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Diffstat (limited to 'arch/alpha/include/asm/uaccess.h')
| -rw-r--r-- | arch/alpha/include/asm/uaccess.h | 511 |
1 files changed, 511 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/uaccess.h b/arch/alpha/include/asm/uaccess.h new file mode 100644 index 00000000000..22de3b434a2 --- /dev/null +++ b/arch/alpha/include/asm/uaccess.h @@ -0,0 +1,511 @@ +#ifndef __ALPHA_UACCESS_H +#define __ALPHA_UACCESS_H + +#include <linux/errno.h> +#include <linux/sched.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. + * + * Or at least it did once upon a time. Nowadays it is a mask that + * defines which bits of the address space are off limits. This is a + * wee bit faster than the above. + * + * For historical reasons, these macros are grossly misnamed. + */ + +#define KERNEL_DS ((mm_segment_t) { 0UL }) +#define USER_DS ((mm_segment_t) { -0x40000000000UL }) + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +#define get_fs() (current_thread_info()->addr_limit) +#define get_ds() (KERNEL_DS) +#define set_fs(x) (current_thread_info()->addr_limit = (x)) + +#define segment_eq(a,b) ((a).seg == (b).seg) + +/* + * Is a address valid? This does a straightforward calculation rather + * than tests. + * + * Address valid if: + * - "addr" doesn't have any high-bits set + * - AND "size" doesn't have any high-bits set + * - AND "addr+size" doesn't have any high-bits set + * - OR we are in kernel mode. + */ +#define __access_ok(addr,size,segment) \ + (((segment).seg & (addr | size | (addr+size))) == 0) + +#define access_ok(type,addr,size) \ +({ \ + __chk_user_ptr(addr); \ + __access_ok(((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. + * + * As the alpha uses the same address space for kernel and user + * data, we can just do these as direct assignments. (Of course, the + * exception handling means that it's no longer "just"...) + * + * Careful to not + * (a) re-use the arguments for side effects (sizeof/typeof is ok) + * (b) require any knowledge of processes at this stage + */ +#define put_user(x,ptr) \ + __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)),get_fs()) +#define get_user(x,ptr) \ + __get_user_check((x),(ptr),sizeof(*(ptr)),get_fs()) + +/* + * The "__xxx" versions do not do address space checking, useful when + * doing multiple accesses to the same area (the programmer has to do the + * checks by hand with "access_ok()") + */ +#define __put_user(x,ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) +#define __get_user(x,ptr) \ + __get_user_nocheck((x),(ptr),sizeof(*(ptr))) + +/* + * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to + * encode the bits we need for resolving the exception. See the + * more extensive comments with fixup_inline_exception below for + * more information. + */ + +extern void __get_user_unknown(void); + +#define __get_user_nocheck(x,ptr,size) \ +({ \ + long __gu_err = 0; \ + unsigned long __gu_val; \ + __chk_user_ptr(ptr); \ + switch (size) { \ + case 1: __get_user_8(ptr); break; \ + case 2: __get_user_16(ptr); break; \ + case 4: __get_user_32(ptr); break; \ + case 8: __get_user_64(ptr); break; \ + default: __get_user_unknown(); break; \ + } \ + (x) = (__typeof__(*(ptr))) __gu_val; \ + __gu_err; \ +}) + +#define __get_user_check(x,ptr,size,segment) \ +({ \ + long __gu_err = -EFAULT; \ + unsigned long __gu_val = 0; \ + const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ + if (__access_ok((unsigned long)__gu_addr,size,segment)) { \ + __gu_err = 0; \ + switch (size) { \ + case 1: __get_user_8(__gu_addr); break; \ + case 2: __get_user_16(__gu_addr); break; \ + case 4: __get_user_32(__gu_addr); break; \ + case 8: __get_user_64(__gu_addr); break; \ + default: __get_user_unknown(); break; \ + } \ + } \ + (x) = (__typeof__(*(ptr))) __gu_val; \ + __gu_err; \ +}) + +struct __large_struct { unsigned long buf[100]; }; +#define __m(x) (*(struct __large_struct __user *)(x)) + +#define __get_user_64(addr) \ + __asm__("1: ldq %0,%2\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda %0, 2b-1b(%1)\n" \ + ".previous" \ + : "=r"(__gu_val), "=r"(__gu_err) \ + : "m"(__m(addr)), "1"(__gu_err)) + +#define __get_user_32(addr) \ + __asm__("1: ldl %0,%2\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda %0, 2b-1b(%1)\n" \ + ".previous" \ + : "=r"(__gu_val), "=r"(__gu_err) \ + : "m"(__m(addr)), "1"(__gu_err)) + +#ifdef __alpha_bwx__ +/* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ + +#define __get_user_16(addr) \ + __asm__("1: ldwu %0,%2\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda %0, 2b-1b(%1)\n" \ + ".previous" \ + : "=r"(__gu_val), "=r"(__gu_err) \ + : "m"(__m(addr)), "1"(__gu_err)) + +#define __get_user_8(addr) \ + __asm__("1: ldbu %0,%2\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda %0, 2b-1b(%1)\n" \ + ".previous" \ + : "=r"(__gu_val), "=r"(__gu_err) \ + : "m"(__m(addr)), "1"(__gu_err)) +#else +/* Unfortunately, we can't get an unaligned access trap for the sub-word + load, so we have to do a general unaligned operation. */ + +#define __get_user_16(addr) \ +{ \ + long __gu_tmp; \ + __asm__("1: ldq_u %0,0(%3)\n" \ + "2: ldq_u %1,1(%3)\n" \ + " extwl %0,%3,%0\n" \ + " extwh %1,%3,%1\n" \ + " or %0,%1,%0\n" \ + "3:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda %0, 3b-1b(%2)\n" \ + " .long 2b - .\n" \ + " lda %0, 3b-2b(%2)\n" \ + ".previous" \ + : "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \ + : "r"(addr), "2"(__gu_err)); \ +} + +#define __get_user_8(addr) \ + __asm__("1: ldq_u %0,0(%2)\n" \ + " extbl %0,%2,%0\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda %0, 2b-1b(%1)\n" \ + ".previous" \ + : "=&r"(__gu_val), "=r"(__gu_err) \ + : "r"(addr), "1"(__gu_err)) +#endif + +extern void __put_user_unknown(void); + +#define __put_user_nocheck(x,ptr,size) \ +({ \ + long __pu_err = 0; \ + __chk_user_ptr(ptr); \ + switch (size) { \ + case 1: __put_user_8(x,ptr); break; \ + case 2: __put_user_16(x,ptr); break; \ + case 4: __put_user_32(x,ptr); break; \ + case 8: __put_user_64(x,ptr); break; \ + default: __put_user_unknown(); break; \ + } \ + __pu_err; \ +}) + +#define __put_user_check(x,ptr,size,segment) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + if (__access_ok((unsigned long)__pu_addr,size,segment)) { \ + __pu_err = 0; \ + switch (size) { \ + case 1: __put_user_8(x,__pu_addr); break; \ + case 2: __put_user_16(x,__pu_addr); break; \ + case 4: __put_user_32(x,__pu_addr); break; \ + case 8: __put_user_64(x,__pu_addr); break; \ + default: __put_user_unknown(); break; \ + } \ + } \ + __pu_err; \ +}) + +/* + * The "__put_user_xx()" 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 + */ +#define __put_user_64(x,addr) \ +__asm__ __volatile__("1: stq %r2,%1\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda $31,2b-1b(%0)\n" \ + ".previous" \ + : "=r"(__pu_err) \ + : "m" (__m(addr)), "rJ" (x), "0"(__pu_err)) + +#define __put_user_32(x,addr) \ +__asm__ __volatile__("1: stl %r2,%1\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda $31,2b-1b(%0)\n" \ + ".previous" \ + : "=r"(__pu_err) \ + : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) + +#ifdef __alpha_bwx__ +/* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ + +#define __put_user_16(x,addr) \ +__asm__ __volatile__("1: stw %r2,%1\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda $31,2b-1b(%0)\n" \ + ".previous" \ + : "=r"(__pu_err) \ + : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) + +#define __put_user_8(x,addr) \ +__asm__ __volatile__("1: stb %r2,%1\n" \ + "2:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda $31,2b-1b(%0)\n" \ + ".previous" \ + : "=r"(__pu_err) \ + : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) +#else +/* Unfortunately, we can't get an unaligned access trap for the sub-word + write, so we have to do a general unaligned operation. */ + +#define __put_user_16(x,addr) \ +{ \ + long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \ + __asm__ __volatile__( \ + "1: ldq_u %2,1(%5)\n" \ + "2: ldq_u %1,0(%5)\n" \ + " inswh %6,%5,%4\n" \ + " inswl %6,%5,%3\n" \ + " mskwh %2,%5,%2\n" \ + " mskwl %1,%5,%1\n" \ + " or %2,%4,%2\n" \ + " or %1,%3,%1\n" \ + "3: stq_u %2,1(%5)\n" \ + "4: stq_u %1,0(%5)\n" \ + "5:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda $31, 5b-1b(%0)\n" \ + " .long 2b - .\n" \ + " lda $31, 5b-2b(%0)\n" \ + " .long 3b - .\n" \ + " lda $31, 5b-3b(%0)\n" \ + " .long 4b - .\n" \ + " lda $31, 5b-4b(%0)\n" \ + ".previous" \ + : "=r"(__pu_err), "=&r"(__pu_tmp1), \ + "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \ + "=&r"(__pu_tmp4) \ + : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \ +} + +#define __put_user_8(x,addr) \ +{ \ + long __pu_tmp1, __pu_tmp2; \ + __asm__ __volatile__( \ + "1: ldq_u %1,0(%4)\n" \ + " insbl %3,%4,%2\n" \ + " mskbl %1,%4,%1\n" \ + " or %1,%2,%1\n" \ + "2: stq_u %1,0(%4)\n" \ + "3:\n" \ + ".section __ex_table,\"a\"\n" \ + " .long 1b - .\n" \ + " lda $31, 3b-1b(%0)\n" \ + " .long 2b - .\n" \ + " lda $31, 3b-2b(%0)\n" \ + ".previous" \ + : "=r"(__pu_err), \ + "=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \ + : "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \ +} +#endif + + +/* + * Complex access routines + */ + +/* This little bit of silliness is to get the GP loaded for a function + that ordinarily wouldn't. Otherwise we could have it done by the macro + directly, which can be optimized the linker. */ +#ifdef MODULE +#define __module_address(sym) "r"(sym), +#define __module_call(ra, arg, sym) "jsr $" #ra ",(%" #arg ")," #sym +#else +#define __module_address(sym) +#define __module_call(ra, arg, sym) "bsr $" #ra "," #sym " !samegp" +#endif + +extern void __copy_user(void); + +extern inline long +__copy_tofrom_user_nocheck(void *to, const void *from, long len) +{ + register void * __cu_to __asm__("$6") = to; + register const void * __cu_from __asm__("$7") = from; + register long __cu_len __asm__("$0") = len; + + __asm__ __volatile__( + __module_call(28, 3, __copy_user) + : "=r" (__cu_len), "=r" (__cu_from), "=r" (__cu_to) + : __module_address(__copy_user) + "0" (__cu_len), "1" (__cu_from), "2" (__cu_to) + : "$1","$2","$3","$4","$5","$28","memory"); + + return __cu_len; +} + +extern inline long +__copy_tofrom_user(void *to, const void *from, long len, const void __user *validate) +{ + if (__access_ok((unsigned long)validate, len, get_fs())) + len = __copy_tofrom_user_nocheck(to, from, len); + return len; +} + +#define __copy_to_user(to,from,n) \ +({ \ + __chk_user_ptr(to); \ + __copy_tofrom_user_nocheck((__force void *)(to),(from),(n)); \ +}) +#define __copy_from_user(to,from,n) \ +({ \ + __chk_user_ptr(from); \ + __copy_tofrom_user_nocheck((to),(__force void *)(from),(n)); \ +}) + +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + + +extern inline long +copy_to_user(void __user *to, const void *from, long n) +{ + return __copy_tofrom_user((__force void *)to, from, n, to); +} + +extern inline long +copy_from_user(void *to, const void __user *from, long n) +{ + return __copy_tofrom_user(to, (__force void *)from, n, from); +} + +extern void __do_clear_user(void); + +extern inline long +__clear_user(void __user *to, long len) +{ + register void __user * __cl_to __asm__("$6") = to; + register long __cl_len __asm__("$0") = len; + __asm__ __volatile__( + __module_call(28, 2, __do_clear_user) + : "=r"(__cl_len), "=r"(__cl_to) + : __module_address(__do_clear_user) + "0"(__cl_len), "1"(__cl_to) + : "$1","$2","$3","$4","$5","$28","memory"); + return __cl_len; +} + +extern inline long +clear_user(void __user *to, long len) +{ + if (__access_ok((unsigned long)to, len, get_fs())) + len = __clear_user(to, len); + return len; +} + +#undef __module_address +#undef __module_call + +/* Returns: -EFAULT if exception before terminator, N if the entire + buffer filled, else strlen. */ + +extern long __strncpy_from_user(char *__to, const char __user *__from, long __to_len); + +extern inline long +strncpy_from_user(char *to, const char __user *from, long n) +{ + long ret = -EFAULT; + if (__access_ok((unsigned long)from, 0, get_fs())) + ret = __strncpy_from_user(to, from, n); + return ret; +} + +/* Returns: 0 if bad, string length+1 (memory size) of string if ok */ +extern long __strlen_user(const char __user *); + +extern inline long strlen_user(const char __user *str) +{ + return access_ok(VERIFY_READ,str,0) ? __strlen_user(str) : 0; +} + +/* Returns: 0 if exception before NUL or reaching the supplied limit (N), + * a value greater than N if the limit would be exceeded, else strlen. */ +extern long __strnlen_user(const char __user *, long); + +extern inline long strnlen_user(const char __user *str, long n) +{ + return access_ok(VERIFY_READ,str,0) ? __strnlen_user(str, n) : 0; +} + +/* + * About the exception table: + * + * - insn is a 32-bit pc-relative offset from the faulting insn. + * - nextinsn is a 16-bit offset off of the faulting instruction + * (not off of the *next* instruction as branches are). + * - errreg is the register in which to place -EFAULT. + * - valreg is the final target register for the load sequence + * and will be zeroed. + * + * Either errreg or valreg may be $31, in which case nothing happens. + * + * The exception fixup information "just so happens" to be arranged + * as in a MEM format instruction. This lets us emit our three + * values like so: + * + * lda valreg, nextinsn(errreg) + * + */ + +struct exception_table_entry +{ + signed int insn; + union exception_fixup { + unsigned unit; + struct { + signed int nextinsn : 16; + unsigned int errreg : 5; + unsigned int valreg : 5; + } bits; + } fixup; +}; + +/* Returns the new pc */ +#define fixup_exception(map_reg, fixup, pc) \ +({ \ + if ((fixup)->fixup.bits.valreg != 31) \ + map_reg((fixup)->fixup.bits.valreg) = 0; \ + if ((fixup)->fixup.bits.errreg != 31) \ + map_reg((fixup)->fixup.bits.errreg) = -EFAULT; \ + (pc) + (fixup)->fixup.bits.nextinsn; \ +}) + + +#endif /* __ALPHA_UACCESS_H */ |