On Sat, Feb 28, 2015 at 10:24:48PM +0100, Peter Zijlstra wrote: > While one must hold RCU-sched (aka. preempt_disable) for find_symbol() > one must equally hold it over the use of the object returned. > > The moment you release the RCU-sched read lock, the object can be dead > and gone. > > Cc: Seth Jennings <[email protected]> > Cc: Josh Poimboeuf <[email protected]> > Cc: Masami Hiramatsu <[email protected]> > Cc: Miroslav Benes <[email protected]> > Cc: Petr Mladek <[email protected]> > Cc: Jiri Kosina <[email protected]> > Cc: "Paul E. McKenney" <[email protected]> > Cc: Rusty Russell <[email protected]> > Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Paul E. McKenney <[email protected]> > --- > kernel/livepatch/core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > --- a/kernel/livepatch/core.c > +++ b/kernel/livepatch/core.c > @@ -248,11 +248,12 @@ static int klp_find_external_symbol(stru > /* first, check if it's an exported symbol */ > preempt_disable(); > sym = find_symbol(name, NULL, NULL, true, true); > - preempt_enable(); > if (sym) { > *addr = sym->value; > + preempt_enable(); > return 0; > } > + preempt_enable(); > > /* otherwise check if it's in another .o within the patch module */ > return klp_find_object_symbol(pmod->name, name, addr); > > -- 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/
