On Thu, 21 Sep 2017 08:18:04 +0200, Baolin Wang wrote:
The struct snd_pcm_status will use 'timespec' type variables to record timestamp, which is not year 2038 safe on 32bits system.
Userspace will use SNDRV_PCM_IOCTL_STATUS and SNDRV_PCM_IOCTL_STATUS_EXT as commands to issue ioctl() to fill the 'snd_pcm_status' structure in userspace. The command number is always defined through _IOR/_IOW/IORW, so when userspace changes the definition of 'struct timespec' to use 64-bit types, the command number also changes.
Thus in the kernel, we now need to define two versions of each such ioctl and corresponding ioctl commands to handle 32bit time_t and 64bit time_t in native mode: struct snd_pcm_status32 { ...... struct { s32 tv_sec; s32 tv_nsec; } trigger_tstamp; struct { s32 tv_sec; s32 tv_nsec; } tstamp; ...... }
struct snd_pcm_status64 { ...... struct { s64 tv_sec; s64 tv_nsec; } trigger_tstamp; struct { s64 tv_sec; s64 tv_nsec; } tstamp; ...... }
I'm confused. It's different from timespec64? So 32bit user-space would need to use a new own-type timespec instead of the standard timespec that is compliant with y2038?
thanks,
Takashi