1 files changed, 13 insertions, 0 deletions
diff --git a/target/arm/machine.c b/target/arm/machine.c
index 81e30de824..c74d8c3f4b 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -781,6 +781,19 @@ static int cpu_post_load(void *opaque, int version_id)
     hw_breakpoint_update_all(cpu);
     hw_watchpoint_update_all(cpu);
 
+    /*
+     * TCG gen_update_fp_context() relies on the invariant that
+     * FPDSCR.LTPSIZE is constant 4 for M-profile with the LOB extension;
+     * forbid bogus incoming data with some other value.
+     */
+    if (arm_feature(env, ARM_FEATURE_M) && cpu_isar_feature(aa32_lob, cpu)) {
+        if (extract32(env->v7m.fpdscr[M_REG_NS],
+                      FPCR_LTPSIZE_SHIFT, FPCR_LTPSIZE_LENGTH) != 4 ||
+            extract32(env->v7m.fpdscr[M_REG_S],
+                      FPCR_LTPSIZE_SHIFT, FPCR_LTPSIZE_LENGTH) != 4) {
+            return -1;
+        }
+    }
     if (!kvm_enabled()) {
         pmu_op_finish(&cpu->env);
     }