On 01/20/2015, 04:26 PM, Josh Poimboeuf wrote: > Only allow the topmost patch on the stack to be enabled or disabled, so > that patches can't be removed or added in an arbitrary order. > > Suggested-by: Jiri Kosina <[email protected]> > Signed-off-by: Josh Poimboeuf <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]> > --- > kernel/livepatch/core.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c > index 3d9c00b..2401e7f 100644 > --- a/kernel/livepatch/core.c > +++ b/kernel/livepatch/core.c > @@ -379,6 +379,11 @@ static int __klp_disable_patch(struct klp_patch *patch) > struct klp_object *obj; > int ret; > > + /* enforce stacking: only the last enabled patch can be disabled */ > + if (!list_is_last(&patch->list, &klp_patches) && > + list_next_entry(patch, list)->state == KLP_ENABLED) > + return -EBUSY; > + > pr_notice("disabling patch '%s'\n", patch->mod->name); > > for (obj = patch->objs; obj->funcs; obj++) { > @@ -435,6 +440,11 @@ static int __klp_enable_patch(struct klp_patch *patch) > if (WARN_ON(patch->state != KLP_DISABLED)) > return -EINVAL; > > + /* enforce stacking: only the first disabled patch can be enabled */ > + if (patch->list.prev != &klp_patches && > + list_prev_entry(patch, list)->state == KLP_DISABLED) > + return -EBUSY; > + > pr_notice_once("tainting kernel with TAINT_LIVEPATCH\n"); > add_taint(TAINT_LIVEPATCH, LOCKDEP_STILL_OK); > > thanks, -- js suse labs -- 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/
