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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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881 lines
19 KiB
C
881 lines
19 KiB
C
![]() |
/*
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* linux/drivers/char/mem.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* Added devfs support.
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* Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu>
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* Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
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*/
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#include <linux/config.h>
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#include <linux/mm.h>
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#include <linux/miscdevice.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/mman.h>
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#include <linux/random.h>
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#include <linux/init.h>
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#include <linux/raw.h>
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#include <linux/tty.h>
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#include <linux/capability.h>
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#include <linux/smp_lock.h>
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#include <linux/devfs_fs_kernel.h>
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#include <linux/ptrace.h>
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#include <linux/device.h>
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#include <linux/backing-dev.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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#ifdef CONFIG_IA64
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# include <linux/efi.h>
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#endif
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#if defined(CONFIG_S390_TAPE) && defined(CONFIG_S390_TAPE_CHAR)
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extern void tapechar_init(void);
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#endif
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/*
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* Architectures vary in how they handle caching for addresses
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* outside of main memory.
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*
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*/
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static inline int uncached_access(struct file *file, unsigned long addr)
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{
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#if defined(__i386__)
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/*
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* On the PPro and successors, the MTRRs are used to set
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* memory types for physical addresses outside main memory,
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* so blindly setting PCD or PWT on those pages is wrong.
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* For Pentiums and earlier, the surround logic should disable
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* caching for the high addresses through the KEN pin, but
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* we maintain the tradition of paranoia in this code.
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*/
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if (file->f_flags & O_SYNC)
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return 1;
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return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
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test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
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test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
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test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) )
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&& addr >= __pa(high_memory);
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#elif defined(__x86_64__)
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/*
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* This is broken because it can generate memory type aliases,
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* which can cause cache corruptions
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* But it is only available for root and we have to be bug-to-bug
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* compatible with i386.
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*/
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if (file->f_flags & O_SYNC)
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return 1;
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/* same behaviour as i386. PAT always set to cached and MTRRs control the
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caching behaviour.
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Hopefully a full PAT implementation will fix that soon. */
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return 0;
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#elif defined(CONFIG_IA64)
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/*
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* On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
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*/
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return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);
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#else
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/*
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* Accessing memory above the top the kernel knows about or through a file pointer
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* that was marked O_SYNC will be done non-cached.
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*/
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if (file->f_flags & O_SYNC)
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return 1;
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return addr >= __pa(high_memory);
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#endif
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}
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#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
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static inline int valid_phys_addr_range(unsigned long addr, size_t *count)
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{
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unsigned long end_mem;
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end_mem = __pa(high_memory);
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if (addr >= end_mem)
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return 0;
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if (*count > end_mem - addr)
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*count = end_mem - addr;
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return 1;
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}
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#endif
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/*
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* This funcion reads the *physical* memory. The f_pos points directly to the
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* memory location.
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*/
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static ssize_t read_mem(struct file * file, char __user * buf,
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size_t count, loff_t *ppos)
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{
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unsigned long p = *ppos;
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ssize_t read, sz;
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char *ptr;
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if (!valid_phys_addr_range(p, &count))
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return -EFAULT;
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read = 0;
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#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
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/* we don't have page 0 mapped on sparc and m68k.. */
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if (p < PAGE_SIZE) {
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sz = PAGE_SIZE - p;
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if (sz > count)
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sz = count;
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if (sz > 0) {
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if (clear_user(buf, sz))
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return -EFAULT;
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buf += sz;
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p += sz;
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count -= sz;
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read += sz;
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}
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}
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#endif
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while (count > 0) {
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/*
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* Handle first page in case it's not aligned
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*/
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if (-p & (PAGE_SIZE - 1))
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sz = -p & (PAGE_SIZE - 1);
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else
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sz = PAGE_SIZE;
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sz = min_t(unsigned long, sz, count);
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/*
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* On ia64 if a page has been mapped somewhere as
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* uncached, then it must also be accessed uncached
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* by the kernel or data corruption may occur
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*/
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ptr = xlate_dev_mem_ptr(p);
