On Mon, Aug 27, 2007 at 01:10:56PM -0500, Dean Nelson wrote: > On Mon, Aug 27, 2007 at 05:13:28PM +0100, Al Viro wrote: > > On Mon, Aug 27, 2007 at 10:59:33AM -0500, Dean Nelson wrote: > > > This patch exports __put_task_struct as it is needed by XPMEM. > > > > > > Signed-off-by: Dean Nelson <[EMAIL PROTECTED]> > > > > > > --- > > > > > > One struct file_operations registered by XPMEM, xpmem_open(), calls > > > 'get_task_struct(current->group_leader)' and another, xpmem_flush(), calls > > > 'put_task_struct(tg->group_leader)'. > > > > Does it? Well, then open the file in question and start doing > > close(dup(fd)) > > in a loop. Won't take long for an oops... > > Actually it won't oops. And that's because when the file is opened, > xpmem_open() creates a structure for that thread group, and when > xpmem_flush() is called on the close() it first looks for that structure > and if it finds it then it does what it needs to do (which includes the > put_task_struct() call) and then finishes off by destroying the structure. > So for subsequent closes xpmem_flush() returns without calling > put_task_struct().
Then what kind of protection does it get you? It can be called immediately after the call of ->open(), so you can't rely on it being there for any operations. Makes no sense... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
