kselftest/arm64: Log the PIDs of the parent and child in sve-ptrace

If the test triggers a problem it may well result in a log message from
the kernel such as a WARN() or BUG(). If these include a PID it can help
with debugging to know if it was the parent or child process that triggered
the issue, since the test is just creating a new thread the process name
will be the same either way. Print the PIDs of the parent and child on
startup so users have this information to hand should it be needed.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220303192817.2732509-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace.c b/tools/testing/selftests/arm64/fp/sve-ptrace.c
index 4bd333768cc45284d8c9e410a71842bca6c3cffb..4c418b2021e02ebb8e1c5792c65d607d95f51d6f 100644 (file)
--- a/tools/testing/selftests/arm64/fp/sve-ptrace.c
+++ b/tools/testing/selftests/arm64/fp/sve-ptrace.c
@@ -487,6 +487,8 @@ static int do_parent(pid_t child)
        unsigned int vq, vl;
        bool vl_supported;
 
+       ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);
+
        /* Attach to the child */
        while (1) {
                int sig;