From: Scott Bauer Sent: 13 February 2017 16:11
> When CONFIG_KASAN is enabled, compilation fails:
>
> block/sed-opal.c: In function 'sed_ioctl':
> block/sed-opal.c:2447:1: error: the frame size of 2256 bytes is larger than 2048 bytes [-Werror=frame-
> larger-than=]
>
> Moved all the ioctl structures off the stack and dynamically activate
> using _IOC_SIZE()
Think I'd not that this simplifies the code considerably.
AFAICT CONFIG_KASAN is a just brainf*ck.
It at least needs annotation that copy_from_user() has properties
similar to memset().
So if the size matches that of the type then no guard space (etc)
is required.
...
> + ioctl_ptr = memdup_user(arg, _IOC_SIZE(cmd));
> + if (IS_ERR_OR_NULL(ioctl_ptr)) {
> + ret = PTR_ERR(ioctl_ptr);
> + goto out;
...
> + out:
> + kfree(ioctl_ptr);
> + return ret;
> }
That error path doesn't look quite right to me.
David
