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@tohanov tohanov commented Oct 15, 2025

Super simple typo fix

Daz-3ux and others added 30 commits October 26, 2024 22:17
This patch fixes the following warnings that appear
when building an RPM package:

+ /usr/lib/rpm/redhat/brp-mangle-shebangs
*** WARNING: ./usr/src/debug/criu-4.0-1.fc42.x86_64/plugins/amdgpu/amdgpu_plugin_util.c is executable but has no shebang, removing executable bit
*** WARNING: ./usr/src/debug/criu-4.0-1.fc42.x86_64/plugins/amdgpu/amdgpu_plugin_util.h is executable but has no shebang, removing executable bit

Signed-off-by: Radostin Stoyanov <[email protected]>
By default, CRIU uses the path "/usr/lib/criu" to install and load
plugins at runtime. This path is defined by the `PLUGINDIR` variable
in Makefile.install and `CR_PLUGIN_DEFAULT` in `criu/include/plugin.h`.
However, some distribution packages might install the CRIU plugins at
"/usr/lib64/criu" instead. This patch updates the makefile to align
the path defined by `CR_PLUGIN_DEFAULT` with the value of `PLUGINDIR`.

Signed-off-by: Radostin Stoyanov <[email protected]>
We only use the last pid from the list in NSpid entry (from
/proc/<pid>/fdinfo/<pidfd>) while restoring pidfds.
The last pid refers to the pid of the process in the most deeply nested
pid namespace. Since CRIU does not currently support nested pid
namespaces, this entry is the one we want.

After Linux 6.9, inode numbers can be used to compare pidfds. pidfds
referring to the same process will have the same inode numbers. We use
inode numbers to restore pidfds that point to dead processes.

Signed-off-by: Bhavik Sachdev <[email protected]>
Process file descriptors (pidfds) were introduced to provide a stable
handle on a process. They solve the problem of pid recycling.

For a detailed explanation, see https://lwn.net/Articles/801319/ and
http://www.corsix.org/content/what-is-a-pidfd

Before Linux 6.9, anonymous inodes were used for the implementation of
pidfds. So, we detect them in a fashion similiar to other fd types that
use anonymous inodes by calling `readlink()`.
After 6.9, pidfs (a file system for pidfds) was introduced.
In 6.9 `S_ISREG()` returned true for pidfds, but this again changed with
6.10.
(https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/pidfs.c?h=v6.11-rc2#n285)
After this change, pidfs inodes have no file type in st_mode in
userspace.
We use `PID_FS_MAGIC` to detect pidfds for kernel >= 6.9
Hence, check for pidfds occurs before the check for regular files.

For pidfds that refer to dead processes, we lose the pid of the process
as the Pid and NSpid fields in /proc/<pid>/fdinfo/<pidfd> change to -1.
So, we create a temporary process for each unique inode and open pidfds
that refer to this process. After all pidfds have been opened we kill
this temporary process.

This commit does not include support for pidfds that point to a specific
thread, i.e pidfds opened with `PIDFD_THREAD` flag.

Fixes: checkpoint-restore#2258

Signed-off-by: Bhavik Sachdev <[email protected]>
Ensures that entries in /proc/<pid>/fdinfo/<pidfd> are same.

Signed-off-by: Bhavik Sachdev <[email protected]>
Ensure `pidfd_send_signal()` syscall works as expected after C/R.

Signed-off-by: Bhavik Sachdev <[email protected]>
Validate that pidfds can been used to send signals to different
processes after C/R using the `pidfd_send_signal()` syscall.

Signed-off-by: Bhavik Sachdev <[email protected]>
After, C/R of pidfds that point to dead processes their inodes might
change. But if two pidfds point to same dead process they should
continue to do so after C/R.

This test ensures that this happens by calling `statx()` on pidfds after
C/R and then comparing their inode numbers.

