Re: [patch] kexec: potetially using uninitialized variable

walter harms
2016-03-11T09:47:58Z

Am 11.03.2016 10:19, schrieb Dan Carpenter:
> On Fri, Mar 11, 2016 at 04:52:43PM +0800, Xunlei Pang wrote:
>> Hi Dan,
>>
>> On 2016/03/11 at 16:07, Dan Carpenter wrote:
>>> At the end of the function we check if "ret" has a negative error code,
>>> but it seems possible that it is uninitialized.
>>>
>>> Fixes: 12db5562e035 ('kexec: load and relocate purgatory at kernel load time')
>>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>>>
>>> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
>>> index 503bc2d..63d1af3 100644
>>> --- a/kernel/kexec_file.c
>>> +++ b/kernel/kexec_file.c
>>> @@ -795,7 +795,7 @@ out:
>>>
>>> static int kexec_apply_relocations(struct kimage *image)
>>> {
>>> - int i, ret;
>>> + int i, ret = 0;
>>> struct purgatory_info *pi = &image->purgatory_info;
>>> Elf_Shdr *sechdrs = pi->sechdrs;
>>>
>>
>> Look further, there is a condition at the beginning of the for loop:
>>
>>
>> if (sechdrs[i].sh_type != SHT_RELA &&
>> sechdrs[i].sh_type != SHT_REL)
>> continue;
>>
>> So, I think that's ok, but I don't konw if GCC is smart enough not to throw warnings.
>
> Ah, right...
>
> This wasn't a GCC warning. GCC misses a lot of uninitialized variable
> bugs so I'm doing this with Smatch.
>
> Anyway, I'll patch this up in Smatch to not warn about this.
>

I am not so sure about this. the point should be that the reviewer can read it easily
not if gcc complains or not.

just my 2 cents,

re,
wh