Robert Millan wrote:
> On Sat, Mar 21, 2009 at 07:05:23PM +0100, phcoder wrote:
>> Robert Millan wrote:
>>> On Sat, Mar 21, 2009 at 06:58:58PM +0100, phcoder wrote:
>>>> Robert Millan wrote:
>>>>> On Wed, Mar 18, 2009 at 02:26:40PM +0100, phcoder wrote:
>>>>>> Robert Millan wrote:
>>>>>>> On Fri, Mar 13, 2009 at 09:52:39PM +0100, phcoder wrote:
>>>>>>>> -  grub_multiboot_payload_entry_offset = ehdr->e_entry - phdr(lowest_segment)->p_vaddr;
>>>>>>>> +  for (i = 0; i < ehdr->e_phnum; i++)
>>>>>>>> +    if (phdr(i)->p_vaddr <= ehdr->e_entry +	&& 
>>>>>>>> phdr(i)->p_vaddr + phdr(i)->p_memsz > ehdr->e_entry)
>>>>>>>> +      grub_multiboot_payload_entry_offset = (ehdr->e_entry - phdr(i)->p_vaddr)
>>>>>>>> +	+ (phdr(i)->p_paddr  - phdr(lowest_segment)->p_paddr);
>>>>>>> You need to handle the case in which grub_multiboot_payload_entry_offset is left
>>>>>>> uninitialized (it needs to be initialized each time the multiboot command is
>>>>>>> run, not just when the module is loaded).
>>>>>>>
>>>>>> module? actually it's when loading image. Perhaps you mean that   
>>>>>> additional error check is necessary
>>>>> I meant GRUB's multiboot.mod, not the payload's module.  Sorry I wasn't clear.
>>>>>
>>>> With this error check if grub_multiboot_payload_entry_offset it can   
>>>> happen only if no image is loaded. And actually   
>>>> grub_multiboot_payload_entry_offset is set to 0 at multiboot.mod load
>>>> So I don't really understand the problem
>>> You can't rely on grub_multiboot_payload_entry_offset being set to 0, because
>>> any subsequent call of "multiboot /something" has the potential to override
>>> this.  You must not assume the multiboot command is only going to be run once.
>>>
>> No but it always corresponds to the current image. It's set either in  
>> multiboot.c or in grub_multiboot_load_elf
> 
> It is now, but your code makes this conditional.
> 


-- 

Regards
Vladimir 'phcoder' Serbinenko