* improve the uswsusp ioctl handling to avoid set_fs
@ 2020-04-06 11:58 Christoph Hellwig
2020-04-06 11:58 ` [PATCH 1/2] PM / sleep: move SNAPSHOT_SET_SWAP_AREA handling into a helper Christoph Hellwig
2020-04-06 11:58 ` [PATCH 2/2] PM / sleep: handle the compat case in snapshot_set_swap_area Christoph Hellwig
0 siblings, 2 replies; 4+ messages in thread
From: Christoph Hellwig @ 2020-04-06 11:58 UTC (permalink / raw)
To: Rafael J. Wysocki, Len Brown, Pavel Machek; +Cc: linux-pm, linux-kernel
Hi all,
this series refactors the uswsusp ioctl so that no rewriting of
the ioctl structure for the compat case, and thus messing with the
address limit is required.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/2] PM / sleep: move SNAPSHOT_SET_SWAP_AREA handling into a helper
2020-04-06 11:58 improve the uswsusp ioctl handling to avoid set_fs Christoph Hellwig
@ 2020-04-06 11:58 ` Christoph Hellwig
2020-04-06 11:58 ` [PATCH 2/2] PM / sleep: handle the compat case in snapshot_set_swap_area Christoph Hellwig
1 sibling, 0 replies; 4+ messages in thread
From: Christoph Hellwig @ 2020-04-06 11:58 UTC (permalink / raw)
To: Rafael J. Wysocki, Len Brown, Pavel Machek; +Cc: linux-pm, linux-kernel
Move the handling of the SNAPSHOT_SET_SWAP_AREA ioctl from the main
ioctl helper into a helper function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/power/user.c | 57 +++++++++++++++++++++++----------------------
1 file changed, 29 insertions(+), 28 deletions(-)
diff --git a/kernel/power/user.c b/kernel/power/user.c
index ef90eb1fb86e..0cb555f526e4 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -196,6 +196,34 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
return res;
}
+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;
+
+ /*
+ * 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;
+ return 0;
+}
+
static long snapshot_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
@@ -351,34 +379,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
break;
case SNAPSHOT_SET_SWAP_AREA:
- if (swsusp_swap_in_use()) {
- error = -EPERM;
- } else {
- struct resume_swap_area swap_area;
- dev_t swdev;
-
- error = copy_from_user(&swap_area, (void __user *)arg,
- sizeof(struct resume_swap_area));
- if (error) {
- error = -EFAULT;
- break;
- }
-
- /*
- * User space encodes device types as two-byte values,
- * so we need to recode them
- */
- swdev = new_decode_dev(swap_area.dev);
- if (swdev) {
- offset = swap_area.offset;
- data->swap = swap_type_of(swdev, offset, NULL);
- if (data->swap < 0)
- error = -ENODEV;
- } else {
- data->swap = -1;
- error = -EINVAL;
- }
- }
+ error = snapshot_set_swap_area(data, (void __user *)arg);
break;
default:
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] PM / sleep: handle the compat case in snapshot_set_swap_area
2020-04-06 11:58 improve the uswsusp ioctl handling to avoid set_fs Christoph Hellwig
2020-04-06 11:58 ` [PATCH 1/2] PM / sleep: move SNAPSHOT_SET_SWAP_AREA handling into a helper Christoph Hellwig
@ 2020-04-06 11:58 ` Christoph Hellwig
2020-04-06 19:45 ` Rafael J. Wysocki
1 sibling, 1 reply; 4+ messages in thread
From: Christoph Hellwig @ 2020-04-06 11:58 UTC (permalink / raw)
To: Rafael J. Wysocki, Len Brown, Pavel Machek; +Cc: linux-pm, linux-kernel
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 = {
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] PM / sleep: handle the compat case in snapshot_set_swap_area
2020-04-06 11:58 ` [PATCH 2/2] PM / sleep: handle the compat case in snapshot_set_swap_area Christoph Hellwig
@ 2020-04-06 19:45 ` Rafael J. Wysocki
0 siblings, 0 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2020-04-06 19:45 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Rafael J. Wysocki, Len Brown, Pavel Machek, Linux PM,
Linux Kernel Mailing List
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!
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-04-06 19:45 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2020-04-06 11:58 improve the uswsusp ioctl handling to avoid set_fs Christoph Hellwig
2020-04-06 11:58 ` [PATCH 1/2] PM / sleep: move SNAPSHOT_SET_SWAP_AREA handling into a helper Christoph Hellwig
2020-04-06 11:58 ` [PATCH 2/2] PM / sleep: handle the compat case in snapshot_set_swap_area Christoph Hellwig
2020-04-06 19:45 ` Rafael J. Wysocki
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