From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 915EBC282CE for ; Wed, 10 Apr 2019 03:55:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BECD217D6 for ; Wed, 10 Apr 2019 03:55:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (4096-bit key) header.d=d-silva.org header.i=@d-silva.org header.b="F/gHDQID" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727220AbfDJDzp (ORCPT ); Tue, 9 Apr 2019 23:55:45 -0400 Received: from ushosting.nmnhosting.com ([167.160.173.127]:49232 "EHLO ushosting.nmnhosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726825AbfDJDzp (ORCPT ); Tue, 9 Apr 2019 23:55:45 -0400 X-Greylist: delayed 1348 seconds by postgrey-1.27 at vger.kernel.org; Tue, 09 Apr 2019 23:55:44 EDT Received: from mail2.nmnhosting.com (unknown [202.169.106.97]) by ushosting.nmnhosting.com (Postfix) with ESMTPS id 67B932F28FBB; Tue, 9 Apr 2019 23:33:15 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=d-silva.org; s=201810a; t=1554867195; bh=nRxc2X9u5eYN5qosM3Fxas/OX7b4OdSe8dRjwyMZHtQ=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=F/gHDQIDK8lLwbRkufrayf3fcwi0pcYnj9JDTiH+U7SbZ6vxcbb7LQ5n2m7LRgC2a fYGlsEV4dpYtorV0TddpZP/T50Xvh/XzqzYysOLqywKCfpFID+JuXJFj4hB6nJj99A a9Kl8juQbXbw1BPb8oB+TZcqpCuWMPiJyJ6cnWl8nNlSCTG8rYQlBc9K/dICXPT+HS sGl2fJny4zHFoNh7ubP2Ma/43roAr8HfvgYaBYEoTG7Ku1xdN8vr/uUU4rjPehxtji f97R3QkVOj3Hdl/N4XQvORMjx3fWDMIE2jUbGGhlSmwAr2QpRtwZmGBtojBsNWOWZu tD7gD+yLXY1XJfXbxhi/RJpKMe5XkffxnQHlyeu4glPNms4+SMZuFT5XcY0e02idKy nvmNIqVq08K6v1iDd3inVtyrYypgVN3TPCiKBeLpMfx7FfnRCKFmMcQp5AXb/pqhG+ RWqtZ3U3wD0lnEjkKtaHkJt4oiFzuyAsG8dSRdINnj3eCFizbrwnudAodUOgSfN0RH TcLjEdSL2+fCVjk0PGrJ9IZ+enh3s/dqUboOOOukZgLbC0mVtVk2nyr8MN6y1aKZa3 xANfWg0lJ5c3dLEolOJSv/HpyiGcvVQ342b0jl3kz8nM5vHRejoJNnfl0mbS3en/Zq n8V8Dh58tDXhoTe2y6TFTIrM= Received: from adsilva.ozlabs.ibm.com (static-82-10.transact.net.au [122.99.82.10] (may be forged)) (authenticated bits=0) by mail2.nmnhosting.com (8.15.2/8.15.2) with ESMTPSA id x3A3Wl7t094875 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Wed, 10 Apr 2019 13:33:02 +1000 (AEST) (envelope-from alastair@d-silva.org) Message-ID: <646b3b03b2c9a2612d3bbc6f1e00d4f9fa79769f.camel@d-silva.org> Subject: Re: [PATCH 2/4] lib/hexdump.c: Optionally suppress lines of filler bytes From: "Alastair D'Silva" To: Jani Nikula Cc: Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , Karsten Keil , Jassi Brar , Tom Lendacky , "David S. Miller" , Jose Abreu , Kalle Valo , Stanislaw Gruszka , Benson Leung , Enric Balletbo i Serra , "James E.J. Bottomley" , "Martin K. Petersen" , Greg Kroah-Hartman , Alexander Viro , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Andrew Morton , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org, devel@driverdev.osuosl.org, linux-fsdevel@vger.kernel.org Date: Wed, 10 Apr 2019 13:32:46 +1000 In-Reply-To: <20190410031720.11067-3-alastair@au1.ibm.com> References: <20190410031720.11067-1-alastair@au1.ibm.com> <20190410031720.11067-3-alastair@au1.ibm.