On Thu, Feb 12, 2015 at 03:08:38PM +0100, Jiri Kosina wrote: > On Thu, 12 Feb 2015, Peter Zijlstra wrote: > I personally am not a big fan of the task_rq_lock() public exposure > either. What might be generally useful though (not only for livepatching) > would be an API that would allow for "safe" stack dump (where "safe" means > that guarantee, that it wouldn't be interferred by process waking up in > the middle of dumping, would be provided).
In general, I think a safe stack dump is needed. A lot of the stack dumping in the kernel seems dangerous. For example, it looks like doing a `cat /proc/pid/stack` while the process is writing the stack could easily go off into the weeds. But I don't see how it would help the livepatch case. What happens if the process starts running in the to-be-patched function after we call the "safe" dump_stack() but before switching it to the new universe? -- Josh -- 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/
