perf test: Skip failing 'perf test aslr' test case

The test case 'perf test aslr' fails on s390. The root cause of the
failure is subtest test_callchain_aslr. This test invokes command

 # ./perf record -g -e task-clock:u -o /tmp/perf-test-aslr \
	-- perf test -w noploop 3

to generate a call stack using event task-clock:u. On s390 this defaults
to '--call-graph dwarf' whereas on x86_64 this defaults to framepointer
(fp) format. The command

 # ./perf inject --aslr -i /tmp/perf-test-aslr

now scans all SAMPLE entries recorded in the perf.data file to convert
possible addresses. This is done in aslr_tool__process_sample() looking
at sample_type bits PERF_SAMPLE_IP, PERF_SAMPLE_TID,
PERF_SAMPLE_TIME, PERF_SAMPLE_PERIOD, PERF_SAMPLE_CALLCHAIN,
PERF_SAMPLE_REGS_USER and PERF_SAMPLE_STACK_USER.
On s390 the samples do not contain FP entries
of type PERF_SAMPLE_CALLCHAIN (the bit is set in sample_type, but the
number of FP entries is 0).
The processing enters the PERF_SAMPLE_STACK_USER portion where the
data is copied to the newly constructed sample and then aborted with
this warning:

 /* TODO: can this be less conservative? */
 pr_debug("Dropping stack user sample as possible ASLR leak\n");

With command line option '--call-graph dwarf' the new output file
does not contain any samples at all. This leads to a missing $new_addr
value in the shell script and a failure.

Fix this and skip this subtest. Emit a hint that this subtest is
currently unsupported on all platform when option --call-graph dwarf
is selected.
Since one subtest is skipped, the complete test is reported as
skipped.

Fixes: 190c45463844 ("perf test: Add inject ASLR test")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Suggested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

0 files changed, 0 insertions, 0 deletions