Messages in this thread | | | Date | Fri, 3 Nov 2017 09:06:55 +0100 (CET) | From | Miroslav Benes <> | Subject | Re: [PATCH v3 1/2] livepatch: send a fake signal to all blocking tasks |
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On Thu, 2 Nov 2017, Josh Poimboeuf wrote:
> On Tue, Oct 31, 2017 at 12:48:52PM +0100, Miroslav Benes wrote: > > diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c > > index bf8c8fd72589..b7c60662baf3 100644 > > --- a/kernel/livepatch/core.c > > +++ b/kernel/livepatch/core.c > > @@ -440,6 +440,7 @@ EXPORT_SYMBOL_GPL(klp_enable_patch); > > * /sys/kernel/livepatch/<patch> > > * /sys/kernel/livepatch/<patch>/enabled > > * /sys/kernel/livepatch/<patch>/transition > > + * /sys/kernel/livepatch/<patch>/signal > > * /sys/kernel/livepatch/<patch>/<object> > > * /sys/kernel/livepatch/<patch>/<object>/<function,sympos> > > */ > > @@ -514,11 +515,37 @@ static ssize_t transition_show(struct kobject *kobj, > > patch == klp_transition_patch); > > } > > > > +static ssize_t signal_store(struct kobject *kobj, struct kobj_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + int ret; > > + bool val; > > + > > + /* > > + * klp_mutex lock is not grabbed here intentionally. It is not really > > + * needed. The race window is harmless and grabbing the lock would only > > + * hold the action back. > > + */ > > + if (!klp_transition_patch) > > + return -EINVAL; > > + > > + ret = kstrtobool(buf, &val); > > + if (ret) > > + return ret; > > + > > + if (val) > > + klp_force_signals(); > > + > > + return count; > > +} > > The function still has global functionality even though the sysfs entry > is now per-patch. So if you do > > echo 1 > /sys/kernel/livepatch/patch1/signal > > But patch2 is in transition, then it will send signals based on patch2. > Instead it should probably return an error. > > There's a similar issue with force_store().
Bah. I still find having "signal" and "force" in /sys/kernel/livepatch/<patch>/ a bit odd, but I'll add
struct klp_patch *patch;
patch = container_of(kobj, struct klp_patch, kobj); /* ... */ if (patch != klp_transition_patch) return -EINVAL;
That should solve it for all cases.
Thanks, Miroslav
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