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

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>
This commit is contained in:
Arnd Bergmann
2017-11-30 11:55:46 -05:00
committed by Mauro Carvalho Chehab
parent 16c3ada89c
commit 3cd890dbe2
12 changed files with 37 additions and 14 deletions

View File

@@ -258,7 +258,9 @@ 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,