Re: [PATCH] dmaengine: pl330: fix a race condition in case of threaded irqs
On Tue, Mar 06, 2018 at 09:13:37AM +0800, Qi Hou wrote: > When booting up with "threadirqs" in command line, all irq handlers of the DMA > controller pl330 will be threaded forcedly. These threads will race for the > same > list, pl330->req_done. > > Before the callback, the spinlock was released. And after it, the spinlock was > taken. This opened an race window where another threaded irq handler could > steal > the spinlock and be permitted to delete entries of the list, pl330->req_done. > > If the later deleted an entry that was still referred to by the former, there > would > be a kernel panic when the former was scheduled and tried to get the next > sibling > of the deleted entry. Applied, thanks -- ~Vinod
Re: [PATCH] dmaengine: pl330: fix a race condition in case of threaded irqs
On Tue, Mar 06, 2018 at 09:13:37AM +0800, Qi Hou wrote: > When booting up with "threadirqs" in command line, all irq handlers of the DMA > controller pl330 will be threaded forcedly. These threads will race for the > same > list, pl330->req_done. > > Before the callback, the spinlock was released. And after it, the spinlock was > taken. This opened an race window where another threaded irq handler could > steal > the spinlock and be permitted to delete entries of the list, pl330->req_done. > > If the later deleted an entry that was still referred to by the former, there > would > be a kernel panic when the former was scheduled and tried to get the next > sibling > of the deleted entry. Applied, thanks -- ~Vinod