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if (copy_to_user(buf, ptr, sz))
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return -EFAULT;
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buf += sz;
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p += sz;
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count -= sz;
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read += sz;
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}
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*ppos += read;
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return read;
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}
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static ssize_t write_mem(struct file * file, const char __user * buf,
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size_t count, loff_t *ppos)
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{
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unsigned long p = *ppos;
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ssize_t written, sz;
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unsigned long copied;
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void *ptr;
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if (!valid_phys_addr_range(p, &count))
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return -EFAULT;
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written = 0;
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#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
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/* we don't have page 0 mapped on sparc and m68k.. */
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if (p < PAGE_SIZE) {
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unsigned long sz = PAGE_SIZE - p;
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if (sz > count)
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sz = count;
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/* Hmm. Do something? */
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buf += sz;
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p += sz;
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count -= sz;
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written += sz;
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}
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#endif
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while (count > 0) {
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/*
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* Handle first page in case it's not aligned
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*/
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if (-p & (PAGE_SIZE - 1))
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sz = -p & (PAGE_SIZE - 1);
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else
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sz = PAGE_SIZE;
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sz = min_t(unsigned long, sz, count);
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/*
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* On ia64 if a page has been mapped somewhere as
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* uncached, then it must also be accessed uncached
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* by the kernel or data corruption may occur
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*/
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ptr = xlate_dev_mem_ptr(p);
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copied = copy_from_user(ptr, buf, sz);
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if (copied) {
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ssize_t ret;
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ret = written + (sz - copied);
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if (ret)
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return ret;
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return -EFAULT;
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}
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buf += sz;
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p += sz;
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count -= sz;
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written += sz;
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}
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*ppos += written;
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return written;
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}
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static int mmap_mem(struct file * file, struct vm_area_struct * vma)
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{
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#if defined(__HAVE_PHYS_MEM_ACCESS_PROT)
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unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
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vma->vm_page_prot = phys_mem_access_prot(file, offset,
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vma->vm_end - vma->vm_start,
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vma->vm_page_prot);
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#elif defined(pgprot_noncached)
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unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
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int uncached;
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uncached = uncached_access(file, offset);
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if (uncached)
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vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
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#endif
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/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
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if (remap_pfn_range(vma,
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vma->vm_start,
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vma->vm_pgoff,
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vma->vm_end-vma->vm_start,
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vma->vm_page_prot))
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return -EAGAIN;
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return 0;
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}
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static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
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{
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unsigned long long val;
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/*
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* RED-PEN: on some architectures there is more mapped memory
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* than available in mem_map which pfn_valid checks
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* for. Perhaps should add a new macro here.
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*
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* RED-PEN: vmalloc is not supported right now.
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*/
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if (!pfn_valid(vma->vm_pgoff))
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return -EIO;
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val = (u64)vma->vm_pgoff << PAGE_SHIFT;
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vma->vm_pgoff = __pa(val) >> PAGE_SHIFT;
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return mmap_mem(file, vma);
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}
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extern long vread(char *buf, char *addr, unsigned long count);
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extern long vwrite(char *buf, char *addr, unsigned long count);
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/*
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* This function reads the *virtual* memory as seen by the kernel.
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*/
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static ssize_t read_kmem(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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unsigned long p = *ppos;
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ssize_t low_count, read, sz;
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char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
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read = 0;
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if (p < (unsigned long) high_memory) {
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low_count = count;
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if (count > (unsigned long) high_memory - p)
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low_count = (unsigned long) high_memory - p;
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#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
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/* we don't have page 0 mapped on sparc and m68k.. */
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if (p < PAGE_SIZE && low_count > 0) {
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size_t tmp = PAGE_SIZE - p;
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if (tmp > low_count) tmp = low_count;
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if (clear_user(buf, tmp))
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return -EFAULT;
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buf += tmp;
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p += tmp;
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read += tmp;
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low_count -= tmp;
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count -= tmp;
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}
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#endif
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while (low_count > 0) {
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/*
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* Handle first page in case it's not aligned
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*/
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if (-p & (PAGE_SIZE - 1))
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sz = -p & (PAGE_SIZE - 1);
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else
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sz = PAGE_SIZE;
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sz = min_t(unsigned long, sz, low_count);
