[PATCH 19/26] [media] r820t: mark register functions as noinline_for_kasan

Arnd Bergmann
2017-03-02T16:48:22Z

With KASAN, we get an overly long stack frame due to inlining
the register access function:

drivers/media/tuners/r820t.c: In function 'generic_set_freq.isra.7':
drivers/media/tuners/r820t.c:1334:1: error: the frame size of 2880 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]

An earlier patch I tried used an open-coded r820t_write_reg()
implementation that may have been more efficent, while this
version simply adds the annotation, which has a lower risk for
regressions.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/media/tuners/r820t.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/tuners/r820t.c b/drivers/media/tuners/r820t.c
index ba80376a3b86..0fbfa6416e38 100644
--- a/drivers/media/tuners/r820t.c
+++ b/drivers/media/tuners/r820t.c
@@ -396,7 +396,7 @@ static int r820t_write(struct r820t_priv *priv, u8 reg, const u8 *val,
return 0;
}

-static int r820t_write_reg(struct r820t_priv *priv, u8 reg, u8 val)
+static noinline_for_kasan int r820t_write_reg(struct r820t_priv *priv, u8 reg, u8 val)
{
return r820t_write(priv, reg, &val, 1);
}
@@ -411,7 +411,7 @@ static int r820t_read_cache_reg(struct r820t_priv *priv, int reg)
return -EINVAL;
}

-static int r820t_write_reg_mask(struct r820t_priv *priv, u8 reg, u8 val,
+static noinline_for_kasan int r820t_write_reg_mask(struct r820t_priv *priv, u8 reg, u8 val,
u8 bit_mask)
{
int rc = r820t_read_cache_reg(priv, reg);
--
2.9.0