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 19:13:09 +0800 [thread overview]
Message-ID: <512F3BC5.8020903@asianux.com> (raw)
In-Reply-To: <512F343E.7010201@suse.cz>
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.
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 11:13 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 [this message]
2013-02-28 11:15 ` Chen Gang
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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