From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2256q2/Y7EKQqGkdyXGwB0er6RtTu4f4OeVWdnabKg+LfiqiGSL9Q3oF4GfrwuDuJaXk2itq ARC-Seal: i=1; a=rsa-sha256; t=1519217847; cv=none; d=google.com; s=arc-20160816; b=O/MUC1ZxFgvxGTEi4Vau3fOiT9PctGkmBGXiTUY/wSCvvP8t5eNE/HKXNRGU5cPAkc Ww5xOLSubaF9bFS5U2kzdN/7W4J8iAx02PD5sXH+EA33oHb9x5KCaZypJEZ7n74nvEYg hvESZr5H/Wg4oE3CCvPhVXi+axckm/FZezGlyBUF6kDbs2HDJa27Rch5/yTGzei0naDl bpiRJVO+cj+vNLSxuyvVFS244KPLnHu9wkeT6GMp2PXsBxiNrbeTEi8Q5rP+MP4qF4Wi hguNfulNsi7c4Qs4ER64Yb1DGhbXYH8A3LGK6QAkZfDo0/j/rudFdfgLJVQoly1Bu60m vbLg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=6szMVwqh4/mDvg6vizrdByo8Nnd5YTsldoi4JDmWIqI=; b=0ZnJbSLgNuz5yx+j7/6Ib+QcCDQKN4wqTrJV/sWAHXfECGs2nWOskYJQ7KcOLrmsTi 5+LRx2tKKSC2WFyNnJln+yybST2yRdZ7D6Cn+tl2RJyphaKh9S2GdPR0K8T/odWN3KOa JfaersaD9ZbGvR7sescgVLYIoCcrqsinBGnIvtm2pqydF1udYiyZEVykpqKBX4hfMVOg Ux0nF2xbt2f/qR1iAKlHzDW5InLH7a16SpfQwm36ZCzNCi5LTovZq+dmDuFyxQTkQbAh z01irXPHO7ci2uaRVSJxEyuPjP5EtBTBv8BUlhGtbLZxEPZ+ZevbIMdAPploDPTJ8Q8D MNQA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Mauro Carvalho Chehab Subject: [PATCH 4.9 75/77] media: r820t: fix r820t_write_reg for KASAN Date: Wed, 21 Feb 2018 13:49:24 +0100 Message-Id: <20180221124435.339734334@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180221124432.172390020@linuxfoundation.org> References: <20180221124432.172390020@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593014700913189109?= X-GMAIL-MSGID: =?utf-8?q?1593015373907239465?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann commit 16c3ada89cff9a8c2a0eea34ffa1aa20af3f6008 upstream. With CONFIG_KASAN, we get an overly long stack frame due to inlining the register access functions: drivers/media/tuners/r820t.c: In function 'generic_set_freq.isra.7': drivers/media/tuners/r820t.c:1334:1: error: the frame size of 2880 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] This is caused by a gcc bug that has now been fixed in gcc-8. To work around the problem, we can pass the register data through a local variable that older gcc versions can optimize out as well. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 Signed-off-by: Arnd Bergmann Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/tuners/r820t.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/drivers/media/tuners/r820t.c +++ b/drivers/media/tuners/r820t.c @@ -396,9 +396,11 @@ static int r820t_write(struct r820t_priv return 0; } -static int r820t_write_reg(struct r820t_priv *priv, u8 reg, u8 val) +static inline int r820t_write_reg(struct r820t_priv *priv, u8 reg, u8 val) { - return r820t_write(priv, reg, &val, 1); + u8 tmp = val; /* work around GCC PR81715 with asan-stack=1 */ + + return r820t_write(priv, reg, &tmp, 1); } static int r820t_read_cache_reg(struct r820t_priv *priv, int reg) @@ -411,17 +413,18 @@ static int r820t_read_cache_reg(struct r return -EINVAL; } -static int r820t_write_reg_mask(struct r820t_priv *priv, u8 reg, u8 val, +static inline int r820t_write_reg_mask(struct r820t_priv *priv, u8 reg, u8 val, u8 bit_mask) { + u8 tmp = val; int rc = r820t_read_cache_reg(priv, reg); if (rc < 0) return rc; - val = (rc & ~bit_mask) | (val & bit_mask); + tmp = (rc & ~bit_mask) | (tmp & bit_mask); - return r820t_write(priv, reg, &val, 1); + return r820t_write(priv, reg, &tmp, 1); } static int r820t_read(struct r820t_priv *priv, u8 reg, u8 *val, int len)