Re: [Qemu-devel] [PATCH] vl.c: Fix memory leak in qemu_register_machine

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Mar 17, 2014 at 10:53:25PM +0100, Christian Borntraeger wrote:
> since commit 261747f176f6 (vl: Use MachineClass instead of global
> QEMUMachine list) valgrind complains about the following:
> 
> ==54082== 57 bytes in 3 blocks are definitely lost in loss record 365 of 729
> ==54082==    at 0x4031AFE: malloc (vg_replace_malloc.c:292)
> ==54082==    by 0x4145569: g_malloc (in /usr/lib64/libglib-2.0.so.0.3400.2)
> ==54082==    by 0x415F9E9: g_strconcat (in /usr/lib64/libglib-2.0.so.0.3400.2)
> ==54082==    by 0x80157FE7: qemu_register_machine (vl.c:1597)
> ==54082==    by 0x80208E6B: module_call_init (module.c:105)
> ==54082==    by 0x80013B91: main (vl.c:3000)
> 
> Turns out that valgrind is right. We simply forget the memory that
> g_strconcat has allocated. Lets free it after the type_register.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  vl.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/vl.c b/vl.c
> index b363a21..97290c9 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1592,6 +1592,7 @@ int qemu_register_machine(QEMUMachine *m)
>      };
>  
>      type_register(&ti);
> +    g_free((void *) ti.name);
>  
>      return 0;
>  }

I think it's best to avoid casting away constness.
How about keeping a copy of name and freeing that?

> -- 
> 1.8.4.2