[PATCH] PM / hibernate: Remove unnecessary compat ioctl overrides

Eric Biggers
2020-03-08T03:27:57Z

From: Eric Biggers <ebiggers@google.com>

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>
---
kernel/power/user.c | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 77438954cc2b..58ed9478787f 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -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));
--
2.25.1