[size],0\n"
"6:\n"
EX_TABLE(0b, 2b)
EX_TABLE(1b, 2b)
EX_TABLE(3b, 6b)
EX_TABLE(4b, 6b)
: [size] "+&a" (size), [to] "+&a" (to), [from] "+&a" (from), [rem] "=&a" (rem)
: [val] "a" (-4096UL), [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
static __always_inline __must_check unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
return raw_copy_to_user_key(to, from, n, 0);
}
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;
}
int __noreturn __put_user_bad(void);
#ifdef CONFIG_KMSAN
#define uaccess_kmsan_or_inline noinline __maybe_unused __no_sanitize_memory
#else
#define uaccess_kmsan_or_inline __always_inline
#endif
#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
#define DEFINE_PUT_USER_NOINSTR(type) \
static uaccess_kmsan_or_inline int \
__put_user_##type##_noinstr(unsigned type __user *to, \
unsigned type *from, \
unsigned long size) \
{ \
asm goto( \
" llilh %%r0,%[spec]\n" \
"0: mvcos %[to],%[from],%[size]\n" \
"1: nopr %%r7\n" \
EX_TABLE(0b, %l[Efault]) \
EX_TABLE(1b, %l[Efault]) \
: [to] "+Q" (*to) \
: [size] "d" (size), [from] "Q" (*from), \
[spec] "I" (0x81) \
: "cc", "0" \
: Efault \
); \
return 0; \
Efault: \
return -EFAULT; \
}
#else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
#define DEFINE_PUT_USER_NOINSTR(type) \
static uaccess_kmsan_or_inline int \
__put_user_##type##_noinstr(unsigned type __user *to, \
unsigned type *from, \
unsigned long size) \
{ \
int rc; \
\
asm volatile( \
" llilh %%r0,%[spec]\n" \
"0: mvcos %[to],%[from],%[size]\n" \
"1: lhi %[rc],0\n" \
"2:\n" \
EX_TABLE_UA_FAULT(0b, 2b, %[rc]) \
EX_TABLE_UA_FAULT(1b, 2b, %[rc]) \
: [rc] "=d" (rc), [to] "+Q" (*to) \
: [size] "d" (size), [from] "Q" (*from), \
[spec] "I" (0x81) \
: "cc", "0"); \
return rc; \
}
#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
DEFINE_PUT_USER_NOINSTR(char);
DEFINE_PUT_USER_NOINSTR(short);
DEFINE_PUT_USER_NOINSTR(int);
DEFINE_PUT_USER_NOINSTR(long);
#define DEFINE_PUT_USER(type) \
static __always_inline int \
__put_user_##type(unsigned type __user *to, unsigned type *from, \
unsigned long size) \
{ \
int rc; \
\
rc = __put_user_##type##_noinstr(to, from, size); \
instrument_put_user(*from, to, size); \
return rc; \
}
DEFINE_PUT_USER(char);
DEFINE_PUT_USER(short);
DEFINE_PUT_USER(int);
DEFINE_PUT_USER(long);
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __x = (x); \
int __prc; \
\
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
__prc = __put_user_char((unsigned char __user *)(ptr), \
(unsigned char *)&__x, \
sizeof(*(ptr))); \
break; \
case 2: \
__prc = __put_user_short((unsigned short __user *)(ptr),\
(unsigned short *)&__x, \
sizeof(*(ptr))); \
break; \
case 4: \
__prc = __put_user_int((unsigned int __user *)(ptr), \
(unsigned int *)&__x, \
sizeof(*(ptr))); \
break; \
case 8: \
__prc = __put_user_long((unsigned long __user *)(ptr), \
(unsigned long *)&__x, \
sizeof(*(ptr))); \
break; \
default: \
__prc = __put_user_bad(); \
break; \
} \
__builtin_expect(__prc, 0); \
})
#define put_user(x, ptr) \
({ \
might_fault(); \
__put_user(x, ptr); \
})
int __noreturn __get_user_bad(void);
#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
#define DEFINE_GET_USER_NOINSTR(type) \
static uaccess_kmsan_or_inline int \
__get_user_##type##_noinstr(unsigned type *to, \
const unsigned type __user *from, \
unsigned long size) \
{ \
asm goto( \
" lhi %%r0,%[spec]\n" \
"0: mvcos %[to],%[from],%[size]\n" \
"1: nopr %%r7\n" \
EX_TABLE(0b, %l[Efault]) \
EX_TABLE(1b, %l[Efault]) \
: [to] "=Q" (*to) \
: [size] "d" (size), [from] "Q" (*from), \
[spec] "I" (0x81) \
: "cc", "0" \
: Efault \
); \
return 0; \
Efault: \
*to = 0; \
return -EFAULT; \
}
#else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
#define DEFINE_GET_USER_NOINSTR(type) \
static uaccess_kmsan_or_inline int \
