[syslinux] [PATCH 2/2] core: Fix stack overflow when reloading config

[Celelibi]

2016-01-27 3:06 UTC+01:00, H. Peter Anvin <hpa at zytor.com>:
> On January 26, 2016 5:46:25 PM PST, Celelibi <celelibi at gmail.com> wrote:
>>2016-01-26 20:22 UTC+01:00, H. Peter Anvin <hpa at zytor.com>:
>>> On 01/26/16 06:55, Celelibi wrote:
>>>>
>>>> Do you mean executables should also stay in memory and just get a
>>>> fast-reinitialization when re-running them?
>>>>
>>>
>>> Yes.  I hope that it would make things a lot faster, especially over
>>the
>>> network.  However, it wouldn't really matter in the common case of
>>just
>>> showing a menu and booting from there; now when we have hierarchical
>>menus.
>>>
>>>> However, unless we do something more heavy-weight, when a config
>>file
>>>> is loaded, I guess all modules will have to be unloaded anyway since
>>>> the search path can be changed by the new config file and other
>>>> modules with the same name can be loaded.
>>>
>>> Hm.  We could rather easily deal with that by storing the full path
>>of
>>> the module; that way we can distinguish them.
>>>
>>
>>That means modules will accumulate in memory. If we add a way to prune
>>the least recently used modules when memory is required, that become
>>quite close to the file system cache I had in mind with the solution
>>3. ^^ Except it's specialized for modules.
>>
>>
>>>> BTW, can ldlinux.c32 be affected by the PATH directive or another
>>>> configuration option?
>>>
>>> Not at the moment, and I don't think it should be.  ldlinux.c32 is
>>very
>>> closely coupled with the bootstrap part of the bootloader itself.
>>
>>Thanks, that's what I thought.
>>
>>
>>Celelibi
>
> Yes, we could expire them, and that probably would make sense once we cross
> a certain memory threshold.  The big question is if that would ever actually
> happen.

I'm not really comfortable about making the assumption that we have a
lot of memory available. I'm far from knowing all the use cases of
syslinux.


Celelibi