From nobody Wed Oct 15 22:31:23 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 383AD27BBCA; Sun, 24 Mar 2024 23:38:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711323524; cv=none; b=dhUsRCdWDiSKouVHMZf9rxn319GhIUNwUwcpZAMjzZshtksF0ZMLKdaFhIpdycaGEy+kGLUdX9A2dJghpb4wrI2RUgbl/dsDi8ODRcUrQwS3t9nFuURy17RO11fjKdDXVQrsWZFfQtDxVozcr2ZIwdextsQfbianq5t6dgQ7w8k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711323524; c=relaxed/simple; bh=EpkfoWx72jhMfIWXfpdojzGNUtDam6OnAiKzo5ntHS0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hSTGPGnz8gmNRRQ+EkuZhoFPrAe+L3SOcMPruwZp/ul6MRBdLGUnBD8iw17gWZtTJ7CxAcVtBt3uSC8aRK+KcscvmkDs5D7j7Xxm4olL4VAGsuQF3DL5gE6C1JnhzB0EsM+vIguJWyh4pqWNMK2c1S04K8BeV8yme+QZEOXF4lc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Hm+NwM3A; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Hm+NwM3A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66B29C43390; Sun, 24 Mar 2024 23:38:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711323524; bh=EpkfoWx72jhMfIWXfpdojzGNUtDam6OnAiKzo5ntHS0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hm+NwM3ASR3JVD4fqTAhOpGANT21PzsliRtRxt6YRf9qKQ2PB/rKUJBIKFm3yx7rk udlxUK9uehYtkKsUCqqik9FBrNTRRpyldrnUC+wmJ0UosCInLncOJsSCiYRa8Jw6eV VW/dwriE7NjNn+2Au/Uun0xmTnWqMzx5IDFBmSE1ugHFJwLIbWDUhgan245wOev2Fx Glas4MCqw6cfTgF48BN5boQ2lFktX4Q2RjFQfautPkw9k3IJf9E24lDuIzXkHvKQa1 uoKaY8jN6frbRJhQfaTSbFn8nJqnN82QHprmn1BHrgTe5mXGGnXRtNDq1+2JvtcgNt +Gxa1qM3f1ObA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arnd Bergmann , Justin Stitt , Hans Verkuil , Sasha Levin Subject: [PATCH 5.15 231/317] media: dvb-frontends: avoid stack overflow warnings with clang Date: Sun, 24 Mar 2024 19:33:31 -0400 Message-ID: <20240324233458.1352854-232-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324233458.1352854-1-sashal@kernel.org> References: <20240324233458.1352854-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann [ Upstream commit 7a4cf27d1f0538f779bf31b8c99eda394e277119 ] A previous patch worked around a KASAN issue in stv0367, now a similar problem showed up with clang: drivers/media/dvb-frontends/stv0367.c:1222:12: error: stack frame size (362= 4) exceeds limit (2048) in 'stv0367ter_set_frontend' [-Werror,-Wframe-large= r-than] 1214 | static int stv0367ter_set_frontend(struct dvb_frontend *fe) Rework the stv0367_writereg() function to be simpler and mark both register access functions as noinline_for_stack so the temporary i2c_msg structures do not get duplicated on the stack when KASAN_STACK is enabled. Fixes: 3cd890dbe2a4 ("media: dvb-frontends: fix i2c access helpers for KASA= N") Signed-off-by: Arnd Bergmann Reviewed-by: Justin Stitt Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/dvb-frontends/stv0367.c | 34 +++++++-------------------- 1 file changed, 8 insertions(+), 26 deletions(-) diff --git a/drivers/media/dvb-frontends/stv0367.c b/drivers/media/dvb-fron= tends/stv0367.c index 0bfca1174e9e7..8cbae8235b174 100644 --- a/drivers/media/dvb-frontends/stv0367.c +++ b/drivers/media/dvb-frontends/stv0367.c @@ -118,50 +118,32 @@ static const s32 stv0367cab_RF_LookUp2[RF_LOOKUP_TABL= E2_SIZE][RF_LOOKUP_TABLE2_S } }; =20 -static -int stv0367_writeregs(struct stv0367_state *state, u16 reg, u8 *data, int = len) +static noinline_for_stack +int stv0367_writereg(struct stv0367_state *state, u16 reg, u8 data) { - u8 buf[MAX_XFER_SIZE]; + u8 buf[3] =3D { MSB(reg), LSB(reg), data }; struct i2c_msg msg =3D { .addr =3D state->config->demod_address, .flags =3D 0, .buf =3D buf, - .len =3D len + 2 + .len =3D 3, }; int ret; =20 - if (2 + len > sizeof(buf)) { - printk(KERN_WARNING - "%s: i2c wr reg=3D%04x: len=3D%d is too big!\n", - KBUILD_MODNAME, reg, len); - return -EINVAL; - } - - - buf[0] =3D MSB(reg); - buf[1] =3D LSB(reg); - memcpy(buf + 2, data, len); - if (i2cdebug) printk(KERN_DEBUG "%s: [%02x] %02x: %02x\n", __func__, - state->config->demod_address, reg, buf[2]); + state->config->demod_address, reg, data); =20 ret =3D i2c_transfer(state->i2c, &msg, 1); if (ret !=3D 1) printk(KERN_ERR "%s: i2c write error! ([%02x] %02x: %02x)\n", - __func__, state->config->demod_address, reg, buf[2]); + __func__, state->config->demod_address, reg, data); =20 return (ret !=3D 1) ? -EREMOTEIO : 0; } =20 -static int stv0367_writereg(struct stv0367_state *state, u16 reg, u8 data) -{ - u8 tmp =3D data; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=3D81715 */ - - return stv0367_writeregs(state, reg, &tmp, 1); -} - -static u8 stv0367_readreg(struct stv0367_state *state, u16 reg) +static noinline_for_stack +u8 stv0367_readreg(struct stv0367_state *state, u16 reg) { u8 b0[] =3D { 0, 0 }; u8 b1[] =3D { 0 }; --=20 2.43.0