Re: [Qemu-devel] [PATCH 1/3] s390: Fix empty kernel command line

[Alexander Graf]

On 11.12.2012, at 12:15, Christian Borntraeger wrote:

> On 11/12/12 11:34, Alexander Graf wrote:
>> 
>> On 07.12.2012, at 14:55, Jens Freimann wrote:
>> 
>>> From: Christian Borntraeger <address@hidden>
>>> 
>>> Since commit 967c0da73a7b0da186baba6632301d83644a570c
>>>   vl.c: Avoid segfault when started with no arguments
>>> 
>>> the user can specify a kernel without a command line. Lets not
>>> overwrite the default command line with \0 in that case.
>>> 
>>> Signed-off-by: Christian Borntraeger <address@hidden>
>>> Signed-off-by: Jens Freimann <address@hidden>
>>> ---
>>> hw/s390-virtio.c |    2 +-
>>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>> 
>>> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
>>> index ca1bb09..d77871a 100644
>>> --- a/hw/s390-virtio.c
>>> +++ b/hw/s390-virtio.c
>>> @@ -290,7 +290,7 @@ static void s390_init(QEMUMachineInitArgs *args)
>>>        stq_p(rom_ptr(INITRD_PARM_SIZE), initrd_size);
>>>    }
>>> 
>>> -    if (rom_ptr(KERN_PARM_AREA)) {
>>> +    if (rom_ptr(KERN_PARM_AREA) && strlen(kernel_cmdline)) {
>> 
>> why strlen()? If no -append option was passed, kernel_cmdline should be 
>> NULL. If -append "" was passed, the user wants to command line to be 
>> overwritten with "\0".
> 
> Nope. kernel_cmdline is always a valid pointer.
> 
> vl.c:
> 
> [..]
>    if (!kernel_cmdline) {
>        kernel_cmdline = "";
>    }

Then that's on purpose. Either we change the default for everyone or not at 
all. But checking for "" only in the s390 machine sounds off.


Alex