From: Huaisheng Ye <yehs1@xxxxxxxxxx> dcssblk_direct_access() needs to check the validity of second rank pointer kaddr for NULL assignment. If kaddr equals to NULL, it doesn't need to calculate the value. Signed-off-by: Huaisheng Ye <yehs1@xxxxxxxxxx> --- drivers/s390/block/dcssblk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 0a312e4..9c13dc5 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -915,7 +915,8 @@ static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show, unsigned long dev_sz; dev_sz = dev_info->end - dev_info->start + 1; - *kaddr = (void *) dev_info->start + offset; + if (kaddr) + *kaddr = (void *) dev_info->start + offset; *pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), PFN_DEV|PFN_SPECIAL); -- 1.8.3.1
