From: Chen Gang <gang.chen@asianux.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-serial@vger.kernel.org
Subject: Re: [Suggestion] drivers/tty: drivers/char/: for MAX_ASYNC_BUFFER_SIZE
Date: Thu, 29 Nov 2012 13:57:59 +0800 [thread overview]
Message-ID: <50B6F967.3050000@asianux.com> (raw)
In-Reply-To: <20121129051335.GA4375@kroah.com>
于 2012年11月29日 13:13, Greg KH 写道:
> On Thu, Nov 29, 2012 at 12:40:49PM +0800, Chen Gang wrote:
>> Hello Greg Kroah-Hartman:
>>
>> for MAX_ASYNC_BUFFER_SIZE:
>> it is defined as 4096;
>> but for the max buffer size which it processes, is 65535.
>> so suggest to #define MAX_ASYNC_BUFFER_SIZE 0x10000 (better than 0xffff)
>
> Please, send tty questions to the linux-serial@vger.kernel.org list
> also.
I cc to linux-serial@vger.kernel.org, in this reply.
I referenced the file MAINTAINERS, before sent original mail:
it seems all drivers/tty/serial/* are relative with
linux-serial@vger.kernel.org. but our case is not relative
drivers/tty/serial. so for not bother them, I am not send to them,
originally.
in MAINTAINERS, line 7438, I find for common of driver/tty/*, can send
to you and no cc, so I send you and cc to linux-kernel@vger.kernel.org.
next time, for all tty questions, I will cc to
linux-serial@vger.kernel.org (not cc to linux-kernel@vger.kernel.org).
>
> And, I really don't understand here, why do you want to change this?
> What is it going to change? And why?
>
Why:
for the context MGSLPC_INFO *info in drivers/char/pcmcia/synclink_cs.c
info->max_frame_size can be the value between 4096 .. 65535 (can be
set by its module input parameter)
info->flag_buf length is 4096 (MAX_ASYNC_BUFFER_SIZE)
in function rx_get_frame
the framesize is limit by info->max_frame_size, but may still be
larger that 4096.
when call function ldisc_receive_buf, info->flag_buf is equal to
4096, but framesize can be more than 4096. it will cause memory over flow.
What:
#define MAX_ASYNC_BUFFER_SIZE 0x10000 (instead of 4096, originally).
let it match the max frame size.
At last:
my suggestion may be incorrect, need relative member (who expert about
it) to help checking.
welcome another suggestion or completions.
thanks.
gchen.
> greg k-h
> --
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>
--
Chen Gang
Asianux Corporation
next prev parent reply other threads:[~2012-11-29 5:57 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <50B6E751.9000000@asianux.com>
2012-11-29 5:07 ` [Suggestion] drivers/tty: drivers/char/: for MAX_ASYNC_BUFFER_SIZE Chen Gang
2012-11-29 13:41 ` Alan Cox
2012-11-30 2:27 ` Chen Gang
2012-11-30 3:39 ` Chen Gang
2012-11-29 5:13 ` 【Suggestion】drivers/tty: " Greg KH
2012-11-29 5:57 ` Chen Gang [this message]
2012-11-29 6:14 ` [PATCH] MAINTAINERS: TTY - Add linux-serial mailing list Joe Perches
2012-11-29 6:27 ` Chen Gang
2012-11-29 8:23 ` Jiri Slaby
2012-11-29 18:32 ` [Suggestion] drivers/tty: drivers/char/: for MAX_ASYNC_BUFFER_SIZE Greg KH
2012-11-30 2:52 ` Chen Gang
[not found] ` <C7D3911F-7B6B-4353-A84B-0218FAB27198@microgate.com>
2012-11-30 6:28 ` Chen Gang
2012-11-30 7:14 ` Chen Gang
2012-11-30 16:24 ` Paul Fulghum
2012-11-30 19:46 ` [PATCH] synclink fix ldisc buffer argument Paul Fulghum
2012-12-02 15:13 ` Alan Cox
[not found] ` <F6B8A325-7DBF-4623-B16C-CDC5642EFD16@microgate.com>
2012-12-02 18:10 ` Alan Cox
[not found] ` <989CB961-79F8-479B-B16C-41358A60AC94@microgate.com>
2012-12-03 2:20 ` Chen Gang
2012-12-03 16:03 ` Paul Fulghum
2012-12-05 1:57 ` Chen Gang
2012-12-19 2:23 ` Chen Gang
2012-12-19 4:09 ` Greg KH
2012-12-19 4:10 ` Chen Gang
2012-12-20 4:16 ` [PATCH] drivers/tty/synclink: let receive buffer size match max frame size Chen Gang
2012-12-03 17:13 ` [PATCH] synclink fix ldisc buffer argument Paul Fulghum
2012-12-05 1:35 ` Chen Gang
2012-12-07 2:15 ` Chen Gang
2012-12-10 1:32 ` [Consult]: " Chen Gang
2012-12-01 9:01 ` [Suggestion] drivers/tty: drivers/char/: for MAX_ASYNC_BUFFER_SIZE Chen Gang
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