From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: [PATCH] ASoC: Simplify format_register_str() without stack usages Date: Tue, 26 May 2015 14:40:14 +0200 Message-ID: <1432644014-16475-1-git-send-email-tiwai@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 430E726520E for ; Tue, 26 May 2015 14:40:16 +0200 (CEST) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Mark Brown Cc: alsa-devel@alsa-project.org, Liam Girdwood List-Id: alsa-devel@alsa-project.org Instead of allocating two string buffers on stack and copying them back, manipulate directly the target string buffer. This simplifies the code well. Signed-off-by: Takashi Iwai --- sound/soc/soc-core.c | 27 +++++++++------------------ 1 file changed, 9 insertions(+), 18 deletions(-) diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 23732523f87c..ee86f84b7ccc 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -92,30 +92,21 @@ static int format_register_str(struct snd_soc_codec *codec, int wordsize = min_bytes_needed(codec->driver->reg_cache_size) * 2; int regsize = codec->driver->reg_word_size * 2; int ret; - char tmpbuf[len + 1]; - char regbuf[regsize + 1]; - - /* since tmpbuf is allocated on the stack, warn the callers if they - * try to abuse this function */ - WARN_ON(len > 63); /* +2 for ': ' and + 1 for '\n' */ if (wordsize + regsize + 2 + 1 != len) return -EINVAL; - ret = snd_soc_read(codec, reg); - if (ret < 0) { - memset(regbuf, 'X', regsize); - regbuf[regsize] = '\0'; - } else { - snprintf(regbuf, regsize + 1, "%.*x", regsize, ret); - } - - /* prepare the buffer */ - snprintf(tmpbuf, len + 1, "%.*x: %s\n", wordsize, reg, regbuf); - /* copy it back to the caller without the '\0' */ - memcpy(buf, tmpbuf, len); + sprintf(buf, "%.*x: ", wordsize, reg); + buf += wordsize + 2; + ret = snd_soc_read(codec, reg); + if (ret < 0) + memset(buf, 'X', regsize); + else + sprintf(buf, "%.*x", regsize, ret); + buf[regsize] = '\n'; + /* no NUL-termination needed */ return 0; } -- 2.4.1