With CONFIG_KASAN, this driver has shown a ridiculously large stack frame in one configuration:
drivers/media/i2c/cx25840/cx25840-core.c:4960:1: error: the frame size of 94000 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
In most builds, it's only about 3300 bytes, but that's still large anough to risk a kernel stack overflow.
Marking the two register access functions as noinline_for_kasan avoids the problem and brings the largest stack frame size down to 232 bytes.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/i2c/cx25840/cx25840-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/i2c/cx25840/cx25840-core.c b/drivers/media/i2c/cx25840/cx25840-core.c index b8d3c070bfc1..fd72e5a11cb9 100644 --- a/drivers/media/i2c/cx25840/cx25840-core.c +++ b/drivers/media/i2c/cx25840/cx25840-core.c @@ -81,7 +81,7 @@ MODULE_PARM_DESC(debug, "Debugging messages [0=Off (default) 1=On]"); /* ----------------------------------------------------------------------- */ static void cx23888_std_setup(struct i2c_client *client);
-int cx25840_write(struct i2c_client *client, u16 addr, u8 value) +noinline_for_kasan int cx25840_write(struct i2c_client *client, u16 addr, u8 value) { u8 buffer[3]; buffer[0] = addr >> 8; @@ -90,7 +90,7 @@ int cx25840_write(struct i2c_client *client, u16 addr, u8 value) return i2c_master_send(client, buffer, 3); }
-int cx25840_write4(struct i2c_client *client, u16 addr, u32 value) +noinline_for_kasan int cx25840_write4(struct i2c_client *client, u16 addr, u32 value) { u8 buffer[6]; buffer[0] = addr >> 8;