Re: [Minios-devel] [PATCH 2/2] lib/ukalloc: Add assertion to page allocator compatibility wrapper

[Florian Schmidt <Florian.Schmidt@xxxxxxxxx>]

On 02/08/2018 04:42 PM, Simon Kuenzer wrote:
> uk_get_real_start() is used by the compatibility wrapper
> to figure out the address of meta information. This patch
> adds an assertion that checks that the meta information pointer
> will never be 0x0.
>
> Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
Reviewed-by: Florian Schmidt <florian.schmidt@xxxxxxxxx>

> ---
>   lib/ukalloc/alloc.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/lib/ukalloc/alloc.c b/lib/ukalloc/alloc.c
> index cf378d0..8a19421 100644
> --- a/lib/ukalloc/alloc.c
> +++ b/lib/ukalloc/alloc.c
> @@ -114,6 +114,12 @@ static void *uk_get_real_start(const void *ptr)
>   {
>         void *intptr;
>   
> +	/* a ptr less or equal to page size
> +        * would mean that the actual allocated
> +        * object started at 0x0, so it was NULL
> +        */
> +       UK_ASSERT((uintptr_t) ptr > __PAGE_SIZE);
> +
>         intptr = (void *) ALIGN_DOWN((uintptr_t) ptr,
>                                      (uintptr_t) __PAGE_SIZE);
>         if (intptr == ptr) {
--
Dr. Florian Schmidt
フローリアン・シュミット
Research Scientist,
Systems and Machine Learning Group
NEC Laboratories Europe
Kurfürsten-Anlage 36, D-69115 Heidelberg
Tel.     +49 (0)6221 4342-265
Fax:     +49 (0)6221 4342-155
e-mail:  florian.schmidt@xxxxxxxxx
============================================================
Registered at Amtsgericht Mannheim, Germany, HRB728558

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