Support for comparing pidfds by using `statx()` and inode numbers was
introduced alongside pidfs. So if `f_type` of pidfd is not equal to
`PID_FS_MAGIC` then we skip this test.

signed-off-by: Bhavik Sachdev <[email protected]>
We get the read end of a pipe using `pidfd_getfd` and check if we can
read from it after C/R.

signed-off-by: Bhavik Sachdev <[email protected]>
We open a pidfd to a thread using `PIDFD_THREAD` flag and after C/R
ensure that we can send signals using it with `PIDFD_SIGNAL_THREAD`.

signed-off-by: Bhavik Sachdev <[email protected]>
The command `ruff <path>` has been deprecated and removed:
https://astral.sh/blog/ruff-v0.5.0#removed-deprecated-features

Signed-off-by: Radostin Stoyanov <[email protected]>
This patch fixes the following errors reported by ruff:

lib/pycriu/images/pb2dict.py:307:24: E721 Use `is` and `is not` for type comparisons, or `isinstance()` for isinstance checks
    |
305 |     elif field.type in _basic_cast:
306 |         cast = _basic_cast[field.type]
307 |         if pretty and (cast == int):
    |                        ^^^^^^^^^^^ E721
308 |             if is_hex:
309 |                 # Fields that have (criu).hex = true option set
    |

lib/pycriu/images/pb2dict.py:379:13: E721 Use `is` and `is not` for type comparisons, or `isinstance()` for isinstance checks
    |
377 |     elif field.type in _basic_cast:
378 |         cast = _basic_cast[field.type]
379 |         if (cast == int) and is_string(value):
    |             ^^^^^^^^^^^ E721
380 |             if _marked_as_dev(field):
381 |                 return encode_dev(field, value)
    |

Signed-off-by: Radostin Stoyanov <[email protected]>
This patch extends the inventory image with a `plugins` field that
contains an array of plugins which were used during checkpoint,
for example, to save GPU state. In particular, the CUDA and AMDGPU
plugins are added to this field only when the checkpoint contains
GPU state. This allows to disable unnecessary plugins during restore,
show appropriate error messages if required CRIU plugin are missing,
and migrate a process that does not use GPU from a GPU-enabled system
to CPU-only environment.

We use the `optional plugins_entry` for backwards compatibility. This
entry allows us to distinguish between *unset* and *missing* field:

- When the field is missing, it indicates that the checkpoint was
  created with a previous version of CRIU, and all plugins should be
  *enabled* during restore.

- When the field is empty, it indicates that no plugins were used during
  checkpointing. Thus, all plugins can be *disabled* during restore.

Signed-off-by: Radostin Stoyanov <[email protected]>
This patch adds two test plugins to verify that CRIU plugins listed
in the inventory image are enabled, while those that are not listed
can be disabled.

Signed-off-by: Radostin Stoyanov <[email protected]>
This patch blocks SIGCHLD during temporary process creation to prevent a
race condition between kill() and waitpid() where sigchld_handler()
causes `criu restore` to fail with an error.

Fixes: checkpoint-restore#2490

Signed-off-by: Bhavik Sachdev <[email protected]>
Signed-off-by: Radostin Stoyanov <[email protected]>
Co-authored-by: Yixue Zhao <[email protected]>
Co-authored-by: stove <[email protected]>
Signed-off-by: Haorong Lu <[email protected]>
---
- rebased
- imported a page_size() type fix (authored by Cryolitia PukNgae)
Signed-off-by: PukNgae Cryolitia <[email protected]>
Signed-off-by: Alexander Mikhalitsyn <[email protected]>
Co-authored-by: Yixue Zhao <[email protected]>
Co-authored-by: stove <[email protected]>
Signed-off-by: Haorong Lu <[email protected]>
---
- rebased
- added a membarrier() to syscall table (fix authored by Cryolitia PukNgae)
Signed-off-by: PukNgae Cryolitia <[email protected]>
Signed-off-by: Alexander Mikhalitsyn <[email protected]>
Co-authored-by: Yixue Zhao <[email protected]>
Co-authored-by: stove <[email protected]>
Signed-off-by: Haorong Lu <[email protected]>
Co-authored-by: Yixue Zhao <[email protected]>
Co-authored-by: stove <[email protected]>
Signed-off-by: Haorong Lu <[email protected]>
Link: SerenityOS/serenity@e300da4

Signed-off-by: PukNgae Cryolitia <[email protected]>
---
- cherry-picked
Signed-off-by: Alexander Mikhalitsyn <[email protected]>
After a fork, both the child and parent processes may trigger a page fault (#PF)
at the same virtual address, referencing the same position in the page image.
If deduplication is enabled, the last process to trigger the page fault will fail.

Therefore, deduplication should be disabled after a fork to prevent this issue.

