/* * include/asm-xtensa/uaccess.h * * User space memory access functions * * These routines provide basic accessing functions to the user memory * space for the kernel. This header file provides functions such as: * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2001 - 2005 Tensilica Inc. */ #ifndef _XTENSA_UACCESS_H #define _XTENSA_UACCESS_H #include <linux/prefetch.h> #include <asm/types.h> #include <asm/extable.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. * * For historical reasons (Data Segment Register?), these macros are * grossly misnamed. */ #define KERNEL_DS ((mm_segment_t) { 0 }) #define USER_DS ((mm_segment_t) { 1 }) #define get_ds() (KERNEL_DS) #define get_fs() (current->thread.current_ds) #define set_fs(val) (current->thread.current_ds = (val)) #define segment_eq(a, b) ((a).seg == (b).seg) #define __kernel_ok (uaccess_kernel()) #define __user_ok(addr, size) \ (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size))) #define __access_ok(addr, size) (__kernel_ok || __user_ok((addr), (size))) #define access_ok(type, addr, size) __access_ok((unsigned long)(addr), (size)) /* * These are the main single-value transfer routines. They * automatically use the right size if we just have the right pointer * type. * * This gets kind of ugly. We want to return _two_ values in * "get_user()" and yet we don't want to do any pointers, because that * is too much of a performance impact. Thus we have a few rather ugly * macros here, and hide all the uglyness from the user. * * Careful to not * (a) re-use the arguments for side effects (sizeof is ok) * (b) require any knowledge of processes at this stage */ #define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr))) #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr))) /* * The "__xxx" versions of the user access functions are versions that * do not verify the address space, that must have been done previously * with a separate "access_ok()" call (this is used when we do multiple * accesses to the same area of user memory). */ #define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr))) #define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr))) extern long __put_user_bad(void); #define __put_user_nocheck(x, ptr, size) \ ({ \ long __pu_err; \ __put_user_size((x), (ptr), (size), __pu_err); \ __pu_err; \ }) #define __put_user_check(x, ptr, size) \ ({ \ long __pu_err = -EFAULT; \ __typeof__(*(ptr)) *__pu_addr = (ptr); \ if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ __put_user_size((x), __pu_addr, (size), __pu_err); \ __pu_err; \ }) #define __put_user_size(x, ptr, size, retval) \ do { \ int __cb; \ retval = 0; \ switch (size) { \ case 1: __put_user_asm(x, ptr, retval, 1, "s8i", __cb); break; \ case 2: __put_user_asm(x, ptr, retval, 2, "s16i", __cb); break; \ case 4: __put_user_asm(x, ptr, retval, 4, "s32i", __cb); break; \ case 8: { \ __typeof__(*ptr) __v64 = x; \ retval = __copy_to_user(ptr, &__v64, 8); \ break; \ } \ default: __put_user_bad(); \ } \ } while (0) /* * Consider a case of a user single load/store would cause both an * unaligned exception and an MMU-related exception (unaligned * exceptions happen first): * * User code passes a bad variable ptr to a system call. * Kernel tries to access the variable. * Unaligned exception occurs. * Unaligned exception handler tries to make aligned accesses. * Double exception occurs for MMU-related cause (e.g., page not mapped). * do_page_fault() thinks the fault address belongs to the kernel, not the * user, and panics. * * The kernel currently prohibits user unaligned accesses. We use the * __check_align_* macros to check for unaligned addresses before * accessing user space so we don't crash the kernel. Both * __put_user_asm and __get_user_asm use these alignment macros, so * macro-specific labels such as 0f, 1f, %0, %2, and %3 must stay in * sync. */ #define __check_align_1 "" #define __check_align_2 \ " _bbci.l %3, 0, 1f \n" \ " movi %0, %4 \n" \ " _j 2f \n" #define __check_align_4 \ " _bbsi.l %3, 0, 0f \n" \ " _bbci.l %3, 1, 1f \n" \ "0: movi %0, %4 \n" \ " _j 2f \n" /* * We don't tell gcc that we are accessing memory, but this is OK * because we do not write to any memory gcc knows about, so there * are no aliasing issues. * * WARNING: If you modify this macro at all, verify that the * __check_align_* macros still work. */ #define __put_user_asm(x, addr, err, align, insn, cb) \ __asm__ __volatile__( \ __check_align_##align \ "1: "insn" %2, %3, 0 \n" \ "2: \n" \ " .section .fixup,\"ax\" \n" \ " .align 4 \n" \ "4: \n" \ " .long 2b \n" \ "5: \n" \ " l32r %1, 4b \n" \ " movi %0, %4 \n" \ " jx %1 \n" \ " .previous \n" \ " .section __ex_table,\"a\" \n" \ " .long 1b, 5b \n" \ " .previous" \ :"=r" (err), "=r" (cb) \ :"r" ((int)(x)), "r" (addr), "i" (-EFAULT), "0" (err)) #define __get_user_nocheck(x, ptr, size) \ ({ \ long __gu_err, __gu_val; \ __get_user_size(__gu_val, (ptr), (size), __gu_err); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) #define __get_user_check(x, ptr, size) \ ({ \ long __gu_err = -EFAULT, __gu_val = 0; \ const __typeof__(*(ptr)) *__gu_addr = (ptr); \ if (access_ok(VERIFY_READ, __gu_addr, size)) \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) extern long __get_user_bad(void); #define __get_user_size(x, ptr, size, retval) \ do { \ int __cb; \ retval = 0; \ switch (size) { \ case 1: __get_user_asm(x, ptr, retval, 1, "l8ui", __cb); break;\ case 2: __get_user_asm(x, ptr, retval, 2, "l16ui", __cb); break;\ case 4: __get_user_asm(x, ptr, retval, 4, "l32i", __cb); break;\ case 8: retval = __copy_from_user(&x, ptr, 8); break; \ default: (x) = __get_user_bad(); \ } \ } while (0) /* * WARNING: If you modify this macro at all, verify that the * __check_align_* macros still work. */ #define __get_user_asm(x, addr, err, align, insn, cb) \ __asm__ __volatile__( \ __check_align_##align \ "1: "insn" %2, %3, 0 \n" \ "2: \n" \ " .section .fixup,\"ax\" \n" \ " .align 4 \n" \ "4: \n" \ " .long 2b \n" \ "5: \n" \ " l32r %1, 4b \n" \ " movi %2, 0 \n" \ " movi %0, %4 \n" \ " jx %1 \n" \ " .previous \n" \ " .section __ex_table,\"a\" \n" \ " .long 1b, 5b \n" \ " .previous" \ :"=r" (err), "=r" (cb), "=r" (x) \ :"r" (addr), "i" (-EFAULT), "0" (err)) /* * Copy to/from user space */ extern unsigned __xtensa_copy_user(void *to, const void *from, unsigned n); static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { prefetchw(to); return __xtensa_copy_user(to, (__force const void *)from, n); } static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) { prefetch(from); return __xtensa_copy_user((__force void *)to, from, n); } #define INLINE_COPY_FROM_USER #define INLINE_COPY_TO_USER /* * We need to return the number of bytes not cleared. Our memset() * returns zero if a problem occurs while accessing user-space memory. * In that event, return no memory cleared. Otherwise, zero for * success. */ static inline unsigned long __xtensa_clear_user(void *addr, unsigned long size) { if ( ! memset(addr, 0, size) ) return size; return 0; } static inline unsigned long clear_user(void *addr, unsigned long size) { if (access_ok(VERIFY_WRITE, addr, size)) return __xtensa_clear_user(addr, size); return size ? -EFAULT : 0; } #define __clear_user __xtensa_clear_user extern long __strncpy_user(char *, const char *, long); static inline long strncpy_from_user(char *dst, const char *src, long count) { if (access_ok(VERIFY_READ, src, 1)) return __strncpy_user(dst, src, count); return -EFAULT; } /* * Return the size of a string (including the ending 0!) */ extern long __strnlen_user(const char *, long); static inline long strnlen_user(const char *str, long len) { unsigned long top = __kernel_ok ? ~0UL : TASK_SIZE - 1; if ((unsigned long)str > top) return 0; return __strnlen_user(str, len); } #endif /* _XTENSA_UACCESS_H */
Name | Type | Size | Permission | Actions |
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Kbuild | File | 685 B | 0644 |
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asm-offsets.h | File | 35 B | 0644 |
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asm-uaccess.h | File | 4.11 KB | 0644 |
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asmmacro.h | File | 2.76 KB | 0644 |
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atomic.h | File | 7.38 KB | 0644 |
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barrier.h | File | 542 B | 0644 |
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bitops.h | File | 5.08 KB | 0644 |
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bootparam.h | File | 1.37 KB | 0644 |
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bugs.h | File | 451 B | 0644 |
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cache.h | File | 969 B | 0644 |
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cacheasm.h | File | 3.77 KB | 0644 |
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cacheflush.h | File | 5.76 KB | 0644 |
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checksum.h | File | 6 KB | 0644 |
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cmpxchg.h | File | 3.9 KB | 0644 |
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coprocessor.h | File | 5.05 KB | 0644 |
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current.h | File | 675 B | 0644 |
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delay.h | File | 1.63 KB | 0644 |
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dma-mapping.h | File | 855 B | 0644 |
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dma.h | File | 1.79 KB | 0644 |
