get_user_pages注意问题

(2011-03-02 09:12)

分类： linux 源码分析

    I'm trying to implement simple network protocol. I'm mapping user pages with get_user_pages() and then accessing them with kmap(),kunmap(). Touching user pages works fine in syscall context, but fails with nasty kboom in a softirq context. I also tried kmap_atomic()/kunmap_atomic(). Am I doing something wrong, or I'm not allowed to access user structures at all from irq/softirq context. ( copy_to_user() also is limited to syscall context). Any help will be appreciated.

stupid question - excuse me for asking =)
when executing in !syscall context there is no current pointer and no userspace at