Commit fba616a4 authored Mar 07, 2020 by Eric Biggers Committed by Rafael J. Wysocki Mar 14, 2020

PM / hibernate: Remove unnecessary compat ioctl overrides



Since the SNAPSHOT_GET_IMAGE_SIZE, SNAPSHOT_AVAIL_SWAP_SIZE, and
SNAPSHOT_ALLOC_SWAP_PAGE ioctls produce an loff_t result, and loff_t is
always 64-bit even in the compat case, there's no reason to have the
special compat handling for these ioctls.  Just remove this unneeded
code so that these ioctls call into snapshot_ioctl() directly, doing
just the compat_ptr() conversion on the argument.

(This unnecessary code was also causing a KMSAN false positive.)

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 51995ff5

kernel/power/user.c

+1 −15

Original line number	Diff line number	Diff line
		@@ -409,21 +409,7 @@ snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
		switch (cmd) {
		case SNAPSHOT_GET_IMAGE_SIZE:
		case SNAPSHOT_AVAIL_SWAP_SIZE:
		case SNAPSHOT_ALLOC_SWAP_PAGE: {
		compat_loff_t __user *uoffset = compat_ptr(arg);
		loff_t offset;
		mm_segment_t old_fs;
		int err;

		old_fs = get_fs();
		set_fs(KERNEL_DS);
		err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
		set_fs(old_fs);
		if (!err && put_user(offset, uoffset))
		err = -EFAULT;
		return err;
		}

		case SNAPSHOT_ALLOC_SWAP_PAGE:
		case SNAPSHOT_CREATE_IMAGE:
		return snapshot_ioctl(file, cmd,
		(unsigned long) compat_ptr(arg));

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