On Tue, Mar 8, 2011 at 8:06 PM, Guzman Lugo, Fernando
<fernando.lugo@xxxxxx> wrote:
> On Tue, Mar 8, 2011 at 6:46 AM, David Cohen <dacohen@xxxxxxxxx> wrote:
>> From: Michael Jones <michael.jones@xxxxxxxxxxxxxxxx>
>>
>> commit c7f4ab26e3bcdaeb3e19ec658e3ad9092f1a6ceb allowed mapping
>> the NULL address if da_start==0, which would then not get unmapped.
>> Disallow this again. ÂAnd spell variable 'alignment' correctly.
>>
>> Signed-off-by: Michael Jones <michael.jones@xxxxxxxxxxxxxxxx>
>> ---
>> Âarch/arm/plat-omap/iovmm.c | Â 16 ++++++++++------
>> Â1 files changed, 10 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm/plat-omap/iovmm.c b/arch/arm/plat-omap/iovmm.c
>> index 6dc1296..11c9b76 100644
>> --- a/arch/arm/plat-omap/iovmm.c
>> +++ b/arch/arm/plat-omap/iovmm.c
>> @@ -271,20 +271,24 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â size_t bytes, u32 flags)
>> Â{
>> Â Â Â Âstruct iovm_struct *new, *tmp;
>> - Â Â Â u32 start, prev_end, alignement;
>> + Â Â Â u32 start, prev_end, alignment;
>>
>> Â Â Â Âif (!obj || !bytes)
>> Â Â Â Â Â Â Â Âreturn ERR_PTR(-EINVAL);
>>
>> Â Â Â Âstart = da;
>> - Â Â Â alignement = PAGE_SIZE;
>> + Â Â Â alignment = PAGE_SIZE;
>>
>> Â Â Â Âif (flags & IOVMF_DA_ANON) {
>> - Â Â Â Â Â Â Â start = obj->da_start;
>> + Â Â Â Â Â Â Â /* Don't map address 0 */
>> + Â Â Â Â Â Â Â if (obj->da_start)
>> + Â Â Â Â Â Â Â Â Â Â Â start = obj->da_start;
>> + Â Â Â Â Â Â Â else
>> + Â Â Â Â Â Â Â Â Â Â Â start = obj->da_start + alignment;
>
> else part obj->da_star is always 0, so why not?
> start = alignment;
The patch is not from me, but I can fix it if Michael agrees.
>
> so, why I understand, it now it is possible mapp address 0x0 only if
> IOVMF_DA_ANON is not set, right? maybe that would be mention in the
> patch.
Indeed address 0x0 was never meant to be mapped. The mentioned commit
on the patch's description did that without noticing. But the new
change is documented in the code by the comment "Don't map address 0"
and it's also mentioned on the patch description. Is it OK for you?
Regards,
David Cohen
>
> Regards,
> Fernando.
>
>>
>> Â Â Â Â Â Â Â Âif (flags & IOVMF_LINEAR)
>> - Â Â Â Â Â Â Â Â Â Â Â alignement = iopgsz_max(bytes);
>> - Â Â Â Â Â Â Â start = roundup(start, alignement);
>> + Â Â Â Â Â Â Â Â Â Â Â alignment = iopgsz_max(bytes);
>> + Â Â Â Â Â Â Â start = roundup(start, alignment);
>> Â Â Â Â} else if (start < obj->da_start || start > obj->da_end ||
>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âobj->da_end - start < bytes) {
>> Â Â Â Â Â Â Â Âreturn ERR_PTR(-EINVAL);
>> @@ -304,7 +308,7 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
>> Â Â Â Â Â Â Â Â Â Â Â Âgoto found;
>>
>> Â Â Â Â Â Â Â Âif (tmp->da_end >= start && flags & IOVMF_DA_ANON)
>> - Â Â Â Â Â Â Â Â Â Â Â start = roundup(tmp->da_end + 1, alignement);
>> + Â Â Â Â Â Â Â Â Â Â Â start = roundup(tmp->da_end + 1, alignment);
>>
>> Â Â Â Â Â Â Â Âprev_end = tmp->da_end;
>> Â Â Â Â}
>> --
>> 1.7.0.4
>>
>>
>
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