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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/testing/selftests/powerpc/security/rfi_flush.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/powerpc/security/rfi_flush.c')
-rw-r--r--tools/testing/selftests/powerpc/security/rfi_flush.c142
1 files changed, 142 insertions, 0 deletions
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 000000000..f73484a64
--- /dev/null
+++ b/tools/testing/selftests/powerpc/security/rfi_flush.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2018 IBM Corporation.
+ */
+
+#define __SANE_USERSPACE_TYPES__
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <malloc.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include "utils.h"
+#include "flush_utils.h"
+
+
+int rfi_flush_test(void)
+{
+ char *p;
+ int repetitions = 10;
+ int fd, passes = 0, iter, rc = 0;
+ struct perf_event_read v;
+ __u64 l1d_misses_total = 0;
+ unsigned long iterations = 100000, zero_size = 24 * 1024;
+ unsigned long l1d_misses_expected;
+ int rfi_flush_orig, rfi_flush;
+ int have_entry_flush, entry_flush_orig;
+
+ SKIP_IF(geteuid() != 0);
+
+ // The PMU event we use only works on Power7 or later
+ SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
+
+ if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
+ perror("Unable to read powerpc/rfi_flush debugfs file");
+ SKIP_IF(1);
+ }
+
+ if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
+ have_entry_flush = 0;
+ } else {
+ have_entry_flush = 1;
+
+ if (entry_flush_orig != 0) {
+ if (write_debugfs_file("powerpc/entry_flush", 0) < 0) {
+ perror("error writing to powerpc/entry_flush debugfs file");
+ return 1;
+ }
+ }
+ }
+
+ rfi_flush = rfi_flush_orig;
+
+ fd = perf_event_open_counter(PERF_TYPE_HW_CACHE, PERF_L1D_READ_MISS_CONFIG, -1);
+ FAIL_IF(fd < 0);
+
+ p = (char *)memalign(zero_size, CACHELINE_SIZE);
+
+ FAIL_IF(perf_event_enable(fd));
+
+ // disable L1 prefetching
+ set_dscr(1);
+
+ iter = repetitions;
+
+ /*
+ * We expect to see l1d miss for each cacheline access when rfi_flush
+ * is set. Allow a small variation on this.
+ */
+ l1d_misses_expected = iterations * (zero_size / CACHELINE_SIZE - 2);
+
+again:
+ FAIL_IF(perf_event_reset(fd));
+
+ syscall_loop(p, iterations, zero_size);
+
+ FAIL_IF(read(fd, &v, sizeof(v)) != sizeof(v));
+
+ if (rfi_flush && v.l1d_misses >= l1d_misses_expected)
+ passes++;
+ else if (!rfi_flush && v.l1d_misses < (l1d_misses_expected / 2))
+ passes++;
+
+ l1d_misses_total += v.l1d_misses;
+
+ while (--iter)
+ goto again;
+
+ if (passes < repetitions) {
+ printf("FAIL (L1D misses with rfi_flush=%d: %llu %c %lu) [%d/%d failures]\n",
+ rfi_flush, l1d_misses_total, rfi_flush ? '<' : '>',
+ rfi_flush ? repetitions * l1d_misses_expected :
+ repetitions * l1d_misses_expected / 2,
+ repetitions - passes, repetitions);
+ rc = 1;
+ } else
+ printf("PASS (L1D misses with rfi_flush=%d: %llu %c %lu) [%d/%d pass]\n",
+ rfi_flush, l1d_misses_total, rfi_flush ? '>' : '<',
+ rfi_flush ? repetitions * l1d_misses_expected :
+ repetitions * l1d_misses_expected / 2,
+ passes, repetitions);
+
+ if (rfi_flush == rfi_flush_orig) {
+ rfi_flush = !rfi_flush_orig;
+ if (write_debugfs_file("powerpc/rfi_flush", rfi_flush) < 0) {
+ perror("error writing to powerpc/rfi_flush debugfs file");
+ return 1;
+ }
+ iter = repetitions;
+ l1d_misses_total = 0;
+ passes = 0;
+ goto again;
+ }
+
+ perf_event_disable(fd);
+ close(fd);
+
+ set_dscr(0);
+
+ if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
+ perror("unable to restore original value of powerpc/rfi_flush debugfs file");
+ return 1;
+ }
+
+ if (have_entry_flush) {
+ if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
+ perror("unable to restore original value of powerpc/entry_flush "
+ "debugfs file");
+ return 1;
+ }
+ }
+
+ return rc;
+}
+
+int main(int argc, char *argv[])
+{
+ return test_harness(rfi_flush_test, "rfi_flush_test");
+}