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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ARCH_POWERPC_UACCESS_H
#define _ARCH_POWERPC_UACCESS_H
#include <asm/ppc_asm.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/extable.h>
#include <asm/kup.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.
*
* The fs/ds values are now the highest legal address in the "segment".
* This simplifies the checking in the routines below.
*/
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#define KERNEL_DS MAKE_MM_SEG(~0UL)
#ifdef __powerpc64__
/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
#define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
#else
#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
#endif
#define get_fs() (current->thread.addr_limit)
static inline void set_fs(mm_segment_t fs)
{
current->thread.addr_limit = fs;
/* On user-mode return check addr_limit (fs) is correct */
set_thread_flag(TIF_FSCHECK);
}
#define segment_eq(a, b) ((a).seg == (b).seg)
#define user_addr_max() (get_fs().seg)
#ifdef __powerpc64__
/*
* This check is sufficient because there is a large enough
* gap between user addresses and the kernel addresses
*/
#define __access_ok(addr, size, segment) \
(((addr) <= (segment).seg) && ((size) <= (segment).seg))
#else
static inline int __access_ok(unsigned long addr, unsigned long size,
mm_segment_t seg)
{
if (addr > seg.seg)
return 0;
return (size == 0 || size - 1 <= seg.seg - addr);
}
#endif
#define access_ok(addr, size) \
(__chk_user_ptr(addr), \
__access_ok((__force unsigned long)(addr), (size), get_fs()))
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*
* This gets kind of ugly. We want to return _two_ values in "get_user()"
* and yet we don't want to do any pointers, because that is too much
* of a performance impact. Thus we have a few rather ugly macros here,
* and hide all the ugliness from the user.
*
* The "__xxx" versions of the user access functions are versions that
* do not verify the address space, that must have been done previously
* with a separate "access_ok()" call (this is used when we do multiple
* accesses to the same area of user memory).
*
* As we use the same address space for kernel and user data on the
* PowerPC, we can just do these as direct assignments. (Of course, the
* exception handling means that it's no longer "just"...)
*
*/
#define get_user(x, ptr) \
__get_user_check((x), (ptr), sizeof(*(ptr)))
#define put_user(x, ptr) \
__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) \
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
#define __put_user(x, ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __get_user_inatomic(x, ptr) \
__get_user_nosleep((x), (ptr), sizeof(*(ptr)))
#define __put_user_inatomic(x, ptr) \
__put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
extern long __put_user_bad(void);
/*
* We don't tell gcc that we are accessing memory, but this is OK
* because we do not write to any memory gcc knows about, so there
* are no aliasing issues.
*/
#define __put_user_asm(x, addr, err, op) \
__asm__ __volatile__( \
"1: " op " %1,0(%2) # put_user\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%3\n" \
" b 2b\n" \
".previous\n" \
EX_TABLE(1b, 3b) \
: "=r" (err) \
: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
#ifdef __powerpc64__
#define __put_user_asm2(x, ptr, retval) \
__put_user_asm(x, ptr, retval, "std")
#else /* __powerpc64__ */
#define __put_user_asm2(x, addr, err) \
__asm__ __volatile__( \
"1: stw %1,0(%2)\n" \
"2: stw %1+1,4(%2)\n" \
"3:\n" \
".section .fixup,\"ax\"\n" \
"4: li %0,%3\n" \
" b 3b\n" \
".previous\n" \
EX_TABLE(1b, 4b) \
EX_TABLE(2b, 4b) \
: "=r" (err) \
: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
#endif /* __powerpc64__ */
#define __put_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
allow_write_to_user(ptr, size); \
switch (size) { \
case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
case 8: __put_user_asm2(x, ptr, retval); break; \
default: __put_user_bad(); \
} \
prevent_write_to_user(ptr, size); \
} while (0)
#define __put_user_nocheck(x, ptr, size) \
({ \
long __pu_err; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
if (!is_kernel_addr((unsigned long)__pu_addr)) \
might_fault(); \
__chk_user_ptr(ptr); \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
})
#define __put_user_check(x, ptr, size) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
might_fault(); \
if (access_ok(__pu_addr, size)) \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
})
#define __put_user_nosleep(x, ptr, size) \
({ \
long __pu_err; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
__chk_user_ptr(ptr); \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
})
extern long __get_user_bad(void);
/*
* This does an atomic 128 byte aligned load from userspace.
* Upto caller to do enable_kernel_vmx() before calling!
