Message-ID: <e2735a3a-4a9b-8b3a-0671-b3f56187cbe2@quicinc.com>
Date:   Tue, 31 Jan 2023 10:06:22 +0800
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Subject: Re: [PATCH v5] trace: acquire buffer from temparary trace sequence
To:     Steven Rostedt <rostedt@goodmis.org>
CC:     Masami Hiramatsu <mhiramat@kernel.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-trace-kernel@vger.kernel.org>
References: <1675065249-23368-1-git-send-email-quic_linyyuan@quicinc.com>
 <28cd9aca-1945-ceed-2756-162132d576ef@quicinc.com>
 <20230130143041.713c4c7b@gandalf.local.home>
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From:   Linyu Yuan <quic_linyyuan@quicinc.com>
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On 1/31/2023 3:30 AM, Steven Rostedt wrote:
> On Mon, 30 Jan 2023 21:14:01 +0800
> Linyu Yuan <quic_linyyuan@quicinc.com> wrote:
>
>> @Steven current design is not safe, as user still can write to buffer
>> which have no enough space.
> I'm assuming that it would never use more that DWC3_MSG_MAX, and that's set
> to 500. The size of the trace_seq() is 4096 (or PAGE_SIZE), I doubt it will
> ever be an issue.
>
> How do you think the user can still write more than enough?


yes, agree it will be safe for dwc3, but i don't know if any possible 
hacker,

as the function always return a valid pointer even when hacker input a 
large size.


>
> -- Steve
>
>> do you think it is better to improve dwc3 trace in fast assign path ?
>>
>