Re: [PATCH v2 05/17] compat_ioctl: move more drivers to generic_compat_ioctl_ptrarg
From: Darren Hart <dvhart@infradead.org>
Date: 2018-09-14 20:35:06
Also in:
amd-gfx, ceph-devel, dri-devel, linux-btrfs, linux-crypto, linux-fbdev, linux-fsdevel, linux-input, linux-media, linux-pci, linux-rdma, linux-remoteproc, linux-scsi, linux-usb, linuxppc-dev, lkml, netdev, nvdimm, platform-driver-x86, sparclinux
On Wed, Sep 12, 2018 at 05:08:52PM +0200, Arnd Bergmann wrote:
The .ioctl and .compat_ioctl file operations have the same prototype so they can both point to the same function, which works great almost all the time when all the commands are compatible. One exception is the s390 architecture, where a compat pointer is only 31 bit wide, and converting it into a 64-bit pointer requires calling compat_ptr(). Most drivers here will ever run in s390, but since we now have a generic helper for it, it's easy enough to use it consistently. I double-checked all these drivers to ensure that all ioctl arguments are used as pointers or are ignored, but are not interpreted as integer values. Signed-off-by: Arnd Bergmann <arnd@arndb.de> ---
...
drivers/platform/x86/wmi.c | 2 +-
...
quoted hunk ↗ jump to hunk
static void link_event_work(struct work_struct *work)diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index 04791ea5d97b..e4d0697e07d6 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c@@ -886,7 +886,7 @@ static const struct file_operations wmi_fops = { .read = wmi_char_read, .open = wmi_char_open, .unlocked_ioctl = wmi_ioctl, - .compat_ioctl = wmi_ioctl, + .compat_ioctl = generic_compat_ioctl_ptrarg, };
For platform/drivers/x86: Acked-by: Darren Hart (VMware) <dvhart@infradead.org> As for a longer term solution, would it be possible to init fops in such a way that the compat_ioctl call defaults to generic_compat_ioctl_ptrarg so we don't have to duplicate this boilerplate for every ioctl fops structure? -- Darren Hart VMware Open Source Technology Center