Messages in this thread | | | Date | Fri, 26 Sep 2008 01:10:22 -0700 | From | "Yinghai Lu" <> | Subject | Re: [patch] ioremap sanity check to catch mapping requests exceeding the BAR sizes |
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On Fri, Sep 26, 2008 at 12:39 AM, Ingo Molnar <mingo@elte.hu> wrote: > > * 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);
need cast with (unsigned long long)...
>> + 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.
in that case, BAR should be disabled already.
YH
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