Signed-off-by: Liu Hua <[email protected]>
When restoring dumps in new mount + pid namespaces where multiple dumps
share the same network namespace, CRIU may fail due to conflicting
unix socket names. This happens because the service worker creates
sockets using a pattern that includes criu_run_id, but util_init()
is called after cr_service_work() starts.

The socket naming pattern "crtools-fd-%d-%d" uses the restore PID
and criu_run_id, however criu_run_id is always 0 when not initialized,
leading to conflicts when multiple restores run simultaneously either
in the same CRIU process or because of multiple CRIU processes
doing the same operation in different PID namespaces.

Fix this by:

- Moving util_init() before cr_service_work() starts
- Adding a second util_init() call in the service worker fork
to ensure unique IDs across multiple worker runs
- Making sure that dump and restore operations have util_init() called
early to generate unique socket names

With this fix, socket names always include the namespace ID, preventing
conflicts when multiple processes with the same pid share a network
namespace.

Fixes checkpoint-restore#2499

[ avagin: minore code changes ]

Signed-off-by: Lorenzo Fontana <[email protected]>
Signed-off-by: Andrei Vagin <[email protected]>
When `check_freezer_cgroup()` has non-zero return value, `goto err` calls
`return ret`. However, the value of `ret` has been set to `0` in the lines
above and CRIU does not handle the error properly.

This problem is related to checkpoint-restore#2508

Signed-off-by: Radostin Stoyanov <[email protected]>
Container runtimes like CRI-O and containerd utilize the freezer cgroup
to create a consistent snapshot of container root filesystem (rootfs)
changes. In this case, the container is frozen before invoking CRIU.
After CRIU successfully completes, a copy of the container rootfs diff
is saved, and the container is then unfrozen.

However, the `cuda-checkpoint` tool is not able to perform a 'lock'
action on frozen threads.  To support GPU checkpointing with these
container runtimes, we need to unfreeze the cgroup and return it to its
original state once the checkpointing is complete.

To reflect this new behavior, the following changes are applied:
 - `dont_use_freeze_cgroup(void)` -> `set_compel_interrupt_only_mode(void)`
 - `bool freeze_cgroup_disabled` -> `bool compel_interrupt_only_mode`
 - `check_freezer_cgroup(void)` -> `prepare_freezer_for_interrupt_only_mode(void)`

Note that when `compel_interrupt_only_mode` is set to `true`,
`compel_interrupt_task()` is used instead of `freeze_processes()`
to prevent tasks from running during `criu dump`.

Fixes: checkpoint-restore#2508

Signed-off-by: Radostin Stoyanov <[email protected]>
The check for `/dev/nvidiactl` to determine if the CUDA plugin can be
used is unreliable because in some cases the default path for driver
installation is different [1]. This patch changes the logic to check
if a GPU device is available in `/proc/driver/nvidia/gpus/`. This
approach is similar to `torch.cuda.is_available()` and it is a more
accurate indicator.

The subsequent check for support of the `cuda-checkpoint --action`
option would confirm if the driver supports checkpoint/restore.

[1] https://github.com/NVIDIA/gpu-operator

Fixes: checkpoint-restore#2509

Signed-off-by: Radostin Stoyanov <[email protected]>
Currently, the `waitpid()` call on the tmp process can be made by a
process which is not its parent. This causes restore to fail.

This patch instead selects one process to create the tmp process and
open all the fds that point to it. These fds are sent to the correct
process(es).

Fixes: checkpoint-restore#2496

Signed-off-by: Andrei Vagin <[email protected]>
Signed-off-by: Bhavik Sachdev <[email protected]>
rst0git and others added 16 commits September 30, 2025 07:38
Currently we run aarch64 tests on both Cirrus CI and GitHub runners.
However, Cirrus CI fails with "Monthly compute limit exceeded!". This
change removes the redundant tests to streamline our CI process.

Signed-off-by: Radostin Stoyanov <[email protected]>
Our previous mailing list had some technical issues and we created
a new one that is hopefully more reliable.

Signed-off-by: Radostin Stoyanov <[email protected]>
page_pipe_read() expects an 'unsigned long *', but pi->nr_pages is u64.
On 32-bit platforms (e.g., armv7), passing &pi->nr_pages directly causes
a compiler error. To fix this we introduce a temporary variable and copy
the result back to pi->nr_pages.