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/*
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* On ia64 if a page has been mapped somewhere as
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* uncached, then it must also be accessed uncached
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* by the kernel or data corruption may occur
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*/
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kbuf = xlate_dev_kmem_ptr((char *)p);
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if (copy_to_user(buf, kbuf, sz))
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return -EFAULT;
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buf += sz;
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p += sz;
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read += sz;
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low_count -= sz;
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count -= sz;
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}
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}
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if (count > 0) {
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kbuf = (char *)__get_free_page(GFP_KERNEL);
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if (!kbuf)
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return -ENOMEM;
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while (count > 0) {
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int len = count;
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if (len > PAGE_SIZE)
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len = PAGE_SIZE;
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len = vread(kbuf, (char *)p, len);
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if (!len)
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break;
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if (copy_to_user(buf, kbuf, len)) {
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free_page((unsigned long)kbuf);
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return -EFAULT;
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}
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count -= len;
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buf += len;
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read += len;
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p += len;
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}
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free_page((unsigned long)kbuf);
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}
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*ppos = p;
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return read;
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}
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static inline ssize_t
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do_write_kmem(void *p, unsigned long realp, const char __user * buf,
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size_t count, loff_t *ppos)
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{
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ssize_t written, sz;
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unsigned long copied;
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written = 0;
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#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
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/* we don't have page 0 mapped on sparc and m68k.. */
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if (realp < PAGE_SIZE) {
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unsigned long sz = PAGE_SIZE - realp;
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if (sz > count)
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sz = count;
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/* Hmm. Do something? */
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buf += sz;
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p += sz;
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realp += sz;
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count -= sz;
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written += sz;
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}
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#endif
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while (count > 0) {
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char *ptr;
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/*
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* Handle first page in case it's not aligned
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*/
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if (-realp & (PAGE_SIZE - 1))
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sz = -realp & (PAGE_SIZE - 1);
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else
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sz = PAGE_SIZE;
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sz = min_t(unsigned long, sz, count);
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/*
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* On ia64 if a page has been mapped somewhere as
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* uncached, then it must also be accessed uncached
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* by the kernel or data corruption may occur
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*/
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ptr = xlate_dev_kmem_ptr(p);
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copied = copy_from_user(ptr, buf, sz);
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if (copied) {
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ssize_t ret;
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ret = written + (sz - copied);
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if (ret)
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return ret;
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return -EFAULT;
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}
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buf += sz;
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p += sz;
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realp += sz;
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count -= sz;
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written += sz;
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}
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*ppos += written;
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return written;
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}
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/*
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* This function writes to the *virtual* memory as seen by the kernel.
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*/
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static ssize_t write_kmem(struct file * file, const char __user * buf,
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size_t count, loff_t *ppos)
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{
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unsigned long p = *ppos;
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ssize_t wrote = 0;
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ssize_t virtr = 0;
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ssize_t written;
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char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
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if (p < (unsigned long) high_memory) {
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wrote = count;
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if (count > (unsigned long) high_memory - p)
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wrote = (unsigned long) high_memory - p;
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written = do_write_kmem((void*)p, p, buf, wrote, ppos);
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if (written != wrote)
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return written;
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wrote = written;
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p += wrote;
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buf += wrote;
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count -= wrote;
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}
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if (count > 0) {
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||
|
kbuf = (char *)__get_free_page(GFP_KERNEL);
|
||
|
if (!kbuf)
|
||
|
return wrote ? wrote : -ENOMEM;
|
||
|
while (count > 0) {
|
||
|
int len = count;
|
||
|
|
||
|
if (len > PAGE_SIZE)
|
||
|
len = PAGE_SIZE;
|
||
|
if (len) {
|
||
|
written = copy_from_user(kbuf, buf, len);
|
||
|
if (written) {
|
||
|
ssize_t ret;
|
||
|
|
||
|
free_page((unsigned long)kbuf);
|
||
|
ret = wrote + virtr + (len - written);
|
||
|
return ret ? ret : -EFAULT;
|
||
|
}
|
||
|
}
|
||
|
len = vwrite(kbuf, (char *)p, len);
|
||
|
count -= len;
|
||
|
buf += len;
|
||
|
virtr += len;
|
||
|
p += len;
|
||
|
}
|
||
|
free_page((unsigned long)kbuf);
|
||
|
}
|
||
|
|
||
|
*ppos = p;
|
||
|
return virtr + wrote;
|
||
|
}
|
||
|
|
||
|
#if defined(CONFIG_ISA) || !defined(__mc68000__)
|
||
|
static ssize_t read_port(struct file * file, char __user * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
unsigned long i = *ppos;
|
||
|
char __user *tmp = buf;
|
||
|
|
||
|
if (!access_ok(VERIFY_WRITE, buf, count))
|
||
|
return -EFAULT;
|
||
|
while (count-- > 0 && i < 65536) {
|
||
|
if (__put_user(inb(i),tmp) < 0)
|
||
|
return -EFAULT;
|
||
|
i++;
|
||
|
tmp++;
|
||
|
}
|
||
|
*ppos = i;
|
||
|
return tmp-buf;
|
||
|
}
|
||
|
|
||
|
static ssize_t write_port(struct file * file, const char __user * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
unsigned long i = *ppos;
|
||
|
const char __user * tmp = buf;
|
||
|
|
||
|
if (!access_ok(VERIFY_READ,buf,count))
|
||
|
return -EFAULT;
|
||
|
while (count-- > 0 && i < 65536) {
|
||
|
char c;
|
||
|
if (__get_user(c, tmp))
|
||
|
return -EFAULT;
|
||
|
outb(c,i);
|
||
|
i++;
|
||
|
tmp++;
|
||
|
}
|
||
|
*ppos = i;
|
||
|
return tmp-buf;
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
static ssize_t read_null(struct file * file, char __user * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static ssize_t write_null(struct file * file, const char __user * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
return count;
|
||
|
}
|
||
|
|
||
|
#ifdef CONFIG_MMU
|
||
|
/*
|
||
|
* For fun, we are using the MMU for this.
