2 files changed, 34 insertions, 1 deletions
diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target
index b617f2ac7e..e7249915e7 100644
--- a/tests/tcg/aarch64/Makefile.target
+++ b/tests/tcg/aarch64/Makefile.target
@@ -19,7 +19,7 @@ run-fcvt: fcvt
 
 # Pauth Tests
 ifneq ($(DOCKER_IMAGE)$(CROSS_CC_HAS_ARMV8_3),)
-AARCH64_TESTS += pauth-1 pauth-2 pauth-4
+AARCH64_TESTS += pauth-1 pauth-2 pauth-4 pauth-5
 pauth-%: CFLAGS += -march=armv8.3-a
 run-pauth-%: QEMU_OPTS += -cpu max
 run-plugin-pauth-%: QEMU_OPTS += -cpu max
diff --git a/tests/tcg/aarch64/pauth-5.c b/tests/tcg/aarch64/pauth-5.c
new file mode 100644
index 0000000000..67c257918b
--- /dev/null
+++ b/tests/tcg/aarch64/pauth-5.c
@@ -0,0 +1,33 @@
+#include <assert.h>
+
+static int x;
+
+int main()
+{
+    int *p0 = &x, *p1, *p2, *p3;
+    unsigned long salt = 0;
+
+    /*
+     * With TBI enabled and a 48-bit VA, there are 7 bits of auth, and so
+     * a 1/128 chance of auth = pac(ptr,key,salt) producing zero.
+     * Find a salt that creates auth != 0.
+     */
+    do {
+        salt++;
+        asm("pacda %0, %1" : "=r"(p1) : "r"(salt), "0"(p0));
+    } while (p0 == p1);
+
+    /*
+     * This pac must fail, because the input pointer bears an encryption,
+     * and so is not properly extended within bits [55:47].  This will
+     * toggle bit 54 in the output...
+     */
+    asm("pacda %0, %1" : "=r"(p2) : "r"(salt), "0"(p1));
+
+    /* ... so that the aut must fail, setting bit 53 in the output ... */
+    asm("autda %0, %1" : "=r"(p3) : "r"(salt), "0"(p2));
+
+    /* ... which means this equality must not hold. */
+    assert(p3 != p0);
+    return 0;
+}