Messages in this thread | | | Date | Wed, 23 Oct 2019 15:29:32 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v2 4/4] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved |
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On Mon, 07 Oct 2019 10:25:45 +0200 Peter Zijlstra <peterz@infradead.org> wrote:
> Nothing ensures the module exists while we're iterating > mod->jump_entries in __jump_label_mod_text_reserved(), take a module > reference to ensure the module sticks around. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
> --- > kernel/jump_label.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > --- a/kernel/jump_label.c > +++ b/kernel/jump_label.c > @@ -539,19 +539,25 @@ static void static_key_set_mod(struct st > static int __jump_label_mod_text_reserved(void *start, void *end) > { > struct module *mod; > + int ret; > > preempt_disable(); > mod = __module_text_address((unsigned long)start); > WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); > + if (!try_module_get(mod)) > + mod = NULL; > preempt_enable(); > > if (!mod) > return 0; > > - > - return __jump_label_text_reserved(mod->jump_entries, > + ret = __jump_label_text_reserved(mod->jump_entries, > mod->jump_entries + mod->num_jump_entries, > start, end); > + > + module_put(mod); > + > + return ret; > } > > static void __jump_label_mod_update(struct static_key *key) >
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