From: Chen Gang <gang.chen@asianux•com>
To: Jiri Slaby <jslaby@suse•cz>
Cc: Greg KH <gregkh@linuxfoundation•org>,
tklauser@distanz•ch, wfp5p@virginia•edu,
linuxppc-dev@lists•ozlabs.org, alan@linux•intel.com
Subject: Re: [PATCH] drivers/tty/hvc: using strlcpy instead of strncpy
Date: Thu, 28 Feb 2013 19:15:44 +0800 [thread overview]
Message-ID: <512F3C60.9070409@asianux.com> (raw)
In-Reply-To: <512F3BC5.8020903@asianux.com>
于 2013年02月28日 19:13, Chen Gang 写道:
> 于 2013年02月28日 18:41, Jiri Slaby 写道:
>> On 02/26/2013 04:43 AM, Chen Gang wrote:
>>>>
>>>> when strlen pi->location_code is larger than HVCS_CLC_LENGTH + 1,
>>>> original implementation can not let hvcsd->p_location_code NUL terminated.
>>>> so need fix it (also can simplify the code)
>> It should never be larger because the +1 is exactly for NUL. But it is a
>> cleanup, so why not...
>>
>
> when strlen(&pi->location_code[0]) == HVCS_CLC_LENGTH + 2
> then clclength will be reset to HVCS_CLC_LENGTH.
>
> when call strncpy, the clclength + 1 == HVCS_CLS_LENGTH + 1
> but the '\0' of src buf is located at HVCS_CLS_LENGTH + 2.
but the '\0' of src buf is located at HVCS_CLS_LENGTH + 3. (not + 2)
> so no '\0' copied to dest buf.
>
> then the dest buf will not be ended by '\0'.
>
> is it correct ?
>
> :-)
>
> gchen.
>
>>>> Signed-off-by: Chen Gang <gang.chen@asianux•com>
>>>> ---
>>>> drivers/tty/hvc/hvcs.c | 9 ++-------
>>>> 1 files changed, 2 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
>>>> index 1956593..81e939e 100644
>>>> --- a/drivers/tty/hvc/hvcs.c
>>>> +++ b/drivers/tty/hvc/hvcs.c
>>>> @@ -881,17 +881,12 @@ static struct vio_driver hvcs_vio_driver = {
>>>> /* Only called from hvcs_get_pi please */
>>>> static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd)
>>>> {
>>>> - int clclength;
>>>> -
>>>> hvcsd->p_unit_address = pi->unit_address;
>>>> hvcsd->p_partition_ID = pi->partition_ID;
>>>> - clclength = strlen(&pi->location_code[0]);
>>>> - if (clclength > HVCS_CLC_LENGTH)
>>>> - clclength = HVCS_CLC_LENGTH;
>>>>
>>>> /* copy the null-term char too */
>>>> - strncpy(&hvcsd->p_location_code[0],
>>>> - &pi->location_code[0], clclength + 1);
>>>> + strlcpy(&hvcsd->p_location_code[0],
>>>> + &pi->location_code[0], sizeof(hvcsd->p_location_code));
>>>> }
>>>>
>>>> /*
>>>>
>
>
--
Chen Gang
Asianux Corporation
next prev parent reply other threads:[~2013-02-28 11:16 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-26 3:43 [PATCH] drivers/tty/hvc: using strlcpy instead of strncpy Chen Gang
2013-02-28 10:41 ` Jiri Slaby
2013-02-28 11:13 ` Chen Gang
2013-02-28 11:15 ` Chen Gang [this message]
2013-02-28 13:47 ` Jiri Slaby
2013-03-05 1:58 ` Chen Gang
2013-03-05 9:36 ` Jiri Slaby
2013-03-07 4:10 ` Chen Gang
2013-03-07 4:34 ` Chen Gang
2013-03-07 6:05 ` Benjamin Herrenschmidt
2013-03-07 7:10 ` Chen Gang
2013-03-08 3:38 ` [PATCH] drivers/tty/hvc: fixup original commit: 9276dfd27897a0b29d8b5814f39a1f82f56b6b6b Chen Gang
2013-03-08 3:46 ` Benjamin Herrenschmidt
2013-03-08 4:23 ` Chen Gang
2013-03-08 4:33 ` Benjamin Herrenschmidt
2013-03-08 4:40 ` Chen Gang
2013-03-08 5:08 ` Benjamin Herrenschmidt
2013-03-08 6:12 ` Chen Gang
2013-03-08 11:11 ` David Laight
2013-03-10 1:18 ` Chen Gang
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