[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] xen: allocate gntdev_copy_batch dynamically
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") --- This is a regression against v4.4, found with ARM randconfig testing. diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index dc495383ad73..cc753b3a7154 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -915,15 +915,16 @@ static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch, static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u) { struct ioctl_gntdev_grant_copy copy; - struct gntdev_copy_batch batch; + struct gntdev_copy_batch *batch; unsigned int i; int ret = 0; if (copy_from_user(©, u, sizeof(copy))) return -EFAULT; - batch.nr_ops = 0; - batch.nr_pages = 0; + batch = kzalloc(sizeof(*batch), GFP_KERNEL); + if (!batch) + return -ENOMEM; for (i = 0; i < copy.count; i++) { struct gntdev_grant_copy_segment seg; @@ -933,18 +934,20 @@ static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u) goto out; } - ret = gntdev_grant_copy_seg(&batch, &seg, ©.segments[i].status); + ret = gntdev_grant_copy_seg(batch, &seg, ©.segments[i].status); if (ret < 0) goto out; cond_resched(); } - if (batch.nr_ops) - ret = gntdev_copy(&batch); + if (batch->nr_ops) + ret = gntdev_copy(batch); + kfree(batch); return ret; out: - gntdev_put_pages(&batch); + gntdev_put_pages(batch); + kfree(batch); return ret; } _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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