[PATCH] hw/misc/bcm2835_thermal: Handle invalid address accesses gracefully

[Zheyu Ma <zheyuma97@gmail.com>]

This commit handles invalid address accesses gracefully in both read and write
functions. Instead of asserting and aborting, it logs an error message and returns
a neutral value for read operations and does nothing for write operations.

Error log:
ERROR:hw/misc/bcm2835_thermal.c:55:bcm2835_thermal_read: code should not be reached
Bail out! ERROR:hw/misc/bcm2835_thermal.c:55:bcm2835_thermal_read: code should not be reached
Aborted

Reproducer:
cat << EOF | qemu-system-aarch64 -display \
none -machine accel=qtest, -m 512M -machine raspi3b -m 1G -qtest stdio
readw 0x3f212003
EOF

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
---
 hw/misc/bcm2835_thermal.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/hw/misc/bcm2835_thermal.c b/hw/misc/bcm2835_thermal.c
index ee7816b8a5..5c2a429d58 100644
--- a/hw/misc/bcm2835_thermal.c
+++ b/hw/misc/bcm2835_thermal.c
@@ -51,8 +51,10 @@ static uint64_t bcm2835_thermal_read(void *opaque, hwaddr addr, unsigned size)
         val = FIELD_DP32(bcm2835_thermal_temp2adc(25), STAT, VALID, true);
         break;
     default:
-        /* MemoryRegionOps are aligned, so this can not happen. */
-        g_assert_not_reached();
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "bcm2835_thermal_read: invalid address 0x%"
+                      HWADDR_PRIx "\n", addr);
+        val = 0;
     }
     return val;
 }
@@ -72,8 +74,10 @@ static void bcm2835_thermal_write(void *opaque, hwaddr addr,
                        __func__, value, addr);
         break;
     default:
-        /* MemoryRegionOps are aligned, so this can not happen. */
-        g_assert_not_reached();
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "bcm2835_thermal_write: invalid address 0x%"
+                      HWADDR_PRIx "\n", addr);
+        break;
     }
 }
 
-- 
2.34.1