[PULL 20/28] riscv_hart: Fix riscv_harts_realize() error API violations

[Markus Armbruster <armbru@redhat.com>]

The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.

riscv_harts_realize() is wrong that way: it passes @errp to
riscv_hart_realize() in a loop.  I can't tell offhand whether this can
fail.

Fix by checking for failure in each iteration.

Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: qemu-riscv@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20200630090351.1247703-19-armbru@redhat.com>
---
 hw/riscv/riscv_hart.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/hw/riscv/riscv_hart.c b/hw/riscv/riscv_hart.c
index e26c382259..f59fe52f0f 100644
--- a/hw/riscv/riscv_hart.c
+++ b/hw/riscv/riscv_hart.c
@@ -40,19 +40,13 @@ static void riscv_harts_cpu_reset(void *opaque)
     cpu_reset(CPU(cpu));
 }
 
-static void riscv_hart_realize(RISCVHartArrayState *s, int idx,
+static bool riscv_hart_realize(RISCVHartArrayState *s, int idx,
                                char *cpu_type, Error **errp)
 {
-    Error *err = NULL;
-
     object_initialize_child(OBJECT(s), "harts[*]", &s->harts[idx], cpu_type);
     s->harts[idx].env.mhartid = s->hartid_base + idx;
     qemu_register_reset(riscv_harts_cpu_reset, &s->harts[idx]);
-    qdev_realize(DEVICE(&s->harts[idx]), NULL, &err);
-    if (err) {
-        error_propagate(errp, err);
-        return;
-    }
+    return qdev_realize(DEVICE(&s->harts[idx]), NULL, errp);
 }
 
 static void riscv_harts_realize(DeviceState *dev, Error **errp)
@@ -63,7 +57,9 @@ static void riscv_harts_realize(DeviceState *dev, Error **errp)
     s->harts = g_new0(RISCVCPU, s->num_harts);
 
     for (n = 0; n < s->num_harts; n++) {
-        riscv_hart_realize(s, n, s->cpu_type, errp);
+        if (!riscv_hart_realize(s, n, s->cpu_type, errp)) {
+            return;
+        }
     }
 }
 
-- 
2.26.2