Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Mon, 6 Apr 2020 21:45:17 +0200 | Subject | Re: [PATCH 2/2] PM / sleep: handle the compat case in snapshot_set_swap_area |
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On Mon, Apr 6, 2020 at 1:58 PM Christoph Hellwig <hch@lst.de> wrote: > > Use in_compat_syscall to copy directly from the 32-bit ABI structure. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > kernel/power/user.c | 54 ++++++++++++++++++--------------------------- > 1 file changed, 22 insertions(+), 32 deletions(-) > > diff --git a/kernel/power/user.c b/kernel/power/user.c > index 0cb555f526e4..7959449765d9 100644 > --- a/kernel/power/user.c > +++ b/kernel/power/user.c > @@ -196,28 +196,44 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf, > return res; > } > > +struct compat_resume_swap_area { > + compat_loff_t offset; > + u32 dev; > +} __packed; > + > static int snapshot_set_swap_area(struct snapshot_data *data, > void __user *argp) > { > - struct resume_swap_area swap_area; > sector_t offset; > dev_t swdev; > > if (swsusp_swap_in_use()) > return -EPERM; > - if (copy_from_user(&swap_area, argp, sizeof(swap_area))) > - return -EFAULT; > + > + if (in_compat_syscall()) { > + struct compat_resume_swap_area swap_area; > + > + if (copy_from_user(&swap_area, argp, sizeof(swap_area))) > + return -EFAULT; > + swdev = new_decode_dev(swap_area.dev); > + offset = swap_area.offset; > + } else { > + struct resume_swap_area swap_area; > + > + if (copy_from_user(&swap_area, argp, sizeof(swap_area))) > + return -EFAULT; > + swdev = new_decode_dev(swap_area.dev); > + offset = swap_area.offset; > + } > > /* > * User space encodes device types as two-byte values, > * so we need to recode them > */ > - swdev = new_decode_dev(swap_area.dev); > if (!swdev) { > data->swap = -1; > return -EINVAL; > } > - offset = swap_area.offset; > data->swap = swap_type_of(swdev, offset, NULL); > if (data->swap < 0) > return -ENODEV; > @@ -394,12 +410,6 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, > } > > #ifdef CONFIG_COMPAT > - > -struct compat_resume_swap_area { > - compat_loff_t offset; > - u32 dev; > -} __packed; > - > static long > snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > { > @@ -410,33 +420,13 @@ snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > case SNAPSHOT_AVAIL_SWAP_SIZE: > case SNAPSHOT_ALLOC_SWAP_PAGE: > case SNAPSHOT_CREATE_IMAGE: > + case SNAPSHOT_SET_SWAP_AREA: > return snapshot_ioctl(file, cmd, > (unsigned long) compat_ptr(arg)); > - > - case SNAPSHOT_SET_SWAP_AREA: { > - struct compat_resume_swap_area __user *u_swap_area = > - compat_ptr(arg); > - struct resume_swap_area swap_area; > - mm_segment_t old_fs; > - int err; > - > - err = get_user(swap_area.offset, &u_swap_area->offset); > - err |= get_user(swap_area.dev, &u_swap_area->dev); > - if (err) > - return -EFAULT; > - old_fs = get_fs(); > - set_fs(KERNEL_DS); > - err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA, > - (unsigned long) &swap_area); > - set_fs(old_fs); > - return err; > - } > - > default: > return snapshot_ioctl(file, cmd, arg); > } > } > - > #endif /* CONFIG_COMPAT */ > > static const struct file_operations snapshot_fops = { > --
Applied along with the [1/2] as 5.7-rc material, thanks!
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