Hello Michal, On 20 December 2017 at 10:20, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > On Tue 19-12-17 17:45:40, Michael Kerrisk wrote: >> But, is >> there a pressing reason to make the change? (Okay, I guess iterating >> using *_STAT is nicer than parsing /proc/sysvipc/*.) > > The reporter of this issue claims that "Reading /proc/sysvipc/shm is way > slower than executing the system call." I haven't checked that but I can > imagine that /proc/sysvipc/shm can take quite some time when there are > _many_ segments registered. Yes, that makes sense. > So they would like to use the syscall but > the interacting parties do not have compatible permissions. So, I don't think there is any security issue, since the same info is available in /proc/sysvipc/*. The only question would be whether change in the *_STAT behavior might surprise some applications into behaving differently. I presume the chances of that are low, but if it was a concert, one could add new shmctl/msgctl/semctl *_STAT_ALL (or some such) operations that have the desired behavior. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
