Messages in this thread | | | Date | Fri, 26 Sep 2008 09:39:02 +0200 | From | Ingo Molnar <> | Subject | Re: [patch] ioremap sanity check to catch mapping requests exceeding the BAR sizes |
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* Suresh Siddha <suresh.b.siddha@intel.com> wrote:
> [patch] ioremap sanity check to catch mapping requests exceeding the BAR sizes > > Go through the iomem resource tree to check if any of the ioremap() requests > span more than any slot in the iomem resource tree and do a WARN_ON() if we hit > this check. > > This will raise a red-flag, if some driver is mapping more than what > is needed. And hopefully identify possible corruptions much earlier. > > Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
applied to tip/core/resources, thanks Suresh.
one question:
> + for (p = p->child; p ; p = r_next(NULL, p, &l)) { > + /* > + * We can probably skip the resources with out > + * IORESOURCE_IO attribute? > + */ > + if (p->start >= addr + size) > + continue; > + if (p->end < addr) > + continue; > + if (p->start <= addr && (p->end >= addr + size - 1)) > + continue; > + printk(KERN_WARNING "resource map sanity check conflict " > + " 0x%llx 0x%llx 0x%llx 0x%llx %s\n", > + addr, addr + size - 1, p->start, p->end, p->name); > + err = -1; > + break;
i think all the checks you added are precise to the byte and you allow all the sensible ioremaps: which nest fully inside a single resource - and you reject all the other partial overlap or multiple overlap scenarios.
One potential thing to check for would be whether addr+size overlaps a 4GB boundary? That would almost always be a bug, and it could also cause problems with the checks above if resource_t is 32 bits. The ioremap code should already prevent it though.
Ingo
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