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-rw-r--r--include/asm-alpha/uaccess.h517
1 files changed, 517 insertions, 0 deletions
diff --git a/include/asm-alpha/uaccess.h b/include/asm-alpha/uaccess.h
new file mode 100644
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--- /dev/null
+++ b/include/asm-alpha/uaccess.h
@@ -0,0 +1,517 @@
+#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()); \
+})
+
+/* this function will go away soon - use access_ok() instead */
+extern inline int __deprecated verify_area(int type, const void __user * addr, unsigned long size)
+{
+ return access_ok(type,addr,size) ? 0 : -EFAULT;
+}
+
+/*
+ * 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 */
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