Re: [PATCH, RESEND] xen: allocate gntdev_copy_batch dynamically

From: Boris Ostrovsky
Date: Fri Feb 26 2016 - 08:44:57 EST

On 02/25/2016 04:25 PM, Arnd Bergmann wrote:
struct gntdev_copy_batch is arguably too large to fit on the kernel stack,
and we get a warning about the stack usage in gntdev_ioctl_grant_copy:

drivers/xen/gntdev.c:949:1: error: the frame size of 1240 bytes is larger than 1024 bytes

This changes the code to us a dynamic allocation instead.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Fixes: a4cdb556cae0 ("xen/gntdev: add ioctl for grant copy")
drivers/xen/gntdev.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

I sent this in January, Boris sent an almost identical patch
but the bug remains present in mainline and linux-next as of
Feb 25.

Could you apply one of the patches before the bug makes it
into v4.5?

David wanted to shrink the structure size instead: