On Mon, May 15, 2017 at 03:46:55PM +0200, Arnd Bergmann wrote: > With CONFIG_KASAN enabled and gcc-7, we get a warning about rather high > stack usage (with a private patch set I have to turn on this warning, > which I intend to get into the next kernel release): > > wireless/ralink/rt2x00/rt2800lib.c: In function 'rt2800_bw_filter_calibration': > wireless/ralink/rt2x00/rt2800lib.c:7990:1: error: the frame size of 2144 bytes is larger than 1536 bytes [-Werror=frame-larger-than=] > > The problem is that KASAN inserts a redzone around each local variable that > gets passed by reference, and the newly added function has a lot of them. > We can easily avoid that here by changing the calling convention to have > the output as the return value of the function. This should also results in > smaller object code, saving around 4KB in .text with KASAN, or 2KB without > KASAN. > > Fixes: 41977e86c984 ("rt2x00: add support for MT7620") > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > drivers/net/wireless/ralink/rt2x00/rt2800lib.c | 319 +++++++++++++------------ > 1 file changed, 164 insertions(+), 155 deletions(-) We have read(, &val) calling convention since forever in rt2x00 and that was never a problem. I dislike to change that now to make some tools happy, I think problem should be fixed in the tools instead. Stanislaw