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elf.h | File | 5.75 KB | 0644 |
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fixmap.h | File | 2.5 KB | 0644 |
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flat.h | File | 686 B | 0644 |
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ftrace.h | File | 979 B | 0644 |
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futex.h | File | 2.59 KB | 0644 |
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highmem.h | File | 2.33 KB | 0644 |
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hw_breakpoint.h | File | 1.45 KB | 0644 |
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hw_irq.h | File | 320 B | 0644 |
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initialize_mmu.h | File | 4.58 KB | 0644 |
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io.h | File | 2.09 KB | 0644 |
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irq.h | File | 1.46 KB | 0644 |
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irqflags.h | File | 1.99 KB | 0644 |
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kmem_layout.h | File | 2.07 KB | 0644 |
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mmu.h | File | 462 B | 0644 |
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mmu_context.h | File | 3.62 KB | 0644 |
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module.h | File | 525 B | 0644 |
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mxregs.h | File | 1.3 KB | 0644 |
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nommu_context.h | File | 602 B | 0644 |
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page.h | File | 5.69 KB | 0644 |
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pci-bridge.h | File | 2.16 KB | 0644 |
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pci.h | File | 1.37 KB | 0644 |
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perf_event.h | File | 108 B | 0644 |
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pgalloc.h | File | 1.84 KB | 0644 |
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pgtable.h | File | 14.89 KB | 0644 |
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platform.h | File | 1.75 KB | 0644 |
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processor.h | File | 7.44 KB | 0644 |
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ptrace.h | File | 3.74 KB | 0644 |
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regs.h | File | 3.87 KB | 0644 |
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segment.h | File | 376 B | 0644 |
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serial.h | File | 443 B | 0644 |
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shmparam.h | File | 561 B | 0644 |
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signal.h | File | 502 B | 0644 |
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smp.h | File | 967 B | 0644 |
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spinlock.h | File | 4.6 KB | 0644 |
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spinlock_types.h | File | 412 B | 0644 |
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stacktrace.h | File | 1.13 KB | 0644 |
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string.h | File | 2.65 KB | 0644 |
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switch_to.h | File | 601 B | 0644 |
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syscall.h | File | 982 B | 0644 |
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sysmem.h | File | 426 B | 0644 |
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thread_info.h | File | 3.62 KB | 0644 |
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timex.h | File | 1.79 KB | 0644 |
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tlb.h | File | 1.1 KB | 0644 |
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tlbflush.h | File | 5.53 KB | 0644 |
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traps.h | File | 1.87 KB | 0644 |
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types.h | File | 501 B | 0644 |
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uaccess.h | File | 8.67 KB | 0644 |
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ucontext.h | File | 540 B | 0644 |
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unaligned.h | File | 864 B | 0644 |
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unistd.h | File | 639 B | 0644 |
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user.h | File | 507 B | 0644 |
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vectors.h | File | 4.05 KB | 0644 |
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vga.h | File | 434 B | 0644 |
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