diff --git a/libcontainer/capabilities/capabilities.go b/libcontainer/capabilities/capabilities.go index 1c4a5f229ff..9179774af6c 100644 --- a/libcontainer/capabilities/capabilities.go +++ b/libcontainer/capabilities/capabilities.go @@ -5,6 +5,7 @@ package capabilities import ( "sort" "strings" + "sync" "github.com/opencontainers/runc/libcontainer/configs" "github.com/sirupsen/logrus" @@ -14,25 +15,25 @@ import ( const allCapabilityTypes = capability.CAPS | capability.BOUNDING | capability.AMBIENT var ( - capabilityMap map[string]capability.Cap - capTypes = []capability.CapType{ + capTypes = []capability.CapType{ capability.BOUNDING, capability.PERMITTED, capability.INHERITABLE, capability.EFFECTIVE, capability.AMBIENT, } -) -func init() { - capabilityMap = make(map[string]capability.Cap, capability.CAP_LAST_CAP+1) - for _, c := range capability.List() { - if c > capability.CAP_LAST_CAP { - continue + capMap = sync.OnceValue(func() map[string]capability.Cap { + cm := make(map[string]capability.Cap, capability.CAP_LAST_CAP+1) + for _, c := range capability.List() { + if c > capability.CAP_LAST_CAP { + continue + } + cm["CAP_"+strings.ToUpper(c.String())] = c } - capabilityMap["CAP_"+strings.ToUpper(c.String())] = c - } -} + return cm + }) +) // KnownCapabilities returns the list of the known capabilities. // Used by `runc features`. @@ -78,9 +79,10 @@ func New(capConfig *configs.Capabilities) (*Caps, error) { // equivalent, and returns them as a slice. Unknown or unavailable capabilities // are not returned, but appended to unknownCaps. func capSlice(caps []string, unknownCaps map[string]struct{}) []capability.Cap { + cm := capMap() out := make([]capability.Cap, 0, len(caps)) for _, c := range caps { - if v, ok := capabilityMap[c]; !ok { + if v, ok := cm[c]; !ok { unknownCaps[c] = struct{}{} } else { out = append(out, v)