On Sun, Jun 25, 2017 at 7:35 PM, Al Viro viro@zeniv.linux.org.uk wrote:
On Sat, Jun 24, 2017 at 11:45:01AM -0700, Deepa Dinamani wrote:
The series aims at isolating data conversions of time_t based structures: struct timespec and struct itimerspec at user space boundaries. This helps to later change the underlying types to handle y2038 changes to these.
Nice... A few questions:
- what about setitimer(2)? Right now that's the only remaining user of
get_compat_itimerval(); similar for getitimer(2) and put_compat_itimerval().
We do not plan to support these beyond y2038 on 32 bit systems. timer_settime() and timer_gettime() are considered to be replacements for these, respectively.
There is also going to be a cleanup of timeval/ timespec/ time_t data types and apis after the new syscalls are ready. At that time I might choose to get rid of these itimerval apis. I'm not sure yet.
- you have two callers of get_compat_itimerspec64(); one is followed by
itimerspec64_valid(), another - by its open-coded analogue. The same goes for get_itimerspec64(); wouldn't it be better to have both check the validity immediately and simply fail with -EINVAL? Matter of taste, but...
This is what I thought also. And, in fact this is how I had it in one of the earlier version of my series. But, the utimensat(2) is what I consider provides a counter example of why this is a bad idea. There is no reason you should not be able to read the itimerspec64 and not check for validity soon after. Meaning there can be special markers like UTIME_NOW and UTIME_OMIT in the nanosecond field which will make the validity check fail. But, is perfectly normal for the syscall under consideration.
- should __sys_recvmmsg() switch to timespec64?
Socket timestamps will be handled in a different series. These could be done a few ways like adding a new flag to recv syscall variants or defining new timestamp types. The above call will be changed at that time.
-Deepa