linux-kernel - Re: [PATCH SPEAKUP v2 1/3] return same error value from spk_set_key

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Date:   Tue, 28 Feb 2017 10:04:44 +0100
From:   Samuel Thibault <samuel.thibault@...-lyon.org>
To:     "Pranay Kr. Srivastava" <pranjas@...il.com>
Cc:     w.d.hubbs@...il.com, chris@...-brannons.com, kirk@...sers.ca,
        gregkh@...uxfoundation.org, sfr@...b.auug.org.au,
        speakup@...ux-speakup.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH SPEAKUP v2 1/3] return same error value from
 spk_set_key_info

Pranay Kr. Srivastava, on mar. 28 févr. 2017 13:57:53 +0530, wrote:
> This patch makes spk_set_key_info return -EINVAL
> in case of failure instead of returning 4 different
> values for the type of error that occurred.
> 
> Print the offending values instead as debug message.
> 
> Signed-off-by: Pranay Kr. Srivastava <pranjas@...il.com>

Reviewed-by: Samuel Thibault <samuel.thibault@...-lyon.org>

> ---
>  drivers/staging/speakup/main.c | 27 +++++++++++++++++++--------
>  1 file changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/speakup/main.c b/drivers/staging/speakup/main.c
> index c2f70ef..a1d5b66 100644
> --- a/drivers/staging/speakup/main.c
> +++ b/drivers/staging/speakup/main.c
> @@ -1216,13 +1216,19 @@ int spk_set_key_info(const u_char *key_info, u_char *k_buffer)
>  	u_char ch, version, num_keys;
>  
>  	version = *cp++;
> -	if (version != KEY_MAP_VER)
> -		return -1;
> +	if (version != KEY_MAP_VER) {
> +		pr_debug("version found %d should be %d\n",
> +			 version, KEY_MAP_VER);
> +		return -EINVAL;
> +	}
>  	num_keys = *cp;
>  	states = (int)cp[1];
>  	key_data_len = (states + 1) * (num_keys + 1);
> -	if (key_data_len + SHIFT_TBL_SIZE + 4 >= sizeof(spk_key_buf))
> -		return -2;
> +	if (key_data_len + SHIFT_TBL_SIZE + 4 >= sizeof(spk_key_buf)) {
> +		pr_debug("too many key_infos (%d over %u)\n",
> +			 key_data_len + SHIFT_TBL_SIZE + 4, (unsigned int)(sizeof(spk_key_buf)));
> +		return -EINVAL;
> +	}
>  	memset(k_buffer, 0, SHIFT_TBL_SIZE);
>  	memset(spk_our_keys, 0, sizeof(spk_our_keys));
>  	spk_shift_table = k_buffer;
> @@ -1233,14 +1239,19 @@ int spk_set_key_info(const u_char *key_info, u_char *k_buffer)
>  	cp1 += 2;		/* now pointing at shift states */
>  	for (i = 1; i <= states; i++) {
>  		ch = *cp1++;
> -		if (ch >= SHIFT_TBL_SIZE)
> -			return -3;
> +		if (ch >= SHIFT_TBL_SIZE) {
> +			pr_debug("(%d) not valid shift state (max_allowed = %d)\n", ch,
> +				 SHIFT_TBL_SIZE);
> +			return -EINVAL;
> +		}
>  		spk_shift_table[ch] = i;
>  	}
>  	keymap_flags = *cp1++;
>  	while ((ch = *cp1)) {
> -		if (ch >= MAX_KEY)
> -			return -4;
> +		if (ch >= MAX_KEY) {
> +			pr_debug("(%d), not valid key, (max_allowed = %d)\n", ch, MAX_KEY);
> +			return -EINVAL;
> +		}
>  		spk_our_keys[ch] = cp1;
>  		cp1 += states + 1;
>  	}
> -- 
> 2.10.2
> 

-- 
Samuel
Progress (n.): The process through which the Internet has evolved from
smart people in front of dumb terminals to dumb people in front of smart
terminals.