From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 394A916C6B7; Mon, 1 Jul 2024 15:07:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719846436; cv=none; b=adpPGB/S+ax0dvvFFnbPDDSWZTJKV3joPOhFrA97TgfPTt6F3+TxRe6JNWij39KnBkcb+8xjT7g7Qz+HvA1jfxI5ObEzReTdatdOUWRZ0nN6MBqoxbhKH0whFY1tMUNKv/mMZnLhqrwnDfNKyP+6z0fEyv7D3RI4Q7zl9Yxt+j8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719846436; c=relaxed/simple; bh=Tk9C5QJZciDa+QpIRAZ2Jlm95KdWTV5gwV0Zmuu14CE=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=K0VHLpA8D1hLSsidqqvZ1jCGfohk+HE67CR8GDNctuTvSWX3ivQ8W523J2HvsCuuS7uHK9EDChnY2U4WZIz0C1hsJXlQ+vFzklCQFO8IRzrnfv/cwGv6P/0KPNcvyvSffvQvxcKJxZgr0bfF1rytYHk0pxzWsZAeDHAhyIl6EOU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4WCTs92LbNz6JBqj; Mon, 1 Jul 2024 23:06:37 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 710DF1400D1; Mon, 1 Jul 2024 23:07:10 +0800 (CST) Received: from localhost (10.203.174.77) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Mon, 1 Jul 2024 16:07:10 +0100 Date: Mon, 1 Jul 2024 16:07:09 +0100 From: Jonathan Cameron To: Mauro Carvalho Chehab CC: Borislav Petkov , James Morse , Shiju Jose , Tony Luck , Alison Schofield , Ard Biesheuvel , Dave Jiang , Ira Weiny , , , Subject: Re: [PATCH v5 2/4] efi/cper: Add a new helper function to print bitmasks Message-ID: <20240701160709.000064c6@Huawei.com> In-Reply-To: References: Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500003.china.huawei.com (7.191.162.67) To lhrpeml500005.china.huawei.com (7.191.163.240) On Mon, 24 Jun 2024 11:19:19 +0200 Mauro Carvalho Chehab wrote: > Sometimes it is desired to produce a single log line for errors. This description is a bit cryptic. Maybe an example would make it easier for anyone coming across this in the future? > Add a new helper function for such purpose. > > Signed-off-by: Mauro Carvalho Chehab Minor comment inline. > --- > drivers/firmware/efi/cper.c | 41 +++++++++++++++++++++++++++++++++++++ > include/linux/cper.h | 2 ++ > 2 files changed, 43 insertions(+) > > diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c > index 7d2cdd9e2227..4cf56657afde 100644 > --- a/drivers/firmware/efi/cper.c > +++ b/drivers/firmware/efi/cper.c > @@ -106,6 +106,47 @@ void cper_print_bits(const char *pfx, unsigned int bits, > printk("%s\n", buf); > } > > +/* > + * cper_bits_to_str - return a string for set bits > + * @buf: buffer to store the output string > + * @buf_size: size of the output string buffer > + * @bits: bit mask > + * @strs: string array, indexed by bit position > + * @strs_size: size of the string array: @strs > + * @mask: a continuous bitmask used to detect the first valid bit of the > + * bitmap. > + * > + * Add to @buf the bitmask in hexadecimal. Then, for each set bit in @bits > + * mask, add the corresponding string describing the bit in @strs to @buf. > + */ > +char *cper_bits_to_str(char *buf, int buf_size, unsigned long bits, > + const char * const strs[], unsigned int strs_size) > +{ > + int len = buf_size; > + char *str = buf; > + int i, size; > + > + for_each_set_bit(i, &bits, strs_size) { > + if (!(bits & (1U << (i)))) > + continue; > + > + if (*buf && len > 0) { That first check on *buf is a bit esoteric. It's more than possible we get a non clear buffer passed in. I'd just use a bool first = true; ... if (!first && len > 0) { *str = '|'; len--; str++; } first = false; > + *str = '|'; > + len--; > + str++; > + } > + > + size = strscpy(str, strs[i], len); > + if (size < 0) > + break; > + > + len -= size; > + str += size; > + } > + return buf; Why return buf? You never use it and it's not entirely obvious that is the right thing to return (as opposed to length written for example). > +} > +EXPORT_SYMBOL_GPL(cper_bits_to_str); > + > static const char * const proc_type_strs[] = { > "IA32/X64", > "IA64", > diff --git a/include/linux/cper.h b/include/linux/cper.h > index 265b0f8fc0b3..c2f14b916bfb 100644 > --- a/include/linux/cper.h > +++ b/include/linux/cper.h > @@ -584,6 +584,8 @@ const char *cper_mem_err_type_str(unsigned int); > const char *cper_mem_err_status_str(u64 status); > void cper_print_bits(const char *prefix, unsigned int bits, > const char * const strs[], unsigned int strs_size); > +char *cper_bits_to_str(char *buf, int buf_size, unsigned long bits, > + const char * const strs[], unsigned int strs_size); > void cper_mem_err_pack(const struct cper_sec_mem_err *, > struct cper_mem_err_compact *); > const char *cper_mem_err_unpack(struct trace_seq *,