From: Kalle Valo <kvalo@codeaurora.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>,
Stanislav Yakovlev <stas.yakovlev@gmail.com>,
Jouni Malinen <j@w1.fi>,
Johannes Berg <johannes@sipsolutions.net>,
"David S. Miller" <davem@davemloft.net>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org
Subject: Re: wireless: fix bogus maybe-uninitialized warning
Date: Thu, 17 Nov 2016 06:46:55 +0000 (UTC) [thread overview]
Message-ID: <20161117064655.B2591615D8@smtp.codeaurora.org> (raw)
In-Reply-To: <20161024153918.2810634-2-arnd@arndb.de>
Arnd Bergmann <arnd@arndb.de> wrote:
> The hostap_80211_rx() function is supposed to set up the mac addresses
> for four possible cases, based on two bits of input data. For
> some reason, gcc decides that it's possible that none of the these
> four cases apply and the addresses remain uninitialized:
>
> drivers/net/wireless/intersil/hostap/hostap_80211_rx.c: In function ‘hostap_80211_rx’:
> arch/x86/include/asm/string_32.h:77:14: warning: ‘src’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/net/wireless/intel/ipw2x00/libipw_rx.c: In function ‘libipw_rx’:
> arch/x86/include/asm/string_32.h:77:14: error: ‘dst’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> arch/x86/include/asm/string_32.h:78:22: error: ‘*((void *)&dst+4)’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> This warning is clearly nonsense, but changing the last case into
> 'default' makes it obvious to the compiler too, which avoids the
> warning and probably leads to better object code too.
>
> The same code is duplicated several times in the kernel, so this
> patch uses the same workaround for all copies. The exact configuration
> was hit only very rarely in randconfig builds and I only saw it
> in three drivers, but I assume that all of them are potentially
> affected, and it's better to keep the code consistent.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Patch applied to wireless-drivers-next.git, thanks.
10f3366b4d89 wireless: fix bogus maybe-uninitialized warning
--
https://patchwork.kernel.org/patch/9392385/
Documentation about submitting wireless patches and checking status
from patchwork:
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
prev parent reply other threads:[~2016-11-17 6:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-24 15:38 [PATCH] staging: rtl8192x: fix bogus maybe-uninitialized warning Arnd Bergmann
2016-10-24 15:38 ` [PATCH] wireless: " Arnd Bergmann
2016-11-09 1:21 ` Kalle Valo
2016-11-09 8:10 ` Johannes Berg
2016-11-09 15:06 ` Arnd Bergmann
2016-11-17 6:46 ` Kalle Valo [this message]
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