Re: [Qemu-devel] [PATCH] hw/arm/realview.c: Fix memory leak in realview_init()

[Markus Armbruster]

Nikita Belov <address@hidden> writes:

> Variable 'ram_lo' is allocated unconditionally, but used only in some cases.
> When it is unused pointer will be lost at function exit, resulting in a
> memory leak. Free memory in this case.
>
> Valgrind output:
> ==16879== 240 bytes in 1 blocks are definitely lost in loss record 6,033 of 
> 7,018
> ==16879==    at 0x4C2AB80: malloc (in 
> /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
> ==16879==    by 0x33D2CE: malloc_and_trace (vl.c:2804)
> ==16879==    by 0x509E610: g_malloc (in 
> /lib/x86_64-linux-gnu/libglib-2.0.so.0.4000.0)
> ==16879==    by 0x288836: realview_init (realview.c:55)
> ==16879==    by 0x28988C: realview_pb_a8_init (realview.c:375)
> ==16879==    by 0x341426: main (vl.c:4413)
>
> Signed-off-by: Nikita Belov <address@hidden>
> ---
>  hw/arm/realview.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/hw/arm/realview.c b/hw/arm/realview.c
> index af65aa4..673a540 100644
> --- a/hw/arm/realview.c
> +++ b/hw/arm/realview.c
> @@ -141,6 +141,8 @@ static void realview_init(MachineState *machine,
>                                 &error_abort);
>          vmstate_register_ram_global(ram_lo);
>          memory_region_add_subregion(sysmem, 0x20000000, ram_lo);
> +    } else {
> +        g_free(ram_lo);
>      }
>
>      memory_region_init_ram(ram_hi, NULL, "realview.highmem", ram_size,
> --
> 1.9.0.msysgit.0

ram_log is allocate unconditionally, but used only conditionally.  Your
patch frees it when it's not used.  Allocating it only when it's used
would be simpler.