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.6.2 (mail2.nmnhosting.com [10.0.1.20]); Wed, 10 Apr 2019 13:33:10 +1000 (AEST) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, 2019-04-10 at 13:17 +1000, Alastair D'Silva wrote: > From: Alastair D'Silva > > Some buffers may only be partially filled with useful data, while the > rest > is padded (typically with 0x00 or 0xff). > This patch introduces flags which allow lines of padding bytes to be > suppressed, making the output easier to interpret: > HEXDUMP_SUPPRESS_0X00, > HEXDUMP_SUPPRESS_0XFF > > The first and last lines are not suppressed by default, so the > function > always outputs something. This behaviour can be further controlled > with > the HEXDUMP_SUPPRESS_FIRST & HEXDUMP_SUPPRESS_LAST flags. > > An inline wrapper function is provided for backwards compatibility > with > existing code, which maintains the original behaviour. > > Signed-off-by: Alastair D'Silva > --- > > diff --git a/lib/hexdump.c b/lib/hexdump.c > index b8a164814744..2f3bafb55a44 100644 > --- a/lib/hexdump.c > +++ b/lib/hexdump.c > @@ -209,8 +209,21 @@ int hex_dump_to_buffer(const void *buf, size_t > len, int rowsize, int groupsize, > EXPORT_SYMBOL(hex_dump_to_buffer); > > #ifdef CONFIG_PRINTK > + > +static bool buf_is_all(const u8 *buf, size_t len, u8 val) > +{ > + size_t i; > + > + for (i = 0; i < len; i++) { > + if (buf[i] != val) > + return false; > + } > + > + return true; > +} > + > /** > - * print_hex_dump - print a text hex dump to syslog for a binary > blob of data > + * print_hex_dump_ext: dump a binary blob of data to syslog in > hexadecimal > * @level: kernel log level (e.g. KERN_DEBUG) > * @prefix_str: string to prefix each line with; > * caller supplies trailing spaces for alignment if desired > @@ -221,42 +234,73 @@ EXPORT_SYMBOL(hex_dump_to_buffer); > * @buf: data blob to dump > * @len: number of bytes in the @buf > * @ascii: include ASCII after the hex output This line should have been removed. I'll address it in V2. > + * @flags: A bitwise OR of the following flags: > + * HEXDUMP_ASCII: include ASCII after the hex output > + * HEXDUMP_SUPPRESS_0X00: suppress lines that are all 0x00 > + * (other than first or last) > + * HEXDUMP_SUPPRESS_0XFF: suppress lines that are all 0xff > + * (other than first or last) > + * HEXDUMP_SUPPRESS_FIRST: allows the first line to be > suppressed > + * HEXDUMP_SUPPRESS_LAST: allows the last line to be suppressed > + * If the first and last line may be > suppressed, > + * an empty buffer will not produce any > output > * > * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII > dump > * to the kernel log at the specified kernel log level, with an > optional > * leading prefix. > * > - * print_hex_dump() works on one "line" of output at a time, i.e., > + * print_hex_dump_ext() works on one "line" of output at a time, > i.e., > * 16, 32 or 64 bytes of input data converted to hex + ASCII output. > - * print_hex_dump() iterates over the entire input @buf, breaking it > into > + * print_hex_dump_ext() iterates over the entire input @buf, > breaking it into > * "line size" chunks to format and print. > * > * E.g.: > - * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, > - * 16, 1, frame->data, frame->len, true); > + * print_hex_dump_ext(KERN_DEBUG, "raw data: ", > DUMP_PREFIX_ADDRESS, > + * 16, 1, frame->data, frame->len, HEXDUMP_ASCII); > * > * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode: > * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e > 4f @ABCDEFGHIJKLMNO > * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode: > * ffffffff88089af0: 73727170 77767574 7b7a7978 > 7f7e7d7c pqrstuvwxyz{|}~. > */ -- Alastair D'Silva mob: 0423 762 819 skype: alastair_dsilva Twitter: @EvilDeece blog: http://alastair.d-silva.org