Fixes: checkpoint-restore#2756

Suggested-by: Andrei Vagin <[email protected]>
Signed-off-by: Radostin Stoyanov <[email protected]>
Compilation on gentoo/arm64 (llvm+musl) fails with:

In file included from compel/include/uapi/compel/asm/sigframe.h:4,
                 from compel/plugins/std/infect.c:14:
/usr/include/asm/sigcontext.h:28:8: error: redefinition of 'struct sigcontext'
   28 | struct sigcontext {
      |        ^~~~~~~~~~

In file included from criu/arch/aarch64/include/asm/restorer.h:4,
                 from criu/arch/aarch64/crtools.c:11:
/usr/include/asm/sigcontext.h:28:8: error: redefinition of 'struct sigcontext'
   28 | struct sigcontext {
      |        ^~~~~~~~~~

This is happening because <asm/sigcontext.h> and <signal.h> are
mutually incompatible on Linux.

To fix, use  <signal.h> instead of <asm/sigcontext.h> for arm64
(like all others arches do).

Fixes: checkpoint-restore#2766
Signed-off-by: Pepper Gray <[email protected]>
These tests reveal the following build error:

In file included from compel/include/uapi/compel/asm/sigframe.h:4,
                 from compel/plugins/std/infect.c:14:
/usr/include/asm/sigcontext.h:28:8: error: redefinition of 'struct sigcontext'
   28 | struct sigcontext {
      |        ^~~~~~~~~~

In file included from criu/arch/aarch64/include/asm/restorer.h:4,
                 from criu/arch/aarch64/crtools.c:11:
/usr/include/asm/sigcontext.h:28:8: error: redefinition of 'struct sigcontext'
   28 | struct sigcontext {
      |        ^~~~~~~~~~

Inspired by checkpoint-restore#2766 / checkpoint-restore#2767.

Signed-off-by: Kir Kolyshkin <[email protected]>
Signed-off-by: Radostin Stoyanov <[email protected]>
Add a ZDTM test case where CRIU uses a helper process to restore
a non-empty process group with a terminated leader and a Unix
domain socket. This reproduces a corner case in which mount
namespace switching can fail during restore:

checkpoint-restore#2687

Signed-off-by: Qiao Ma <[email protected]>
Signed-off-by: Radostin Stoyanov <[email protected]>
This flag will be used for a "[uprobes]" vma.

Signed-off-by: Shashank Balaji <[email protected]>
Signed-off-by: Shashank Balaji <[email protected]>
This commit teaches criu to deal with processes which have a "[uprobes]" vma.

This vma is mapped by the kernel when execution hits a uprobe location. This
is done so as to execute the uprobe'd instruciton out-of-line in the special
vma. The uprobe'd location is replaced by a software breakpoint instruction,
which is int3 on x86. When execution reaches that location, control is
transferred over to the kernel, which then executes whatever handler code
it has to, for the uprobe, and then executed the replaced instruction out-of-line
in the special vma. For more details, refer to this commit:
torvalds/linux@d4b3b63

Reason for adding a new option
------------------------------

A new option is added instead of making the uprobes vma handling transparent
to the user, so that when a dump is attempted on a process tree in which a
process has the uprobes vma, criu will error, asking the user to use this option.
This gives the user a chance to check what uprobes are attached to the processes
being dumped, and try to ensure that those uprobes are active on restore as well.

Again, the same reason for requiring this option on restore as well. Because
if a process is dumped with an active uprobe, and on restore if the uprobe
is not active, then if execution reaches the uprobe location, then the process
will be sent a SIGTRAP, whose default behaviour will terminate and core dump
the process. This is because the code pages are dumped with the software
breakpoint instruction replacement at the uprobe'd locations. On restore, if
execution reaches these locations and the kernel sees no associated active
uprobes, then it'll send a SIGTRAP.

So, using this option is on dump and restore is an implicit guarantee on the
user's behalf that they'll take care of the active uprobes and that any future
SIGTRAPs because of this are not on us! :)

Handling uprobes vma on dump
----------------------------

We don't need to store any information about the uprobes vma because it's
completely handled by the kernel, transparent to userspace. So, when a uprobes
vma is detected, we check if the --allow-uprobes option was specified or not.
If so, then the allow_uprobes boolean in the inventory image is set (this is
used on restore). The uprobes vma is skipped from being added to the vma list.