|
||
|
*/
|
||
|
static inline size_t read_zero_pagealigned(char __user * buf, size_t size)
|
||
|
{
|
||
|
struct mm_struct *mm;
|
||
|
struct vm_area_struct * vma;
|
||
|
unsigned long addr=(unsigned long)buf;
|
||
|
|
||
|
mm = current->mm;
|
||
|
/* Oops, this was forgotten before. -ben */
|
||
|
down_read(&mm->mmap_sem);
|
||
|
|
||
|
/* For private mappings, just map in zero pages. */
|
||
|
for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
|
||
|
unsigned long count;
|
||
|
|
||
|
if (vma->vm_start > addr || (vma->vm_flags & VM_WRITE) == 0)
|
||
|
goto out_up;
|
||
|
if (vma->vm_flags & (VM_SHARED | VM_HUGETLB))
|
||
|
break;
|
||
|
count = vma->vm_end - addr;
|
||
|
if (count > size)
|
||
|
count = size;
|
||
|
|
||
|
zap_page_range(vma, addr, count, NULL);
|
||
|
zeromap_page_range(vma, addr, count, PAGE_COPY);
|
||
|
|
||
|
size -= count;
|
||
|
buf += count;
|
||
|
addr += count;
|
||
|
if (size == 0)
|
||
|
goto out_up;
|
||
|
}
|
||
|
|
||
|
up_read(&mm->mmap_sem);
|
||
|
|
||
|
/* The shared case is hard. Let's do the conventional zeroing. */
|
||
|
do {
|
||
|
unsigned long unwritten = clear_user(buf, PAGE_SIZE);
|
||
|
if (unwritten)
|
||
|
return size + unwritten - PAGE_SIZE;
|
||
|
cond_resched();
|
||
|
buf += PAGE_SIZE;
|
||
|
size -= PAGE_SIZE;
|
||
|
} while (size);
|
||
|
|
||
|
return size;
|
||
|
out_up:
|
||
|
up_read(&mm->mmap_sem);
|
||
|
return size;
|
||
|
}
|
||
|
|
||
|
static ssize_t read_zero(struct file * file, char __user * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
unsigned long left, unwritten, written = 0;
|
||
|
|
||
|
if (!count)
|
||
|
return 0;
|
||
|
|
||
|
if (!access_ok(VERIFY_WRITE, buf, count))
|
||
|
return -EFAULT;
|
||
|
|
||
|
left = count;
|
||
|
|
||
|
/* do we want to be clever? Arbitrary cut-off */
|
||
|
if (count >= PAGE_SIZE*4) {
|
||
|
unsigned long partial;
|
||
|
|
||
|
/* How much left of the page? */
|
||
|
partial = (PAGE_SIZE-1) & -(unsigned long) buf;
|
||
|
unwritten = clear_user(buf, partial);
|
||
|
written = partial - unwritten;
|
||
|
if (unwritten)
|
||
|
goto out;
|
||
|
left -= partial;
|
||
|
buf += partial;
|
||
|
unwritten = read_zero_pagealigned(buf, left & PAGE_MASK);
|
||
|
written += (left & PAGE_MASK) - unwritten;
|
||
|
if (unwritten)
|
||
|
goto out;
|
||
|
buf += left & PAGE_MASK;
|
||
|
left &= ~PAGE_MASK;
|
||
|
}
|
||
|
unwritten = clear_user(buf, left);
|
||
|
written += left - unwritten;
|
||
|
out:
|
||
|
return written ? written : -EFAULT;
|
||
|
}
|
||
|
|
||
|
static int mmap_zero(struct file * file, struct vm_area_struct * vma)
|
||
|
{
|
||
|
if (vma->vm_flags & VM_SHARED)
|
||
|
return shmem_zero_setup(vma);
|
||
|
if (zeromap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot))
|
||
|
return -EAGAIN;
|
||
|
return 0;
|
||
|
}
|
||
|
#else /* CONFIG_MMU */
|
||
|
static ssize_t read_zero(struct file * file, char * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
size_t todo = count;
|
||
|
|
||
|
while (todo) {
|
||
|
size_t chunk = todo;
|
||
|
|
||
|
if (chunk > 4096)
|
||
|
chunk = 4096; /* Just for latency reasons */
|
||
|
if (clear_user(buf, chunk))
|
||
|
return -EFAULT;
|
||
|
buf += chunk;
|
||
|
todo -= chunk;
|
||
|
cond_resched();
|
