Re: [patch] mfd: snprintf() returns largish values

[Feng Tang]

On Thu, 12 Aug 2010 15:50:09 +0800
Dan Carpenter <error27@xxxxxxxxx> wrote:

> snprintf() returns the number of bytes which would have been written
> so it can be larger than the size of the buffer.  In this case it's
> fine, but people copy and paste this code so I've fixed it.
> 
> Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> 
> diff --git a/drivers/serial/mfd.c b/drivers/serial/mfd.c
> index bc9af50..5aa25e5 100644
> --- a/drivers/serial/mfd.c
> +++ b/drivers/serial/mfd.c
> @@ -171,6 +171,9 @@ static ssize_t port_show_regs(struct file *file,
> char __user *user_buf, len += snprintf(buf + len, HSU_REGS_BUFSIZE -
> len, "DIV: \t\t0x%08x\n", serial_in(up, UART_DIV));
>  
> +	if (len > HSU_REGS_BUFSIZE)
> +		len = HSU_REGS_BUFSIZE;
> +
>  	ret =  simple_read_from_buffer(user_buf, count, ppos, buf,
> len); kfree(buf);
>  	return ret;
> @@ -218,6 +221,9 @@ static ssize_t dma_show_regs(struct file *file,
> char __user *user_buf, len += snprintf(buf + len, HSU_REGS_BUFSIZE -
> len, "D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3TSR));
>  
> +	if (len > HSU_REGS_BUFSIZE)
> +		len = HSU_REGS_BUFSIZE;
> +
>  	ret =  simple_read_from_buffer(user_buf, count, ppos, buf,
> len); kfree(buf);
>  	return ret;

Hi Carpenter,

It looks ok to me, thanks,

- Feng
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