| Message ID | 20220731105356.1741086-1-qiang1.zhang@intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f8c9027f9c81be92344996a51babaa5a23bd88db |
| Headers | show |
| Series | rcutorture: Use the barrier operation corresponding to rcutorture.torture_type | expand |
On Sun, Jul 31, 2022 at 06:53:56PM +0800, Zqiang wrote: > when the rcutorture.torture_type value is 'rcu', this is correct for > invoke rcu_barrier() to wait all in-flight call_rcu() callbacks > (rcu_torture_fwd_cb_cr()) complete in rcutorture_oom_notify(). but when > the rcutorture.torture_type value is 'tasks-tracing', invoke rcu_barrier() > won't wait all in-flight call_rcu_tasks_trace() callbacks complete, the > rcu_barrier_tasks_trace() should be invoked. > > This commit fix it by using barrier operation corresponding to > rcutorture.torture_type to wait all in-flight rcu_torture_fwd_cb_cr() > complete. > > Signed-off-by: Zqiang <qiang1.zhang@intel.com> Good catch, thank you! I have done my usual wordsmithing as shown below. Could you please double-check it? Thanx, Paul ------------------------------------------------------------------------ commit f8c9027f9c81be92344996a51babaa5a23bd88db Author: Zqiang <qiang1.zhang@intel.com> Date: Sun Jul 31 18:53:56 2022 +0800 rcutorture: Use the barrier operation specified by cur_ops The rcutorture_oom_notify() function unconditionally invokes rcu_barrier(), which is OK when the rcutorture.torture_type value is "rcu", but unhelpful otherwise. The purpose of these barrier calls is to wait for all outstanding callback-flooding callbacks to be invoked before cleaning up their data. Using the wrong barrier function therefore risks arbitrary memory corruption. Thus, this commit changes these rcu_barrier() calls into cur_ops->cb_barrier() to make things work when torturing non-vanilla flavors of RCU. Signed-off-by: Zqiang <qiang1.zhang@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 7f13f2e5ed62f..7e7d54841613c 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -2638,12 +2638,12 @@ static int rcutorture_oom_notify(struct notifier_block *self, for (i = 0; i < fwd_progress; i++) ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); - rcu_barrier(); + cur_ops->cb_barrier(); ncbs = 0; for (i = 0; i < fwd_progress; i++) ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); - rcu_barrier(); + cur_ops->cb_barrier(); ncbs = 0; for (i = 0; i < fwd_progress; i++) ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 7f13f2e5ed62..7e7d54841613 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -2638,12 +2638,12 @@ static int rcutorture_oom_notify(struct notifier_block *self, for (i = 0; i < fwd_progress; i++) ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); - rcu_barrier(); + cur_ops->cb_barrier(); ncbs = 0; for (i = 0; i < fwd_progress; i++) ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); - rcu_barrier(); + cur_ops->cb_barrier(); ncbs = 0; for (i = 0; i < fwd_progress; i++) ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
when the rcutorture.torture_type value is 'rcu', this is correct for invoke rcu_barrier() to wait all in-flight call_rcu() callbacks (rcu_torture_fwd_cb_cr()) complete in rcutorture_oom_notify(). but when the rcutorture.torture_type value is 'tasks-tracing', invoke rcu_barrier() won't wait all in-flight call_rcu_tasks_trace() callbacks complete, the rcu_barrier_tasks_trace() should be invoked. This commit fix it by using barrier operation corresponding to rcutorture.torture_type to wait all in-flight rcu_torture_fwd_cb_cr() complete. Signed-off-by: Zqiang <qiang1.zhang@intel.com> --- kernel/rcu/rcutorture.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)