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Message-ID: <91af4a8c-d2e2-416f-b02e-5d69553c5998@web.de>
Date: Fri, 19 Jan 2024 11:40:48 +0100
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Subject: Re: [PATCH v3] x86/xen: Add some null pointer checking to smp.c
Content-Language: en-GB
To: Kunwu Chan <chentao@kylinos.cn>, xen-devel@lists.xenproject.org,
 kernel-janitors@vger.kernel.org, Boris Ostrovsky
 <boris.ostrovsky@oracle.com>, Borislav Petkov <bp@alien8.de>,
 Dave Hansen <dave.hansen@linux.intel.com>, "H. Peter Anvin" <hpa@zytor.com>,
 Ingo Molnar <mingo@redhat.com>, =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?=
 <jgross@suse.com>, Thomas Gleixner <tglx@linutronix.de>, x86@kernel.org
Cc: kernel test robot <lkp@intel.com>, LKML <linux-kernel@vger.kernel.org>
References: <20240119094948.275390-1-chentao@kylinos.cn>
From: Markus Elfring <Markus.Elfring@web.de>
In-Reply-To: <20240119094948.275390-1-chentao@kylinos.cn>
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 HIfFig==

> kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure. Ensure the allocation was successful
> by checking the pointer validity.
=E2=80=A6
> ---
> Changes in v3:
>     - Remove rc initialization
>     - Simply error paths by adding a new label 'fail_mem'
=E2=80=A6

I became curious if you would like to simplify further source code places.


> +++ b/arch/x86/xen/smp.c
> @@ -65,6 +65,8 @@ int xen_smp_intr_init(unsigned int cpu)
>  	char *resched_name, *callfunc_name, *debug_name;
>
>  	resched_name =3D kasprintf(GFP_KERNEL, "resched%d", cpu);
> +	if (!resched_name)
> +		goto fail_mem;

Would you like to add a blank line after such a statement?


>  	per_cpu(xen_resched_irq, cpu).name =3D resched_name;
=E2=80=A6

Please compare with your subsequent suggestion.

=E2=80=A6
> @@ -101,6 +108,9 @@ int xen_smp_intr_init(unsigned int cpu)
>  	}
>
>  	callfunc_name =3D kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
> +	if (!callfunc_name)
> +		goto fail_mem;
> +
>  	per_cpu(xen_callfuncsingle_irq, cpu).name =3D callfunc_name;
=E2=80=A6

Regards,
Markus