1 files changed, 172 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/dexcr/lsdexcr.c b/tools/testing/selftests/powerpc/dexcr/lsdexcr.c
new file mode 100644
index 000000000000..7588929180ab
--- /dev/null
+++ b/tools/testing/selftests/powerpc/dexcr/lsdexcr.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/prctl.h>
+
+#include "dexcr.h"
+#include "utils.h"
+
+static unsigned int dexcr;
+static unsigned int hdexcr;
+static unsigned int effective;
+
+static void print_list(const char *list[], size_t len)
+{
+	for (size_t i = 0; i < len; i++) {
+		printf("%s", list[i]);
+		if (i + 1 < len)
+			printf(", ");
+	}
+}
+
+static void print_dexcr(char *name, unsigned int bits)
+{
+	const char *enabled_aspects[ARRAY_SIZE(aspects) + 1] = {NULL};
+	size_t j = 0;
+
+	printf("%s: 0x%08x", name, bits);
+
+	if (bits == 0) {
+		printf("\n");
+		return;
+	}
+
+	for (size_t i = 0; i < ARRAY_SIZE(aspects); i++) {
+		unsigned int mask = DEXCR_PR_BIT(aspects[i].index);
+
+		if (bits & mask) {
+			enabled_aspects[j++] = aspects[i].name;
+			bits &= ~mask;
+		}
+	}
+
+	if (bits)
+		enabled_aspects[j++] = "unknown";
+
+	printf(" (");
+	print_list(enabled_aspects, j);
+	printf(")\n");
+}
+
+static void print_aspect(const struct dexcr_aspect *aspect)
+{
+	const char *attributes[8] = {NULL};
+	size_t j = 0;
+	unsigned long mask;
+
+	mask = DEXCR_PR_BIT(aspect->index);
+	if (dexcr & mask)
+		attributes[j++] = "set";
+	if (hdexcr & mask)
+		attributes[j++] = "set (hypervisor)";
+	if (!(effective & mask))
+		attributes[j++] = "clear";
+
+	printf("%12s %c (%d): ", aspect->name, effective & mask ? '*' : ' ', aspect->index);
+	print_list(attributes, j);
+	printf("  \t(%s)\n", aspect->desc);
+}
+
+static void print_aspect_config(const struct dexcr_aspect *aspect)
+{
+	const char *reason = NULL;
+	const char *reason_hyp = NULL;
+	const char *reason_prctl = "no prctl";
+	bool actual = effective & DEXCR_PR_BIT(aspect->index);
+	bool expected = actual;  /* Assume it's fine if we don't expect a specific set/clear value */
+
+	if (actual)
+		reason = "set by unknown";
+	else
+		reason = "cleared by unknown";
+
+	if (aspect->prctl != -1) {
+		int ctrl = pr_get_dexcr(aspect->prctl);
+
+		if (ctrl < 0) {
+			reason_prctl = "failed to read prctl";
+		} else {
+			if (ctrl & PR_PPC_DEXCR_CTRL_SET) {
+				reason_prctl = "set by prctl";
+				expected = true;
+			} else if (ctrl & PR_PPC_DEXCR_CTRL_CLEAR) {
+				reason_prctl = "cleared by prctl";
+				expected = false;
+			} else {
+				reason_prctl = "unknown prctl";
+			}
+
+			reason = reason_prctl;
+		}
+	}
+
+	if (hdexcr & DEXCR_PR_BIT(aspect->index)) {
+		reason_hyp = "set by hypervisor";
+		reason = reason_hyp;
+		expected = true;
+	} else {
+		reason_hyp = "not modified by hypervisor";
+	}
+
+	printf("%12s (%d): %-28s (%s, %s)\n",
+	       aspect->name,
+	       aspect->index,
+	       reason,
+	       reason_hyp,
+	       reason_prctl);
+
+	/*
+	 * The checks are not atomic, so this can technically trigger if the
+	 * hypervisor makes a change while we are checking each source. It's
+	 * far more likely to be a bug if we see this though.
+	 */
+	if (actual != expected)
+		printf("                : ! actual %s does not match config\n", aspect->name);
+}
+
+int main(int argc, char *argv[])
+{
+	if (!dexcr_exists()) {
+		printf("DEXCR not detected on this hardware\n");
+		return 1;
+	}
+
+	dexcr = get_dexcr(DEXCR);
+	hdexcr = get_dexcr(HDEXCR);
+	effective = dexcr | hdexcr;
+
+	printf("current status:\n");
+
+	print_dexcr("    DEXCR", dexcr);
+	print_dexcr("   HDEXCR", hdexcr);
+	print_dexcr("Effective", effective);
+	printf("\n");
+
+	for (size_t i = 0; i < ARRAY_SIZE(aspects); i++)
+		print_aspect(&aspects[i]);
+	printf("\n");
+
+	if (effective & DEXCR_PR_NPHIE) {
+		printf("DEXCR[NPHIE] enabled: hashst/hashchk ");
+		if (hashchk_triggers())
+			printf("working\n");
+		else
+			printf("failed to trigger\n");
+	} else {
+		printf("DEXCR[NPHIE] disabled: hashst/hashchk ");
+		if (hashchk_triggers())
+			printf("unexpectedly triggered\n");
+		else
+			printf("ignored\n");
+	}
+	printf("\n");
+
+	printf("configuration:\n");
+	for (size_t i = 0; i < ARRAY_SIZE(aspects); i++)
+		print_aspect_config(&aspects[i]);
+	printf("\n");
+
+	return 0;
+}