Separate initProcessCgroupPath code out of addIntoCgroupV2.
To be used by the next patch.
While at it, describe the new scenario in which the container's
configured cgroup might not be available.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
When parsing mount options into recAttrSet and recAttrClr,
the code sets attr_clr to individual atime flags (e.g.
MOUNT_ATTR_NOATIME or MOUNT_ATTR_STRICTATIME) when clearing
atime attributes. However, this violates the kernel's
requirement documented in mount_setattr(2)[1]:
> Note that, since the access-time values are an enumeration
> rather than bit values, a caller wanting to transition to a
> different access-time setting cannot simply specify the
> access-time setting in attr_set, but must also include
> MOUNT_ATTR__ATIME in the attr_clr field. The kernel will
> verify that MOUNT_ATTR__ATIME isn't partially set in
> attr_clr (i.e., either all bits in the MOUNT_ATTR__ATIME
> bit field are either set or clear), and that attr_set
> doesn't have any access-time bits set if MOUNT_ATTR__ATIME
> isn't set in attr_clr.
Passing only a single atime flag (e.g. MOUNT_ATTR_RELATIME) in
attr_clr causes mount_setattr() to fail with EINVAL.
This change ensures that whenever an atime mode is updated,
attr_clr includes MOUNT_ATTR__ATIME to properly reset the
entire access-time attribute field before applying the new mode.
[1] https://man7.org/linux/man-pages/man2/mount_setattr.2.html
Signed-off-by: lifubang <lifubang@acmcoder.com>
Since [PR 4812], runc exec tries to use clone3 syscall with
CLONE_INTO_CGROUP, falling back to the old method if it is not
supported.
One issue with that approach is, a
> Cmd cannot be reused after calling its [Cmd.Start], [Cmd.Run],
> [Cmd.Output], or [Cmd.CombinedOutput] methods.
(from https://pkg.go.dev/os/exec#Cmd).
This is enforced since Go 1.26, see [CL 728642], and so runc exec
actually fails in specific scenarios (go1.26 and no CLONE_INTO_CGROUP
support).
The easiest workaround is to pre-copy the p.cmd structure (copy = *cmd).
From the [CL 734200] it looks like it is an acceptable way, but it might
break in the future as it also copies the private fields, so let's do a
proper field-by-field copy. If the upstream will add cmd.Clone method,
we will switch to it.
Also, we can probably be fine with a post-copy (once the first Start has
failed), but let's be conservative here and do a pre-copy.
[PR 4812]: https://github.com/opencontainers/runc/pull/4812
[CL 728642]: https://go.dev/cl/728642
[CL 734200]: https://go.dev/cl/734200
Reported-by: Efim Verzakov <efimverzakov@gmail.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Theoretically, exec.Command can set cmd.Err.
Practically, this should never happen (Linux, Go <= 1.26, exePath is
absolute), but in the unlikely case it does, let's fail early.
This is related to the cloneCmd (to be introduced by the following
commit) which chooses to not copy the Err field. Theoretically,
exec.Command can set Err and so the first call to cmd.Start will fail
(since Err != nil), and the second call to cmd.Start may succeed because
Err == nil. Yet, this scenario is highly unlikely, but better be safe
than sorry.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The Process type is quite big (currently 368 bytes on a 64 bit Linux)
and using non-pointer receivers in its methods results in copying which
is totally unnecessary.
Change the methods to use pointer receivers.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The Config type is quite big (currently 554 bytes on a 64 bit Linux)
and using non-pointer receivers in its methods results in copying which
is totally unnecessary.
Change the methods to use pointer receivers.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Rename a function parameter (containerId -> containerID) to avoid a
linter warning:
> var-naming: method parameter containerId should be containerID (revive)
In many other places, including config.json (.linux.uidMappings and
.gidMappings) it is already called containerID, so let's rename.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Apparently Write (and WriteString) must return an error (apparently
io.ErrShortWrite) on short writes (see [1], [2]), so no explicit check
for a short write is needed.
While at it, use (*os.File).WriteString directly rather than
io.WriteString.
[1]: https://pkg.go.dev/os#File.Write
[2]: https://pkg.go.dev/io#Writer
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The modernize documentation used to suggest -test flag but it's not
needed as it is enabled by default. Drop it.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Since we use modernize@latest, it may require latest Go as well (and now it does),
so use "go-version: stable" explicitly (which resolves to latest Go).
This fixes the issue with CI:
> go: golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest: golang.org/x/tools/gopls@v0.21.0 requires go >= 1.25 (running go 1.24.11; GOTOOLCHAIN=local)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin