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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PARISC_UACCESS_H
#define __PARISC_UACCESS_H
/*
* User space memory access functions
*/
#include <asm/page.h>
#include <asm/cache.h>
#include <linux/bug.h>
#include <linux/string.h>
#define KERNEL_DS ((mm_segment_t){0})
#define USER_DS ((mm_segment_t){1})
#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
/*
* Note that since kernel addresses are in a separate address space on
* parisc, we don't need to do anything for access_ok().
* We just let the page fault handler do the right thing. This also means
* that put_user is the same as __put_user, etc.
*/
#define access_ok(uaddr, size) \
( (uaddr) == (uaddr) )
#define put_user __put_user
#define get_user __get_user
#if !defined(CONFIG_64BIT)
#define LDD_USER(val, ptr) __get_user_asm64(val, ptr)
#define STD_USER(x, ptr) __put_user_asm64(x, ptr)
#else
#define LDD_USER(val, ptr) __get_user_asm(val, "ldd", ptr)
#define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
#endif
/*
* The exception table contains two values: the first is the relative offset to
* the address of the instruction that is allowed to fault, and the second is
* the relative offset to the address of the fixup routine. Since relative
* addresses are used, 32bit values are sufficient even on 64bit kernel.
*/
#define ARCH_HAS_RELATIVE_EXTABLE
struct exception_table_entry {
int insn; /* relative address of insn that is allowed to fault. */
int fixup; /* relative address of fixup routine */
};
#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
".section __ex_table,\"aw\"\n" \
".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
".previous\n"
/*
* ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry
* (with lowest bit set) for which the fault handler in fixup_exception() will
* load -EFAULT into %r8 for a read or write fault, and zeroes the target
* register in case of a read fault in get_user().
*/
#define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\
ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1)
/*
* load_sr2() preloads the space register %%sr2 - based on the value of
* get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
* is 0), or with the current value of %%sr3 to access user space (USER_DS)
* memory. The following __get_user_asm() and __put_user_asm() functions have
* %%sr2 hard-coded to access the requested memory.
*/
#define load_sr2() \
__asm__(" or,= %0,%%r0,%%r0\n\t" \
" mfsp %%sr3,%0\n\t" \
" mtsp %0,%%sr2\n\t" \
: : "r"(get_fs()) : )
#define __get_user_internal(val, ptr) \
({ \
register long __gu_err __asm__ ("r8") = 0; \
\
switch (sizeof(*(ptr))) { \
case 1: __get_user_asm(val, "ldb", ptr); break; \
case 2: __get_user_asm(val, "ldh", ptr); break; \
case 4: __get_user_asm(val, "ldw", ptr); break; \
case 8: LDD_USER(val, ptr); break; \
default: BUILD_BUG(); \
} \
\
__gu_err; \
})
#define __get_user(val, ptr) \
({ \
load_sr2(); \
__get_user_internal(val, ptr); \
})
#define __get_user_asm(val, ldx, ptr) \
{ \
register long __gu_val; \
\
__asm__("1: " ldx " 0(%%sr2,%2),%0\n" \
"9:\n" \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
: "=r"(__gu_val), "=r"(__gu_err) \
: "r"(ptr), "1"(__gu_err)); \
\
(val) = (__force __typeof__(*(ptr))) __gu_val; \
}
#if !defined(CONFIG_64BIT)
#define __get_user_asm64(val, ptr) \
{ \
union { \
unsigned long long l; \
__typeof__(*(ptr)) t; \
} __gu_tmp; \
\
__asm__(" copy %%r0,%R0\n" \
"1: ldw 0(%%sr2,%2),%0\n" \
"2: ldw 4(%%sr2,%2),%R0\n" \
"9:\n" \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
: "=&r"(__gu_tmp.l), "=r"(__gu_err) \
: "r"(ptr), "1"(__gu_err)); \
\
(val) = __gu_tmp.t; \
}
#endif /* !defined(CONFIG_64BIT) */
#define __put_user_internal(x, ptr) \
({ \
register long __pu_err __asm__ ("r8") = 0; \
__typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
\
switch (sizeof(*(ptr))) { \
case 1: __put_user_asm("stb", __x, ptr); break; \
case 2: __put_user_asm("sth", __x, ptr); break; \
case 4: __put_user_asm("stw", __x, ptr); break; \
case 8: STD_USER(__x, ptr); break; \
default: BUILD_BUG(); \
} \
\
__pu_err; \
})
#define __put_user(x, ptr) \
({ \
load_sr2(); \
__put_user_internal(x, ptr); \
})
/*
* The "__put_user/kernel_asm()" macros tell gcc they read from memory
* instead of writing. This is because they do not write to any memory
* gcc knows about, so there are no aliasing issues. These macros must
* also be aware that fixups are executed in the context of the fault,
* and any registers used there must be listed as clobbers.
* r8 is already listed as err.
*/
#define __put_user_asm(stx, x, ptr) \
__asm__ __volatile__ ( \
"1: " stx " %2,0(%%sr2,%1)\n" \
"9:\n" \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
: "=r"(__pu_err) \
: "r"(ptr), "r"(x), "0"(__pu_err))
#if !defined(CONFIG_64BIT)
#define __put_user_asm64(__val, ptr) do { \
__asm__ __volatile__ ( \
"1: stw %2,0(%%sr2,%1)\n" \
"2: stw %R2,4(%%sr2,%1)\n" \
"9:\n" \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
: "=r"(__pu_err) \
: "r"(ptr), "r"(__val), "0"(__pu_err)); \
} while (0)
#endif /* !defined(CONFIG_64BIT) */
/*
* Complex access routines -- external declarations
*/
extern long strncpy_from_user(char *, const char __user *, long);
extern unsigned lclear_user(void __user *, unsigned long);
extern long lstrnlen_user(const char __user *, long);
/*
* Complex access routines -- macros
*/
#define user_addr_max() (~0UL)
#define strnlen_user lstrnlen_user
#define clear_user lclear_user
#define __clear_user lclear_user
unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src,
unsigned long len);
unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src,
unsigned long len);
unsigned long __must_check raw_copy_in_user(void __user *dst, const void __user *src,
unsigned long len);
#define INLINE_COPY_TO_USER
#define INLINE_COPY_FROM_USER
struct pt_regs;
int fixup_exception(struct pt_regs *regs);
#endif /* __PARISC_UACCESS_H */
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