Merge pull request opencontainers#1012 from justincormack/personality

Add Linux personality support

Author: vbatts

config-linux.md

@@ -702,6 +702,23 @@ The following parameters can be specified to set up seccomp:
     "mountLabel": "system_u:object_r:svirt_sandbox_file_t:s0:c715,c811"
 ```
 
+## <a name="configLinuxPersonality" />Personality
+
+**`personality`** (object, OPTIONAL) sets the Linux execution personality. For more information
+see the [personality](personality.2) syscall documentation. As most of the options are
+obsolete and rarely used, and some reduce security, the currently supported set is a small
+subset of the available options.
+
+* **`domain`** *(string, REQUIRED)* - the execution domain.
+    The valid list of constants is shown below. `LINUX32` will set the `uname` system call to show
+    a 32 bit CPU type, such as `i686`.
+
+    * `LINUX`
+    * `LINUX32`
+
+* **`flags`** *(array of strings, OPTIONAL)* - the additional flags to apply.
+    Currently no flag values are supported.
+
 
 [cgroup-v1]: https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt
 [cgroup-v1-blkio]: https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt
@@ -729,6 +746,7 @@ The following parameters can be specified to set up seccomp:
 [mknod.2]: http://man7.org/linux/man-pages/man2/mknod.2.html
 [namespaces.7_2]: http://man7.org/linux/man-pages/man7/namespaces.7.html
 [null.4]: http://man7.org/linux/man-pages/man4/null.4.html
+[personality.2]: http://man7.org/linux/man-pages/man2/personality.2.html
 [pts.4]: http://man7.org/linux/man-pages/man4/pts.4.html
 [random.4]: http://man7.org/linux/man-pages/man4/random.4.html
 [sysctl.8]: http://man7.org/linux/man-pages/man8/sysctl.8.html

specs-go/config.go

@@ -167,6 +167,8 @@ type Linux struct {
 	// IntelRdt contains Intel Resource Director Technology (RDT) information for
 	// handling resource constraints (e.g., L3 cache, memory bandwidth) for the container
 	IntelRdt *LinuxIntelRdt `json:"intelRdt,omitempty"`
+	// Personality contains configuration for the Linux personality syscall
+	Personality *LinuxPersonality `json:"personality,omitempty"`
 }
 
 // LinuxNamespace is the configuration for a Linux namespace
@@ -391,6 +393,28 @@ type LinuxDeviceCgroup struct {
 	Access string `json:"access,omitempty"`
 }
 
+// LinuxPersonalityDomain refers to a personality domain.
+type LinuxPersonalityDomain string
+
+// LinuxPersonalityFlag refers to an additional personality flag. None are currently defined.
+type LinuxPersonalityFlag string
+
+// Define domain and flags for Personality
+const (
+	// PerLinux is the standard Linux personality
+	PerLinux LinuxPersonalityDomain = "LINUX"
+	// PerLinux32 sets personality to 32 bit
+	PerLinux32 LinuxPersonalityDomain = "LINUX32"
+)
+
+// LinuxPersonality represents the Linux personality syscall input
+type LinuxPersonality struct {
+	// Domain for the personality
+	Domain LinuxPersonalityDomain `json:"domain"`
+	// Additional flags
+	Flags []LinuxPersonalityFlag `json:"flags,omitempty"`
+}
+
 // Solaris contains platform-specific configuration for Solaris application containers.
 type Solaris struct {
 	// SMF FMRI which should go "online" before we start the container process.