*/
#define __get_user_atomic_128_aligned(kaddr, uaddr, err) \
__asm__ __volatile__( \
".machine push\n" \
".machine altivec\n" \
"1: lvx 0,0,%1 # get user\n" \
" stvx 0,0,%2 # put kernel\n" \
".machine pop\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%3\n" \
" b 2b\n" \
".previous\n" \
EX_TABLE(1b, 3b) \
: "=r" (err) \
: "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err))
#define __get_user_asm(x, addr, err, op) \
__asm__ __volatile__( \
"1: "op" %1,0(%2) # get_user\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%3\n" \
" li %1,0\n" \
" b 2b\n" \
".previous\n" \
EX_TABLE(1b, 3b) \
: "=r" (err), "=r" (x) \
: "b" (addr), "i" (-EFAULT), "0" (err))
#ifdef __powerpc64__
#define __get_user_asm2(x, addr, err) \
__get_user_asm(x, addr, err, "ld")
#else /* __powerpc64__ */
#define __get_user_asm2(x, addr, err) \
__asm__ __volatile__( \
"1: lwz %1,0(%2)\n" \
"2: lwz %1+1,4(%2)\n" \
"3:\n" \
".section .fixup,\"ax\"\n" \
"4: li %0,%3\n" \
" li %1,0\n" \
" li %1+1,0\n" \
" b 3b\n" \
".previous\n" \
EX_TABLE(1b, 4b) \
EX_TABLE(2b, 4b) \
: "=r" (err), "=&r" (x) \
: "b" (addr), "i" (-EFAULT), "0" (err))
#endif /* __powerpc64__ */
#define __get_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
__chk_user_ptr(ptr); \
if (size > sizeof(x)) \
(x) = __get_user_bad(); \
allow_read_from_user(ptr, size); \
switch (size) { \
case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
case 8: __get_user_asm2(x, ptr, retval); break; \
default: (x) = __get_user_bad(); \
} \
prevent_read_from_user(ptr, size); \
} while (0)
/*
* This is a type: either unsigned long, if the argument fits into
* that type, or otherwise unsigned long long.
*/
#define __long_type(x) \
__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
#define __get_user_nocheck(x, ptr, size) \
({ \
long __gu_err; \
__long_type(*(ptr)) __gu_val; \
__typeof__(*(ptr)) __user *__gu_addr = (ptr); \
__chk_user_ptr(ptr); \
if (!is_kernel_addr((unsigned long)__gu_addr)) \
might_fault(); \
barrier_nospec(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_check(x, ptr, size) \
({ \
long __gu_err = -EFAULT; \
__long_type(*(ptr)) __gu_val = 0; \
__typeof__(*(ptr)) __user *__gu_addr = (ptr); \
might_fault(); \
if (access_ok(__gu_addr, (size))) { \
barrier_nospec(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
} \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_nosleep(x, ptr, size) \
({ \
long __gu_err; \
__long_type(*(ptr)) __gu_val; \
__typeof__(*(ptr)) __user *__gu_addr = (ptr); \
__chk_user_ptr(ptr); \
barrier_nospec(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
/* more complex routines */
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
#ifdef __powerpc64__
static inline unsigned long
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
unsigned long ret;
barrier_nospec();
allow_read_write_user(to, from, n);
ret = __copy_tofrom_user(to, from, n);
prevent_read_write_user(to, from, n);
return ret;
}
#endif /* __powerpc64__ */
static inline unsigned long raw_copy_from_user(void *to,
const void __user *from, unsigned long n)
{
unsigned long ret;
if (__builtin_constant_p(n) && (n <= 8)) {
ret = 1;
switch (n) {
case 1:
barrier_nospec();
__get_user_size(*(u8 *)to, from, 1, ret);
break;
case 2:
barrier_nospec();
__get_user_size(*(u16 *)to, from, 2, ret);
break;
case 4:
barrier_nospec();
__get_user_size(*(u32 *)to, from, 4, ret);
break;
case 8:
barrier_nospec();
__get_user_size(*(u64 *)to, from, 8, ret);
break;
}
if (ret == 0)
return 0;
}
barrier_nospec();
allow_read_from_user(from, n);
ret = __copy_tofrom_user((__force void __user *)to, from, n);
prevent_read_from_user(from, n);
return ret;
}
static inline unsigned long raw_copy_to_user(void __user *to,
const void *from, unsigned long n)
{
unsigned long ret;
if (__builtin_constant_p(n) && (n <= 8)) {
ret = 1;
switch (n) {
case 1:
__put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret);
break;
case 2:
__put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret);
break;
case 4:
__put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret);
break;
case 8:
__put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret);
break;
}
if (ret == 0)
return 0;
}
allow_write_to_user(to, n);
ret = __copy_tofrom_user(to, (__force const void __user *)from, n);
prevent_write_to_user(to, n);
return ret;
}
static __always_inline unsigned long __must_check
copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
{
if (likely(check_copy_size(from, n, true))) {
if (access_ok(to, n)) {
allow_write_to_user(to, n);
n = memcpy_mcsafe((void *)to, from, n);
prevent_write_to_user(to, n);
}
}
return n;
}
unsigned long __arch_clear_user(void __user *addr, unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)
{
unsigned long ret = size;
might_fault();
if (likely(access_ok(addr, size))) {
allow_write_to_user(addr, size);
ret = __arch_clear_user(addr, size);
prevent_write_to_user(addr, size);
}
return ret;
}
static inline unsigned long __clear_user(void __user *addr, unsigned long size)
{
return clear_user(addr, size);
}
extern long strncpy_from_user(char *dst, const char __user *src, long count);
extern __must_check long strnlen_user(const char __user *str, long n);
extern long __copy_from_user_flushcache(void *dst, const void __user *src,
unsigned size);
extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
size_t len);
#endif /* _ARCH_POWERPC_UACCESS_H */
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