media: dvb-frontends: fix i2c access helpers for KASAN

commit 3cd890dbe2a4f14cc44c85bb6cf37e5e22d4dd0e upstream.

A typical code fragment was copied across many dvb-frontend drivers and
causes large stack frames when built with with CONFIG_KASAN on gcc-5/6/7:

drivers/media/dvb-frontends/cxd2841er.c:3225:1: error: the frame size of 3992 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/cxd2841er.c:3404:1: error: the frame size of 3136 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/stv0367.c:3143:1: error: the frame size of 4016 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/stv090x.c:3430:1: error: the frame size of 5312 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/stv090x.c:4248:1: error: the frame size of 4872 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]

gcc-8 now solves this by consolidating the stack slots for the argument
variables, but on older compilers we can get the same behavior by taking
the pointer of a local variable rather than the inline function argument.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/dvb-frontends/ascot2e.c b/drivers/media/dvb-frontends/ascot2e.c
index f770f6a2c987b00356e25d39d15bc7024c35c115..3ea9edc8cdbed42d5d105baac0a3d49e12195c1d 100644 (file)
--- a/drivers/media/dvb-frontends/ascot2e.c
+++ b/drivers/media/dvb-frontends/ascot2e.c
@@ -155,7 +155,9 @@ static int ascot2e_write_regs(struct ascot2e_priv *priv,
 
 static int ascot2e_write_reg(struct ascot2e_priv *priv, u8 reg, u8 val)
 {
-       return ascot2e_write_regs(priv, reg, &val, 1);
+       u8 tmp = val; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return ascot2e_write_regs(priv, reg, &tmp, 1);
 }
 
 static int ascot2e_read_regs(struct ascot2e_priv *priv,

diff --git a/drivers/media/dvb-frontends/cxd2841er.c b/drivers/media/dvb-frontends/cxd2841er.c
index 107853b0fdddc8ce3d7a5d9607c8dd7cf25a387c..bde77671a37c884ddc98046fc6c03dc7f0cbe47c 100644 (file)
--- a/drivers/media/dvb-frontends/cxd2841er.c
+++ b/drivers/media/dvb-frontends/cxd2841er.c
@@ -241,7 +241,9 @@ static int cxd2841er_write_regs(struct cxd2841er_priv *priv,
 static int cxd2841er_write_reg(struct cxd2841er_priv *priv,
                               u8 addr, u8 reg, u8 val)
 {
-       return cxd2841er_write_regs(priv, addr, reg, &val, 1);
+       u8 tmp = val; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return cxd2841er_write_regs(priv, addr, reg, &tmp, 1);
 }
 
 static int cxd2841er_read_regs(struct cxd2841er_priv *priv,

diff --git a/drivers/media/dvb-frontends/horus3a.c b/drivers/media/dvb-frontends/horus3a.c
index 000606af70f7461def1f187521e6ce12d191b6a7..f770ab72a8e3335a32e9c7bfc51b9e646fc2c40d 100644 (file)
--- a/drivers/media/dvb-frontends/horus3a.c
+++ b/drivers/media/dvb-frontends/horus3a.c
@@ -89,7 +89,9 @@ static int horus3a_write_regs(struct horus3a_priv *priv,
 
 static int horus3a_write_reg(struct horus3a_priv *priv, u8 reg, u8 val)
 {
-       return horus3a_write_regs(priv, reg, &val, 1);
+       u8 tmp = val; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return horus3a_write_regs(priv, reg, &tmp, 1);
 }
 
 static int horus3a_enter_power_save(struct horus3a_priv *priv)

diff --git a/drivers/media/dvb-frontends/itd1000.c b/drivers/media/dvb-frontends/itd1000.c
index cadcae4cff89122dbf90cad2d02cfa9fa13854b4..ac9d2591bb6fca292cca0fc44171ef1d9a4a7575 100644 (file)
--- a/drivers/media/dvb-frontends/itd1000.c
+++ b/drivers/media/dvb-frontends/itd1000.c
@@ -99,8 +99,9 @@ static int itd1000_read_reg(struct itd1000_state *state, u8 reg)
 
 static inline int itd1000_write_reg(struct itd1000_state *state, u8 r, u8 v)
 {
-       int ret = itd1000_write_regs(state, r, &v, 1);
-       state->shadow[r] = v;
+       u8 tmp = v; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+       int ret = itd1000_write_regs(state, r, &tmp, 1);
+       state->shadow[r] = tmp;
        return ret;
 }
 

diff --git a/drivers/media/dvb-frontends/mt312.c b/drivers/media/dvb-frontends/mt312.c
index c36e6764eeadc8764edacfe546cd0cd0389a83c0..c44188271028063b510b07a993e2f6be6916b674 100644 (file)
--- a/drivers/media/dvb-frontends/mt312.c
+++ b/drivers/media/dvb-frontends/mt312.c
@@ -142,7 +142,10 @@ static inline int mt312_readreg(struct mt312_state *state,
 static inline int mt312_writereg(struct mt312_state *state,
                                 const enum mt312_reg_addr reg, const u8 val)
 {
-       return mt312_write(state, reg, &val, 1);
+       u8 tmp = val; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+
+       return mt312_write(state, reg, &tmp, 1);
 }
 
 static inline u32 mt312_div(u32 a, u32 b)

diff --git a/drivers/media/dvb-frontends/stb0899_drv.c b/drivers/media/dvb-frontends/stb0899_drv.c
index 756650f154abe4d778fce5554eb629ba144953cb..ad9b7d4f8d959d8382ea85160c688b1095257ddf 100644 (file)
--- a/drivers/media/dvb-frontends/stb0899_drv.c
+++ b/drivers/media/dvb-frontends/stb0899_drv.c
@@ -552,7 +552,8 @@ int stb0899_write_regs(struct stb0899_state *state, unsigned int reg, u8 *data,
 
 int stb0899_write_reg(struct stb0899_state *state, unsigned int reg, u8 data)
 {
-       return stb0899_write_regs(state, reg, &data, 1);
+       u8 tmp = data;
+       return stb0899_write_regs(state, reg, &tmp, 1);
 }
 
