Go 1.18 and up now provides a strings.Cut() which is better suited for
splitting key/value pairs (and similar constructs), and performs better:
```go
func BenchmarkSplit(b *testing.B) {
b.ReportAllocs()
data := []string{"12hello=world", "12hello=", "12=hello", "12hello"}
for i := 0; i < b.N; i++ {
for _, s := range data {
_ = strings.SplitN(s, "=", 2)[0]
}
}
}
func BenchmarkCut(b *testing.B) {
b.ReportAllocs()
data := []string{"12hello=world", "12hello=", "12=hello", "12hello"}
for i := 0; i < b.N; i++ {
for _, s := range data {
_, _, _ = strings.Cut(s, "=")
}
}
}
```
BenchmarkSplit
BenchmarkSplit-10 8244206 128.0 ns/op 128 B/op 4 allocs/op
BenchmarkCut
BenchmarkCut-10 54411998 21.80 ns/op 0 B/op 0 allocs/op
While looking at occurrences of `strings.Split()`, I also updated some for alternatives,
or added some constraints; for cases where an specific number of items is expected, I used `strings.SplitN()`
with a suitable limit. This prevents (theoretical) unlimited splits.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
Go 1.15.7 contained a security fix for CVE-2021-3115, which allowed arbitrary
code to be executed at build time when using cgo on Windows. This issue also
affects Unix users who have “.” listed explicitly in their PATH and are running
“go get” outside of a module or with module mode disabled.
This issue is not limited to the go command itself, and can also affect binaries
that use `os.Command`, `os.LookPath`, etc.
From the related blogpost (ttps://blog.golang.org/path-security):
> Are your own programs affected?
>
> If you use exec.LookPath or exec.Command in your own programs, you only need to
> be concerned if you (or your users) run your program in a directory with untrusted
> contents. If so, then a subprocess could be started using an executable from dot
> instead of from a system directory. (Again, using an executable from dot happens
> always on Windows and only with uncommon PATH settings on Unix.)
>
> If you are concerned, then we’ve published the more restricted variant of os/exec
> as golang.org/x/sys/execabs. You can use it in your program by simply replacing
This patch replaces all uses of `os/exec` with `golang.org/x/sys/execabs`. While
some uses of `os/exec` should not be problematic (e.g. part of tests), it is
probably good to be consistent, in case code gets moved around.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
On newer kernels and systems, AppArmor will block sending signals in
many scenarios by default resulting in strange behaviours (container
programs cannot signal each other, or host processes like containerd
cannot signal containers).
The reason this happens only on some distributions (and is not a kernel
regression) is that the kernel doesn't enforce signal mediation unless
the profile contains signal rules. However because our profies #include
the distribution-managed <abstractions/base>, some distributions added
signal rules -- which results in AppArmor enforcing signal mediation and
thus a regression. On these systems, containers cannot send and receive
signals at all -- meaning they cannot signal each other and the
container runtime cannot kill them either.
This issue was fixed in Docker in 2018[1] but this code was copied
before then and thus the patches weren't carried. It also contains a new
fix for a more esoteric case[2]. Ideally this code should live in a
project like "containerd/apparmor" so that Docker, libpod, and
containerd can share it, but that's probably something to do separately.
In addition, the copyright header is updated to reference that the code
is copied from Docker (and thus was not written entirely by the
containerd authors).
[1]: https://github.com/docker/docker/pull/37831
[2]: https://github.com/docker/docker/pull/41337
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This adds default apparmor profile generation to the containerd client
so that profiles can be generated with a SpecOpt
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
