[OpenBIOS] [PATCH 2/2] SPARC64: Remove limit on kernel command line length caused by using a static buffer

[Mark Cave-Ayland]

On 13/04/13 10:07, Blue Swirl wrote:

>> Instead use strdup() so that we can dynamically allocate the string ourselves. As
>
> Actually there's no call to strdup()...
>
>> reported by Rob Landley<rob at landley.net>.
>>
>> Signed-off-by: Mark Cave-Ayland<mark.cave-ayland at ilande.co.uk>
>> ---
>>   openbios-devel/arch/sparc64/openbios.c |   11 ++++-------
>>   1 file changed, 4 insertions(+), 7 deletions(-)
>>
>> diff --git a/openbios-devel/arch/sparc64/openbios.c b/openbios-devel/arch/sparc64/openbios.c
>> index 3b372b9..440e505 100644
>> --- a/openbios-devel/arch/sparc64/openbios.c
>> +++ b/openbios-devel/arch/sparc64/openbios.c
>> @@ -42,9 +42,6 @@
>>   #define NVRAM_OB_START   (0)
>>   #define NVRAM_OB_SIZE    ((0x1fd0 - NVRAM_OB_START)&  ~15)
>>
>> -#define OBIO_CMDLINE_MAX 256
>> -static char obio_cmdline[OBIO_CMDLINE_MAX];
>> -
>>   static uint8_t idprom[NVRAM_IDPROM_SIZE];
>>
>>   struct hwdef {
>> @@ -370,6 +367,7 @@ static uint8_t qemu_uuid[16];
>>
>>   void arch_nvram_get(char *data)
>>   {
>> +    char *obio_cmdline = { '\0' };
>
> Isn't this allocated in the stack? So ...
>
>>       uint32_t size = 0;
>>       const struct cpudef *cpu;
>>       char buf[256];
>> @@ -401,12 +399,11 @@ void arch_nvram_get(char *data)
>>           kernel_image = fw_cfg_read_i64(FW_CFG_KERNEL_ADDR);
>>
>>       size = fw_cfg_read_i32(FW_CFG_CMDLINE_SIZE);
>> -    if (size>  OBIO_CMDLINE_MAX - 1)
>> -        size = OBIO_CMDLINE_MAX - 1;
>>       if (size) {
>> +       obio_cmdline = (char *)malloc(size + 1);
>>           fw_cfg_read(FW_CFG_CMDLINE_DATA, obio_cmdline, size);
>> -    }
>> -    obio_cmdline[size] = '\0';
>> +       obio_cmdline[size] = '\0';
>> +    }
>
> ... I'd add an 'else' case here with something like obio_cmdline = strdup("").
>
>>       qemu_cmdline = (uint64_t)obio_cmdline;
>>       cmdline_size = size;
>>       boot_device = fw_cfg_read_i16(FW_CFG_BOOT_DEVICE);

Thanks for the feedback - I've just posted a revised v2 patch to the 
list based upon your comments.


ATB,

Mark.