ubuntu_ftrace_smoke_test failed on T-ARM64 due to no FUNCTION_TRACER support

[Po-Hsu Lin]

The ubuntu_ftrace_smoke_test is failing on Trusty ARM64.

It looks like it will need the following configs for get it work:
CONFIG_FUNCTION_TRACER=y
CONFIG_FUNCTION_GRAPH_TRACER=y
CONFIG_STACK_TRACER=y
CONFIG_DYNAMIC_FTRACE=y

ftrace is useful for debugging. We should enable it.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-167-generic 3.13.0-167.217
ProcVersionSignature: User Name 3.13.0-167.217-generic 3.13.11-ckt39
Uname: Linux 3.13.0-167-generic aarch64
AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access /dev/snd/: No such file or directory
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.14.1-0ubuntu3.29
Architecture: arm64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
CRDA: Error: [Errno 2] No such file or directory: 'iw'
CurrentDmesg:

Date: Wed Mar 20 10:14:53 2019
IwConfig:
 lo no wireless extensions.

 enp1s0 no wireless extensions.

 enp1s0d1 no wireless extensions.
Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize libusb: -99
PciMultimedia:

ProcFB:

ProcKernelCmdLine: console=ttyS0,9600n8r ro
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-167-generic N/A
 linux-backports-modules-3.13.0-167-generic N/A
 linux-firmware 1.127.24
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Po-Hsu Lin (cypressyew)]

It looks like ARM64 in Trusty does not have the Function Tracer support:

phlin@tangerine:~/ubuntu-trusty$ git grep "ifdef CONFIG_FUNCTION_TRACER"
Makefile:ifdef CONFIG_FUNCTION_TRACER
arch/arm/include/asm/ftrace.h:#ifdef CONFIG_FUNCTION_TRACER
arch/arm/kernel/Makefile:ifdef CONFIG_FUNCTION_TRACER
arch/arm/kernel/armksyms.c:#ifdef CONFIG_FUNCTION_TRACER
arch/arm/kernel/entry-common.S:#ifdef CONFIG_FUNCTION_TRACER
arch/blackfin/kernel/bfin_ksyms.c:#ifdef CONFIG_FUNCTION_TRACER
arch/ia64/include/asm/ftrace.h:#ifdef CONFIG_FUNCTION_TRACER
arch/ia64/kernel/entry.S:#ifdef CONFIG_FUNCTION_TRACER
arch/ia64/kernel/ia64_ksyms.c:#ifdef CONFIG_FUNCTION_TRACER
arch/metag/include/asm/ftrace.h:#ifdef CONFIG_FUNCTION_TRACER
...

phlin@tangerine:~/ubuntu-trusty/arch/arm64$ grep -r HAVE_FUNCTION_TRACER *
phlin@tangerine:~/ubuntu-trusty/arch/arm64$

I will just disable the test for Trusty ARM64.

[Po-Hsu Lin (cypressyew)]

The ARM64 ftrace support was added in upstream commit 819e50e2 (arm64: Add ftrace support)

A quick cherry-pick attempt shows that this will need some backport work in arch/arm64/Kconfig file. (Not sure if there will be more commits to pull)

[Po-Hsu Lin (cypressyew)]

Test disabled for T-ARM64
https://kernel.ubuntu.com/git/ubuntu/autotest-client-tests.git/commit/?id=d7e11e51c0bb04ca2fb124a051fc5031a70959d5

We can re-enable it if we decided to pull the function tracer support to the Trusty ARM64 kernel.