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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 122/128] media: saa7146: avoid high stack usage with clang
Date:   Wed, 29 May 2019 20:07:34 -0700
Message-Id: <20190530030456.369529231@linuxfoundation.org>
In-Reply-To: <20190530030432.977908967@linuxfoundation.org>
References: <20190530030432.977908967@linuxfoundation.org>
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[ Upstream commit 03aa4f191a36f33fce015387f84efa0eee94408e ]

Two saa7146/hexium files contain a construct that causes a warning
when built with clang:

drivers/media/pci/saa7146/hexium_orion.c:210:12: error: stack frame size of 2272 bytes in function 'hexium_probe'
      [-Werror,-Wframe-larger-than=]
static int hexium_probe(struct saa7146_dev *dev)
           ^
drivers/media/pci/saa7146/hexium_gemini.c:257:12: error: stack frame size of 2304 bytes in function 'hexium_attach'
      [-Werror,-Wframe-larger-than=]
static int hexium_attach(struct saa7146_dev *dev, struct saa7146_pci_extension_data *info)
           ^

This one happens regardless of KASAN, and the problem is that a
constructor to initialize a dynamically allocated structure leads
to a copy of that structure on the stack, whereas gcc initializes
it in place.

Link: https://bugs.llvm.org/show_bug.cgi?id=40776

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: fix checkpatch warnings]
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/pci/saa7146/hexium_gemini.c | 5 ++---
 drivers/media/pci/saa7146/hexium_orion.c  | 5 ++---
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/media/pci/saa7146/hexium_gemini.c b/drivers/media/pci/saa7146/hexium_gemini.c
index c889ec9f8a5a0..f5fc8bcbd14b1 100644
--- a/drivers/media/pci/saa7146/hexium_gemini.c
+++ b/drivers/media/pci/saa7146/hexium_gemini.c
@@ -270,9 +270,8 @@ static int hexium_attach(struct saa7146_dev *dev, struct saa7146_pci_extension_d
 	/* enable i2c-port pins */
 	saa7146_write(dev, MC1, (MASK_08 | MASK_24 | MASK_10 | MASK_26));
 
-	hexium->i2c_adapter = (struct i2c_adapter) {
-		.name = "hexium gemini",
-	};
+	strscpy(hexium->i2c_adapter.name, "hexium gemini",
+		sizeof(hexium->i2c_adapter.name));
 	saa7146_i2c_adapter_prepare(dev, &hexium->i2c_adapter, SAA7146_I2C_BUS_BIT_RATE_480);
 	if (i2c_add_adapter(&hexium->i2c_adapter) < 0) {
 		DEB_S("cannot register i2c-device. skipping.\n");
diff --git a/drivers/media/pci/saa7146/hexium_orion.c b/drivers/media/pci/saa7146/hexium_orion.c
index c306a92e89095..dc07ca37ebd06 100644
--- a/drivers/media/pci/saa7146/hexium_orion.c
+++ b/drivers/media/pci/saa7146/hexium_orion.c
@@ -232,9 +232,8 @@ static int hexium_probe(struct saa7146_dev *dev)
 	saa7146_write(dev, DD1_STREAM_B, 0x00000000);
 	saa7146_write(dev, MC2, (MASK_09 | MASK_25 | MASK_10 | MASK_26));
 
-	hexium->i2c_adapter = (struct i2c_adapter) {
-		.name = "hexium orion",
-	};
+	strscpy(hexium->i2c_adapter.name, "hexium orion",
+		sizeof(hexium->i2c_adapter.name));
 	saa7146_i2c_adapter_prepare(dev, &hexium->i2c_adapter, SAA7146_I2C_BUS_BIT_RATE_480);
 	if (i2c_add_adapter(&hexium->i2c_adapter) < 0) {
 		DEB_S("cannot register i2c-device. skipping.\n");
-- 
2.20.1