Since the leafloop test program was moved into the main Perf binary as a
workload, it inherited the same compiler options as Perf. In this case
the -fstack-protector option broke the assumption that simple leaf
frames don't have a stack frame on Arm. This causes
test_arm_callgraph_fp.sh to pass even if the stack isn't augmented with
the link register, making the test useless.
Fix it by rewriting the leaf function in assembly seeing as it's so
simple. Adding -fno-stack-protector would also work, but wouldn't be
robust against other future compiler option additions.
The local variables and 'a' variable were never needed so remove them to
simplify.
Reviewed-by: Ian Rogers <[email protected]>
Assisted-by: GitHub-Copilot:GPT-5.5
Signed-off-by: James Clark <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
The 2 second sleep can cause the test to fail on very slow network file
systems because Perf ends up being killed before it finishes starting
up.
Fix it by making the leafloop workload end after a fixed time like the
other workloads so there is no need to kill it after 2 seconds.
Also remove the 1 second start sampling delay because it is similarly
fragile. Instead, search through all samples for a matching one, rather
than just checking the first sample and hoping it's in the right place.
Fixes: cd6382d827 ("perf test arm64: Test unwinding using fame-pointer (fp) mode")
Signed-off-by: James Clark <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: German Gomez <[email protected]>
Cc: Spoorthy S <[email protected]>
Cc: Kajol Jain <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
James Clark