[Qemu-devel] [PATCH v2 03/26] armv7m: Explicit error for bad vector table

[Michael Davidsaver <mdavidsaver@gmail.com>]

Give an explicit error and abort when a load
from VECBASE fails.  Otherwise would likely
jump to 0, which for v7-m holds the reset stack
pointer address.
---
 target-arm/helper.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 2c631e3..7b76f32 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -5414,6 +5414,25 @@ static void do_v7m_exception_exit(CPUARMState *env)
        pointer.  */
 }
 
+static
+uint32_t arm_v7m_load_vector(ARMCPU *cpu)
+
+{
+    CPUState *cs = &cpu->parent_obj;
+    CPUARMState *env = &cpu->env;
+    MemTxResult result;
+    hwaddr vec = env->v7m.vecbase + env->v7m.exception * 4;
+    uint32_t addr;
+
+    addr = address_space_ldl(cs->as, vec,
+                             MEMTXATTRS_UNSPECIFIED, &result);
+    if (result != MEMTX_OK) {
+        cpu_abort(cs, "Failed to read from exception vector table "
+                  "entry %08x\n", (unsigned)vec);
+    }
+    return addr;
+}
+
 void arm_v7m_cpu_do_interrupt(CPUState *cs)
 {
     ARMCPU *cpu = ARM_CPU(cs);
@@ -5495,7 +5514,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs)
     /* Clear IT bits */
     env->condexec_bits = 0;
     env->regs[14] = lr;
-    addr = ldl_phys(cs->as, env->v7m.vecbase + env->v7m.exception * 4);
+    addr = arm_v7m_load_vector(cpu);
     env->regs[15] = addr & 0xfffffffe;
     env->thumb = addr & 1;
 }
-- 
2.1.4