Re: [PATCH 0/2] blackfin: ptrace mm/sram_list fixes

[Mike Frysinger]

On Thu, May 27, 2010 at 15:55, Oleg Nesterov wrote:
> On 05/26, Oleg Nesterov wrote:
>> On 05/25, Mike Frysinger wrote:
>> > we probably should add proper locking to this
>> > structure though.
>>
>> Agreed. I'll try to make the trivial patch tomorrow. I think we
>> can just use mm->mmap_sem, is_user_addr_valid() needs this lock
>> for find_vma() anyway.
>
> please see the patches.

awesome !  wasnt expecting someone to do the work for us :).

> UNTESTED! the second one certainly needs the review from someone
> who knows what this code does ;)

np.  after i look them over, i'll suck them into the Blackfin tree and
let them settle for a release for our test suites to shake out
problems.

> BTW. Obviously sys_sram_alloc() can create multiple sram_list_struct
> nodes with the same ->addr (with or without this patch), I hope this
> is fine.

how so ?  Blackfin is a nommu arch, so there should be no aliasing
issues.  each of the individual L1 sub-allocators manage a different
address range, and none of those should return an address that is
already in use.  it could happen that the code calling these funcs
calls a free func directly instead of going through the lsl free, but
that's a bug in the usage, not this code.
-mike
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