From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752935AbaIAJKZ (ORCPT ); Mon, 1 Sep 2014 05:10:25 -0400 Received: from mga01.intel.com ([192.55.52.88]:38858 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752734AbaIAJKY (ORCPT ); Mon, 1 Sep 2014 05:10:24 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,441,1406617200"; d="scan'208";a="584483916" Message-ID: <1409562596.30155.43.camel@linux.intel.com> Subject: Re: [PATCH v3 1/5] seq_file: provide an analogue of print_hex_dump() From: Andy Shevchenko To: Geert Uytterhoeven Cc: Al Viro , Tadeusz Struk , Herbert Xu , Mauro Carvalho Chehab , Helge Deller , Ingo Tuchscherer , "linux-kernel@vger.kernel.org" , Joe Perches , Marek Vasut Date: Mon, 01 Sep 2014 12:09:56 +0300 In-Reply-To: References: <1408957395-404-1-git-send-email-andriy.shevchenko@linux.intel.com> <1408957395-404-2-git-send-email-andriy.shevchenko@linux.intel.com> <20140830225407.GF7996@ZenIV.linux.org.uk> <1409560606.30155.41.camel@linux.intel.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.5-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-09-01 at 10:58 +0200, Geert Uytterhoeven wrote: > Hi Andy, > > On Mon, Sep 1, 2014 at 10:36 AM, Andy Shevchenko > 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. But what the condition for "buffer is too small", the same groupsize * 2 + 1 or you mean something else? > > > > > @@ -794,6 +795,47 @@ void seq_pad(struct seq_file *m, char c) > > } > > EXPORT_SYMBOL(seq_pad); > > > > +/* Analogue of print_hex_dump() */ > > +void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, > > + int rowsize, int groupsize, const void *buf, size_t len, > > + bool ascii) > > +{ > > + const u8 *ptr = buf; > > + int i, linelen, remaining = len; > > + int ret; > > + > > + if (rowsize != 16 && rowsize != 32) > > + rowsize = 16; > > + > > + for (i = 0; i < len; i += rowsize) { > > + linelen = min(remaining, rowsize); > > + remaining -= rowsize; > > + > > + ret = seq_printf(m, "%s", prefix_str); > > + if (ret < 0) > > + break; > > + > > + if (prefix_type == DUMP_PREFIX_ADDRESS) > > + ret = seq_printf(m, "%p: ", ptr + i); > > + else if (prefix_type == DUMP_PREFIX_OFFSET) > > + ret = seq_printf(m, "%.8x: ", i); > > + if (ret < 0) > > + break; > > + > > + if (m->size < m->count + groupsize * 2 + 1) > > + break; > > + > > + hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, > > + m->buf + m->count, m->size - m->count, > > + ascii); > > + > > + ret = seq_putc(m, '\n'); > > + if (ret < 0) > > + break; > > + } > > +} > > +EXPORT_SYMBOL(seq_hex_dump); > > 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 -- Andy Shevchenko Intel Finland Oy