Re: [PATCH] x86: Fix memory leak of init_vdso_vars()

[Andrew Lutomirski]

On Thu, Jul 21, 2011 at 1:08 PM, Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
> On Thu, Jul 21, 2011 at 10:33:14AM -0400, Andy Lutomirski wrote:
>> From: Zhitong Wang <wzt.wzt@xxxxxxxxx>
>>
>> If init_vdso_vars ran out of memory (not very likely), then it would
>> leak a few pages as well.
>>
>> Also rename init_vdso_vars to just init_vdso, since initializing
>> vvars is just about the only thing this function doesn't do.
>
> Just add a GFP_PANIC, there's no way to recover from this.
> Your system will not work without a vdso.

Ingo objected to this before, although I'm not convinved.  Calling
init_vdso_vars more than once will cause major problems (like
double-patching of alternatives).  If there's too little memory for it
to work, then presumably there's also too little memory to start init.
 (Also, I bet that no one ever audited whether the ELF loader works
right if the vDSO failed to load.)

Ingo?

--Andy

>
> -Andi
>
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