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Diffstat (limited to 'arch/parisc/include/asm/uaccess.h')
| -rw-r--r-- | arch/parisc/include/asm/uaccess.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h new file mode 100644 index 000000000..ed2cd4fb4 --- /dev/null +++ b/arch/parisc/include/asm/uaccess.h @@ -0,0 +1,226 @@ +/* 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 */ |