||
|
}
|
||
|
return count;
|
||
|
}
|
||
|
|
||
|
static int mmap_zero(struct file * file, struct vm_area_struct * vma)
|
||
|
{
|
||
|
return -ENOSYS;
|
||
|
}
|
||
|
#endif /* CONFIG_MMU */
|
||
|
|
||
|
static ssize_t write_full(struct file * file, const char __user * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
return -ENOSPC;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Special lseek() function for /dev/null and /dev/zero. Most notably, you
|
||
|
* can fopen() both devices with "a" now. This was previously impossible.
|
||
|
* -- SRB.
|
||
|
*/
|
||
|
|
||
|
static loff_t null_lseek(struct file * file, loff_t offset, int orig)
|
||
|
{
|
||
|
return file->f_pos = 0;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* The memory devices use the full 32/64 bits of the offset, and so we cannot
|
||
|
* check against negative addresses: they are ok. The return value is weird,
|
||
|
* though, in that case (0).
|
||
|
*
|
||
|
* also note that seeking relative to the "end of file" isn't supported:
|
||
|
* it has no meaning, so it returns -EINVAL.
|
||
|
*/
|
||
|
static loff_t memory_lseek(struct file * file, loff_t offset, int orig)
|
||
|
{
|
||
|
loff_t ret;
|
||
|
|
||
|
down(&file->f_dentry->d_inode->i_sem);
|
||
|
switch (orig) {
|
||
|
case 0:
|
||
|
file->f_pos = offset;
|
||
|
ret = file->f_pos;
|
||
|
force_successful_syscall_return();
|
||
|
break;
|
||
|
case 1:
|
||
|
file->f_pos += offset;
|
||
|
ret = file->f_pos;
|
||
|
force_successful_syscall_return();
|
||
|
break;
|
||
|
default:
|
||
|
ret = -EINVAL;
|
||
|
}
|
||
|
up(&file->f_dentry->d_inode->i_sem);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static int open_port(struct inode * inode, struct file * filp)
|
||
|
{
|
||
|
return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
|
||
|
}
|
||
|
|
||
|
#define zero_lseek null_lseek
|
||
|
#define full_lseek null_lseek
|
||
|
#define write_zero write_null
|
||
|
#define read_full read_zero
|
||
|
#define open_mem open_port
|
||
|
#define open_kmem open_mem
|
||
|
|
||
|
static struct file_operations mem_fops = {
|
||
|
.llseek = memory_lseek,
|
||
|
.read = read_mem,
|
||
|
.write = write_mem,
|
||
|
.mmap = mmap_mem,
|
||
|
.open = open_mem,
|
||
|
};
|
||
|
|
||
|
static struct file_operations kmem_fops = {
|
||
|
.llseek = memory_lseek,
|
||
|
.read = read_kmem,
|
||
|
.write = write_kmem,
|
||
|
.mmap = mmap_kmem,
|
||
|
.open = open_kmem,
|
||
|
};
|
||
|
|
||
|
static struct file_operations null_fops = {
|
||
|
.llseek = null_lseek,
|
||
|
.read = read_null,
|
||
|
.write = write_null,
|
||
|
};
|
||
|
|
||
|
#if defined(CONFIG_ISA) || !defined(__mc68000__)
|
||
|
static struct file_operations port_fops = {
|
||
|
.llseek = memory_lseek,
|
||
|
.read = read_port,
|
||
|
.write = write_port,
|
||
|
.open = open_port,
|
||
|
};
|
||
|
#endif
|
||
|
|
||
|
static struct file_operations zero_fops = {
|
||
|
.llseek = zero_lseek,
|
||
|
.read = read_zero,
|
||
|
.write = write_zero,
|
||
|
.mmap = mmap_zero,
|
||
|
};
|
||
|
|
||
|
static struct backing_dev_info zero_bdi = {
|
||
|
.capabilities = BDI_CAP_MAP_COPY,
|
||
|
};
|
||
|
|
||
|
static struct file_operations full_fops = {
|
||
|
.llseek = full_lseek,
|
||
