Call Traces seen when running hugemmap test suite

[Anasuya M Shankar]

Description
============

When running the hugetlb test cases specific to hugemmap, Call traces as below are observed.

Unable to handle kernel paging request for data at address 0x00058206
Faulting instruction address: 0xc00000000046ebe8
Oops: Kernel access of bad area, sig: 11 [#2]
SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: dm_crypt
CPU: 0 PID: 996 Comm: rm Tainted: G D W 3.13.0-0-generic #10+ppc64el-Ubuntu
task: c00000027913c3a0 ti: c000000279248000 task.ti: c000000279248000
NIP: c00000000046ebe8 LR: c00000000042108c CTR: c00000000046ebe0
REGS: c00000027924b920 TRAP: 0300 Tainted: G D W (3.13.0-0-generic)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 22000482 XER: 20000000
CFAR: 00003fff928f16d4 DAR: 0000000000058206 DSISR: 40000000 SOFTE: 1
GPR00: c0000000001e34a8 c00000027924bba0 c000000001045c80 c00000027917b1a0
GPR04: c00000027db89e40 0000000000000001 c000000000e9e528 000000000002bab0
GPR08: 000000000073b000 c00000027db8b010 00000000000581b6 c00000027db89e40
GPR12: 0000000082000488 c00000000fe80000 0000000000000000 0000000000000000
GPR16: 0000000000000002 0000000000000000 0000000000000002 000000001000d770
GPR20: 000000001000d4c0 000000001000d740 000000001000d7b0 000000001000d7e8
GPR24: 00000100361a905c 000000001000d720 000000001000d668 c00000027924bdb0
GPR28: 00000100361b26b8 0000000000000004 c00000027924bdb0 c00000027924bd00
NIP [c00000000046ebe8] .apparmor_inode_getattr+0x8/0x70
LR [c00000000042108c] .security_inode_getattr+0x3c/0x60
Call Trace:
[c00000027924bba0] [c00000027924bc40] 0xc00000027924bc40 (unreliable)
[c00000027924bc10] [c0000000001e34a8] .vfs_getattr+0x28/0x70
[c00000027924bc90] [c0000000001e360c] .vfs_fstatat+0x8c/0x130
[c00000027924bd40] [c0000000001e3c64] .SyS_newfstatat+0x24/0x50
[c00000027924be30] [c000000000009e58] syscall_exit+0x0/0x98
Instruction dump:
60000000 60420000 7c691b78 7c852378 38600005 7d244b78 4bffff10 60000000
60000000 60420000 e9240030 e9490028 <e94a0050> 79480025 41820010 38600000
---[ end trace 8633e311dec7685f ]---

Segmentation fault

Easily recreatable.

./runltp -f hugetlb
cat hugetlb
hugemmap01 hugemmap01

Environment:
============

Host: Power8
Guest : ubuntu hosted on Power8

Command line to spawn the ubuntu guest:
qemu-system-ppc64 -enable-kvm -M pseries -cpu POWER8 -smp 1 -m 10G -nographic -nodefaults -monitor stdio -serial pty -append "root=/dev/sda" -kernel trusty-server-cloudimg-ppc64el-vmlinuz-generic -device spapr-vscsi -device spapr-vlan,netdev=net0,mac=6c:ae:8b:69:16:11 -netdev bridge,br=virbr0,id=net0 -drive file=trusty-server-cloudimg-ppc64el.img.qcow2

[Robie Basak (racb)]

Marking as Confirmed to stop the linux bug bot, since we have the details to reproduce based on the qemu image.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.13 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.13-rc7-trusty/

[Joseph Salisbury (jsalisbury)]

Actually I see that the arch is ppc64el, so a pre-built kernel is not available at the links I posted. Do you have a way to build the 3.13-rc7 kernel to see if it also exhibits the bug?

[Andy Whitcroft (apw)]

The Ubuntu-3.13.0-0.15 kernel has been copied into the bootstrap archive and should be available for update. This kernel is based on the v3.13-rc7 kernel. If we could retest with that kernel that would help. Please report any testing here.

[Andy Whitcroft (apw)]

There is now a full 3.13-rc8 based kernel in the archive (3.13.0-2.17) could we confirm this issue there please.

[Anasuya M Shankar (anasuyams)]

Tested the same Test Case on the latest available Kernel.

Performed to following :
====================
In the ubuntu_guest:
----------------------------
root@ubuntu:/boot# uname -a
Linux ubuntu 3.13.0-3-generic #18-Ubuntu SMP Mon Jan 13 18:49:22 UTC 2014 ppc64le ppc64le ppc64le GNU/Linux
root@ubuntu:/boot#

Copied the latest Kernel to the Host
scp /boot/vmlinux-3.13.0-3-generic root@9.3.189.114

Spawned the VM using the latest vmlinux as:
qemu-system-ppc64 -enable-kvm -M pseries -cpu POWER8 -smp 1 -m 10G -nographic -nodefaults -monitor stdio -serial pty -append "root=/dev/sda" -kernel vmlinux-3.13.0-3-generic -device spapr-vscsi -device spapr-vlan,netdev=net0,mac=6c:ae:8b:69:16:22 -netdev bridge,br=virbr0,id=net0 -drive file=ubuntu_new.qcow2 -mem-path /hugetlbfs

Logged into the ubuntu guest and ran the hugemmap Test Cases in LTP.

I DO NOT SEE the call traces happening.