Re: [PATCH] powerpc/kexec: Fix the return of uninitialized variable

[Madhavan Srinivasan <maddy@linux.ibm.com>]

On 9/30/24 1:57 PM, Christophe Leroy wrote:
> 
> 
> Le 30/09/2024 à 09:56, Zhang Zekun a écrit :
>> [Vous ne recevez pas souvent de courriers de zhangzekun11@huawei.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
>>
>> The of_property_read_u64() can fail and remain the variable uninitialized,
> 
> Replace "remain" by "leave".
> 
>> which will then be used. Return error if we failed to read the property.
> 
> Rewrite to avoid "we".  For instance "Return error if reading the property failed"
> 
>>
>> Fixes: 2e6bd221d96f ("powerpc/kexec_file: Enable early kernel OPAL calls")
>> Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
>> ---
>>   arch/powerpc/kexec/file_load_64.c | 9 +++++++--
>>   1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
>> index 9738adabeb1f..dc65c1391157 100644
>> --- a/arch/powerpc/kexec/file_load_64.c
>> +++ b/arch/powerpc/kexec/file_load_64.c
>> @@ -736,13 +736,18 @@ int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
>>          if (dn) {
>>                  u64 val;

Instead cant we init val as -1 ??
Why to add check?


>>
>> -               of_property_read_u64(dn, "opal-base-address", &val);
>> +               ret = of_property_read_u64(dn, "opal-base-address", &val);
>> +               if (ret)
>> +                       goto out;
>> +
>>                  ret = kexec_purgatory_get_set_symbol(image, "opal_base", &val,
>>                                                       sizeof(val), false);
>>                  if (ret)
>>                          goto out;
>>
>> -               of_property_read_u64(dn, "opal-entry-address", &val);
>> +               ret = of_property_read_u64(dn, "opal-entry-address", &val);
>> +               if (ret)
>> +                       goto out;
>>                  ret = kexec_purgatory_get_set_symbol(image, "opal_entry", &val,
>>                                                       sizeof(val), false);
>>          }
>> -- 
>> 2.17.1
>>