From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 9E46B125A1 for ; Sat, 27 Jan 2024 05:19:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=140.211.166.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706332774; cv=none; b=rjznKEWbJT+niB17qZh4U5WPSDquWPeAh/3g/ohM+rwwXYICrWqBU/Vx6gyYW2BFNFMb/azhcqUFnR0EOyY6k9U5V8NajYeTpOAJKhHs2Qb+1eSu/s5PIEYNEV51y9t0aedQrEARLlKOco+KYiOESB9BogzM0+53iw6XQn/f4S0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706332774; c=relaxed/simple; bh=UUm52DDs1DdO1GYqGNEYQ/2MhKLs1aaBpZYltmJR5oc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mxBtN4n0tfODIVK9mnxxMvtFOnMpAAG9y3LGPpuFO2lJ6JU7KtSS0/YKbveDXkdK0PBQlQxnrb3Oi5SdmkxZrMMD8qM5v1ABRFuZRGHuHZ6KcWdhXd8U1pW8HyyRGIwxD6M5hvkc6fCDXTVe3VcvLLfbaCaLyvHoOTY25kUnwAs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=dDEb5Bbd; arc=none smtp.client-ip=140.211.166.136 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dDEb5Bbd" Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 0B15360AE1 for ; Sat, 27 Jan 2024 05:19:33 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 0B15360AE1 Authentication-Results: smtp3.osuosl.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20230601 header.b=dDEb5Bbd X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.099 X-Spam-Level: Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cvM8JcjrKNzp for ; Sat, 27 Jan 2024 05:19:32 +0000 (UTC) Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) by smtp3.osuosl.org (Postfix) with ESMTPS id 2835F60ADE for ; Sat, 27 Jan 2024 05:19:32 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 2835F60ADE Received: by mail-pg1-x52a.google.com with SMTP id 41be03b00d2f7-5cdbc4334edso602258a12.3 for ; Fri, 26 Jan 2024 21:19:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1706332771; x=1706937571; darn=lists.linuxfoundation.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=ZlwPUAl6/WE0Iz5wtvJeDFbKAkv1tr9cB03w9FhW5zw=; b=dDEb5BbdrKme5KjOIWr8RLaf3tYhxl/GqldbfXy8OIPU5fwG9zdYq9brjBqPw6RCGc 7q5ehYAQ0NfQKd1auxkG3r4KlkuwkKYe/XLRZn0ji8a2Gw0jpXuUmXKnVUzyote/Ds4+ WmO8DlYa4tp9WooX9ofLJGUnixKYgtu+dps2bDG9wsOLMyaFqdxt8naj57pKCtpQPmgT S3ZwDudURWjt/ooZ8MkcRybwYl3sjfKSWRwedO04a8mUJiqXUklqQDxNyIK9iZlqPAlf nzZ+xUE/nBn/6glD3UDfGOOXLUnSTOGfdTnXYn6phz/6ZwDsmlqZnpbonERDJf2oXHXn pDGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706332771; x=1706937571; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ZlwPUAl6/WE0Iz5wtvJeDFbKAkv1tr9cB03w9FhW5zw=; b=QBrwypMY2tgQZrDGPgWajURbXIUCiAhi/dXLeCcDbOL5Xmc2rPp4Cu4bEmaEvcAqDO sOWo029bjPqQ5IRbLPTZ4M/sRScoPYfHp4WswdHIOPFFr6xI0BHRjWICa6dRm6sG7i3X Mr5rQUN8MylxC+/oLBUP46A+DOX4jMaIZ4WJ6gmnSTU5Av3Z8c1hhTR1GBHcdHP8arlK xpa/gb4Fgkr3WH3hq7dC/x/tvqj9iA6vHZ+BqzO95uWGLd0mhaG0lDI3nTnFRWW/6qPJ cJH55Mvv8w3arM/Y9sakXkIvtxC2Es33FxYfOYYmFI2BHyzG5BXIzCjI0nRnPnccaRbd S2Uw== X-Gm-Message-State: AOJu0YyDJL1an4nnxfWFEXHImc9U98oXkZl2IJEHD9jMSgnNNXEwUsFt UNPX+P7gJwjfQOyZr+PBEZ+GnFSBKpJWS5IAoAsLUcI/+jTZ68+/ X-Google-Smtp-Source: AGHT+IGoQk/AVJgLYnRpz/t6BgHCALxC1mQhdVMBlv+sN8qu9oUMcPZo2z7delqcT0PguXyU5JsdNg== X-Received: by 2002:a62:f252:0:b0:6dd:8a4c:bfb2 with SMTP id y18-20020a62f252000000b006dd8a4cbfb2mr506242pfl.60.1706332771321; Fri, 26 Jan 2024 21:19:31 -0800 (PST) Received: from ?IPV6:2601:204:df00:9cd0:106a:b3d9:2374:e3a5? ([2601:204:df00:9cd0:106a:b3d9:2374:e3a5]) by smtp.gmail.com with ESMTPSA id a10-20020a63d40a000000b005bd980cca56sm1742316pgh.29.2024.01.26.21.19.