This patch was picked up in Cosmic http://bugs.launchpad.net/bugs/1810820 via updates, and should be available in the latest bionic-hwe kernel. Could you please test with the bionic-hwe kernel to see if this is still an issue?
-- 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/1799388 Title: TM (Hardware Transactional Memory) instructions halt application on baremetal POWER9 DD2.1 Status in The Ubuntu-power-systems project: Incomplete Status in linux package in Ubuntu: Incomplete Status in linux source package in Bionic: Incomplete Status in linux source package in Cosmic: Incomplete Bug description: == Comment: #0 - Michael Ranweiler <mranw...@us.ibm.com> - 2018-10-15 08:55:55 == +++ This bug was initially created as a clone of Bug #167756 +++ ---Problem Description--- TM (Hardware Transactional Memory) instructions halt application on baremetal POWER9 DD2.1 Contact Information = grom...@br.ibm.com ---Additional Hardware Info--- POWER9 DD2.1 (pvr 004e 1201) baremetal. Witherspoon. Machine Type = POWER9 DD2.1 (pvr 004e 1201) baremetal ---Debugger--- A debugger is not configured ---Steps to Reproduce--- Currently TM (Hardware Transactional Memory) on baremetal POWER9 DD2.1 (pvr 004e 1201) with the latest firmware [1] (Firmware level [2] was also tested with the same result) and running Linux from Linus' upstream tree [3] or powerpc/next branch [4] is not working as expected. Once a TM instruction is executed in a process (any instruction), the process halts completely and has to be killed. A simple test case is to execute a 'tend.' which accordingly to POWER8 behaviour and the ISA v3.00 if executed "in Non-transactional state is treated as a no-op." [5]. It means that the instruction in the test case below should be treated simply as a 'nop' instruction and the process would terminate normally but instead it halts and the process never terminates: root@io83:~/gromero# cat t.c int main() { asm ("tend.;"); } root@io83:~/gromero# make t make: 't' is up to date. root@io83:~/gromero# ./t ^C <CTRL-C was pressed to kill the process since PC got stuck at 'tend.' instruction forever> Ubuntu stock kernel 4.15.0-20-generic was also tested with the same result. I confirmed with Erich Hauptli (FW team) that FW stack levels [1] contain all the TM fixes we have at the moment. Thus, that issue affects any application that uses TM on a baremetal POWER9 DD2.1 (pvr 004e 1201). [1] IBM-witherspoon-ibm-OP9_v1.19_1.160 op-build-v1.21.2-255-g6ad1636-dirty buildroot-2017.11-5-g65679be skiboot-v5.10.5-op910-1 hostboot-ed53939 linux-4.14.24-openpower1-paed97e8 petitboot-v1.6.6-p41a158a machine-xml-22224af occ-ef5d466 hostboot-binaries-6a92b6d capp-ucode-p9-dd2-v3 sbe-7e02c23 [2] open-power-witherspoon-v1.22-82-gebe1295-dirty buildroot-2018.02.1-6-ga8d11267c2 skiboot-v6.0-rc1 hostboot-d9bf361-p6755b85 occ-f741c41 linux-4.16.7-openpower1-p945838d petitboot-v1.7.1-pd695626 machine-xml-7cd20a6 hostboot-binaries-53aece6 capp-ucode-p9-dd2-v4 sbe-8e0105e hcode-hw050318a.op920 [3] https://github.com/torvalds/linux.git (master) [4] https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git (next) [5] Power ISA - Book II, p. 894 Stack trace output: no Oops output: no Userspace tool common name: any tool using TM instruction set Userspace rpm: not relevant The userspace tool has the following bit modes: 64-bit System Dump Info: The system is not configured to capture a system dump. Userspace tool obtained from project website: na *Additional Instructions for grom...@br.ibm.com: -Attach sysctl -a output output to the bug. -Attach ltrace and strace of userspace application. The following patch fixes this issue: http://patchwork.ozlabs.org/patch/968375/ Author: Michael Neuling <mi...@neuling.org> Date: Tue Sep 11 13:07:56 2018 +1000 powerpc/tm: Fix HFSCR bit for no suspend case Currently on P9N DD2.1 we end up taking infinite TM facility unavailable exceptions on the first TM usage by userspace. In the special case of TM no suspend (P9N DD2.1), Linux is told TM is off via CPU dt-ftrs but told to (partially) use it via OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED. So HFSCR[TM] will be off from dt-ftrs but we need to turn it on for the no suspend case. This patch fixes this by enabling HFSCR TM in this case. Cc: sta...@vger.kernel.org # 4.15+ Signed-off-by: Michael Neuling <mi...@neuling.org> == Comment: #2 - Michael Ranweiler <mranw...@us.ibm.com> - 2018-10-15 13:52:13 == This is in the powerpc -next branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=dd9a8c5a87395b6f05552c3b44e42fdc95760552 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1799388/+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
