On Fri, May 15, 2015 at 05:04:03PM +0800, Pan Xinhui wrote: > this patch reverts commit 3440a1 which causes the regression and fix a list corruption. > > base knowledge: kernel call cp->func using cp->info as its argument. like cp->func(cp->info); > > current code is totally wrong, as 1) &softirq is at stack. 2) cp->info don't point to struct call_single_data. > So in remote_softirq_receive, > 1) If the caller had left __try_remote_softirq, dereferencing cp->info could not fetch the correct value. > 2) And we can't get struct call_single_data *cp anymore. > > The list corruption is below. > __local_trigger will add cp->list into softirq_work_list. But no one will delete cp->list on behalf of us. > if we can succeed to raise_softirq_irqoff, we must delete it from softirq_work_list. because we will lost control of pointer cp. > cp is passed in and may be freed later in other places. > > Signed-off-by: Pan Xinhui <xinhuix.pan@xxxxxxxxx> > --- > Changes in v2: > no codes changed from v1, just update the comment. > upstream commit fc21c0 fix this issue, as it removes the total feature. :) > the buggy codes exist in v3.10 and v3.12. Why shouldn't we just include fc21c0 instead? I don't like patches that are not identical to what is in Linus's tree. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html