Re: [PATCH] mm/kasan: Don't vfree() nonexistent vm_area.

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

 




On 02/02/2018 08:20 PM, Matthew Wilcox wrote:
> On Thu, Feb 01, 2018 at 11:22:55PM +0300, Andrey Ryabinin wrote:
>>>> +		vm = find_vm_area((void *)shadow_start);
>>>> +		if (vm)
>>>> +			vfree((void *)shadow_start);
>>>> +	}
>>>
>>> This looks like a complicated way to spell 'is_vmalloc_addr' ...
>>>
>>
>> It's not. shadow_start is never vmalloc address.
> 
> I'm confused.  How can you call vfree() on something that isn't a vmalloc
> address?
> 

​vfree() is able to free any address returned by __vmalloc_node_range().
And __vmalloc_node_range() gives you any address you ask.
It doesn't have to be an address in [VMALLOC_START, VMALLOC_END] range.

That's also how the module_alloc()/module_memfree() works on architectures that
have designated area for modules.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux