Re: [Qemu-devel] [PATCH] hostmem: Fix qemu_opt_get_bool() crash in host_memory_backend_init()

[Igor Mammedov]

On Thu, 16 Jul 2015 17:39:17 -0300
Eduardo Habkost <address@hidden> wrote:

> This fixes the following crash, introduced by commit
> 49d2e648e8087d154d8bf8b91f27c8e05e79d5a6:
> 
>   $ gdb --args qemu-system-x86_64 -machine pc,mem-merge=off -object
> memory-backend-ram,id=ram-node0,size=1024 [...]
>   Program received signal SIGABRT, Aborted.
>   (gdb) bt
>   #0  0x00007ffff253b8c7 in raise () at /lib64/libc.so.6
>   #1  0x00007ffff253d52a in abort () at /lib64/libc.so.6
>   #2  0x00007ffff253446d in __assert_fail_base () at /lib64/libc.so.6
>   #3  0x00007ffff2534522 in  () at /lib64/libc.so.6
>   #4  0x00005555558bb80a in qemu_opt_get_bool_helper
> (opts=0x55555621b650, address@hidden "mem-merge",
> address@hidden, address@hidden) at
> qemu/util/qemu-option.c:388 #5  0x00005555558bbb5a in
> qemu_opt_get_bool (opts=<optimized out>,
> address@hidden "mem-merge", address@hidden)
> at qemu/util/qemu-option.c:398 #6  0x0000555555720a24 in
> host_memory_backend_init (obj=0x5555562ac970) at
> qemu/backends/hostmem.c:226
> 
> Instead of using qemu_opt_get_bool(), that didn't work with
> qemu_machine_opts for a long time, we can use the machine QOM
> properties directly.
> 
> Signed-off-by: Eduardo Habkost <address@hidden>
> ---
>  backends/hostmem.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index 61c1ac0..38a32ed 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -10,6 +10,7 @@
>   * See the COPYING file in the top-level directory.
>   */
>  #include "sysemu/hostmem.h"
> +#include "hw/boards.h"
>  #include "qapi/visitor.h"
>  #include "qapi-types.h"
>  #include "qapi-visit.h"
> @@ -223,10 +224,10 @@ static void host_memory_backend_init(Object
> *obj) {
>      HostMemoryBackend *backend = MEMORY_BACKEND(obj);
>  
> -    backend->merge = qemu_opt_get_bool(qemu_get_machine_opts(),
> -                                       "mem-merge", true);
> -    backend->dump = qemu_opt_get_bool(qemu_get_machine_opts(),
> -                                      "dump-guest-core", true);
> +    backend->merge =
> object_property_get_bool(OBJECT(current_machine),
maybe use qdev_get_machine() instead of OBJECT(current_machine)


> +                                              "mem-merge",
> &error_abort);
> +    backend->dump = object_property_get_bool(OBJECT(current_machine),
> +                                            "dump-guest-core",
> &error_abort); backend->prealloc = mem_prealloc;
>  
>      object_property_add_bool(obj, "merge",