remap
在驱动程序中我用__get_free_pages申请了1MB的内存，将这1MB内存用remap_page_range映射到用户空间。但应用程序用mmap()的地址读不到数据，但用在驱动中增加一个IOCTL命令用copy_to_user却可以拿到数据。这是为什么?
by zhuoyuesky - 内核/嵌入技术 - 2006-11-06 16:48:16 阅读（473） 回复（1）
驱动里面 mmap函数： volatile void *offset=(volatile void *)kmalloc(100,GFP_ATOMIC); vma->vm_flags |= VM_RESERVED; physical_addr=virt_to_phys(offset); if (remap_page_range(vma->vm_start, physical_addr ,vma->vm_end-vma->vm_start, vma->vm_page_prot)) { printk("remap error\n"); return -EAGAIN; } line_addr=offset; 应用程序...
man in.tftpd如下 FILENAME remapPING The -m option specifies a file which contains filename remapping rules. Each non-comment line (comments begin with hash marks, #) contains an operation, specified below; a regex, a regular expression in the style of egrep; and optionally a replacement pattern. The operation indicated by operation is performed if the regex matches al...
static int remap_mmap(struct file *filp, struct vm_area_struct *vma) { int i = 0; int j = 0x0; if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff， vma->vm_end - vma->vm_start, vma->vm_page_prot)) return -EAGAIN; vma->vm_ops = &remap_vm_ops; return 0; } 想用上述程序实现mmap，但是发现在用户态调用mmap大于2...
