Problem with 'test-pci'

[Norman Feske]

Hi Frank,

thanks for your investigation. We have also hit this issue (hence my
initial guess) on real hardware and it will be fixed in the upcoming
release. Until then, I hope you are fine with the interim solution of
appending the zero-termination manually. Of course, the pending null
character does not comply to the XML syntax. It's just a work-around.

Regards
Norman

Frank Kaiser wrote:
> Your guess is right: The page fault is caused while parsing the config
> file. The trigger is the method /Xml_node::content()/, which tries to
> copy the process’ filename from the config file, but the root cause is a
> nasty bug in function /Genode::strncpy()/ which is used to obtain the
> filename. In the function’s first line /Genode::strlen()/ is used to
> determine the length of the source string. In the given case, where the
> source is a tagged item of the config file having no null termination,
> /strlen()/ runs thru the memory until it randomly finds a null
> character. For my opinion /Genode::strncpy()/ is not allowed to parse
> the source string beyond the given /size/ argument. Your suggestion of
> appending a null character to the config file (by the way: how is this
> to be done w/o corrupting the XML syntax?) heals a symptome, but does
> not solve the root cause.
> 
> I tried to fix /Genode::strncpy()/ myself. Since there is no function
> /Genode::strnlen()/, I made the following change:
> 
>         size_t i = 0;
> 
>         while (i < size)
> 
>         {
> 
>             if (src[i] == 0)
> 
>             {
> 
>                 size = i;
> 
>                 break;
> 
>             }
> 
>             ++i;
> 
>         }
> 
> Interestingly this seem to trigger another problem. Now I get on all
> platforms the following two errors:
> 
> virtual Genode::Session_capability Genode::Core_parent::session(const
> char*, const char*): service_name="RM" arg="ram_quota=4K" not handled
> 
> virtual Genode::Session_capability Genode::Core_parent::session(const
> char*, const char*): service_name="PD" arg="ram_quota=4K" not handled
> 
> Could it be that there are already some workarounds for buggy
> /Genode::strncpy()/, which do not work anymore once the function is fixed?
> 
>  
> 
> Frank