/* * User memory access support for Hexagon * * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. */ #ifndef _ASM_UACCESS_H #define _ASM_UACCESS_H /* * User space memory access functions */ #include <linux/mm.h> #include <asm/segment.h> #include <asm/sections.h> /* * access_ok: - Checks if a user space pointer is valid * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe * to write to a block, it is always safe to read from it. * @addr: User space pointer to start of block to check * @size: Size of block to check * * Context: User context only. This function may sleep if pagefaults are * enabled. * * Checks if a pointer to a block of memory in user space is valid. * * Returns true (nonzero) if the memory block *may* be valid, false (zero) * if it is definitely invalid. * * User address space in Hexagon, like x86, goes to 0xbfffffff, so the * simple MSB-based tests used by MIPS won't work. Some further * optimization is probably possible here, but for now, keep it * reasonably simple and not *too* slow. After all, we've got the * MMU for backup. */ #define __access_ok(addr, size) \ ((get_fs().seg == KERNEL_DS.seg) || \ (((unsigned long)addr < get_fs().seg) && \ (unsigned long)size < (get_fs().seg - (unsigned long)addr))) /* * When a kernel-mode page fault is taken, the faulting instruction * address is checked against a table of exception_table_entries. * Each entry is a tuple of the address of an instruction that may * be authorized to fault, and the address at which execution should * be resumed instead of the faulting instruction, so as to effect * a workaround. */ /* Assembly somewhat optimized copy routines */ unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n); unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n); #define INLINE_COPY_FROM_USER #define INLINE_COPY_TO_USER __kernel_size_t __clear_user_hexagon(void __user *dest, unsigned long count); #define __clear_user(a, s) __clear_user_hexagon((a), (s)) #define __strncpy_from_user(dst, src, n) hexagon_strncpy_from_user(dst, src, n) /* get around the ifndef in asm-generic/uaccess.h */ #define __strnlen_user __strnlen_user extern long __strnlen_user(const char __user *src, long n); static inline long hexagon_strncpy_from_user(char *dst, const char __user *src, long n); #include <asm-generic/uaccess.h> /* Todo: an actual accelerated version of this. */ static inline long hexagon_strncpy_from_user(char *dst, const char __user *src, long n) { long res = __strnlen_user(src, n); if (unlikely(!res)) return -EFAULT; if (res > n) { long left = raw_copy_from_user(dst, src, n); if (unlikely(left)) memset(dst + (n - left), 0, left); return n; } else { long left = raw_copy_from_user(dst, src, res); if (unlikely(left)) memset(dst + (res - left), 0, left); return res-1; } } #endif
Name | Type | Size | Permission | Actions |
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Kbuild | File | 886 B | 0644 |
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asm-offsets.h | File | 35 B | 0644 |
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atomic.h | File | 5.27 KB | 0644 |
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bitops.h | File | 6.62 KB | 0644 |
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cache.h | File | 1.16 KB | 0644 |
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cacheflush.h | File | 3.8 KB | 0644 |
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checksum.h | File | 1.61 KB | 0644 |
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cmpxchg.h | File | 2.55 KB | 0644 |
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delay.h | File | 978 B | 0644 |
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dma-mapping.h | File | 1.31 KB | 0644 |
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dma.h | File | 934 B | 0644 |
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elf.h | File | 6.34 KB | 0644 |
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exec.h | File | 1.01 KB | 0644 |
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fixmap.h | File | 1.11 KB | 0644 |
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fpu.h | File | 90 B | 0644 |
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futex.h | File | 2.25 KB | 0644 |
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hexagon_vm.h | File | 6.39 KB | 0644 |
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intrinsics.h | File | 1003 B | 0644 |
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io.h | File | 6.95 KB | 0644 |
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irq.h | File | 1.13 KB | 0644 |
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irqflags.h | File | 1.46 KB | 0644 |
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kgdb.h | File | 1.36 KB | 0644 |
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linkage.h | File | 871 B | 0644 |
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mem-layout.h | File | 3.42 KB | 0644 |
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mmu.h | File | 1.1 KB | 0644 |
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mmu_context.h | File | 2.59 KB | 0644 |
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module.h | File | 910 B | 0644 |
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page.h | File | 4.74 KB | 0644 |
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perf_event.h | File | 841 B | 0644 |
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pgalloc.h | File | 4.08 KB | 0644 |
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pgtable.h | File | 14.15 KB | 0644 |
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processor.h | File | 3.8 KB | 0644 |
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smp.h | File | 1.31 KB | 0644 |
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spinlock.h | File | 3.84 KB | 0644 |
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spinlock_types.h | File | 1.15 KB | 0644 |
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string.h | File | 1.08 KB | 0644 |
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suspend.h | File | 872 B | 0644 |
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switch_to.h | File | 1.09 KB | 0644 |
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syscall.h | File | 1.38 KB | 0644 |
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thread_info.h | File | 4.05 KB | 0644 |
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time.h | File | 980 B | 0644 |
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timer-regs.h | File | 1.23 KB | 0644 |
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timex.h | File | 1.13 KB | 0644 |
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tlb.h | File | 1.21 KB | 0644 |
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tlbflush.h | File | 2.08 KB | 0644 |
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traps.h | File | 1.02 KB | 0644 |
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uaccess.h | File | 3.67 KB | 0644 |
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vdso.h | File | 941 B | 0644 |
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vm_fault.h | File | 993 B | 0644 |
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vm_mmu.h | File | 3.37 KB | 0644 |
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