APPLIED: [SRU Eoan] UBUNTU: SAUCE: kselftest: ftrace: check for existing probe

[Kelsey Skunberg]

Applied to Eoan/master-next. Thank you!

-Kelsey

On 2020-05-29 19:12:38 , Thadeu Lima de Souza Cascardo wrote:
> Buglink: https://bugs.launchpad.net/bugs/1866972
> 
> When testing multiple_kprobes.tc, it will try to add repeated probes. On
> 5.4, it will return EEXIST, and the test will keep adding probes until it
> gets to 256 probes. On 5.3, it will return success, but not add a new
> probe. The test will then fail expecting 256 probes, but less than that
> were really added.
> 
> Fixing the test to check for those existing probes before adding them is
> less prone to regressions. After that, the test will succeed, as it skips
> trying to add existing probes.
> 
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
> ---
>  tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc b/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc
> index 6e3dbe5f96b7..4b860bfc64be 100644
> --- a/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc
> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc
> @@ -16,6 +16,7 @@ N=0
>  echo "Setup up kprobes on first available 256 text symbols"
>  grep -i " t " /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* | \
>  while read i; do
> +  grep -qw ${i} kprobe_events && continue
>    echo p ${i}+${OFFS} >> kprobe_events && N=$((N+1)) ||:
>    test $N -eq 256 && break
>  done
> -- 
> 2.25.1
> 
> 
> -- 
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