Handling uprobes vma on restore
-------------------------------

If allow_uprobes is set in the inventory image, then check if --allow-uprobes
is specified or not. Restoring the vma is not required.

Fixes: checkpoint-restore#1961
Signed-off-by: Shashank Balaji <[email protected]>
Most people know this, don't they? :)

Suggested-by: Radostin Stoyanov <[email protected]>
Signed-off-by: Shashank Balaji <[email protected]>
Program flow:
- Parse the test's own executable to calculate the file offset of the uprobe
target function symbol
- Enable the uprobe at the target function
- Call the target function to trigger the uprobe, and hence the uprobes vma
creation
- C/R
- Call the target function again to check that no SIGTRAP is sent, since the
uprobe is still active

At least v1.7 of libtracefs is required because that's when
tracefs_instance_reset was introduced. The uprobes API was introduced in v1.4,
and the dynamic events API was introduced in v1.3.

Ubuntu Focal doesn't have libtracefs. Jammy has v1.2.5, and Noble has v1.7.

Signed-off-by: Shashank Balaji <[email protected]>
When an additional configuration file is specified via RPC, this file is
parsed twice: first at an early stage to load options such as --log-file,
--work-dir, and --images-dir; and again after all RPC options and
configuration files have been evaluated.

This allows users to overwrite options specified via RPC by the
container runtime (e.g., --tcp-established). However, processing
the RPC config file twice leads to silently duplicating the values
of repeatable options such as `--action-script`.

To address this problem, we adjust the order of options parsing so
that the RPC config file is evaluated only once. This change should
not introduce any functional changes. Note that this change does
not affect the logging functionality, as early log messages are
temporarily buffered and only written to the log file once it has
been initialized (see commit 1ff2333 "Printout early log messages").

Fixes checkpoint-restore#2727

Suggested-by: Andrei Vagin <[email protected]>
Signed-off-by: Radostin Stoyanov <[email protected]>
Extend the test for overwriting config options via RPC with
repeatable option (--action-script) and verify that the value
will not be silently duplicated.

Signed-off-by: Radostin Stoyanov <[email protected]>
@avagin
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avagin commented Oct 15, 2025

Please format the commit message properly. A sign-off email should be a valid email address that can be used to communicate with the author.

@tohanov
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tohanov commented Oct 16, 2025

Please format the commit message properly. A sign-off email should be a valid email address that can be used to communicate with the author.

I've fixed the email address.
Not sure what you mean by formatting the commit message properly.

@rst0git
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rst0git commented Oct 18, 2025

@tohanov The following contributor guidelines provide more information on how to format commit messages:

https://github.com/checkpoint-restore/criu/blob/criu-dev/CONTRIBUTING.md

@herheliuk
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herheliuk commented Oct 20, 2025

@tohanov

Basically you can't do it here on GitHub. (as far as I know)

copy your forked repo to your machine with the following command:

git clone https://github.com/tohanov/criu --branch patch-1

open the folder and run these two commands:

git branch -m patch-1
git remote add origin https://github.com/tohanov/criu

edit last commit:

git commit --amend

e.g. using following format:

[component]: [commit message]

[description]

Signed-off-by: Your Name <[email protected]>

save & exit with: Ctrl + X, Shift + Y, Enter. I'd do:

cr-restore: typo fix

Changed 'do' to 'does'

Signed-off-by: :| <[email protected]>

force push, this should update this PR automatically.

git push origin patch-1 --force

Any questions or issues during the process, you may ask ChatGPT (no login required).

You are very welcome.

@tohanov
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tohanov commented Oct 25, 2025

I fixed the commit message

@herheliuk
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@tohanov, you forgot < and > by your email.

Changed 'do' to 'does' in a log message.

Signed-off-by: :| <[email protected]>
@tohanov
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tohanov commented Oct 29, 2025

😅 whoops
Now it's ok hopefully

@avagin
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avagin commented Oct 30, 2025

Just a reminder: CRIU does not accept contributions from anonymous or pseudonymous individuals. This policy is primarily driven by legal and licensing requirements.

I would prefer to see a verifiable name instead of :|. Currently, this sign-off tag looks suspicious to me, and I would recommend we ignore this minor change.

@avagin avagin marked this pull request as draft October 30, 2025 16:20
@tohanov tohanov closed this Nov 16, 2025
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