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Date: Wed, 14 Jun 2023 12:53:04 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc: vburru@marvell.com, aayarekar@marvell.com, davem@davemloft.net,
 edumazet@google.com, pabeni@redhat.com, sburla@marvell.com,
 netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] octeon_ep: Add missing check for ioremap
Message-ID: <20230614125304.294dd2ef@kernel.org>
In-Reply-To: <20230614032347.32940-1-jiasheng@iscas.ac.cn>
References: <20230614032347.32940-1-jiasheng@iscas.ac.cn>
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On Wed, 14 Jun 2023 11:23:47 +0800 Jiasheng Jiang wrote:
> @@ -981,6 +981,9 @@ int octep_device_setup(struct octep_device *oct)
>  		oct->mmio[i].hw_addr =
>  			ioremap(pci_resource_start(oct->pdev, i * 2),
>  				pci_resource_len(oct->pdev, i * 2));
> +		if (!oct->mmio[i].hw_addr)
> +			goto unsupported_dev;
> +
>  		oct->mmio[i].mapped = 1;
>  	}
>  
> @@ -1015,8 +1018,8 @@ int octep_device_setup(struct octep_device *oct)
>  	return 0;
>  
>  unsupported_dev:
> -	for (i = 0; i < OCTEP_MMIO_REGIONS; i++)
> -		iounmap(oct->mmio[i].hw_addr);
> +	for (j = 0; j < i; j++)
> +		iounmap(oct->mmio[j].hw_addr);

Assuming @i is not changed by the rest of the function is a bit fragile.

Better way of handling this situation is:

unsupported_dev:
	i = OCTEP_MMIO_REGIONS;
unmap_prev:
	while (i--)
		iounmap(oct->mmio[i].hw_addr);

and jump to unmap_prev
-- 
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