From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Tadeusz Struk <tadeusz.struk@intel.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Mauro Carvalho Chehab <m.chehab@samsung.com>,
Helge Deller <deller@gmx.de>,
Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Joe Perches <joe@perches.com>, Marek Vasut <marex@denx.de>
Subject: Re: [PATCH v3 1/5] seq_file: provide an analogue of print_hex_dump()
Date: Mon, 1 Sep 2014 11:25:49 +0200 [thread overview]
Message-ID: <CAMuHMdXUsK9Uwd8EVqiWW8rDsUe=h7U8bGntx=bfWYQ5j91x+A@mail.gmail.com> (raw)
In-Reply-To: <1409562596.30155.43.camel@linux.intel.com>
Hi Andy,
On Mon, Sep 1, 2014 at 11:09 AM, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> On Mon, 2014-09-01 at 10:58 +0200, Geert Uytterhoeven wrote:
>> On Mon, Sep 1, 2014 at 10:36 AM, Andy Shevchenko
>> <andriy.shevchenko@linux.intel.com> wrote:
>> >> ... and extra copying for no good reason. Why not check that we have
>> >> enough space in buffer and generate directly into it? See what e.g.
>> >> seq_escape() is doing...
>> >
>> > What about this variant?
>>
>> I think it needs a call to seq_set_overflow() in case the buffer is too small,
>> so the caller will retry with a bigger buffer.
>
> Yes, in two places it would be useful to do.
Two places? I see only one, just before calling hex_dump_to_buffer.
> But what the condition for "buffer is too small", the same groupsize * 2
> + 1 or you mean something else?
"groupsize * 2 + 1" is not the amount of bytes hex_dump_to_buffer() wants
to write. It's only the size for one word.
You could check if there are at least "32 * 3 + 2 + 32 + 1" bytes (your
old linebuf size) available.
However, to protect against overflows if hex_dump_to_buffer() ever changes,
I think it would be better to let hex_dump_to_buffer() indicate if the
passed buffer was to small (it already checks the passed linebuflen).
Then you can just check for that.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2014-09-01 9:25 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-25 9:03 [PATCH v3 0/5] fs/seq_file: introduce seq_hex_dump() helper Andy Shevchenko
2014-08-25 9:03 ` [PATCH v3 1/5] seq_file: provide an analogue of print_hex_dump() Andy Shevchenko
2014-08-30 22:54 ` Al Viro
2014-09-01 8:36 ` Andy Shevchenko
2014-09-01 8:58 ` Geert Uytterhoeven
2014-09-01 9:09 ` Andy Shevchenko
2014-09-01 9:25 ` Geert Uytterhoeven [this message]
2014-09-01 10:15 ` Andy Shevchenko
2014-09-01 10:59 ` Geert Uytterhoeven
2014-09-01 11:33 ` Andy Shevchenko
2014-09-01 11:49 ` Geert Uytterhoeven
2014-09-01 11:53 ` Andy Shevchenko
2014-08-25 9:03 ` [PATCH v3 2/5] saa7164: convert to seq_hex_dump() Andy Shevchenko
2014-08-25 9:03 ` [PATCH v3 3/5] crypto: qat - use seq_hex_dump() to dump buffers Andy Shevchenko
2014-08-25 9:03 ` [PATCH v3 4/5] parisc: " Andy Shevchenko
2014-08-26 19:36 ` Helge Deller
2014-08-25 9:03 ` [PATCH v3 5/5] [S390] zcrypt: " Andy Shevchenko
2014-08-27 13:26 ` Ingo Tuchscherer
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