On a HiSilicon D05 system: ubuntu@ubuntu:~$ cat /proc/version Linux version 4.10.0-22-generic (buildd@bos01-arm64-038) (gcc version 6.3.0 20170406 (Ubuntu/Linaro 6.3.0-12ubuntu2) ) #24-Ubuntu SMP Mon May 22 17:43:39 UTC 2017 ubuntu@ubuntu:~$ ./test freq 50000000
** Tags removed: verification-needed-zesty ** Tags added: verification-done-zesty -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1688164 Title: arm64: Add CNTFRQ_EL0 handler Status in linux package in Ubuntu: Fix Committed Status in linux source package in Zesty: Fix Committed Bug description: [Impact] Userspace reads of CNTVCT_EL0 are broken on HiSilicon D05 systems, which breaks some applications such as OpenMPI. [Test Case] #include <sys/times.h> #include <stdio.h> int main(int argc, char *argv[]) { unsigned int freq; __asm__ __volatile__ ("mrs %0, CNTFRQ_EL0" : "=r" (freq)); printf("freq %d\n",freq); return (int)freq; } ================================== gcc test.c test ./test This will report an illegal instruction, but should print a frequency value. [Regression Risk] The best way we can minimize risk is to verify on both a system that has an errata handler for the timer (D05) and a system that doesn't. We should then be exercising both code paths. I have regression tested this, using the above test case, on the HP m400, the QDT Centriq 2400, and a Cavium ThunderX CRB. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1688164/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
