On 4/28/20 2:19 AM, Luck, Tony wrote:
> On Thu, Apr 16, 2020 at 04:40:31PM +0800, He Zhe wrote:
>> Can this be considered for the moment?
>>
>> Thanks,
>> Zhe
>>
>> On 3/4/20 2:39 PM, zhe...@windriver.com wrote:
>>> From: He Zhe <zhe...@windriver.com>
>>>
>>> 32-bit user-space program would get errors like the following from ioctl
>>> syscall due to missing compat_ioctl.
>>> MCE_GET_RECORD_LEN: Inappropriate ioctl for device
>>>
>>> compat_ptr_ioctl is provided as a generic implementation of .compat_ioctl
>>> file operation to ioctl functions that either ignore the argument or pass
>>> a pointer to a compatible data type.
> I'm not super-familiar with the compat ioctl bits. But this looks plausible.
>
> All three of the ioctl's for this driver have a "pointer to integer" for the
> "return" value. And "int" is a compatible type between i386 and x86_64.
>
> I don't have a system setup to build a 32-bit binary to test the theory,
> but I assume that you have built something that tests all three:
>
> MCE_GET_RECORD_LEN
> MCE_GET_LOG_LEN
> MCE_GETCLEAR_FLAGS
>
> So I guess:
>
> Acked-by: Tony Luck <tony.l...@intel.com>
Thanks, and yes, I had tested all three.
Zhe
>
>>> Signed-off-by: He Zhe <zhe...@windriver.com>
>>> ---
>>> arch/x86/kernel/cpu/mce/dev-mcelog.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/arch/x86/kernel/cpu/mce/dev-mcelog.c
>>> b/arch/x86/kernel/cpu/mce/dev-mcelog.c
>>> index 7c8958d..6c9b91b7 100644
>>> --- a/arch/x86/kernel/cpu/mce/dev-mcelog.c
>>> +++ b/arch/x86/kernel/cpu/mce/dev-mcelog.c
>>> @@ -328,6 +328,7 @@ static const struct file_operations mce_chrdev_ops = {
>>> .write = mce_chrdev_write,
>>> .poll = mce_chrdev_poll,
>>> .unlocked_ioctl = mce_chrdev_ioctl,
>>> + .compat_ioctl = compat_ptr_ioctl,
>>> .llseek = no_llseek,
>>> };
>>>
