Messages in this thread | | | Subject | Re: [PATCH 6/7] module: add two missing synchronize_sched() | From | Eric Dumazet <> | Date | Thu, 15 Mar 2012 09:26:49 -0700 |
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On Thu, 2012-03-15 at 22:49 +0800, Cong Wang wrote: > In RCU doc, it said synchronize_sched() is used to mark the end > of update, so two synchronize_sched() are missing after > module list add/del. > > Cc: Eric Dumazet <eric.dumazet@gmail.com> > Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > Cc: Rusty Russell <rusty@rustcorp.com.au> > Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> > --- > kernel/module.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/kernel/module.c b/kernel/module.c > index 06e7dc5..2e7a5c5 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -1775,6 +1775,7 @@ static void free_module(struct module *mod) > mutex_lock(&module_mutex); > stop_machine(__unlink_module, mod, NULL); > mutex_unlock(&module_mutex); > + synchronize_sched(); > mod_sysfs_teardown(mod); > > /* Remove dynamic debug info */ > @@ -2928,6 +2929,7 @@ static struct module *load_module(void __user *umod, > module_bug_finalize(info.hdr, info.sechdrs, mod); > list_add_rcu(&mod->list, &modules); > mutex_unlock(&module_mutex); > + synchronize_sched(); > > /* Module is ready to execute: parsing args may do that. */ > err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
Have a look at stop_machine() first
after list_add_rcu(), there is absolutely no such requirement.
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