[coreboot] NULL pointer dereference in search_bus_device()
mylesgw at gmail.com
Sat Jan 15 01:13:53 CET 2011
>> > That doesn't happen, because the if (subbus... is in the for loop, which
>> > checks for NULL. the search_bus_resources() is always called outside the
>> > for loop.
>> You're right. I should have looked at the code first, instead of just
>> the patch. There wasn't enough context.
>> If there is no bus there, maybe the resource shouldn't be subtractive.
>> Maybe we should print a message when that happens so that we can fix
>> the problem.
> What would cause it to be subtractive? We should print an error message
> if this occurs, but be should also react sanely. How do we proceed?
This has always been confusing to me. I don't know if we use it
"correctly" anywhere in coreboot.
My understanding is that subtractive resources should be used when
there is nothing explicitly directing an address range to a specific
bus or device. So, if an address arrives that doesn't match anything
you have and there is a subtractive resource, pass it that way.
I'd guess that it's left over from another era, but I'm not sure. Is
there another use for subtractive resources?
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