diff options
Diffstat (limited to 'arch/tile/include/asm/uaccess.h')
| -rw-r--r-- | arch/tile/include/asm/uaccess.h | 222 |
1 files changed, 132 insertions, 90 deletions
diff --git a/arch/tile/include/asm/uaccess.h b/arch/tile/include/asm/uaccess.h index ef34d2caa..c3dd275 100644 --- a/arch/tile/include/asm/uaccess.h +++ b/arch/tile/include/asm/uaccess.h @@ -114,45 +114,75 @@ struct exception_table_entry { extern int fixup_exception(struct pt_regs *regs); /* - * We return the __get_user_N function results in a structure, - * thus in r0 and r1. If "err" is zero, "val" is the result - * of the read; otherwise, "err" is -EFAULT. - * - * We rarely need 8-byte values on a 32-bit architecture, but - * we size the structure to accommodate. In practice, for the - * the smaller reads, we can zero the high word for free, and - * the caller will ignore it by virtue of casting anyway. + * Support macros for __get_user(). + * + * Implementation note: The "case 8" logic of casting to the type of + * the result of subtracting the value from itself is basically a way + * of keeping all integer types the same, but casting any pointers to + * ptrdiff_t, i.e. also an integer type. This way there are no + * questionable casts seen by the compiler on an ILP32 platform. + * + * Note that __get_user() and __put_user() assume proper alignment. */ -struct __get_user { - unsigned long long val; - int err; -}; -/* - * FIXME: we should express these as inline extended assembler, since - * they're fundamentally just a variable dereference and some - * supporting exception_table gunk. Note that (a la i386) we can - * extend the copy_to_user and copy_from_user routines to call into - * such extended assembler routines, though we will have to use a - * different return code in that case (1, 2, or 4, rather than -EFAULT). - */ -extern struct __get_user __get_user_1(const void __user *); -extern struct __get_user __get_user_2(const void __user *); -extern struct __get_user __get_user_4(const void __user *); -extern struct __get_user __get_user_8(const void __user *); -extern int __put_user_1(long, void __user *); -extern int __put_user_2(long, void __user *); -extern int __put_user_4(long, void __user *); -extern int __put_user_8(long long, void __user *); - -/* Unimplemented routines to cause linker failures */ -extern struct __get_user __get_user_bad(void); -extern int __put_user_bad(void); +#ifdef __LP64__ +#define _ASM_PTR ".quad" +#else +#define _ASM_PTR ".long" +#endif + +#define __get_user_asm(OP, x, ptr, ret) \ + asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \ + ".pushsection .fixup,\"ax\"\n" \ + "0: { movei %1, 0; movei %0, %3 }\n" \ + "j 9f\n" \ + ".section __ex_table,\"a\"\n" \ + _ASM_PTR " 1b, 0b\n" \ + ".popsection\n" \ + "9:" \ + : "=r" (ret), "=r" (x) \ + : "r" (ptr), "i" (-EFAULT)) + +#ifdef __tilegx__ +#define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret) +#define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret) +#define __get_user_4(x, ptr, ret) __get_user_asm(ld4u, x, ptr, ret) +#define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret) +#else +#define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret) +#define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret) +#define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret) +#ifdef __LITTLE_ENDIAN +#define __lo32(a, b) a +#define __hi32(a, b) b +#else +#define __lo32(a, b) b +#define __hi32(a, b) a +#endif +#define __get_user_8(x, ptr, ret) \ + ({ \ + unsigned int __a, __b; \ + asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n" \ + "2: { lw %2, %2; movei %0, 0 }\n" \ + ".pushsection .fixup,\"ax\"\n" \ + "0: { movei %1, 0; movei %2, 0 }\n" \ + "{ movei %0, %4; j 9f }\n" \ + ".section __ex_table,\"a\"\n" \ + ".word 1b, 0b\n" \ + ".word 2b, 0b\n" \ + ".popsection\n" \ + "9:" \ + : "=r" (ret), "=r" (__a), "=&r" (__b) \ + : "r" (ptr), "i" (-EFAULT)); \ + (x) = (__typeof(x))(__typeof((x)-(x))) \ + (((u64)__hi32(__a, __b) << 32) | \ + __lo32(__a, __b)); \ + }) +#endif + +extern int __get_user_bad(void) + __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8"))); -/* - * Careful: we have to cast the result to the type of the pointer - * for sign reasons. - */ /** * __get_user: - Get a simple variable from user space, with less checking. * @x: Variable to store result. @@ -174,30 +204,62 @@ extern int __put_user_bad(void); * function. */ #define __get_user(x, ptr) \ -({ struct __get_user __ret; \ - __typeof__(*(ptr)) const __user *__gu_addr = (ptr); \ - __chk_user_ptr(__gu_addr); \ - switch (sizeof(*(__gu_addr))) { \ - case 1: \ - __ret = __get_user_1(__gu_addr); \ - break; \ - case 2: \ - __ret = __get_user_2(__gu_addr); \ - break; \ - case 4: \ - __ret = __get_user_4(__gu_addr); \ - break; \ - case 8: \ - __ret = __get_user_8(__gu_addr); \ - break; \ - default: \ - __ret = __get_user_bad(); \ - break; \ - } \ - (x) = (__typeof__(*__gu_addr)) (__typeof__(*__gu_addr - *__gu_addr)) \ - __ret.val; \ - __ret.err; \ -}) + ({ \ + int __ret; \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: __get_user_1(x, ptr, __ret); break; \ + case 2: __get_user_2(x, ptr, __ret); break; \ + case 4: __get_user_4(x, ptr, __ret); break; \ + case 8: __get_user_8(x, ptr, __ret); break; \ + default: __ret = __get_user_bad(); break; \ + } \ + __ret; \ + }) + +/* Support macros for __put_user(). */ + +#define __put_user_asm(OP, x, ptr, ret) \ + asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \ + ".pushsection .fixup,\"ax\"\n" \ + "0: { movei %0, %3; j 9f }\n" \ + ".section __ex_table,\"a\"\n" \ + _ASM_PTR " 1b, 0b\n" \ + ".popsection\n" \ + "9:" \ + : "=r" (ret) \ + : "r" (ptr), "r" (x), "i" (-EFAULT)) + +#ifdef __tilegx__ +#define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret) +#define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret) +#define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret) +#define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret) +#else +#define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret) +#define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret) +#define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret) +#define __put_user_8(x, ptr, ret) \ + ({ \ + u64 __x = (__typeof((x)-(x)))(x); \ + int __lo = (int) __x, __hi = (int) (__x >> 32); \ + asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n" \ + "2: { sw %0, %3; movei %0, 0 }\n" \ + ".pushsection .fixup,\"ax\"\n" \ + "0: { movei %0, %4; j 9f }\n" \ + ".section __ex_table,\"a\"\n" \ + ".word 1b, 0b\n" \ + ".word 2b, 0b\n" \ + ".popsection\n" \ + "9:" \ + : "=&r" (ret) \ + : "r" (ptr), "r" (__lo32(__lo, __hi)), \ + "r" (__hi32(__lo, __hi)), "i" (-EFAULT)); \ + }) +#endif + +extern int __put_user_bad(void) + __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8"))); /** * __put_user: - Write a simple value into user space, with less checking. @@ -217,39 +279,19 @@ extern int __put_user_bad(void); * function. * * Returns zero on success, or -EFAULT on error. - * - * Implementation note: The "case 8" logic of casting to the type of - * the result of subtracting the value from itself is basically a way - * of keeping all integer types the same, but casting any pointers to - * ptrdiff_t, i.e. also an integer type. This way there are no - * questionable casts seen by the compiler on an ILP32 platform. */ #define __put_user(x, ptr) \ ({ \ - int __pu_err = 0; \ - __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ - typeof(*__pu_addr) __pu_val = (x); \ - __chk_user_ptr(__pu_addr); \ - switch (sizeof(__pu_val)) { \ - case 1: \ - __pu_err = __put_user_1((long)__pu_val, __pu_addr); \ - break; \ - case 2: \ - __pu_err = __put_user_2((long)__pu_val, __pu_addr); \ - break; \ - case 4: \ - __pu_err = __put_user_4((long)__pu_val, __pu_addr); \ - break; \ - case 8: \ - __pu_err = \ - __put_user_8((__typeof__(__pu_val - __pu_val))__pu_val,\ - __pu_addr); \ - break; \ - default: \ - __pu_err = __put_user_bad(); \ - break; \ + int __ret; \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: __put_user_1(x, ptr, __ret); break; \ + case 2: __put_user_2(x, ptr, __ret); break; \ + case 4: __put_user_4(x, ptr, __ret); break; \ + case 8: __put_user_8(x, ptr, __ret); break; \ + default: __ret = __put_user_bad(); break; \ } \ - __pu_err; \ + __ret; \ }) /* @@ -378,7 +420,7 @@ static inline unsigned long __must_check copy_from_user(void *to, /** * __copy_in_user() - copy data within user space, with less checking. * @to: Destination address, in user space. - * @from: Source address, in kernel space. + * @from: Source address, in user space. * @n: Number of bytes to copy. * * Context: User context only. This function may sleep. |
