On Mon, Feb 16, 2015 at 11:16:11AM +0100, Jiri Slaby wrote: > On 02/09/2015, 06:31 PM, Josh Poimboeuf wrote: > > Update a tasks's universe when returning from a system call or user > > space interrupt, or after handling a signal. > > > > This greatly increases the chances of a patch operation succeeding. If > > a task is I/O bound, it can switch universes when returning from a > > system call. If a task is CPU bound, it can switch universes when > > returning from an interrupt. If a task is sleeping on a to-be-patched > > function, the user can send SIGSTOP and SIGCONT to force it to switch. > > > > Since the idle "swapper" tasks don't ever exit the kernel, they're > > updated from within the idle loop. > > > > Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > > --- > > arch/x86/include/asm/thread_info.h | 4 +++- > > arch/x86/kernel/signal.c | 4 ++++ > > include/linux/livepatch.h | 2 ++ > > kernel/livepatch/transition.c | 15 +++++++++++++++ > > kernel/sched/idle.c | 4 ++++ > ... > > --- a/kernel/sched/idle.c > > +++ b/kernel/sched/idle.c > > @@ -7,6 +7,7 @@ > > #include <linux/tick.h> > > #include <linux/mm.h> > > #include <linux/stackprotector.h> > > +#include <linux/livepatch.h> > > > > #include <asm/tlb.h> > > > > @@ -250,6 +251,9 @@ static void cpu_idle_loop(void) > > > > sched_ttwu_pending(); > > schedule_preempt_disabled(); > > + > > + if (unlikely(test_thread_flag(TIF_KLP_NEED_UPDATE))) > > + klp_update_task_universe(current); > > Oh, this is indeed broken on non-x86 archs as kbuild reports. > (TIF_KLP_NEED_UPDATE undefined) > > We need a klp_maybe_update_task_universe inline or something like that > and define it void for non-LIVEPATCH configs. Doh, thanks. -- Josh -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