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 26 Jan 2024 21:19:30 -0800 (PST) Message-ID: Date: Fri, 26 Jan 2024 21:19:28 -0800 Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] brcmfmac: replace one-element array with flexible-array member Content-Language: en-US To: Lukas Bulwahn , Kees Cook Cc: Arend van Spriel , aspriel@gmail.com, franky.lin@broadcom.com, kvalo@kernel.org, linux-wireless@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, linux-kernel-mentees@lists.linuxfoundation.org References: <20230803052238.12147-1-rauji.raut@gmail.com> <20230803052238.12147-2-rauji.raut@gmail.com> <202401181217.1D75C32E@keescook> From: Atul Raut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Thank You Kees, Hello Lukas, Arend & Kalle, Sorry for not getting back to you sooner, am out of county & hence unable to push the patch right away. Will share once back, apologize for inconvenience caused. -Atul On 1/19/24 05:00, Lukas Bulwahn wrote: > On Thu, Jan 18, 2024 at 9:20 PM Kees Cook wrote: >> On Thu, Jan 18, 2024 at 02:53:28PM +0100, Arend van Spriel wrote: >>> + Kees >>> >>> On 8/3/2023 7:22 AM, Atul Raut wrote: >>>> One-element arrays are obsolete, and flexible >>>> array members have taken their place. So, in >>>> struct cca_stats_n_flags, replace the one-element >>>> array with a flexible-array member. >>>> >>>> This fixes warnings such as: >>>> ./drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:119:6-9: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays) >>> I think this correct, but maybe Kees can give definitive answer here. >>> >>>> Signed-off-by: Atul Raut >>>> --- >>>> drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c >>>> index de8a2e27f49c..fff32e54833d 100644 >>>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c >>>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c >>>> @@ -116,7 +116,7 @@ struct brcmf_dump_survey { >>>> struct cca_stats_n_flags { >>>> u32 msrmnt_time; /* Time for Measurement (msec) */ >>>> u32 msrmnt_done; /* flag set when measurement complete */ >>>> - char buf[1]; >>>> + char buf[]; >>>> }; >>>> struct cca_msrmnt_query { >> Normally a [1] -> [] conversion needs some details in the commit log >> about why this is safe (since it runs the risk of changing sizeof(struct >> cca_stats_n_flags). In this case, there's only a single user of the >> struct, and nothing about its use depends on its size: >> >> #define BRCMF_DCMD_MEDLEN 1536 >> ... >> struct cca_stats_n_flags *results; >> char *buf; >> ... >> buf = kzalloc(sizeof(char) * BRCMF_DCMD_MEDLEN, GFP_KERNEL); >> ... >> results = (struct cca_stats_n_flags *)(buf); >> ... >> brcmf_parse_dump_obss(results->buf, survey); >> >> So, the allocation size is big enough for the struct, and nothing >> depends on the struct size. >> >> Reviewed-by: Kees Cook >> > As the linux-kernel-mentees mailing list is in CC, I assume that Atul > is a linux-kernel mentee. In that case, it is certainly reasonable and > at least of educational value for Atul to take Kees' explanation and > add this to the patch's commit message in his own words. Then, with > that, submit a PATCH v3. > > > Lukas