Re: mm: insure topdown mmap chooses addresses above security minimum

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



* Timothy Pepper <timothy.c.pepper@xxxxxxxxxxxxxxx> wrote:

> On Wed 25 Sep at 09:30:49 +0200 mingo@xxxxxxxxxx said:
> > >  	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
> > >  	info.length = len;
> > > -	info.low_limit = PAGE_SIZE;
> > > +	info.low_limit = max(PAGE_SIZE, PAGE_ALIGN(mmap_min_addr));
> > >  	info.high_limit = mm->mmap_base;
> > >  	info.align_mask = filp ? get_align_mask() : 0;
> > >  	info.align_offset = pgoff << PAGE_SHIFT;
> > 
> > There appears to be a lot of repetition in these methods - instead of 
> > changing 6 places it would be more future-proof to first factor out the 
> > common bits and then to apply the fix to the shared implementation.
> 
> Besides that existing redundancy in the multiple somewhat similar
> arch_get_unmapped_area_topdown() functions, I was expecting people might
> question the added redundancy of the six instances of:
> 
> 	max(PAGE_SIZE, PAGE_ALIGN(mmap_min_addr));

That redundancy would be automatically addressed by my suggestion.

Thanks,

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Kernel Development]     [DCCP]     [Linux ARM Development]     [Linux]     [Photo]     [Yosemite Help]     [Linux ARM Kernel]     [Linux SCSI]     [Linux x86_64]     [Linux Hams]

  Powered by Linux