From patchwork Wed Jun 3 23:31:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11586623 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 97F93739 for ; Wed, 3 Jun 2020 23:32:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F72220897 for ; Wed, 3 Jun 2020 23:32:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="oLglV2NF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbgFCXcT (ORCPT ); Wed, 3 Jun 2020 19:32:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726189AbgFCXcR (ORCPT ); Wed, 3 Jun 2020 19:32:17 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9FCBC08C5C2 for ; Wed, 3 Jun 2020 16:32:16 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id 185so2645105pgb.10 for ; Wed, 03 Jun 2020 16:32:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=z79mte9tXyXKJqcwg2to640Wx2Eg5qdbPrxISPqquNw=; b=oLglV2NFfWcYacYEWd+TtydM20VTgwWe1gq21Fthy+SgsdpnjxFQ4Ga6u1Qy8QOuhq 1+c/7ALdx0vchA5G8glRAPu5IZRrjlpO6MXFnSd1l4xnQge821R1YpyaThNWtUXXRQkZ BdWautw1YEzJ6ceFFpGiknqeHem+S3a8xUfFg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=z79mte9tXyXKJqcwg2to640Wx2Eg5qdbPrxISPqquNw=; b=Ux4IkSROOwPAfwR4DqX0R4ayYU5oK+VJFi8K8bXGL/YwqhSRheYRCd7AmpDYN1N3Zp fFoANwjWFAggyiEd2VfRpJRBFEbNn27J3E+Ta43ERb0gn3F78qfxK3N74nxT+x2j/kM3 r3hXlq1mInDatP+64nTNy4Cd0HxvgIcvdyy6YiynA6srhv+iiLp5Bcpm0W1BgfSVzhXN MJBaw37Josj1xVnldLtscnjGB7ZjWKQy3f9c/Z3fAnm/Sa7gXxQmUf4GBZCEe63catPt gNvnXPAiepp7RMFM4WCupgVBi7vwOb8sK1D/b2w3ulsb6astZYHpbx1+TDQ1dCUmgZ7m DaKQ== X-Gm-Message-State: AOAM5320uX1SfQrK03gzMI+mBe3030c+RQSPCMo978RFEKUeFW2I+rvc 5QTB3IAEHW3Fx7EXghE6wyzBpA== X-Google-Smtp-Source: ABdhPJzEnF0voBtIhVxbXIY3ed6bQ+lYw39TPSGZER6ztQVM7GNLumS6Ixq11iEOXvbkyysEKAiNmA== X-Received: by 2002:aa7:9a93:: with SMTP id w19mr1488633pfi.155.1591227136432; Wed, 03 Jun 2020 16:32:16 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id j8sm3442213pjw.11.2020.06.03.16.32.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Jun 2020 16:32:12 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Linus Torvalds , Miguel Ojeda , Alexander Potapenko , Joe Perches , Andy Whitcroft , x86@kernel.org, drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, b43-dev@lists.infradead.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, linux-ide@vger.kernel.org, linux-clk@vger.kernel.org, linux-spi@vger.kernel.org, linux-mm@kvack.org, clang-built-linux@googlegroups.com Subject: [PATCH 03/10] b43: Remove uninitialized_var() usage Date: Wed, 3 Jun 2020 16:31:56 -0700 Message-Id: <20200603233203.1695403-4-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200603233203.1695403-1-keescook@chromium.org> References: <20200603233203.1695403-1-keescook@chromium.org> MIME-Version: 1.0 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. As a precursor to removing[2] this[3] macro[4], just initialize this variable to NULL, and make the (unreachable!) code do a conditional test. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Signed-off-by: Kees Cook --- drivers/net/wireless/broadcom/b43/phy_n.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c b/drivers/net/wireless/broadcom/b43/phy_n.c index d3c001fa8eb4..88cdcea10d61 100644 --- a/drivers/net/wireless/broadcom/b43/phy_n.c +++ b/drivers/net/wireless/broadcom/b43/phy_n.c @@ -4222,7 +4222,7 @@ static void b43_nphy_tx_gain_table_upload(struct b43_wldev *dev) u32 rfpwr_offset; u8 pga_gain, pad_gain; int i; - const s16 *uninitialized_var(rf_pwr_offset_table); + const s16 *rf_pwr_offset_table = NULL; table = b43_nphy_get_tx_gain_table(dev); if (!table) @@ -4256,9 +4256,13 @@ static void b43_nphy_tx_gain_table_upload(struct b43_wldev *dev) pga_gain = (table[i] >> 24) & 0xf; pad_gain = (table[i] >> 19) & 0x1f; if (b43_current_band(dev->wl) == NL80211_BAND_2GHZ) - rfpwr_offset = rf_pwr_offset_table[pad_gain]; + rfpwr_offset = rf_pwr_offset_table + ? rf_pwr_offset_table[pad_gain] + : 0; else - rfpwr_offset = rf_pwr_offset_table[pga_gain]; + rfpwr_offset = rf_pwr_offset_table + ? rf_pwr_offset_table[pga_gain] + : 0; } else { pga_gain = (table[i] >> 24) & 0xF; if (b43_current_band(dev->wl) == NL80211_BAND_2GHZ)