[BUG] sandbox error handling broken on origin/next

[Heinrich Schuchardt]

On 3/22/21 7:16 PM, Simon Glass wrote:
> Hi Heinrich,
>
> On Tue, 23 Mar 2021 at 07:12, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>>
>> Hello Simon,
>>
>> using sandbox_defconfig on origin/master:
>>
>> Hit any key to stop autoboot:  0
>> => exception sigsegv
>>
>> Segmentation violation
>> pc = 0x55d3566d04f9, pc_reloc = 0x554f9
>>
>> $
>>
>> Here the SIGSEGV is correctly handled by the sandbox.
>>
>> On origin/next:
>>
>> => exception sigsegv
>>
>> Segmentation violation
>> pc = 0x5567966da96b, pc_reloc = 0x5567866da96b
>>
>> Writing sandbox state
>> Segmentation fault
>> $
>>
>> The same problem is visible when executing the poweroff command.
>>
>> => poweroff
>> poweroff ...
>> Segmentation fault
>> $
>>
>> Bisecting points to your commit
>>
>> b308d9fd18fa
>> sandbox: Avoid using malloc() for system state
>>
>> The segmentation fault occurs when os_exit() calls dm_uninit().
>> The value of gd is invalid at this point.
>
> Can you please check this patch?
>
> http://patchwork.ozlabs.org/project/uboot/patch/20210315051124.1940496-10-sjg@chromium.org/
>
> Also, is there no test covering the above?
>
> Regards,
> Simon
>

Hello Simon,

We have a poweroff test but there is no detection for the 'Segmentation
fault' string.

For CONFIG_SANDBOX_CRASH_RESET=n the patch helps.

For CONFIG_SANDBOX_CRASH_RESET=y you still get a segmentation fault when
executing 'exception sigsegv'.

Unfortunately you decided to disable CONFIG_SANDBOX_CRASH_RESET in
sandbox_defconfig. Otherwise you would have detected the problem as
"FAILED test/py/tests/test_sandbox_exit.py::test_exception_reset".

Please, adjust sandbox_reset().

Best regards

Heinrich