omap iommu: Insert a gap page between IOVMAs against override

Inserting a gap page between IOVMAs could detect an override on other
IOVMA with iommu fault. This was originally suggested by Sakari Ailus
and based on the work and comment by David Cohen.

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Cc: David Cohen <david.cohen@nokia.com>
Cc: Sakari Ailus <Sakari.Ailus@nokia.com>
This commit is contained in:
Hiroshi DOYU 2010-05-06 16:10:18 +03:00
parent 347815fcc6
commit fa460b88e0

View file

@ -287,16 +287,16 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
prev_end = 0;
list_for_each_entry(tmp, &obj->mmap, list) {
if ((prev_end <= start) && (start + bytes < tmp->da_start))
if ((prev_end < start) && (start + bytes < tmp->da_start))
goto found;
if (flags & IOVMF_DA_ANON)
start = roundup(tmp->da_end, alignement);
start = roundup(tmp->da_end + 1, alignement);
prev_end = tmp->da_end;
}
if ((start >= prev_end) && (ULONG_MAX - start >= bytes))
if ((start > prev_end) && (ULONG_MAX - start >= bytes))
goto found;
dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",