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
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 ad304eed656d7e16f14261281145706fe2e73330..c61227cfff2583f746a9595949ffa5f7213844d1 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 fd0f25ee251f8dd86ce496551d6c8cbc6b083f4b..b97647cd7dc61b3703c44636614a15a87f765fcd 100644 (file)
--- a/drivers/media/dvb-frontends/cxd2841er.c
+++ b/drivers/media/dvb-frontends/cxd2841er.c
@@ -261,7 +261,9 @@ 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/helene.c b/drivers/media/dvb-frontends/helene.c
index dc43c5f6d0ea450c96b8e8c27d4533b0ed59c1a6..e06bcd4b3ddc0379a9d4dda6eaaf8f9a74318de2 100644 (file)
--- a/drivers/media/dvb-frontends/helene.c
+++ b/drivers/media/dvb-frontends/helene.c
@@ -331,7 +331,9 @@ static int helene_write_regs(struct helene_priv *priv,
 
 static int helene_write_reg(struct helene_priv *priv, u8 reg, u8 val)
 {
-       return helene_write_regs(priv, reg, &val, 1);
+       u8 tmp = val; /* see gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
+
+       return helene_write_regs(priv, reg, &tmp, 1);
 }
 
 static int helene_read_regs(struct helene_priv *priv,

diff --git a/drivers/media/dvb-frontends/horus3a.c b/drivers/media/dvb-frontends/horus3a.c
index 0c089b5986a1928faceabdedf65034396f549fcd..4ebddc895137d93bd69370009e66bd209eb22b96 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 fc08429c99b7debbe2848c0d2f76e1c6d15aa8ee..7824926a37440fbc6fc39618b80710b1cb44d88c 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 3d171b0e00c2a742d41737b176418d40d155093d..3deddbcaa8b76303fa3d9d1a1afab0efee777aaf 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 5add1182c3cae6f5f172d0a4e57e82c46ea8ed74..4746b1e0d637bfeddd1bd830e1d05a9d46a0aa54 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 abc379aea713f5e6a93ac34dc5531e1cbf6124b9..94cec81d0a5c7514ea17df15d8b392eb496dba2a 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 c611ad210b5c264fe2f3c5f0dfa0b452f7ed5f6c..924f16fee1fb602c371141042d78b7d699321da7 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 f8c271be196c19180007560b73f7272f3c804719..0d2bef62ff0532fdc7e0cf999d98164c9072c35e 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)