[RFC PATCH v3 12/12] PM / hibernate: update the resume offset on SNAPSHOT_SET_SWAP_AREA

From: Anchal Agarwal
Date: Fri Feb 14 2020 - 18:28:39 EST


From: Aleksei Besogonov <cyberax@xxxxxxxxxx>

The SNAPSHOT_SET_SWAP_AREA is supposed to be used to set the hibernation
offset on a running kernel to enable hibernating to a swap file.
However, it doesn't actually update the swsusp_resume_block variable. As
a result, the hibernation fails at the last step (after all the data is
written out) in the validation of the swap signature in
mark_swapfiles().

Before this patch, the command line processing was the only place where
swsusp_resume_block was set.

Signed-off-by: Aleksei Besogonov <cyberax@xxxxxxxxxx>
Signed-off-by: Munehisa Kamata <kamatam@xxxxxxxxxx>
Signed-off-by: Anchal Agarwal <anchalag@xxxxxxxxxx>
---
kernel/power/user.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 77438954cc2b..d396e313cb7b 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -374,8 +374,12 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
if (swdev) {
offset = swap_area.offset;
data->swap = swap_type_of(swdev, offset, NULL);
- if (data->swap < 0)
+ if (data->swap < 0) {
error = -ENODEV;
+ } else {
+ swsusp_resume_device = swdev;
+ swsusp_resume_block = offset;
+ }
} else {
data->swap = -1;
error = -EINVAL;
--
2.24.1.AMZN