[PATCH 02/14] lmb: Use CONFIG_LMB_*_REGIONS only if they are defined

Marek Vasut marex at denx.de
Sat Sep 4 18:49:03 CEST 2021


On 9/4/21 6:09 PM, Tom Rini wrote:
> On Sat, Sep 04, 2021 at 06:05:50PM +0200, Marek Vasut wrote:
>> On 9/4/21 5:17 PM, Tom Rini wrote:
>>> On Sat, Sep 04, 2021 at 05:15:45PM +0200, Marek Vasut wrote:
>>>> On 9/4/21 4:10 PM, Tom Rini wrote:
>>>> [...]
>>>>
>>>>>>>>> At this point, I think you should rework things to stop making
>>>>>>>>> CONFIG_LMB be optional, it should be a def_bool y.
>>>>>>>>
>>>>>>>> I disagree, see above.
>>>>>>>
>>>>>>> The only reason "tools-only_defconfig" builds a useless u-boot binary
>>>>>>> today is in CI where it would be more work than it's worth to make CI
>>>>>>> exclude that from the build list.  But if you want to just do that
>>>>>>> instead, I'll also accept adding -x tools-only to the azure/gitlab jobs
>>>>>>> that build all other architectures, as tools-only is tested in its own
>>>>>>> build job, for it's only valid build target.
>>>>>>
>>>>>> The tools-only build is also used elsewhere, to build just that, tools.
>>>>>
>>>>> I've repeatedly explained myself and what I'm looking for in v2 of this
>>>>> series.  I will summarize one last time.  The "tools-only_defconfig" is
>>>>> for tools, only.  Building anything other than the "tools-only" target
>>>>> isn't useful.  In U-Boot itself, LMB is required as that is how we
>>>>> prevent a number of CVEs from being trivial to exploit.  v2 of this
>>>>> series needs to drop patches 1 and 2 of v1 of this series.  It can
>>>>> further do any of:
>>>>> 1. Nothing else.
>>>>> 2. Add tools-only to the exclude list in the "build everything else" CI
>>>>>       job.
>>>>> 3. Make CONFIG_LMB be def_bool y.
>>>>
>>>> If tools-only is for tools, only, then why should it enable LMB ?
>>>> The tools are userspace tools, they do not need LMB, and so LMB can be
>>>> disabled.
>>>>
>>>> This is the part which is unclear to me.
>>>
>>> I don't know why it's unclear to you at this point, sorry.
>>
>> Well why exactly does a userspace program require LMB enabled ?
>> What does LMB protect in there ? obviously not U-Boot.
> 
> I feel like you've lost the thread.

Can you please answer my questions above ?

This is exactly what patch 1/14 is about -- disable LMB for tools build, 
because it is useless for tools build.


More information about the U-Boot mailing list