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.

Cc: stable@vger.kernel.org Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 Signed-off-by: Arnd Bergmann arnd@arndb.de --- v2: add a comment for each instance of the problem, linking to the gcc bugzilla (I left out the http:// so it would fit in one line) --- drivers/media/dvb-frontends/ascot2e.c | 4 +++- drivers/media/dvb-frontends/cxd2841er.c | 4 +++- drivers/media/dvb-frontends/helene.c | 4 +++- drivers/media/dvb-frontends/horus3a.c | 4 +++- drivers/media/dvb-frontends/itd1000.c | 5 +++-- drivers/media/dvb-frontends/mt312.c | 5 ++++- drivers/media/dvb-frontends/stb0899_drv.c | 3 ++- drivers/media/dvb-frontends/stb6100.c | 6 ++++-- drivers/media/dvb-frontends/stv0367.c | 4 +++- drivers/media/dvb-frontends/stv090x.c | 4 +++- drivers/media/dvb-frontends/stv6110x.c | 4 +++- drivers/media/dvb-frontends/zl10039.c | 4 +++- 12 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/drivers/media/dvb-frontends/ascot2e.c b/drivers/media/dvb-frontends/ascot2e.c index 0ee0df53b91b..79d5d89bc95e 100644 --- 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 48ee9bc00c06..ccbd84fd6428 100644 --- a/drivers/media/dvb-frontends/cxd2841er.c +++ b/drivers/media/dvb-frontends/cxd2841er.c @@ -257,7 +257,9 @@ 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 4bf5a551ba40..2ab8d83e5576 100644 --- 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 68d759c4c52e..5c8b405f2ddc 100644 --- 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 5bb1e73a10b4..ce7c443d3eac 100644 --- a/drivers/media/dvb-frontends/itd1000.c +++ b/drivers/media/dvb-frontends/itd1000.c @@ -95,8 +95,9 @@ 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 961b9a2508e0..0b23cbc021b8 100644 --- 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 02347598277a..db5dde3215f0 100644 --- a/drivers/media/dvb-frontends/stb0899_drv.c +++ b/drivers/media/dvb-frontends/stb0899_drv.c @@ -539,7 +539,8 @@ 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 17a955d0031b..75509bec66e4 100644 --- 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 f3529df8211d..1a726196c126 100644 --- a/drivers/media/dvb-frontends/stv0367.c +++ b/drivers/media/dvb-frontends/stv0367.c @@ -166,7 +166,9 @@ 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 7ef469c0c866..2695e1eb6d9c 100644 --- a/drivers/media/dvb-frontends/stv090x.c +++ b/drivers/media/dvb-frontends/stv090x.c @@ -755,7 +755,9 @@ 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 66eba38f1014..7e8e01389c55 100644 --- 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 623355fc2666..3208b866d1cb 100644 --- a/drivers/media/dvb-frontends/zl10039.c +++ b/drivers/media/dvb-frontends/zl10039.c @@ -134,7 +134,9 @@ 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)