Re: [PATCH] ARM: imx: Check return value of devm_kasprintf in imx_mmdc_perf_init

[Kunwu Chan]

Hi,Ahmad

Thank you for your guidance to me
It's my bad, i will update a v2 patch follow your suggestions, and send 
it in a new thread.

v2 changes:
1、use the first commit 'e76bdfd7403a' in the 'Fixes' tag.
2、Add new tag 'pmu_release_id' to release the id allocated in 
'mmdc_pmu_init', move 'ida_simple_remove(&mmdc_ida, pmu_mmdc->id);' into 
'pmu_release_id'.

the v2 patch look like:

+       if (!name) {
+               ret = -ENOMEM;
+               goto pmu_release_id;
+       }

        pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
        pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data 
*)of_id->data;
@@ -523,9 +527,10 @@ static int imx_mmdc_perf_init(struct 
platform_device *pdev, void __iomem *mmdc_b

 pmu_register_err:
        pr_warn("MMDC Perf PMU failed (%d), disabled\n", ret);
-       ida_simple_remove(&mmdc_ida, pmu_mmdc->id);
        cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, 
&pmu_mmdc->node);
        hrtimer_cancel(&pmu_mmdc->hrtimer);
+pmu_release_id:
+       ida_simple_remove(&mmdc_ida, pmu_mmdc->id);
 pmu_free:


Thanks,
Kunwu

On 2023/11/21 17:37, Ahmad Fatoum wrote:
> Hello Kunwu,
>
> On 21.11.23 10:25, Kunwu Chan wrote:
> > devm_kasprintf() returns a pointer to dynamically allocated memory
> > which can be NULL upon failure. Ensure the allocation was successful
> > by checking the pointer validity.
> >
> > Fixes: ebeb49f43c89 ("ARM: imx: Call ida_simple_remove() for ida_simple_get")
>
> This commit only moves the allocation around, but it didn't introduce it.
> Please reference the first commit that added the allocation.
>
> > Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
> > ---
> >   arch/arm/mach-imx/mmdc.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
> > index 2157493b78a9..7c471d6a851d 100644
> > --- a/arch/arm/mach-imx/mmdc.c
> > +++ b/arch/arm/mach-imx/mmdc.c
> > @@ -501,6 +501,10 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b
> >   
> >   	name = devm_kasprintf(&pdev->dev,
> >   				GFP_KERNEL, "mmdc%d", ret);
> > +	if (!name) {
> > +		ret = -ENOMEM;
> > +		goto pmu_free;
>
> Cleanup is incomplete if you goto pmu_free, e.g. ida_simple_remove()
> isn't called. pmu_register_err does too much cleanup, so you'll need
> to add a new cleanup label.
>
> Cheers,
> Ahmad
>
>
> > +	}
> >   
> >   	pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
> >   	pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data *)of_id->data;