Re: [PATCH v2 2/2] selftests/powerpc: Add test to verify rfi flush across a system call

[Naveen N. Rao]

Michael Ellerman wrote:
"Naveen N. Rao" <naveen.n....@linux.vnet.ibm.com> writes:
diff --git a/tools/testing/selftests/powerpc/security/rfi_flush.c 
b/tools/testing/selftests/powerpc/security/rfi_flush.c
new file mode 100644
index 000000000000..a20fe8eca161
--- /dev/null
+++ b/tools/testing/selftests/powerpc/security/rfi_flush.c
@@ -0,0 +1,132 @@
...
+
+int rfi_flush_test(void)
+{
+       char *p;
+       int repetitions = 10;
+       int fd, passes = 0, iter, rc = 0;
+       struct perf_event_read v;
+       uint64_t l1d_misses_total = 0;
+       unsigned long iterations = 100000, zero_size = 24*1024;
+       int rfi_flush_org, rfi_flush;
+
+       SKIP_IF(geteuid() != 0);
+
+       if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_org)) {
+               perror("error reading powerpc/rfi_flush debugfs file");
+               printf("unable to determine current rfi_flush setting");
+               return 1;
+       }

This leads to a hard error on old kernels, which I don't want (breaks my CI).

Hmm... didn't realize new tests would be run on older kernels. Are those 
older stable/distro releases, or actually just earlier kernel versions?


So I changed it to:

        if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_org)) {
                perror("Unable to read powerpc/rfi_flush debugfs file");
                SKIP_IF(1);
        }

Sure, thanks!
- Naveen