linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: Hans Verkuil <hverkuil@xs4all.nl>,
	Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>,
	Mark Brown <broonie@kernel.org>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] media: saa7146: avoid high stack usage with clang
Date: Tue, 19 Feb 2019 18:01:56 +0100	[thread overview]
Message-ID: <20190219170209.4180739-1-arnd@arndb.de> (raw)

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 initalize 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>
---
 drivers/media/pci/saa7146/hexium_gemini.c | 4 +---
 drivers/media/pci/saa7146/hexium_orion.c  | 4 +---
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/media/pci/saa7146/hexium_gemini.c b/drivers/media/pci/saa7146/hexium_gemini.c
index 5817d9cde4d0..f7ce0e1770bf 100644
--- a/drivers/media/pci/saa7146/hexium_gemini.c
+++ b/drivers/media/pci/saa7146/hexium_gemini.c
@@ -270,9 +270,7 @@ 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 0a05176c18ab..b9f4a09c744d 100644
--- a/drivers/media/pci/saa7146/hexium_orion.c
+++ b/drivers/media/pci/saa7146/hexium_orion.c
@@ -231,9 +231,7 @@ 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");
-- 
2.20.0


             reply	other threads:[~2019-02-19 17:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-19 17:01 Arnd Bergmann [this message]
2019-02-19 17:01 ` [PATCH 2/3] media: vicodec: avoic clang frame size warning Arnd Bergmann
2019-02-19 19:01   ` Nick Desaulniers
2019-02-19 19:14     ` Arnd Bergmann
2019-02-19 19:56   ` Hans Verkuil
2019-02-19 17:01 ` [PATCH 3/3] media: go7007: avoid clang frame overflow warning with KASAN Arnd Bergmann
2019-02-19 18:41 ` [PATCH 1/3] media: saa7146: avoid high stack usage with clang Nick Desaulniers

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190219170209.4180739-1-arnd@arndb.de \
    --to=arnd@arndb.de \
    --cc=broonie@kernel.org \
    --cc=hverkuil@xs4all.nl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=mchehab@kernel.org \
    --cc=natechancellor@gmail.com \
    --cc=ndesaulniers@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).