 /*

diff --git a/drivers/media/dvb-frontends/stb6100.c b/drivers/media/dvb-frontends/stb6100.c
index 4ef8a5c7003e907c2836e3ad77f6306fbafe1576..44fac257003485d0a5491be7ecbb33db37e0421e 100644 (file)
--- a/drivers/media/dvb-frontends/stb6100.c
+++ b/drivers/media/dvb-frontends/stb6100.c
@@ -226,12 +226,14 @@ static int stb6100_write_reg_range(struct stb6100_state *state, u8 buf[], int st
 
 static int stb6100_write_reg(struct stb6100_state *state, u8 reg, u8 data)
 {
+       u8 tmp = data; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
        if (unlikely(reg >= STB6100_NUMREGS)) {
                dprintk(verbose, FE_ERROR, 1, "Invalid register offset 0x%x", reg);
                return -EREMOTEIO;
        }
-       data = (data & stb6100_template[reg].mask) | stb6100_template[reg].set;
-       return stb6100_write_reg_range(state, &data, reg, 1);
+       tmp = (tmp & stb6100_template[reg].mask) | stb6100_template[reg].set;
+       return stb6100_write_reg_range(state, &tmp, reg, 1);
 }
 
 

diff --git a/drivers/media/dvb-frontends/stv0367.c b/drivers/media/dvb-frontends/stv0367.c
index 44cb73f68af658cf0a8f94c7a3e4476e51d9de5f..ddd0d778ad6e9a10f492282e27fd89243493f026 100644 (file)
--- a/drivers/media/dvb-frontends/stv0367.c
+++ b/drivers/media/dvb-frontends/stv0367.c
@@ -804,7 +804,9 @@ int stv0367_writeregs(struct stv0367_state *state, u16 reg, u8 *data, int len)
 
 static int stv0367_writereg(struct stv0367_state *state, u16 reg, u8 data)
 {
-       return stv0367_writeregs(state, reg, &data, 1);
+       u8 tmp = data; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return stv0367_writeregs(state, reg, &tmp, 1);
 }
 
 static u8 stv0367_readreg(struct stv0367_state *state, u16 reg)

diff --git a/drivers/media/dvb-frontends/stv090x.c b/drivers/media/dvb-frontends/stv090x.c
index 25bdf6e0f9632d18a64c0c4e42bda005d0d80c51..f0377e2b341b7933122cc71ca595aeb0b6803909 100644 (file)
--- a/drivers/media/dvb-frontends/stv090x.c
+++ b/drivers/media/dvb-frontends/stv090x.c
@@ -761,7 +761,9 @@ static int stv090x_write_regs(struct stv090x_state *state, unsigned int reg, u8
 
 static int stv090x_write_reg(struct stv090x_state *state, unsigned int reg, u8 data)
 {
-       return stv090x_write_regs(state, reg, &data, 1);
+       u8 tmp = data; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return stv090x_write_regs(state, reg, &tmp, 1);
 }
 
 static int stv090x_i2c_gate_ctrl(struct stv090x_state *state, int enable)

diff --git a/drivers/media/dvb-frontends/stv6110x.c b/drivers/media/dvb-frontends/stv6110x.c
index e66154e5c1d7710e0ddcc8c6183f707be0e388ea..45d14869e7b8726f82fded12669d4d5a04f7d817 100644 (file)
--- a/drivers/media/dvb-frontends/stv6110x.c
+++ b/drivers/media/dvb-frontends/stv6110x.c
@@ -97,7 +97,9 @@ static int stv6110x_write_regs(struct stv6110x_state *stv6110x, int start, u8 da
 
 static int stv6110x_write_reg(struct stv6110x_state *stv6110x, u8 reg, u8 data)
 {
-       return stv6110x_write_regs(stv6110x, reg, &data, 1);
+       u8 tmp = data; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return stv6110x_write_regs(stv6110x, reg, &tmp, 1);
 }
 
 static int stv6110x_init(struct dvb_frontend *fe)

diff --git a/drivers/media/dvb-frontends/zl10039.c b/drivers/media/dvb-frontends/zl10039.c
index ee09ec26c553ef7aa4e8387f4ba7bcab3948db37..b273e4fd80244e023dc9cacd28b8c012774072a9 100644 (file)
--- a/drivers/media/dvb-frontends/zl10039.c
+++ b/drivers/media/dvb-frontends/zl10039.c
@@ -138,7 +138,9 @@ static inline int zl10039_writereg(struct zl10039_state *state,
                                const enum zl10039_reg_addr reg,
                                const u8 val)
 {
-       return zl10039_write(state, reg, &val, 1);
+       const u8 tmp = val; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return zl10039_write(state, reg, &tmp, 1);
 }
 
 static int zl10039_init(struct dvb_frontend *fe)