|
.read = read_full,
|
||
|
.write = write_full,
|
||
|
};
|
||
|
|
||
|
static ssize_t kmsg_write(struct file * file, const char __user * buf,
|
||
|
size_t count, loff_t *ppos)
|
||
|
{
|
||
|
char *tmp;
|
||
|
int ret;
|
||
|
|
||
|
tmp = kmalloc(count + 1, GFP_KERNEL);
|
||
|
if (tmp == NULL)
|
||
|
return -ENOMEM;
|
||
|
ret = -EFAULT;
|
||
|
if (!copy_from_user(tmp, buf, count)) {
|
||
|
tmp[count] = 0;
|
||
|
ret = printk("%s", tmp);
|
||
|
}
|
||
|
kfree(tmp);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static struct file_operations kmsg_fops = {
|
||
|
.write = kmsg_write,
|
||
|
};
|
||
|
|
||
|
static int memory_open(struct inode * inode, struct file * filp)
|
||
|
{
|
||
|
switch (iminor(inode)) {
|
||
|
case 1:
|
||
|
filp->f_op = &mem_fops;
|
||
|
break;
|
||
|
case 2:
|
||
|
filp->f_op = &kmem_fops;
|
||
|
break;
|
||
|
case 3:
|
||
|
filp->f_op = &null_fops;
|
||
|
break;
|
||
|
#if defined(CONFIG_ISA) || !defined(__mc68000__)
|
||
|
case 4:
|
||
|
filp->f_op = &port_fops;
|
||
|
break;
|
||
|
#endif
|
||
|
case 5:
|
||
|
filp->f_mapping->backing_dev_info = &zero_bdi;
|
||
|
filp->f_op = &zero_fops;
|
||
|
break;
|
||
|
case 7:
|
||
|
filp->f_op = &full_fops;
|
||
|
break;
|
||
|
case 8:
|
||
|
filp->f_op = &random_fops;
|
||
|
break;
|
||
|
case 9:
|
||
|
filp->f_op = &urandom_fops;
|
||
|
break;
|
||
|
case 11:
|
||
|
filp->f_op = &kmsg_fops;
|
||
|
break;
|
||
|
default:
|
||
|
return -ENXIO;
|
||
|
}
|
||
|
if (filp->f_op && filp->f_op->open)
|
||
|
return filp->f_op->open(inode,filp);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static struct file_operations memory_fops = {
|
||
|
.open = memory_open, /* just a selector for the real open */
|
||
|
};
|
||
|
|
||
|
static const struct {
|
||
|
unsigned int minor;
|
||
|
char *name;
|
||
|
umode_t mode;
|
||
|
struct file_operations *fops;
|
||
|
} devlist[] = { /* list of minor devices */
|
||
|
{1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
|
||
|
{2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
|
||
|
{3, "null", S_IRUGO | S_IWUGO, &null_fops},
|
||
|
#if defined(CONFIG_ISA) || !defined(__mc68000__)
|
||
|
{4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
|
||
|
#endif
|
||
|
{5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
|
||
|
{7, "full", S_IRUGO | S_IWUGO, &full_fops},
|
||
|
{8, "random", S_IRUGO | S_IWUSR, &random_fops},
|
||
|
{9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
|
||
|
{11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
|
||
|
};
|
||
|
|
||
|
static struct class_simple *mem_class;
|
||
|
|
||
|
static int __init chr_dev_init(void)
|
||
|
{
|
||
|
int i;
|
||
|
|
||
|
if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
|
||
|
printk("unable to get major %d for memory devs\n", MEM_MAJOR);
|
||
|
|
||
|
mem_class = class_simple_create(THIS_MODULE, "mem");
|
||
|
for (i = 0; i < ARRAY_SIZE(devlist); i++) {
|
||
|
class_simple_device_add(mem_class,
|
||
|
MKDEV(MEM_MAJOR, devlist[i].minor),
|
||
|
NULL, devlist[i].name);
|
||
|
devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor),
|
||
|
S_IFCHR | devlist[i].mode, devlist[i].name);
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
fs_initcall(chr_dev_init);
|