[PULL 19/28] riscv/sifive_u: Fix sifive_u_soc_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.

sifive_u_soc_realize() is wrong that way: it passes &err to
sysbus_realize() four times before checking it.  Harmless, because the
first three can't actually fail (I think).

Fix by checking for failure right away.

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: <20200630090351.1247703-18-armbru@redhat.com>
---
 hw/riscv/sifive_u.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index 7d051e7c92..a1d2edfe13 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -677,11 +677,15 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
         memmap[SIFIVE_U_CLINT].size, ms->smp.cpus,
         SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE, false);
 
-    sysbus_realize(SYS_BUS_DEVICE(&s->prci), &err);
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->prci), errp)) {
+        return;
+    }
     sysbus_mmio_map(SYS_BUS_DEVICE(&s->prci), 0, memmap[SIFIVE_U_PRCI].base);
 
     qdev_prop_set_uint32(DEVICE(&s->gpio), "ngpio", 16);
-    sysbus_realize(SYS_BUS_DEVICE(&s->gpio), &err);
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->gpio), errp)) {
+        return;
+    }
     sysbus_mmio_map(SYS_BUS_DEVICE(&s->gpio), 0, memmap[SIFIVE_U_GPIO].base);
 
     /* Pass all GPIOs to the SOC layer so they are available to the board */
@@ -695,7 +699,9 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
     }
 
     qdev_prop_set_uint32(DEVICE(&s->otp), "serial", s->serial);
-    sysbus_realize(SYS_BUS_DEVICE(&s->otp), &err);
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->otp), errp)) {
+        return;
+    }
     sysbus_mmio_map(SYS_BUS_DEVICE(&s->otp), 0, memmap[SIFIVE_U_OTP].base);
 
     if (nd->used) {
-- 
2.26.2