hw/misc/aspeed_hace: Do not crash if address_space_map() failed

address_space_map() can fail:

  uart:~$ hash test
  sha256_test
  tv[0]:
  Segmentation fault: 11
  Thread 3 "qemu-system-arm" received signal SIGSEGV, Segmentation fault.
  gen_acc_mode_iov (req_len=0x7ffff18b7778, id=<optimized out>, iov=0x7ffff18b7780, s=0x555556ce0bd0)
      at ../hw/misc/aspeed_hace.c:171
  171         if (has_padding(s, &iov[id], *req_len, &total_msg_len, &pad_offset)) {
  (gdb) bt
  #0  gen_acc_mode_iov (req_len=0x7ffff18b7778, id=<optimized out>, iov=0x7ffff18b7780, s=0x555556ce0bd0)
      at ../hw/misc/aspeed_hace.c:171
  #1  do_hash_operation (s=s@entry=0x555556ce0bd0, algo=3, sg_mode=sg_mode@entry=true, acc_mode=acc_mode@entry=true)
      at ../hw/misc/aspeed_hace.c:224
  espressif#2  0x00005555559bdbb8 in aspeed_hace_write (opaque=<optimized out>, addr=12, data=262488, size=<optimized out>)
      at ../hw/misc/aspeed_hace.c:358

This change doesn't fix much, but at least the guest
can't crash QEMU anymore. Instead it is still usable:

  uart:~$ hash test
  sha256_test
  tv[0]:hash_final error
  sha384_test
  tv[0]:hash_final error
  sha512_test
  tv[0]:hash_final error
  [00:00:06.278,000] <err> hace_global: HACE poll timeout
  [00:00:09.324,000] <err> hace_global: HACE poll timeout
  [00:00:12.261,000] <err> hace_global: HACE poll timeout
  uart:~$

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Peter Delevoryas <[email protected]>
Reviewed-by: Cédric Le Goater <[email protected]>
Signed-off-by: Cédric Le Goater <[email protected]>

Author: philmd

hw/misc/aspeed_hace.c

@@ -193,6 +193,7 @@ static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
     size_t digest_len = 0;
     int niov = 0;
     int i;
+    void *haddr;
 
     if (sg_mode) {
         uint32_t len = 0;
@@ -217,9 +218,13 @@ static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
             addr &= SG_LIST_ADDR_MASK;
 
             plen = len & SG_LIST_LEN_MASK;
-            iov[i].iov_base = address_space_map(&s->dram_as, addr, &plen, false,
-                                                MEMTXATTRS_UNSPECIFIED);
-
+            haddr = address_space_map(&s->dram_as, addr, &plen, false,
+                                      MEMTXATTRS_UNSPECIFIED);
+            if (haddr == NULL) {
+                qemu_log_mask(LOG_GUEST_ERROR, "%s: qcrypto failed\n", __func__);
+                return;
+            }
+            iov[i].iov_base = haddr;
             if (acc_mode) {
                 niov = gen_acc_mode_iov(s, iov, i, &plen);
 
@@ -230,10 +235,14 @@ static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
     } else {
         hwaddr len = s->regs[R_HASH_SRC_LEN];
 
+        haddr = address_space_map(&s->dram_as, s->regs[R_HASH_SRC],
+                                  &len, false, MEMTXATTRS_UNSPECIFIED);
+        if (haddr == NULL) {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s: qcrypto failed\n", __func__);
+            return;
+        }
+        iov[0].iov_base = haddr;
         iov[0].iov_len = len;
-        iov[0].iov_base = address_space_map(&s->dram_as, s->regs[R_HASH_SRC],
-                                            &len, false,
-                                            MEMTXATTRS_UNSPECIFIED);
         i = 1;
 
         if (s->iov_count) {