David Hildenbrand <da...@redhat.com> writes:
> On 22.11.21 12:29, Marc Hartmayer wrote:
>> In the past s390 used a fixed command line length of 896 bytes. This has
>> changed
>> with the Linux commit 5ecb2da660ab ("s390: support command lines longer than
>> 896
>> bytes"). There is now a parm area indicating the maximum command line size.
>> This
>> parm area has always been initialized to zero, so with older kernels this
>> field
>> would read zero and we must then assume that only 896 bytes are available.
>>
>> Acked-by: Viktor Mihajlovski <mihaj...@de.ibm.com>
>> Signed-off-by: Marc Hartmayer <mhart...@linux.ibm.com>
>> ---
>> hw/s390x/ipl.c | 23 ++++++++++++++++++++---
>> 1 file changed, 20 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
>> index 7ddca0127fc2..092c66b3f9f1 100644
>> --- a/hw/s390x/ipl.c
>> +++ b/hw/s390x/ipl.c
>> @@ -37,8 +37,9 @@
>>
>> #define KERN_IMAGE_START 0x010000UL
>> #define LINUX_MAGIC_ADDR 0x010008UL
>> +#define KERN_PARM_AREA_SIZE_ADDR 0x010430UL
>> #define KERN_PARM_AREA 0x010480UL
>> -#define KERN_PARM_AREA_SIZE 0x000380UL
>> +#define LEGACY_KERN_PARM_AREA_SIZE 0x000380UL
>> #define INITRD_START 0x800000UL
>> #define INITRD_PARM_START 0x010408UL
>> #define PARMFILE_START 0x001000UL
>> @@ -110,6 +111,21 @@ static uint64_t bios_translate_addr(void *opaque,
>> uint64_t srcaddr)
>> return srcaddr + dstaddr;
>> }
>>
>> +static uint64_t get_max_kernel_cmdline_size(void)
>> +{
>> + uint64_t *size_ptr = rom_ptr(KERN_PARM_AREA_SIZE_ADDR,
>> sizeof(*size_ptr));
>> +
>> + if (size_ptr) {
>> + uint64_t size;
>> +
>> + size = be64_to_cpu(*size_ptr);
>> + if (size != 0) {
>
> Could do "if (size) {"
Ok.
>
>> + return size;
>> + }
>> + }
>> + return LEGACY_KERN_PARM_AREA_SIZE;
>> +}
>> +
>> static void s390_ipl_realize(DeviceState *dev, Error **errp)
>> {
>> MachineState *ms = MACHINE(qdev_get_machine());
>> @@ -197,10 +213,11 @@ static void s390_ipl_realize(DeviceState *dev, Error
>> **errp)
>> ipl->start_addr = KERN_IMAGE_START;
>> /* Overwrite parameters in the kernel image, which are "rom" */
>> if (parm_area) {
>> - if (cmdline_size > KERN_PARM_AREA_SIZE) {
>> + uint64_t max_cmdline_size = get_max_kernel_cmdline_size();
>
> We might want an empty line here.
Yep.
>
>> + if (cmdline_size > max_cmdline_size) {
>> error_setg(errp,
>> "kernel command line exceeds maximum size:
>> %zu > %lu",
>> - cmdline_size, KERN_PARM_AREA_SIZE);
>> + cmdline_size, max_cmdline_size);
>> return;
>> }
>>
>>
>
> Reviewed-by: David Hildenbrand <da...@redhat.com>
Thanks for the review!
>
> --
> Thanks,
>
> David / dhildenb
>
--
Kind regards / Beste Grüße
Marc Hartmayer
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Gregor Pillen
Geschäftsführung: Dirk Wittkopp
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