Messages in this thread | | | From | David Brownell <> | Subject | Re: [linux-usb-devel] Re: kexec and IRQ sharing | Date | Mon, 7 Mar 2005 14:24:18 -0800 |
| |
On Monday 07 March 2005 2:08 pm, Eric W. Biederman wrote:
> > The ongoing DMA transfers which are companions of the irq generating > events are what really concern me, as we could get all kinds of > interesting memory stomps. Do you think you could implement > a reboot notifier or a shutdown() method to handle that case? > > This appears to be yet another case of kexec transforming theoretical > bugs into actual ones. Groan.
Reboot notifiers seem to be a more general solution than the driver model shutdown() hooks, since as Alan noted not every bus framework uses shutdown() ... and although remove() would solve the issue too, for essentially all busses, it doesn't kick in here (and linker tricks may have removed it anyway).
Of possible relevance: Documentation/arm/Booting lists, at the end, requirements the boot firmware must meet before it runs Linux. (Stuff like U-Boot, BLOB, HaRET, or dozens of other open-sourced analogues of x86 BIOS code.) Seems like the same rules will apply before kexec ... yes? That mentions DMA, though not IRQs (possibly an omission).
- Dave
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |