On Tue, Dec 18, 2012 at 09:06:04PM +0100, Oleg Nesterov wrote: > On 12/17, Neil Horman wrote: > > > > On Mon, Dec 17, 2012 at 05:04:08PM +0100, Oleg Nesterov wrote: > > > > > > > Is there a way to switch all namespaces, except for the pid > > > > namespace? > > > > > > Which exactly namespaces you want to change? > > > > > Ideally, I want the pipe reader process to execute in the same namespaces > > that > > the crashing process executed in (i.e. the pipe reader should execute as > > though > > the crashing process forked it). > > Yes, and we probably want to change pid_ns as well. But afaics currently > this is not possible, even setns can't do this. > > I am starting to think that in this case, perhaps, do_coredump() should > not use call_usermode_helper() at all. Perhaps we can do clone(CLONE_VM) + > commit_creds/restore_root/etc + kernel_execve. > Yeah, I was comming to this same conclusion last night as well. I'd rather keep using the call_usermode_helper solution if at all possible, but perhaps we can integrate a clone path into it.
> > > To be honest, I do not understand this patch at all. It seems that > > > you need to do something like sys_setns(). But if we do this, then > > > why we can't make core_pattern per-namespace? > > > > > That actually would make sense, although we can't really use setns > > directly, as > > I don't think we want to open file descriptors to do this manipulation in > > the > > kernel. > > Yes, yes, sure. But this is solveable. We do not really need to open > the files in /proc, we could use proc_ns_operations->install() directly. > Although this is not pretty. > Its not pretty, no. If we use the above clone solution however, we can avoid this entirely. > > Perhaps its best just to restrict this patch to adjusting the root fs > > location > > for the chroot case. > > Probably... at least for the start. > > BTW. Of course this is subjective, but personally I think that "||" > looks strange. Perhaps it would be better to add something like > --croot argument? > The || is ambiguous with its simmilarity to a shell 'or' command, but I don't think the --croot argument is much better on that front, as that then becomes ambiguous with arguments supplied to the pipe reader directly. The token should be leading the pipe_reader string in core_pattern to indicate a change in environment independent of the executable path. Perhaps |^ or something simmilar? Either way, Andrew, could you please drop this patch? Olegs comments I think make it pretty clear I've got some more work to do on this. Thanks! Neil -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