__get_user_##type##_noinstr(unsigned type *to, \
const unsigned type __user *from, \
unsigned long size) \
{ \
int rc; \
\
asm volatile( \
" lhi %%r0,%[spec]\n" \
"0: mvcos %[to],%[from],%[size]\n" \
"1: lhi %[rc],0\n" \
"2:\n" \
EX_TABLE_UA_FAULT(0b, 2b, %[rc]) \
EX_TABLE_UA_FAULT(1b, 2b, %[rc]) \
: [rc] "=d" (rc), [to] "=Q" (*to) \
: [size] "d" (size), [from] "Q" (*from), \
[spec] "I" (0x81) \
: "cc", "0"); \
if (likely(!rc)) \
return 0; \
*to = 0; \
return rc; \
}
#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
DEFINE_GET_USER_NOINSTR(char);
DEFINE_GET_USER_NOINSTR(short);
DEFINE_GET_USER_NOINSTR(int);
DEFINE_GET_USER_NOINSTR(long);
#define DEFINE_GET_USER(type) \
static __always_inline int \
__get_user_##type(unsigned type *to, const unsigned type __user *from, \
unsigned long size) \
{ \
int rc; \
\
rc = __get_user_##type##_noinstr(to, from, size); \
instrument_get_user(*to); \
return rc; \
}
DEFINE_GET_USER(char);
DEFINE_GET_USER(short);
DEFINE_GET_USER(int);
DEFINE_GET_USER(long);
#define __get_user(x, ptr) \
({ \
const __user void *____guptr = (ptr); \
int __grc; \
\
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
const unsigned char __user *__guptr = ____guptr; \
unsigned char __x; \
\
__grc = __get_user_char(&__x, __guptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 2: { \
const unsigned short __user *__guptr = ____guptr; \
unsigned short __x; \
\
__grc = __get_user_short(&__x, __guptr, sizeof(*(ptr)));\
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 4: { \
const unsigned int __user *__guptr = ____guptr; \
unsigned int __x; \
\
__grc = __get_user_int(&__x, __guptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 8: { \
const unsigned long __user *__guptr = ____guptr; \
unsigned long __x; \
\
__grc = __get_user_long(&__x, __guptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
default: \
__grc = __get_user_bad(); \
break; \
} \
__builtin_expect(__grc, 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);
static inline void *s390_kernel_write(void *dst, const void *src, size_t size)
{
if (__is_defined(__DECOMPRESSOR))
return memcpy(dst, src, size);
return __s390_kernel_write(dst, src, size);
}
void __noreturn __mvc_kernel_nofault_bad(void);
#if defined(CONFIG_CC_HAS_ASM_GOTO_OUTPUT) && defined(CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS)
#define __mvc_kernel_nofault(dst, src, type, err_label) \
do { \
switch (sizeof(type)) { \
case 1: \
case 2: \
case 4: \
case 8: \
asm goto( \
"0: mvc %O[_dst](%[_len],%R[_dst]),%[_src]\n" \
"1: nopr %%r7\n" \
EX_TABLE(0b, %l[err_label]) \
EX_TABLE(1b, %l[err_label]) \
: [_dst] "=Q" (*(type *)dst) \
: [_src] "Q" (*(type *)(src)), \
[_len] "I" (sizeof(type)) \
: \
: err_label); \
break; \
default: \
__mvc_kernel_nofault_bad(); \
break; \
} \
} while (0)
#else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT) && CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS */
#define __mvc_kernel_nofault(dst, src, type, err_label) \
do { \
type *(__dst) = (type *)(dst); \
int __rc; \
\
switch (sizeof(type)) { \
case 1: \
case 2: \
case 4: \
case 8: \
asm_inline volatile( \
"0: mvc 0(%[_len],%[_dst]),%[_src]\n" \
"1: lhi %[_rc],0\n" \
"2:\n" \
EX_TABLE_UA_FAULT(0b, 2b, %[_rc]) \
EX_TABLE_UA_FAULT(1b, 2b, %[_rc]) \
: [_rc] "=d" (__rc), \
"=m" (*__dst) \
: [_src] "Q" (*(type *)(src)), \
[_dst] "a" (__dst), \
[_len] "I" (sizeof(type))); \
if (__rc) \
goto err_label; \
break; \
default: \
__mvc_kernel_nofault_bad(); \
break; \
} \
} while (0)
#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT && CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS */
#define __get_kernel_nofault __mvc_kernel_nofault
#define __put_kernel_nofault __mvc_kernel_nofault
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 */