On Sun, 2013-05-19 at 19:40 +0300, Michael S. Tsirkin wrote: > OK I get it. So let me correct myself. The simple code > that does something like this under a spinlock: > > preempt_disable > > pagefault_disable > > error = copy_to_user > > pagefault_enable > > preempt_enable > > > is not doing anything wrong and should not get a warning, > as long as error is handled correctly later. > Right? I came in mid thread and I don't know the context. Anyway, the above looks to me as you just don't want to sleep. If you try to copy data to user space that happens not to be currently mapped for any reason, you will get an error. Even if the address space is completely valid. Is that what you want? -- Steve -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>