On Tue, Mar 8, 2011 at 1:06 PM, David Cohen <dacohen@xxxxxxxxx> wrote:
> 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. And spell variable 'alignment' correctly.
>>>
>>> Signed-off-by: Michael Jones <michael.jones@xxxxxxxxxxxxxxxx>
>>> ---
>>> arch/arm/plat-omap/iovmm.c | 16 ++++++++++------
>>> 1 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,
>>> size_t bytes, u32 flags)
>>> {
>>> struct iovm_struct *new, *tmp;
>>> - u32 start, prev_end, alignement;
>>> + u32 start, prev_end, alignment;
>>>
>>> if (!obj || !bytes)
>>> return ERR_PTR(-EINVAL);
>>>
>>> start = da;
>>> - alignement = PAGE_SIZE;
>>> + alignment = PAGE_SIZE;
>>>
>>> if (flags & IOVMF_DA_ANON) {
>>> - start = obj->da_start;
>>> + /* Don't map address 0 */
>>> + if (obj->da_start)
>>> + start = obj->da_start;
>>> + else
>>> + 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"
yeah, but it only applies when "flags & IOVMF_DA_ANON", So if I use
IOVMF_DA_FIXED and da_start == 0, I will be able to map some area
which starts from address 0x0, right? if so, that looks good to me
and the description should mention that if is disallowing mapping
address 0x0 when IOVMF_DA_ANON is used.
Regards,
Fernando.
> and it's also mentioned on the patch description. Is it OK for you?
>
> Regards,
>
> David Cohen
>
>>
>> Regards,
>> Fernando.
>>
>>>
>>> if (flags & IOVMF_LINEAR)
>>> - alignement = iopgsz_max(bytes);
>>> - start = roundup(start, alignement);
>>> + alignment = iopgsz_max(bytes);
>>> + start = roundup(start, alignment);
>>> } else if (start < obj->da_start || start > obj->da_end ||
>>> obj->da_end - start < bytes) {
>>> return ERR_PTR(-EINVAL);
>>> @@ -304,7 +308,7 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
>>> goto found;
>>>
>>> if (tmp->da_end >= start && flags & IOVMF_DA_ANON)
>>> - start = roundup(tmp->da_end + 1, alignement);
>>> + start = roundup(tmp->da_end + 1, alignment);
>>>
>>> prev_end = tmp->da_end;
>>> }
>>> --
>>> 1.7.0.4
>>>
>>>
>>
>
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