Messages in this thread | | | Date | Wed, 9 Nov 2011 14:38:46 -0800 (PST) | From | Andrei Warkentin <> | Subject | Re: /dev/mem "unbounded?" |
| |
Hi Peter,
----- Original Message ----- > > That would be incorrect behavior, though, except perhaps for the > range > that cannot be addressed by the processor. It is explicitly > permitted > to address ranges that does not have addresses mapped to it.
There is a current mechanism for restricting access to a subset of addresses, and it is used to enforce < 1MB accesses on x86 if CONFIG_STRICT_DEVMEM. This could be extended.
Do you think there is any value in specifying something like CONFIG_DEV_MEM_ONLY_CLAIMED, which would only allow accesses until the end of the last range claimed with request_region (but could, of course, well be unmapped). This will allow accesses to any unclaimed "holes" in between. I.e., if you have 0-100m claimed, followed by 300-700m claimed, then reading /dev/mem will work up until you reach 700m.
> > -EFAULT would also be wrong. If anything it should be -EIO. >
Ok, I'll submit a patch for that.
A
| |